Radiation Protection Issues

Current regulations are too much stringent?

2011-12-01T02:55:00.000-08:00

Like any other pollutant, radioactive materials and radiation are also present in our environment since the formation of earth.

The fear of radiation in everyone’s mind is due to the destruction caused by the effects of explosions of atomic bombs over Japan in 1945. The possible innumerable benefits of radiation in medicine and industry are simply not considered or exploited enough or publicized by the policy makers due to fear of negative reaction by the public. The ghost memories of the bombings and the Chernobyl disaster always remained fresh in the public mind! This is typical “Culture of fear” being promoted by various groups of people (so-called anti-nuclear lobby) with vested interests.

The organizations dealing with radiation protection also promote this culture by accepting the Linear Non-Threshold (LNT) approach for radiation protection and safety. Regulators have not much choice but to formulate regulations to address the acceptable dose limits which are based on the calculated risks assuming much debated LNT approach.

As such, the background radiation levels around us vary quite a bit from place to place and in some places it is of the order of the current dose limits. People are living in those places of high background radiation for ages. No abnormal health issues are observed.

At the Chernobyl accident site, the emergency workers (about 30 workers) who received doses above 4000 mSv have died within a few weeks due to Acute Radiation Syndrome (ARS). There were 140 workers who received less than 2000 mSv dose (which is 100 times more than the annual dose limit for radiation workers) and none died. In Fukushima (Japan), 30 workers received doses in the range of 100 and 250 mSv range in a few days and none is expected to die of the radiation exposure. In medical therapy, for the treatment of cancer, thousands of mSv doses are given to kill the cancer tissues.

There was no increased risk of cancer observed amongst the survivors of Hiroshima and Nagasaki whose exposures were below 100 mSv. Animal experiments could not prove the non-threshold theory to induction of cancer by radiation exposure assumed by the radiation protection fraternity.

Once we accept this fact, there is no need to have such stringent regulations for the applications of radiation and radioisotopes. One can save un-justified expenditure of resources, hardship and suffering to the population (based on the lecture given by Prof. Wade Allison, University of Oxford, August 2011).

Let us NOT say NO to the benefits of applications of radiation such as food irradiation, medical / industrial applications, pest control and electricity generation.

Radiation emission from towers

2011-09-13T00:17:00.000-07:00

Since last three years, “I care for you” has been pursuing the issue of potential health hazard from exposure to radiation from mobile phones and towers through the blog: http://radsafe.blogspot.com. The potential hazards to the public from exposure to radiation from the towers are being highlighted. Periodically, articles are appearing in Mumbai Mirror, Times of India and DNA. But, there is no persistence in the reporting.

However, it is understood now that some actions are being taken in this direction by the Indian Government authorities to control this avoidable public health concern. DNA Navi Mumbai reported on September 4, 2011 that the radiation levels measured in certain areas of Navi Mumbai are 100 times higher than what is considered safe!

Is this not a matter of grave concern for every one of us?

NORM MANAGEMENT

2011-09-10T03:37:00.000-07:00

The acronym NORM means all Naturally Occurring Radioactive Materials. Humans are continuously exposed to these materials such as potassium-40, uranium, thorium and their daughter products present in our environment. Some times, human activities such as uranium mining, phosphate mining, oil exploration, etc enhance the NORM concentration, which increases the potential of exposures of population groups to the radiation. Two important decay products of concern are Ra-226 and a radioactive gas - Radon-222. NORM received a global attention during last 4 decades.

Hence, it is important that the concentration of NORM is measured in suspected industrial activities and take appropriate measures to protect the workers and the environment. The industrial activities which generate NORM waste should be regulated to prevent environmental hazard from the disposal of the waste. Many countries have already aware of the issue and initiated remedial measures to control occupational exposures and to ensure environmental safety. NORM is discovered in the sludge being generated in deep oil well exploration /production activities. GM detectors or scintillation detectors are used for the NORM survey.

Radiation levels due to NORM are measured at the work sites. Personnel monitoring and personal protective equipments, if required are used to measure radiation exposures of the workers and its control. Thermoluminescence dosimeters (TLDs) are used to measure personal exposures and respirators (dust/gas), gloves, overalls, goggles are some of the personal protective equipments (PPEs) used. Above all, the workers should be made aware of the possible NORM exposures so that they follow proper and safe work procedures for the NORM management and environmental safety.

Revision of the Basic Safety Standards (BSS)

2011-06-24T00:28:00.000-07:00

The IAEA International Basic Safety Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources is in the final stage of revision.

A review of the Basic Safety Standards (the BSS) was carried out in 2006 in cooperation with the cosponsors (FAO, ILO, NEA, PAHO and WHO) and potential cosponsors UNEP and EC. The review concluded that, while there was no major issue requiring urgent revision, there was a case to be made for the revision of the BSS in order to take account of the many improvements that have been suggested. The International Atomic Energy Agency (IAEA), in cooperation with the co-sponsoring and potential co-sponsoring organizations, initiated the revision of the BSS in 2007.

The revised International Basic Safety Standards was endorsed by the Commission on Safety Standards (CSS) at its meeting from 25-27 May 2011. The CSS has asked that Member States be consulted about the change (Draft 5.0) to the dose limit for the lens of the eye. Member States are invited to on this change by 7 July 2011. This is a major milestone in the development process of the revision. The revised BSS will now be submitted to the Board of Governors for approval at its meeting to be held from 12-16 September 2011 (IAEA News).

Risk of radiation exposure – ICRP Recommendations

2011-05-18T02:23:00.000-07:00

The International Commission of Radiological Protection (ICRP) provides recommendations on radiation protection standards. Since the ICRP-60, there has been significant progress in understanding the genetic risk associated with the induction of mutations in germ cells. The clearer understanding is that the genetic risk is much lower than the earlier estimates. In ICRP-103 (2007), the risk estimates considered only two generations rather than the all generations (theoretical equilibrium) considered in ICRP-60. The overall contribution to the detriment (total harm) from genetic effects works out to be 3-4% as compared to 18% considered in ICRP-60. Hence, the tissue weighting factor was reduced from 0.2 (ICRP-60) to 0.08 (ICRP-103).

The radiation detriment (overall harm to stochastic effects) was assessed (ICRP-60) taking in to account the cancer incidence, mortality, length of life lost if cancer occurs and the morbidity and quality of life lost due to suffering in incidences of non-fatal cancers. The ICRP-103 considered the detriment based on lethality and life impairment weighted on cancer incidence data.

The detriment values were assessed for both genders and also for working (18 to 64 years) the whole population (0 to 85years). The detriment adjusted nominal risk coefficients for cancer and hereditary effects combined have been estimated to be 5.7 and 4.2% per Sv for the whole population and working population respectively.

Based on the new risk assessments, the Tissue Weighting Factors (WT) for specific organ/tissue are the fractional harm associated with the stochastic effect (gender averaged relative detriment) were also reviewed by the ICRP in ICRP-103. The important changes in ICRP-103 are the upgrading the value of risk for breast from 0.05 (ICRP-60) to 0.12 and for gonads, the WT was reduced from 0.12 (ICRP-60) to 0.08.

Conclusion

In-spite of the some changes in the nominal risk coefficients and in WT values, the total detriment remains close to 5% per Sv. In view of this, the dose limits for occupational and public exposures remain same at an average of 20mSv/y and 1mSv/y respectively as in ICRP-60 (1991).

ICRP - Statement on Tissue Reactions

2011-05-01T05:04:00.000-07:00

As per the ICRP communication, it has approved “Statement on Tissue Reactions” in April 21, 2011. The effects of radiation which was called as deterministic effects previously are now referred as Tissue Reactions. Based on the data various aspects of the effects with very late manifestation such as cataract of the eyes, the threshold in absorbed dose is now considered as 0.5Gy.

Similarly, for occupational exposure in planned exposure situations the Commission now recommends an equivalent dose limit for the lens of the eye of 20mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50mSv.

The Commission continues to recommend that optimization of protection be applied in all exposure situations and for all categories of exposure, including patient’s exposure during some complex interventional procedures, With the recent evidence, the Commission further emphasizes that protection should be optimized not only for whole body exposures, but also for exposures to specific tissues, particularly the lens of the eye, and to the heart and the cerebrovascular system.

Spend national resources in proportionate to the risks. Say no for over-protection.

2011-04-29T00:08:00.000-07:00

WHO report is sighted in Indian News Papers show that out of 57 million global deaths in 2008, 36 million deaths are due to non communicable diseases (NCDs) like cancer, stroke, diabetes and cardio-vascular diseases, and it is increasing! Assumed to be old-age diseases, the NCDs are now taking toll at younger ages (below 60 y) also. Cancer kills 7.6 million people a year; tobacco use kills about 6 million and alcohol 2.5 million a year.

Bhopal gas-leak tragedy, in the year 1984, killed over 3000 people, within days. In Chernobyl nuclear reactor accident, only 47 people died of acute radiation dose and fire burns. Some more may die of cancer over the years. Similarly, over 9000 people died of Tsunami in Japan and the on-going nuclear situation in Fukushima may also cause some fatalities over the years. These deaths are not due to acute radiation doses.

Over 1.5 lakh deaths a year are reported due to accidents on Indian roads. Today, while driving from Belapur, Navi Mumbai to Chembur (18 km), I met near-death situation on the road at least 5 times. This is not due to my fault but due to other’s faults such as: cutting lanes, drunken driving and three wheeler nuisance. Road discipline simply does not exist in Mumbai roads.

Under such scenarios, some vested interests and politicians are creating nuisance everywhere criticizing against developmental projects, particularly nuclear power plants at Jaitapur. Reason is safety! If they are so much concerned about safety, what they are doing about safety on the roads, high pollution levels, floods, crime, etc?

If one sees the risks in proper perspective, it is unimaginable to understand why the designers are spending so much money on safety in nuclear power plants? How many thousands are spend to save ONE life in nuclear power sector?

Let us spend our resources in proportionate to the risks. Say no for over-protection.

ICRP New publication - ICRP-113, 2009, Education and Training in Radiological Protection

2011-04-25T06:34:00.000-07:00

Title: Education and Training in Radiological Protection for Diagnostic and Interventional Procedures, ICRP Publication 113, ICRP, Ann. ICRP 39 (5), 2009 - New Publication from ICRP

Abstract: In view of the increase in the number of diagnostic and interventional medical procedures using ionizing radiations, there is compelling need for education and training of medical staff (including medical students) and other healthcare professionals in the principles of radiation protection.

Based on the current ICRP basic recommendations (2007) for such education and training of these individuals, the ICRP is providing guidance through ICRP-113 regarding the necessary radiological protection education and training for use by various categories of medical practitioners and other healthcare professionals who perform or provide support for diagnostic and interventional procedures utilizing ionizing radiation and nuclear medicine therapy.

The publication is useful for regulators, health authorities, medical institutions, and professional bodies with responsibility for radiological protection in medicine; an the industry that produces and markets the equipment used in these procedures and universities and other academic institutions responsible for the education of professionals involved in the use of ionizing radiation in health care.

Advice is also provided on the accreditation and certification of the recommended education and training. The accredited organization is required to meet standards that have been set by the authorized body (based on ICRP News).

Important of Exclusion Zone in safety of public

2011-04-05T22:44:00.000-07:00

Exclusion Zone is one of the five and the last barriers before radioactive releases from nuclear power plants reach the public domain. This is not a physical barrier. However, no permanent residence is allowed within the 1.6 km radius from nuclear reactor. This ensures significant dilution of an airborne radioactive release before it reaches any public habitation, thus reducing the resulting public dose. Radiation dose to the public at the distance of 1.6km is calculated for the releases during normal/abnormal working of the nuclear reactors, to check compliance with the regulatory limits for releases to the public domain.

Thus Exclusion Zone is an important barrier which has prevented large public doses during the on-going nuclear emergency situation at Fukushima nuclear power reactor in Japan.

In spite of the best possible design and safety records, accidents can still occur and hence the concept of defense-in-depth should never be compromised.

Uranium in drinking water and chemical toxicity

2011-03-31T03:35:00.000-07:00

As per US-EPA (US-DOE, 2007) the maximum concentration level (MCL) in drinking water is 0.03mg/L or 27pCi/L for natural uranium. Level of 67pCi/L of natural uranium in drinking water is also suggested by some authors. It is assumed that 02 to 5% of the intake is absorbed in to the blood stream of which 22% is deposited on bone, 12% in kidneys and rest excreted. The uranium deposited in kidneys is excreted within few days. The mean U concentration in drinking water detected in some SU cities is 2.55 micro-g/L

WHO threshold value to prevent sub-clinical renal effects is 0.002mg/L.

The chemical toxicity value for soluble salts of uranium is 0.003mg /kg-day. This is the highest dose that can be taken every day, over a life time without causing adverse health effects. This is generated based on animal studies and normalized to humans using an uncertainty factor of 1000. Lowest observed adverse health effect is at an intake level of soluble uranium of 3mg/kg-day. Daily intake of uranium by adults (60kg) through air, water and food is 2.2 micro-g and total body burden of uranium in humans is 40 micro-g. At equilibrium, the excretion rate through urine is 4.4 micro-g per day.

In alkaline conditions in the kidney, uranium hydrogen carbonate complex is most stable and hence uranium is excreted out from the kidney. In acidic conditions the uranium (as uranyl ion) gets deposited in the tubular wall in the kidney. The most common renal injury caused by uranium in experimental animals is damage to the proximal convoluted tubules in kidney. Nephritis is the primary induced effect of uranium in humans.

The threshold uranium concentration for chemical toxicity is 1 micro-g/g of kidney tissue. For protection of the public, further safety factor of 10 is applied and values in the range of 0.1 to 0.3 micro-g/g of the tissue are reported as threshold limits for public by some authors.

Physical Barriers to Environmental Release of radioactive releases in case of reactor accidents: Defense-in-Depth concept

2011-03-28T05:44:00.000-07:00

The following five barriers are built into the reactor design to prevent radioactivity escaping from the reactor to the public:

1. Ceramic Fuel - The ceramic uranium dioxide fuel in pellet form entraps most of the fission products generated due to the fission reaction in the fuel. These fission products would be released if the fuel were to melt. The fuel has a high melting point, but continuous cooling is required so that the fuel is not over-heated resulting in melting of the fuel. Another safety feature of the ceramic fuel is that it is relatively chemically inert with the heavy water coolant.

2. Fuel Sheath (cladding) - The fuel pellets are enclosed in a high integrity, welded zircalloy sheath. This sheath contains the gaseous and volatile fission products which escape from the pellets. The sheath is designed to withstand the stresses resulting from pellet thermal expansion, gaseous fission product build-up and external hydraulic pressure.

3. Heat Transport System Boundary - The high integrity pressure tubes, piping, and vessels contain most fission products escaping via sheath defects until they are removed via the coolant purification system.

4. Containment Boundary - This is designed to withstand the pressure surge of a worst case LOCA, with a small ‘puff release’ during the overpressure transient. Post LOCA containment venting via a filtered, monitored pathway minimizes the environmental radioactive release.

5. Exclusion Zone - No permanent residence is allowed within a 1.6 km radius from nuclear reactor. This ensures significant dilution of an airborne radioactive release before it reaches any public habitation, thus reducing the resulting public dose.

Inadequate fuel cooling due to cooling system failure, the situation which is prevailing now at Fukushima nuclear power reactor in Japanese, results in overheating of the fuel, with potential for large scale fuel failures. In the event of large scale fuel failures, at least two of the five physical barriers would be breached, i.e., the fuel and the fuel sheath. In the case of a LOCA, the third barrier, the heat transport system is also breached, leaving only the containment and exclusion zone barriers.

In the case of a LOCA coincident with containment failure (dual failure), only the exclusion zone would remain as a physical barrier. Thus, the Containment boundary is a very strategic defense-in-depth barrier to fission product release in to the public domain. .

Contamination of foods and feedstuffs by the nuclear disaster

2011-03-24T03:49:00.000-07:00

The releases from the damaged reactors are contaminating food and feedstuffs in the nearby areas in Japan. Radioactive iodine will be seen quickly in the milk. As most of the radioactive particles may end up in the ocean it is imperious to avoid sea foods of any kind. Water sources are likely to be contaminated. The Japan government declared that the tap water in Tokyo is contaminated with radioactive iodine and is unsafe for infants.

Continuous monitoring for radioactivity of the food products, milk and drinking water is being done to ensure that the radiation exposure of the public does not exceed the acceptable limits prescribed by the WHO. Since some of the radioactive isotopes released are having half lives in years, the food chain safety will be compromised in the next decades by the situation in Fukushima.

The WHO guideline levels in drinking water, for the most predominant radio-nuclides, Iodine-131 and Cesium-137, in the releases from the reactors are: 0.01 Bq/mL. These guideline levels of radionuclides in drinking water were calculated on the basis of an annual dose criterion of 0.1 mSv (10mR) from drinking 2 liters of water per day. The average natural background radiation to which we are all exposed is 2 mSv in a year.

The International Atomic Energy Agency (IAEA) has also been monitoring the environment for radioactivity and radiation levels at the nearby areas from the Fukushima plant in Japan. As per IAEA update, the dose-rate results ranged from 0.8 to 9.1 micro-Sievert per hour. The beta-gamma activity contamination measurements ranged from 0.08 to 0.9 MBq per square metre.

The Agency continues to receive data confirming high levels of radioactivity (above permissible limits) in food, notably spinach, in samples taken from 37 locations in the vicinity of five cities south of the Fukishima site. Higher levels of both Iodine-131 and Caesium-137 have been measured by the Japanese authorities in milk, water, in spinach and some other fresh vegetables. In view of this, it is reported that distribution of food from the areas affected has been restricted. The Japanese authorities are monitoring the situation in the rest of the country.

Further radioactivity releases from the stricken reactors in to the environment should be controlled somehow to keep the public exposures as low as possible.

Radiation dose control from releases from “damaged” nuclear reactors

2011-03-22T04:53:00.000-07:00

The recent nuclear crisis in Japan where four nuclear power reactors were damaged due to earthquake has raised questions with respect to the public exposures. In such accidental situations, the atmospheric releases from the damaged reactor core are mainly radio-nuclides in vapour form, such as of Iodine. Let us take an example of radioactive Iodine isotope, I-131.

The half-life - the time required for the radioactivity to reduce by one-half - for I-131 isotope is 8 days. Since the half life is considerably long, the isotope can travel long distances along the direction of the wind. On the way, the iodine isotope gets deposited on the soil, on water surfaces and on grass and “contaminates” them. Human consumption of such contaminated items results in radiation dose to the exposed population. Biologically, the thyroid hormone contains iodine in stable (not radioactive) form. If one is exposed to radioactive iodine, it will get uploaded into the thyroid and gets deposited there, giving radiation dose. Prophylaxis is a process where the thyroid is deliberately saturated by “stable” iodine and hence the uptake of “radioactive” iodine from the releases is minimized. A tablet of Potassium iodide/iodate (around 130 mg) is consumed, just before or just after the releases, for “blocking” the thyroid from radioactive iodine uptake.

In general, staying indoors, use of proper respirators and consumption of stable iodine tablets (if advised), reduces exposure of people from the atmospheric releases of radioactive isotopes/materials.

Public needs to be sensitized on this aspect for their protection.

ICRP Publication 104 (2007): Scope of Radiological Protection Control Measures

2011-02-26T01:51:00.000-08:00

In this report, the ICRP recommends approaches to national authorities for their definition of the scope of radiological protection control measures through regulations, by using its principles of justification and optimisation. The report provides advice for deciding the radiation exposure situations that should be covered by the relevant regulations because their regulatory control can be justified, and, conversely, those that may be considered for exclusion from the regulations because their regulatory control is deemed to be unamenable and unjustified.

It also provides advice on the situations resulting from regulated circumstances but which may be considered by regulators for exemption from complying with specific requirements because the application of these requirements is unwarranted and exemption is the optimum option. Thus, the report describes exclusion criteria for defining the scope of radiological protection regulations, exemption criteria for planned exposure situations, and the application of these concepts in emergency exposure situations and in existing exposure situations. The report also addresses specific exposure situations such as exposure to low-energy or low-intensity adventitious radiation, cosmic radiation, naturally occurring radioactive materials, radon, commodities, and low-level radioactive waste.

The quantitative criteria in the report are intended only as generic suggestions to regulators for defining the regulatory scope, in the understanding that the definitive boundaries for establishing the situations that can be or need to be regulated will depend on national approaches (From ICRP Site).

The ICRP draft report on Early and late effects of radiation in normal tissues and organs----at its site for comments

2011-02-21T03:05:00.000-08:00

The International Commission on Radiological Protection (ICRP) invites comments on the draft document: “Early and late effects of radiation in normal tissues and organs: threshold doses for tissue reactions and other non-cancer effects of radiation in a radiation protection context” which can be downloaded through the consultations page of the ICRP web site. The last date for receiving the comments is April 1, 2011.

This radiation protection related draft report provides a review of early and late effects of radiation in normal tissues and organs considering recent advances in the scientific results. It follows the ICRP Publication 103, and provides updated estimates of dose responses and threshold doses for tissue reactions (deterministic effects). Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated or chronic exposure.

In light of the new information, ICRP may consider how best to manage and control exposures to ionizing radiation to protect human health with respect to certain tissue reactions

ICRP Committee 4 meeting

2011-02-19T23:23:00.000-08:00

Committee 4 of the International Commission on Radiological Protection (ICRP) met in Geneva, Switzerland, from 15 to 19 November 2010. The meeting was hosted by the World Health Organization headquarters (WHO) which is an official observer organization to ICRP Committees.

The Committee devoted significant time to further clarifying how the basic radiation protection principles and the dose criteria recommended in the new recommendations of the Commission apply to protection of the public and workers according to the three exposure situations defined in Publication 103, i.e. planned, existing and emergency exposure situations.

The Committee also reviewed several draft reports under preparation:

• Protection against enhanced exposure from industrial processes using NORM, prepared by Task Group 76 chaired by Peter Burns (Australia)
• Protection in disposal of long lived solid radioactive waste prepared by Task Group 80 chaired by Wolfgang Weiss (Germany)
• Protection against radon exposure prepared by Task Group 81 chaired by Jean-François Lecomte (France)
• The ICRP approach to integrate human and environmental protection prepared by the joint Committee 4 – Committee 5 Task Group 82 co-chaired by Jan Pentreath (UK) and Jacques Lochard (France)

The Committee also discussed the general orientation to be given to Task Group 83 on the protection of aircraft crew from cosmic radiation exposure chaired by Jacques Lochard (France). The next meeting of the Committee will take place in Bethesda, Maryland, USA, from 24 to 28 October, 2011 (Extract from ICRP Site).

Exposure to radiation from mobile phones and towers

2011-02-04T02:24:00.000-08:00

Bloggers like me have been relentlessly calling attention of the authorities to the health effects of exposure from radiation from the cell phones. Like most us, endocrinologist Dr. Shashank Joshi also says the mobile phone should be used only as an emergency toll to pass on messages. Some reports say that the mobile phones can cause cancer. This is over-exaggeration. Cancer is a multi cause disease with a latency period of 10 to 30 year after exposure. Nobody can say for sure that the EMF radiation exposure can cause cancer.

Mobile towers are particularly more dangerous due to the emission higher levels of EM radiation for 24x7 basis. Ideally, the towers should be put up at a sufficient height away from populated areas. The guidelines specified should be followed by the service providers. Instead of erecting separate towers, the existing towers should be shared by the service providers. The city areas should be monitored frequently by the designated agencies to ensure that the levels are below the prescribed guidelines. Specific Absorption Rate (SAR) values of mobile phones should be displayed continuously on the screen to caution or alert the user in case of any over-exposure. Keep the mobile phones away from the children.

As regards to the standards, India also should follow the International Standards Specified by International Commission for Non-ionizing Radiation (ICNIRP), a non-governmental expert body to recommend permissible limits for exposures to non-ionizing radiations such as electromagnetic radiation. The guidelines are based on science and should be respected by one and all.

Mobile phones - a health risk

2011-02-03T02:28:00.000-08:00

Finally, the much awaited report from the India Government Inter-ministerial Panel’s study is out. Radiation from mobile phones and towers poses serious health risks, says the Panel. The study also attributed disappearances of bees, insects, sparrows and butterflies from cities for the EMF radiation emission from the towers. The reported health risks are memory loss, lack of concentration, sleep disruptions, etc. The eight-member panel recommended that mobile phones not adhering to the international standards be barred. It is also recommended that mobile towers should not be installed near high density residential areas, schools, hospitals, etc.

Precautions: Use wireless hand-free system, keep your calls short- use for sending messages only and do not use mobile phones for gossip and long chats. Do not give mobiles to children. They are more sensitive to radiation.

Note: There are many posts in this blog since last two years calling authorities to take urgent action against this public health concern.

Handle radioactivity carefully and not fearfully

2011-01-10T01:31:00.002-08:00

Half-life is a term used to express the rate at which a given radionuclide gives up its radioactivity. With time, the radioactivity comes down, but not the mass. More or less, the mass of the radioactive material remains the same even after very many years of radioactive decay. And Specific Activity is the term used to express the quantity of radioactivity per gram of a material.

Take an example of a source of Cobalt-60 (Co-60). The source is generally used in gamma irradiators/chambers used in industry and medicine. The half life of Co-60 is 5.27 years. This means, in 5.27 years the radioactivity of the source reduces by one-half. The mass of the source remains the same. A typical irradiator source of strength 1000 Curie (Similar to sources recovered in Mayapuri, Delhi) will give gamma radiation dose rate of 13.25 Gray per hour. After say, 25 years of decay, the dose rate of the source will reduce to 0.4 Gray per hour. If some one is exposed to this source (the so-called decayed source) for about 10 hours, the person is likely to get dose of 4 Gray which is in the range of Lethal dose -50 (LD-50).

Lethal dose – 50/60 means, if 100 people are exposed to the dose of 4 to 5 Gray, 50 persons will die in 60 days’ time after the exposure.

That is precisely the reason why the “decayed sources” just lying in some cup-boards in laboratories or in hospitals for over 25 to 30 years can still be dangerous and can deliver fatal doses if the sources are not properly shielded, or not handled with care. The decayed sources should be disposed off by strictly following the procedure suggested by the national regulators. In India, the regulator is Atomic Energy Regulatory Board (AERB), located at Anushaktinagar, Mumbai, 400094.

Handle radioactivity carefully and not fearfully.

Handle radioactivity carefully and not fearfully

2011-01-10T01:31:00.001-08:00

Over-exposures in medical applications of radiation

2010-12-30T06:33:00.000-08:00

It is now well known that in radiation therapy, high doses are given to the affected tissues/organs so as to kill the diseased tissues. It is expected that the physician decides and optimizes the dose requirement in consultation with a radiation physicist to ensure radiation protection of the patient. A recent report on the above topic in the Times of India is a matter of grave concern. During medical procedures in US, three patients were given over doses which resulted in organ failures crippling the patients.

Highly collimated radiation beams are used to treat tiny tumors in sensitive organs such as brain or in spinal cord. The collimated beam ensures protection of healthy surrounding tissues. However, any malfunctioning of the system, mismatch of electronic components and improper use of the equipments used in medical diagnosis (X-rays and CT scans) and external radiation beam therapy sources (medical accelerators and Co-60 sources) may result in leakage of the radiation and exposure of other healthy tissues which may ultimately result in long- term severe health problems.

Stringent regulations and quality assurance programs are absolutely necessary for the protection of the patients. The medical and paramedical staff should be well trained in all aspects of radiation protection. Medical procedures involving radiation should be recommended only if the benefits outweigh risks of the radiation exposure.

Exposure to EMF radiations from mobile phones and towers

2010-12-07T21:51:00.000-08:00

The health effect Electro-Magnetic Frequency (EMF) radiation from the towers/mobile phones is of great concern. As reported, the probability of health effects is about 5 times higher in case of children and teenagers. Pregnant women should also be protected from the exposures so that the fetus is not exposed.

It is reported that about 50% of Indian population are using mobile phones! There are several thousands of transmission towers mushrooming all over the country. The convenience of mobile phone in passing on messages is undisputed. But it is over-used and unregulated. That is the concern.

Since last three years, I have been fighting a lone battle to create public awareness about the issue. I have written many posts in my blog site http://radsafe.blogspot.com. I also have written a 11 page write-up on the safety concerns and protection standards for EMF radiation in my web site www.radsafetyinfo.com. As a radiation protection professional, in my anxiety to sensitize the authorities, I have written letters to Municipal Commissioners of Mumbai and Navi Mumbai, Mayer of Navi Mumbai and Maharashtra Health Minister highlighting the public health concerns due to the EM radiation pollution and the possible health effects from the excessive usage of mobile phones, and exposure to EMF radiation from the towers. I have copies of the communications.

I doubt whether India has a separate regulator to ensure safety from the EMF radiation exposures. It was suggested that BARC/AERB should start monitoring the EMF density in different locations to ensure see compliance with the available international standards.

Somehow, nothing happened. I felt at that time that the telecom lobby is too strong and it is very difficult to make the government take action on the issue. However, about 6 month's back, Maharashtra Government has formed a committee to look into the matter. It is heartening to note that the newspapers like Times of India and Mumbai Mirror have started realizing the impending public health disaster from excessive usage of mobile phones and EMF emissions from the towers. It is already late. Better late than never.

The International Nuclear and Radiological Event Scale (INES): 20 Years of Nuclear Communication

2010-11-22T05:30:00.000-08:00

The International Atomic Energy Agency (IAEA) and the OECD Nuclear Energy Agency (NEA) are celebrating the 20th anniversary of the International Nuclear and Radiological Event Scale (INES). The scale has sound technical background.

Jointly developed by the IAEA and the NEA in 1990, in the aftermath of the Chernobyl accident, the INES is to help nuclear and radiation safety authorities and the nuclear industry worldwide to rate nuclear and radiological events and to communicate their safety significance to the general public, the media and the technical community. The INES was initially used to classify events at nuclear power plants only. It was subsequently extended to rate events occurring in any nuclear facility and during the transport and storage of radioactive material and covers events related to the overexposure of workers.

Since its inception, it has been adopted in 69 countries, and an increasing number of countries have expressed their interest in using INES. Over the years, national nuclear safety authorities have made growing use of INES, while the public and the media have become more familiar with the scale and its significance.

Irradiation to Ensure the Safety and Quality of Prepared Meals

2010-11-20T02:28:00.000-08:00

This publication (STI/PUB/1365, 375 pp. Date of Issue: 8 April 2009) presents the results of an FAO/IAEA coordinated research project (CRP) on the use of irradiation to ensure the safety and quality of pre-prepared foods. There is an increasing worldwide demand for pre-prepared and take-away meals. However, the traditional methods of preparing convenience foods via retort-processing and freezing are being replaced in favour of chilled foods, due mainly to their fresher and often more appealing appearance. Chilled prepared foods, however, are non-sterile and their heightened potential for microbiological contamination creates a considerable limitation to their shelf-life. The findings of this CRP demonstrate that radiation processing of pre-prepared meals results in a safer product by eliminating existing pathogens, and thereby reducing health risks while extending the foods’ commercial shelf-life.

This publication presents the findings of the CRP and offers a discussion of the possible further utilization and marketing of this new application of irradiation technology (IAEA News)

FDA Unveils Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging

2010-11-15T23:56:00.000-08:00

The U.S. Food and Drug Administration (FDA) today announced an initiative to reduce unnecessary radiation exposure from three types of medical imaging procedures: computed tomography (CT), nuclear medicine studies, and fluoroscopy. These procedures are the greatest contributors to total radiation exposure within the U.S. population and use much higher radiation doses than other radiographic procedures, such as standard X-rays, dental X-rays, and mammography.

These types of imaging exams expose patients to ionizing radiation, a type of radiation that can increase a person’s lifetime cancer risk. Accidental exposure to very high amounts of radiation also can cause injuries, such as skin burns, hair loss and cataracts. Health care decisions made by patients and their physicians should include discussions of the medical need and associated risks for each procedure.

While there is some disagreement over the extent of the cancer risk associated with exposure to radiation from medical imaging, there is broad agreement that steps can and should be taken to reduce unnecessary radiation exposure. For example, the radiation dose associated with a CT abdomen scan is the same as the dose from approximately 400 chest X-rays. In comparison, a dental X-ray calls for approximately one-half the radiation dose of a chest X-ray. Both diagnostics serve important, sometimes critical, public health needs.

Through the FDA’s regulatory oversight of medical imaging devices, such as CT scanners, and through collaboration with other federal agencies and health care professional groups, the FDA is advocating the adoption of two principles of radiation protection: appropriate justification of the radiation procedure and optimization of the radiation dose used during each procedure. The three-pronged initiative the FDA is announcing is expected to promote the safe use of medical imaging devices, support informed clinical decision-making, and increase patient awareness of their own exposure.

The FDA recommends that health care professional organizations continue to develop, in collaboration with the agency, diagnostic radiation reference levels for medical imaging procedures, and increase efforts to develop one or more national registries for radiation doses. Quality assurance practices into the mandatory accreditation and conditions of participation survey processes for imaging facilities and hospitals. In a bid to empower patients and increase awareness, the FDA is collaborating with other organizations to develop and disseminate a patient medical imaging history card. This tool, which will be available on the FDA’s Web site, will allow patients to track their own medical imaging history and share it with their physicians, especially when it may not be included in their medical records (FDA NEWS RELEASE).

Training requirements in radiological and nuclear safety

2010-11-13T21:38:00.000-08:00

Education and training are indispensable to the development of human resources in industries around the world. Nuclear industries promote the safe use of nuclear technologies for peaceful applications in various fields, in medicine, industry and agriculture. Medical applications and radiation processing of products (food stuff, medical supplies, synthetic and rubber items, cables, etc) have seen tremendous growth. This is in addition to the on-going growth, world wide, in nuclear power generation. Different categories of man power, such as scientists, engineers, biologists, technical, semi-technical and labor are required for the safe operations of the facilities and the activities. Unlike other industries, due to the radioactive nature of the activities, there is potential for radiation exposures, which can be harmful if not controlled.

Thus, for the safe conduct of these applications, the man power required should be suitably educated and trained in the fields of nuclear and radiological safety. This is the mandatory requirement as per the regulations covering all the activities involving radiation and radioisotopes. The fields of nuclear and radiation safety are multi-disciplinary in nature, comprising of inter-related parts of nuclear physics, chemistry, biology, statistics and other specialized areas.

To meet these requirements, there is tremendous scope for private agencies, universities and scientific associations to develop nuclear industry-specific human resources which are trained / educated in nuclear and radiation safety. The national regulators should take proactive steps in this direction.

Preventing Accidental Exposures from New External Beam Radiation Therapy Technologies

2010-11-10T01:47:00.000-08:00

ICRP Publication 112; Ann. ICRP 39 (4), 2009

Disseminating the knowledge and lessons learned from accidental exposures is crucial in preventing re-occurrence. This is particularly important in radiation therapy; the only application of radiation in which very high radiation doses are deliberately given to patients to achieve cure or palliation of disease. This ICRP report is expected to be a valuable resource for radiation oncologists, hospital administrators, medical physicists, technologists, dosimetrists, maintenance engineers, radiation safety specialists, and regulators. While the report applies specifically to new external beam therapies, the general principles for prevention are applicable to the broad range of radiotherapy practices where mistakes could result in serious consequences for the patient and practitioner (ICRP News)

ICRP SYMPOSIUM ON THE INTERNATIONAL SYSTEM OF RADIOLOGICAL PROTECTION

2010-10-08T02:27:00.000-07:00

The International Commission on Radiological Protection (ICRP), that issues recommendations on protection against ionizing radiation, will hold its first ICRP Symposium on the International System of Radiological Protection during October 24-26, 2011, at Bethesda North Marriott Hotel and Conference Center North Bethesda, Maryland, USA.

With participation from North and South America, Europe, Africa, Asia and Australia, this symposium will be of interest to everyone in the field of radiological protection. Participants will learn not only about how the System operates, but also its ethical foundations, the logic behind it, and how it has been applied in practical situations.

The opening plenary session will provide useful information on the System of Radiological Protection, and insight into the ongoing work of ICRP in relation to other key organisations in radiological protection. Other sessions will cover topical issues such as: protection against radon in homes and workplaces; protection of medical patients; environmental protection; and radiological protection related to security screening. Presentations will be made by ICRP Main Commission and Committee members, senior members of other international organizations, and officials and industry representatives from around the world.

It is reported that this symposium is made possible in part through support from the US Nuclear Regulatory Commission and the US Environmental Protection Agency. For details contact Christopher Clement, ICRP Scientific Secretary, at: sci.sec@icrp.org (IAEA News).

Cancer in Developing Countries

2010-10-06T05:56:00.000-07:00

The 2010 IAEA Scientific Forum was devoted to cancer in developing countries. The IAEA could secure the participation of so many top cancer specialists, scientists and experts from all over the world, as well as distinguished representatives from government, the private sector and leading foundations.

During his first year in office, the Director General of the IAEA visited cancer treatment centres in a number of Member States. He admired very highly about the world-class being offered in many developing countries. Some countries like Korea have also donated funds to the IAEA’s Cancer Programme. Since 1980, the IAEA has delivered over $220 million worth of cancer-related assistance to developing countries. The IAEA´s expertise lies in radiotherapy, nuclear medicine, radiology and medical radiation physics. It is reported that the IAEA provide equipment and training, deliver know-how and technical support and help developing countries establish cancer control policies and centres.

He said that the cancer represents an imminent crisis for developing countries. Most new cancer cases and cancer deaths already occur in the developing world. Around 70 percent of cancers in developing countries are diagnosed too late for life-saving treatment. By 2030, over 13 million people worldwide will die from cancer every year. Almost 9 million of these deaths will be in developing countries. In many low-income countries, there is not a single radiation therapy machine. More than 80% of Africa´s one billion inhabitants still have no access to basic radiotherapy and related cancer services. Millions of people who could be successfully treated die every year.

The message at the forum was very clear: There is a great need work together, to share experiences, expertise and knowledge with each other and to pool resources to ensure that cancer patients in developing countries gain access to the best modern treatment and care (IAEA News).

Lung cancer risk from radon and progeny – ICRP Draft report for consultation

2010-09-08T02:21:00.000-07:00

Subsequent to the publication of Statement on Radon, the ICRP has brought out a draft report on Lung Cancer Risk from Radon and Progeny. Now, both of these are on the ICRP site and the ICRP is seeking feedback on these. As reported, the last date for receiving comments is September 30, 2010.

The report reviews recent epidemiological studies of lung cancer risk linked to exposure to radon and its progeny. It concentrates on the results from pooled case-control studies of residential exposures and cohorts of underground miners exposed to low levels of radon and radon progeny. Consistent with the approach used in ICRP Publication 65 (1993), recent miner data are used to recommend a revised detriment-adjusted nominal risk coefficient of 5x10-4 per WLM replacing the ICRP Publication 65 value of 2.8x10-4 per WLM.

The pooled analyses of epidemiological studies of lung cancer risk from residential exposures demonstrate a statistically significant increase per unit of exposure below average annual concentrations of about 200 Bq per cubic meter.

For occupational protection purposes and for compliance with the dose limits and constraints, ICRP proposes to treat radon and radon progeny in the same way as other radionuclides and will publish dose coefficients calculated using dosimetric models for use within the ICRP system of protection.

Environmental Protection: Transfer parameters for Reference Animals and Plants

2010-07-13T04:27:00.000-07:00

The ICRP has prepared a draft report on the above much needed topic. The report is put up in the ICRP website requesting comments from individuals and groups. The last date is October 1, 2010.

The approach followed by the Commission to environmental protection uses the concept of a limited set of Reference Animals and Plants as a basis for relating exposure to dose, and dose to radiation effects, for different types of animals and plants in an internally consistent manner.

A set of Dose Conversion Factors is derived for the Reference Animals and Plants, to enable dose rates to be calculated when the concentrations of radionuclides within these organisms have been established by direct measurement. The resultant dose rates can then be compared with evaluations of the effects of dose rates on the different Reference Animals and Plants. These data have been compiled in such a way that Derived Consideration Reference Levels can then be established, each of which constitutes a band of dose rates for each Reference Animal and Plant within which there is likely to be some chance of deleterious effects occurring in individuals of that type of animal or plant. Site specific data on Representative Organisms can then be compared with such values and used as a basis for decision making.

An enormous data base has been brought together and used to provide the most up to date data available.

Whole-body scanners at airports

2010-07-04T05:26:00.000-07:00

Airports, world –over will be using full-body scanners to foil possible terror attempts in flights. The United States has tested 40 whole-body scanners as part of a pilot program. These machines - millimeter wavelength imaging and backscatter X-ray scanners, will be used to see under clothes and identify unusual objects. Skin is the likely target organ for the radiation from such body scanners.

It is possible that the radiations may not be penetrating-type and hence risk may be low However, large numbers of people around the world would be exposed to a small risk which may ultimately lead to major public health concern over log time. The exposure from such scanners will be considerable for the air crew and frequent fliers.

It is known that there is no threshold dose that could be considered as risk free to an individual's health, particularly for induction of cancer. As per the recommendations of the International Commission on Radiological Protection, mass scanning of public using radiation is not justified by any means. If any exposure to radiation can be avoided, it should be avoided.

Members of the public already exposed to low-level radiation from various sources, such as medical X-rays, cosmic radiation during flights at high altitudes, EMF radiation from cellphones, micro-wave radiation from ovens, TV sets, etc, etc. It is time that research should be focused on developing systems which will not expose members of the public to radiations.

Countries should not just rush to install such machines without proper study with respect to its social concerns of intruding into the privacy of passengers; radiation exposure issues; regulatory aspects, ensuring proper maintenance, particularly calibration of the systems so that no member of the public will be exposed to higher levels of radiation at any time.

Radiation from Mobile towers and cellphones

2010-06-17T02:26:00.000-07:00

Members of the public have been sensitized on the possible harmful effects of EMF radiation being emitted by the mobile phones and the radiation being transmitted by the towers, by the responsible newspapers like Mumbai Mirror, The Times of India and The Times of Navi Mumbai. There are sites and blogs (www.radsafetyinfo.com; radsafe.blogspot.com) which also highlight the issue time and again. Now, things started moving. This is going to be a major public health concern, globally. In a US city, San Francisco, for the first time anywhere, it is mandated that the cellphone manufacturers post information about the amount of radio waves absorbed – specific absorption rate (SAR value) - into the cellphone user’s body touching the mobiles. There are international limits (1.6 watts per kg) on the SAR value for checking compliance. A good move indeed. All countries should follow this practice.

The gravity of the situation can be judged by the fact that every mobile service provider has over 75,000 towers erected in different parts of the country. Possibly, equal umbers of unauthorized towers exist over buildings, bridges and streetlight poles. Residential buildings are also not spared. In a small township like Navi Mumbai there are 451 an-authorized towers (as per the Navi Mumbai Municipal Corporation report). This is in addition to the authorized towers.

In view of the seriousness of the issue, there is a need of mass sensitization about the radiation and radiation hazards from the long-term mobile usage, followed by a law and regulation to control the avoidable exposure of the unsuspecting public to radiation from mobile towers/cellphones.

ICRP’S New Draft Report of the Task Group for Consultation: Radiological Protection Education and Training for Healthcare Staff and Students

2010-06-14T03:45:00.000-07:00

The number of diagnostic and interventional medical procedures using ionising radiations is rising, and procedures resulting in higher patient and staff doses are being performed more frequently. The need for education and training of medical staff, medical students, and other healthcare professionals in the principles of radiation protection is therefore now even more compelling that in the past.

The present publication expands considerably on the basic recommendations provided for education and training in publications, ICRP-103 and 105 with regard to various categories of medical practitioners, and other healthcare professionals that perform or provide support for diagnostic and interventional procedures utilising ionizing radiation. It provides guidance regarding the necessary radiological protection education and training for use by:

In the context of this publication, the term education refers to imparting knowledge and understanding on the topics of radiation health effects, radiation quantities and units, principles of radiological protection, radiological protection legislation and the factors in practice that affect patient and staff doses. Such education should be part of the curriculum in pursuit of medical, dental and other healthcare degrees, and for specialists such as radiologists, medical physicists and radiographers as part of the curriculum of postgraduate degrees.

The term training refers to providing instruction with regard to radiological protection for the justified application of the specific ionizing radiation modalities (e.g. CT, fluoroscopy) that a medical practitioner or other healthcare or support professional will utilize in that individual’s role during medical practice. Advice is also provided on the accreditation and certification of the recommended education and training.

Last date for submitting comments is August 6, 2010 (Ref. www.icrp.org)

Mumbai mirror for cellphone user’s safety

2010-05-22T02:21:00.000-07:00

The Mumbai Mirror, an Indian daily has been continuously publishing posts/reports highlighting the exposures from mobile towers and asking for regulation on the installation of towers and control on usage of mobile phones by children and others. The latest report published in the Mumbai Mirror (May 18, 2010) says that “half an hour of cellphone use a day increases brain cancer risk”. The study was undertaken by the World Health Organization (WHO).

The research findings are as expected. None of the mobile manufactures or the service providers seem to be bothered about the health effects which are being only confirmed over time by research. According to International Communication Union, there were estimated 4.6 billion phone subscriptions at the end of last year! This is becoming a global problem which needs urgent intervention by the countries world-over.

The International Commission on Non-Ionizing Radiation Protection has recommended the relevant safety standards which are accepted internationally. Why not enforce the standards? Governments should respect the public concerns and give clear instructions to all concerned without unduly inducing radiophobia towards radiation.

All missing Cobalt-60 pencils recovered

2010-05-06T02:30:00.000-07:00

It is reported that the BARC expert team has recovered all the cobalt pencils from the scrap yard at Mayapuri, Delhi, after a month of exposure of eight people to the gamma radiation from the Cobalt-60 source. The sources were inside the Gamma Cell which was sold (as junk sale) by the Delhi University and was dismantled by the scrap dealer. It is reported, however, that there were 48 slots inside the Gamma Cell for keeping the pencils. Only 16 pencils are recovered. What about other pencils? Dummy pencils?

The incident was reported to the International Atomic energy Agency and the agency after though investigation will assign severity level for the incident. The level may be probably 3 or 4. The International Nuclear Event Scale (INES) is made up of 7 levels of increasing severity; 3 incident-levels and 4 accident-levels.

There are issues to be resolved by the concerned authorities:

1. Common man wants to know the action taken against the persons responsible for such an event. This is a criminally careless action. The action should severe enough to serve as a warning to others.

2. Investigation should be ordered to check/confirm whether such so-called decayed sources are still available in other institutes. India Government should ensure that such incidents are not repeated.

3. Proper inventory of all sources lying in research institutes and in industrial units should be made by the national regulator, AERB on Cradle to Grave basis.

4. The government should publish full report on the incident and all information/actions taken should be made transparent.

Radiation emergency in Mayapuri, Delhi

2010-05-05T03:49:00.000-07:00

As per the reports, a Gamma Cell imported in 1968 from Canada, was being used for research at the Delhi University. It was lying unused since 1985 i.e., for the last 25 years. The Cell contained a high-intensity radioactive source, Cobalt-60 with a half life of about 5.3 years. The source is well-shielded inside the cell using lead or depleted uranium as shield material. The source is safe for handling when it is inside the shield. Without shield, it is an open, bare source which can cause severe radiation exposure to people nearby. This is a typical radiation emergency situation, which requires radiation protection experts to manage.

In every 5.3 years, the radioactivity will be reduced by half of the existing activity. The sources lose considerable radioactivity after some years and are called decayed sources (misnomer), the sources still will have enough radioactivity, the exposure to which can be fatal to humans. Such decayed sources are required to be sent to either to the supplier or to the national waste management facility at BARC. Such transfers can be done only after consulting the national regulatory body, Atomic Energy Regulatory Board (AERB) located at Anushaktinagar, Mumbai. In this case, it was just auctioned as metallic scrap material in February this year.

Legally, such radioactive source shall never be disposed off through auction or otherwise to any scrap dealer. All institutions using radioactive sources are required to inform the AERB regarding possession of the sources. AERB is supposed to keep inventory of all the radioactive sources existing with institutions/Universities and in industry. Large numbers of radioactive sources are used in industrial radiography a NDT used in quality control programs.

Gamma cell – Mayapuri incident

2010-05-03T00:09:00.000-07:00

Gamma cell (also called gamma irradiator) is used for irradiation of materials to study the effects of radiation. The cell generally contains high energy gamma radiation sources like cobalt-60. The cobal-60 is artificially produced in nuclear reactor by neutron irradiation of Cobalt-59 isotope. The Cobalt-59 is naturally occurring isotope and is not radioactive. Cobalt-60 has a half life of 5.3 years. This only means, in 5.3 years, the radioactive content of the source becomes one-half of the initial radioactivity. As per the decay law, in 2, 3, 4, half lives (in 10.6, 15.9 and 21.2 years), the radioactivity will reduce by one-fourth, one-ninth and one-sixteenth of the initial activity. It will take many more years for the radioactivity to come down to any acceptable, safe levels.

In some news papers, it was reported that the source found in a Mayapuri (Delhi, India) scrap dealer was showing radiation level of 1000 R/h (R is the unit of exposure rate, Roentgen per hour). It is also reported that the gamma cell was bought in 1968. That means the source has decayed by 8 half-lives. The initial dose rate must have been (8x8=64) in the range of 64,000 R/h.

Invariably the gamma cells are accompanied by the operating manuals and the design details. These documents, if available will give details about the number of source pencils and their configuration inside the cell which will vary depending on the required radiation dose for irradiation.

Sources of this high dose levels are never handled openly. They are handled remotely in specially designed and well-shielded enclosures called Hot Cells. The gamma cell is also a well-designed enclosure with the radiation source inside the lead or depleted uranium shield to prevent radiation leakage outside the cell. The design is such that only authorized persons with lock & key arrangement can remotely operate the source for irradiation of sample materials.

IAEA Study on Child Radiation Doses from CT Scans

2010-04-29T23:45:00.000-07:00

An international study, conducted by the IAEA, has shown that in some countries children are over-exposed while performing computed tomography (CT) scans. These children are receiving adult-sized radiation doses, although experts have warned against the practice for over a decade.

The study, which was carried out at 128 healthcare facilities in 28 developing countries in Africa, Asia and Eastern Europe, also found great variation in radiation levels and in the frequency of CT scans performed on children under 15 years of age. The study showed that 11 CT centres in six countries were using adult exposure parameters for paediatric patients. This is due to the operator´s lack of awareness and with CT scans it is difficult to detect higher exposures from the image obtained. If the exposure is too high, the image does not deteriorate and in fact, it tends to look better.

This is in contrast to the conventional X-rays. If the exposure is slightly higher, the image goes black indicating that a higher radiation dose is given than required.
(IAEA News)

Some more radioactive sources found in Delhi

2010-04-15T06:41:00.000-07:00

Radiation monitoring experts from BARC have detected two more Co-60 sources in a scrap shop in the Mayapuri junk market. In view of the high energy radiations of Co-60 and its potential for causing harm in case of exposures, it is desirable that the authorities seriously look into the causes for the incidents and rectify the same so that there is nuclear-scare amongst the public. Among others, the authorities should also consider:

1. As a matter of requirement, all the scrap yards and metallic scrap shops should have radiation detection systems in place.
2. Import of metallic scrap should be banned.
3. Steel companies also should have radiation monitoring system in place for scrap monitoring before the scrap is processed for melting.
4. Medical management of radiation injuries should be part of curriculum in all the medical colleges.
5. Public awareness regarding radiation and radiation detection should be inculcated amongst para-medical staff and crime detection agencies.

Radioactive source search and recovery – Mayapuri Delhi

2010-04-13T02:39:00.000-07:00

Finding a radioactive source in scrap has become a common radiological occurrence world-wide. This is unfortunate because there is no way of knowing that a person is exposed to a radioactive source unless the exposure is severe and clinical changes are detectable in the exposed individuals as in the case of Mayapuri incident. BARC scientists have done a good job of searching and recovering the source in a scrap-yard in the locality. The so-called decayed sources and scraped industrial and medical cameras containing radioactive sources find entry into the scrap yards. This is a global problem and needs to be addressed by the regulators.

India, being a terror-targeted country, stringent monitoring and surveillance programs should be in place at all the scrap entry points like ports and all scrap-yards should be equipped with radiation detection systems. The existing laws governing the handling and disposal of radioactive sources should be enforced strictly to ensure safety of members of the public. The mass media channels should be used to create awareness about the radiation, radiation detection and radiation protection aspects. It is high time, we should wake up!

Health risks of mobile phone towers

2010-03-15T04:21:00.000-07:00

Finally, the Maharashtra Government wakes up to the threat of potential health risks posed by the radiofrequency (RF) radiation emitted by the mobile phone towers. The government has appointed a high-level committee of experts to look into the matter and recommend norms for erecting the towers. Radiation protection-dedicated blogs (http://radsafe.blogspot.com and http://icareforyou2007.blogspot.com) and the Mumbai Mirror have been continuously publishing posts/reports asking for regulation on the installation of towers and control on usage of mobile phones by children and others.

Research findings have shown that the radiation is harmful and internationally accepted standards are available for controlling the exposures (see www.radsafetyinfo.com).

It is a good move by the government and the ignorant public is waiting to see how the government tackles the strong lobby of telecom service providers who will oppose the government’s move at all costs.

Nuclear energy and high safety standards

2010-03-12T05:13:00.000-08:00

In Indian scenario, as on today, the safety status in nuclear power plants apparently looks good. The Atomic Energy Regulatory Board, the regulator in India publishes detailed annual reports giving all the incidents occurred in the power plants and in other related facilities. Anyone can have access to these reports (www.aerb.gov.in).

However, the news papers keep on publishing insignificant and trivial occurrences, thus causing unnecessary doubts in the minds of a common man. For example: some depleted uranium pieces found with scrap dealer or tritium activity in water cooler at Kaiga, etc. etc. Depleted uranium is used as a shield material in industrial radiography cameras used for Non-Destructive Testing (NDT). Once scrapped, these high density spares are likely to find its way to the scrap dealers. The second incident of tritium must be a deliberate attempt by some staff member to create confusion in the plant. Tritium is the least toxic radioactive material and the limits on intake as tritiated water or as tritium gas are very high. These are some radiological incidents are NOT related to nuclear safety of the power plants and the safety record of the power plants continues to be very satisfactory.

May be, there is some need of enforcing the existing regulations strictly in the plants, and security provisions of the radioactive sources should be augmented in public domain since the sources in sealed form are used in industrial and medical therapy applications. Let us not ignore the immense benefit of radiation in comparison with small amount of risk of remotely possible incidents which are common, and much more in other industries.

Terahertz radiation (T rays)

2010-02-14T03:30:00.000-08:00

Terahertz radiation band covers the electro-magnetic wavelength in the range between 0.1 and 1 mm in microwave region. It is non-ionizing type of radiation. The radiation can pass through clothing, paper, cardboard, wood, plastic and ceramics. It can also penetrate fog and clouds, but cannot penetrate metal or water. The rays are highly sensitive to material’s composition.

Recently, a linear accelerator was used to generate a strong beam of T rays. More recently, an electron storage ring used for producing powerful X-rays was used to produce high-power T rays. The high energy T rays can penetrate living cells, without damaging them (unlike X-rays).

The possible applications for T-rays range from basic research, such as studying the properties of superconductors, to medical imaging, and even security. It is expected that effects on tissues are thermal in nature, similar to RF radiation. Further studies need to be carried out to investigate the health effects of the T rays.

If it is safer than X-rays, it is expected to replace X-rays in various applications, particularly in mass screening and in security applications. Anything safer is better.

Nuclear Waste disposal

2009-12-17T02:37:00.000-08:00

Radioactive waste disposal continues to be an emotional subject worldwide. The concern is more with the disposal of high-level waste which will remain radioactive for thousands of years. Thus, the issue of nuclear waste and methods of its disposal remain one of the most pressing problems facing the nuclear sector.

There are technical solutions for the waste disposal and they are certainly safe. Deep geological disposal is one of the viable options available for the purpose. There are international publications and guidelines available on the subject. However, what has been missing so far is a uniform, global approach to this issue at a level which is clearly understood by the clever public. Public acceptance is very important and somehow the authorities are not able to convince the educated and knowledgeable public about the safety and security of such technology in the long term. Private sector participation in nuclear sector and terrorist activity are the two new dimensions which should be addressed to convince the public.

The opinion is to have safety demonstration of such a technology and internationally harmonized regulations to control such activities. As part of its effort to tackle this issue, the International Atomic Energy Agency (IAEA) held this week in Cape Town, South Africa, an international workshop on the safety and licensing of radioactive waste disposal. More than 90 international experts participated in the one-day event. The outcome of the workshop is awaited.

Mobile phone radiations & health effects

2009-11-09T22:41:00.000-08:00

There have been many posts in this blog on the health concerns of indiscriminate use of mobile phones. Also, articles periodically appear on this issue which is of serious concern from public health considerations. The most recent ones appeared in an Indian news paper Mumbai Mirror. The reported study indicated that the radiation from the mobile phones weakened the bones by reducing the bone density. A decade-long investigation in UK, overseen by World Health Organization (WHO), says that heavy mobile users have higher risk (39% increase) of developing brain tumours later in life. Most of the health effects are of long-term nature and will be manifested only after a few years of usage.

In spite of all these, one fails to understand why the government authorities turning a blind eye to these concerns about the potential health effects, likely to be in catastrophic scale in the near future?

New Reference Computational Phantoms of the Adult Male and Female of the ICRP

2009-11-08T23:52:00.000-08:00

In its recent recommendations (ICRP Publication 103: Recommendations of the ICRP. Annals of the ICRP 37(2-4)), ICRP adopted the new reference male and female computational phantoms, called RMCP and RFCP. These voxel phantoms will be used for the forthcoming update of organ dose conversion coefficients. The phantoms are based on medical image data of real persons and are consistent with the information given in ICRP Publication 89 (2002) on the reference anatomical and physiological parameters for both male and female subjects.

The reference voxel models are constructed after modifying the voxel models (Golem and Laura) of two individuals whose body height and weight resembled the reference data. The organ masses of both models were adjusted to the ICRP data on the Reference Adult Male and Reference Adult Female, without spoiling their realistic anatomy.

The numerical data representing the phantoms will be contained in electronic data storage medium (CD-ROM) that will accompany the upcoming publication. The phantoms' technical description is contained in a series of Annexes that form the larger part of the publication:

One of the aims of the report is to assist those who want to implement the phantoms for their own calculations.

ICRP Publication 98: Radiation safety aspects of brachytherapy for prostate cancer

2009-09-05T04:35:00.000-07:00

It is now well known that radiation sources are implanted in the body to treat localized cancers such as prostate cancers. The radioactive sources used are Iodine-125 or Palladium-103. The application of the technique, known as brachytherapy, has been rapidly increasing all over the world in the last fifteen years. To date, it is estimated that globally more than 50,000 patients are treated this way every year. Although no accident or adverse effects involving the medical staff and/or members of the patient family have been reported so far, the brachytherapy technique raises a number of radiation safety issues which need specific recommendations from the expert body, International Commission on Radiological Protection (ICRP).

The available data show that, in the vast majority of cases, the dose to comforters and carers remains well below the 1 mSv/year limit. Only in rare case where the patient's partner is pregnant at the time of implantation may need specific precautions. Other related issues are: rare possibility of expulsion of the sources through the urine, the semen or the gastro-intestinal tract; incident/accident linked to the radioactive seed loss; cremation of bodies containing the sources; guidelines for the surgery of pelvic or abdominal regions of the patient; possible modifications of the semen due to the radiation exposure; a limited risk of genetic effects for the child fathered by the patient with the implantation; the possibility of triggering certain types of security radiation monitors; induction of the radiation-induced secondary tumors, etc.

The ICRP publication 93 (2006) provides specific recommendations on the above issues.

Health Concerns of radiation exposure from mobile towers/phones

2009-07-23T05:30:00.000-07:00

Please refer to the article entitled “Addicted to cellphones? – India Government tells Parliament excessive use of mobiles harmful” published in today’s Times of India (Times Nation, page no. 15). The Union Health Minister is cautioning the public against the excessive usage of mobile phones. There were articles which appeared in Mumbai Mirror (“Red alert on Cell tower radiation”, in July, 2008, and the recent article “JJ hospital docs get cell tower jitters”, dated January 24, 2009) and Times of Navi Mumbai article “Illegal mobile towers to go”, dated January 11, 2009) reporting the radiation levels in different areas much exceeding the internationally accepted levels.

In spite of repeated news appearing in World Wide Web,
http://radsafe.blogspot.com
www.radsafetyinfo.com
http://icareforyou2007.blogspot.com

little attention is paid to the harmful effects of such non-ionizing radio-frequency (RF) radiation emitted by the towers and mobile phones. The expected mobile phone usage is projected to be 500 million (half of the population) within a short period of time. As per the recent reports, of the service providers have projected erection of over 90,000 base stations, signal booster antennae all over India to meet the ever increasing demand even from rural areas.

Why no serious efforts are made by the government to regulate and control these activities? Are politicians and Babus are being pressurized by the rich service providers’ lobby against taking any action? Why not ban the latest silly ad – Walk while talk - from Idea Cellular? Before RF related health effects are shown in the public in catastrophic magnitude, it is absolutely necessary to take action on war footing. Better late than never!

Nuclear disarmament

2009-07-10T03:40:00.000-07:00

The US President Barack Obama has been actively proposing nuclear disarmament at a time when even the smaller nations such as North Korea and Iran are trying to build-up their own nuclear arsenal. The concept of nuclear disarmament is easy to talk about, but very difficult to implement.

What happens to the thousands of tons of fissile materials such as plutonium and enriched uranium in the war-heads which will become redundant and can fall into the hands of the terrorist groups? In the nuclear-weapon countries, the weapons must be of very old design and assumed to be in a state which calls for up-gradation to ensure safety and suitability for current strategic applications. Considering the cost of dismantling and reassembling, it is advisable for these countries to go for disarmament.

Unless serious efforts are made to recycle the fissile materials, probably as fuel in nuclear power reactors, it is dangerous to go for nuclear disarmament.

Risk Equivalent Radiation Dose (RERD)-for policy decisions

2009-06-16T01:34:00.000-07:00

A unifying concept of radiation dose should be used to express the total health risk from exposure to radiation and chemicals. For example, many chemical pollutants we come across in day-to-day life and in industrial releases are carcinogenic. The risk factors (risk per unit exposure) are assessed by different agencies and are known. Carcinogenic risk from radiation is also well known.

Thus, it is possible to add up the chemical risks due to known amount of exposures or intakes (=measured concentration of the pollutant multiplied by the time period of exposure), and the risk from radiation exposure (=radiation dose rate multiplied by the time period of exposure) to get the total risks of cancer due to radiation and chemical pollutants in any given environment.

The total risk can be expressed in terms of the total Risk Equivalent Radiation Dose (RERD).

This can be conveniently employed by the policy makers to take decisions based on health detriment, due to a decision, say, to build a type of power plant, nuclear, thermal or hydro.

Mobile hot cell for handling highly radioactive sources

2009-06-11T03:30:00.000-07:00

The IAEA has conceived an idea of employing mobile hot cell facility to handle radioactive sources in developing countries. The idea was successfully employed for the first time in a real field operation in Sudan in early May to process high-activity disused radioactive sources. This was the first operation of its kind undertaken by IAEA in a developing country.

Disused/decayed high-activity radioactive sources, used for diagnosing and treating medical patients, sterilizing blood and medical appliances or protecting stored crops, need to be handled before its safe disposal. Unlike in developed countries, developing countries may not have the specialized infra-structure for handling such sources.

The project in Sudan was performed at the radioactive waste storage site of the country´s Atomic Energy Commission. The inventory included disused sources that had been used in research and medical teletherapy machines containing high-activity Cobalt 60 sources. Inside the mobile hot cell, the disused radioactive sources were removed from the original equipment and transferred into a stronger storage container that was designed for their safe and secure storage.

The creation of the mobile hot cell and its successful operation illustrates an excellent example of technical cooperation between developing countries. It is an opportunity to extend disused source recovery and conditioning work to cover other developing countries (source: IAEA News).

Radioactive Cargo in aircrafts

2009-05-12T22:36:00.000-07:00

Millions of radioactive packages are transported regularly by air between different destinations around the world. I believe, India also imports and exports these radioactive sources for different applications, mainly for the diagnosis and treatment of patients in hospitals.

There are very stringent international regulations applicable for transportation of radioactive materials. The rules and regulations apply with respect to type of the radioactive source, nature of the package and the total radioactive material permitted inside the package. The purpose of this is to make sure that even in case of any accident no radioactivity comes out of the package and harm anybody.

Under such situations, there is no reason for any alarm and no need for the media to give undue importance for the presence of radioactive cargo in the aircrafts. Let us not make patients suffer because of our ignorance.

Mobile user base has gone up seven times in India!

2009-04-15T01:03:00.000-07:00

During the last 4 fours, a lot of changes have taken place in Indian telecom sector. The number of fixed-line users has come down. People want to go for mobile phone whether it is necessary or not. The revolution is a phenomenon. As of end of February 2009, the mobile phone user base was 376 million. The major GSM players are: Bharti, Vodafone, BSNL and Idea, while the CDMA firms are mainly Reliance and Tata Teleservices. The time spent by people making or receiving calls on mobile phones is one the rise. At the end of December 2008, minutes of GSM mobile usage (mou) worked out to be an average 496 minutes per month. The demand for mobile phones from rural sector is also increasing greatly.

One can see the many tall mobile tower structures coming up in the rural skylines. In cities, mobile towers are erected on building tops in heavily populated areas. The electromagnetic pollution levels measured in some places are much more than the permissible levels. It is also reported that the radiation from the towers can cause many health effects, including cancer, headaches, genetic disorders, etc. None of the service providers has come forward to explain the higher radiation levels measured and the actual position to the common man.

The mobile users in the country have a right to know what are the benefits and harmful effects of such radiation exposures and what precautions should be taken to prevent any possible harmful effects.

Scrap monitoring for radioactivity - global issue

2009-04-14T03:44:00.000-07:00

International experts from several countries said in a meeting held at Spain recently that urgent steps are needed to protect people from radioactive material that can inadvertently end up at junk and scrap yards.

In the last three years, the International Atomic Energy Agency (IAEA) has become aware of around 500 events involving uncontrolled ionizing radiation sources, about 150 of which were related to sources found in scrap metal or contaminated goods or materials. A large portion of the scrap metal that is consumed annually is traded internationally, and may originate in one country and be transported long distances before being processed in another country. This is clearly a global problem that hence requires the application of a globally harmonized approach involving all stakeholders, says the IAEA official.

The regulatory approach is based on providing International Safety Standards by the IAEA (which is in place), and provide better guidance to regulators, scrap dealers, and metal recycling industries on how to deal with problems when they occur. The scope of the new protocol involves the detection and monitoring of radioactivity in the storage facilities and industries where scrap metal is collected and handled. Key elements include creating a register of ascribed companies, monitoring material at the entrance of the facilities as well as the final products and waste, and establishing sequence of actions to be taken when radioactivity is detected in the scrap.

Chemical toxicity of natural uranium

2009-04-04T01:08:00.000-07:00

Uranium is a naturally occurring element, with an atomic number of 92 and density as high as 18 g/cc. Its radioactive nature was discovered in 1896 by A.H. Becqueral. Initially, it was used as a coloring agent in glass and as a homeopathic medicine. Subsequently, uranium is used as a fuel in nuclear power reactors. The uranium deposits are mined (mainly from Singhbhum area of Bihar) and the metal is produced by series of chemical and metallurgical operations.

Uranium is distributed widely in nature and is estimated to be present in the earth’s crust to the extent of about 4 parts per million. It is more abundant than many familiar elements such as gold, silver and mercury. Uranium content of sea water is 3 parts per billion. Traces of uranium are also found in both food and drinking water. The average daily intake of uranium through food and fluids is estimated to be 1.9 micro gram.

The chemical toxicity of uranium is more dominating when it is in water soluble compounds such as carbonates, nitrates, phosphates, fluorides, etc. One of the three oxides of uranium, i.e., UO3 is more soluble as compared to other insoluble oxides, viz., UO2 and U3O8. In soluble form, it can be transported by ground/surface water. Very small part of the ingested uranium is absorbed by the body which ultimately gets deposited in bone and kidney. While passing through kidney, uranium gets precipitated, thus increasing kidney burden. The assessed safe threshold for uranium in kidney is in the range of 1 to 3 microgram/g of kidney tissue. The quantity of uranium in blood that might produce a human fatality is 60 mg. The threshold limit value in blood for uranium induced proteinurea is 2.7 mg. Drinking water standards vary considerably and are reported in the range of 15 to 100 microgram uranium per liter of water.

To control the kidney burden, uranium should be kept in body fluids as a stable complex, such as bicarbonate complex, so that it is filterable in kidney and excreted through urine. That is the reason why sodium bicarbonate solution (1 to 1.5% in saline) is used for internal decontamination of uranium.

Uranium deforming children of Faridkot?

2009-04-03T03:40:00.000-07:00

Reputed News papers like Times of India should not publish stories of this kind which is definitely “misinformation” without any specific scientific evidence.

Uranium is a naturally occurring element and is present in the rock to the extent of about 4 part per million. In trace levels, uranium is also present in ground water sources. The compounds of uranium differ in their solubility. Some compounds such as chloride, phosphates, carbonates and nitrates are soluble and compounds like oxides are insoluble in water. Uranium is a radioactive element. Because of very long half life, the specific activity, i.e., radioactivity per gram is very low.

Hexavalent uranium compounds with carbonates and phosphates are most stable compounds and forms soluble compounds with water and hence are transported through soil to some distances. If there is any source of uranium in nearby areas, it is possible that soluble uranium compounds can get into ground water sources and get ingested in the body. A very small fraction of the ingested uranium gets metabolized in the body and gets deposited in bone and kidney.

Uranium is used in nuclear reactors as fuel. The fuel production facilities, such as mines, uranium concentration and purification plants discharge very small amount of uranium in well controlled and regulated manner into the environment.

It is highly improbable that the deformation or any genetic effects occurring due to the intake of uranium. Radiation is categorized as a weak mutagen. The probability of uranium causing the health effect described in the story is almost zero. However, there is a good possibility of chemical entities such as fluorides, and heavy metals such as lead, etc pollute ground water to a great extent. It is also well known that chemical pollutants cause mutation of the body cells to a much greater extent which ultimately may manifest as genetic disorder in exposed population.

Hence, it is important that complete chemical analysis of the water samples be done before coming out with any premature conclusion which will adversely influence public opinion on nuclear applications

Radiation from mobile phones and towers

2009-01-17T03:20:00.000-08:00

In view of the large scale usage of mobile phones, there has been much apprehension worldwide about the health concerns of its prolonged use.

It is reported that the latest Bluetooth devices use Radio Frequency (RF) with the spectrum in the range 2.4 GHz to 2.4835 GHz. The power output from a typical Class 3 Bluetooth device is 1 mW/square cm, which is of the same order of the limit for exposure of RF from cell-phones, which uses RF of 0.9 GHz. The Bluetooth devices are meant for attachment to the ear all the time. This may do irreversible damage to the ear internals.

RF radiation is also emitting from the towers erected on the buildings and almost everywhere. Some towers are legal and most of them are illegally erected. Some measurements carried out have shown that the levels of radiation exposures from the towers are significant and often exceed the limit. Long term effects are still not well known. Keeping in mind the uncertainty and the gaps in our knowledge about the health effects of exposure to the RF radiation, particularly due to its prolonged usage, it is not advisable to completely rule out adverse health effects, even at levels of RF exposures below the existing international guidelines.

Under the circumstance, it is advised to use mobiles for sending only messages and not for long gossip sessions. The mobiles should be kept away from the children. A separate regulatory body should be set up by the government to monitor the exposure levels from the towers at different areas to check compliance with the international regulatory limits.

Half a Century of Nuclear Safety

2009-01-02T04:07:00.000-08:00

The International Atomic Energy Agency (IAEA)’s contribution to nuclear safety worldwide is marking a significant milestone this December 2008 with the fiftieth anniversary of the launch of the Agency’s safety standards. The first IAEA safety series publication, entitled Safe Handling of Radioisotopes, was issued in December 1958.

The IAEA safety standards are a collection of fundamental radiation protection principles, requirements for the protection and guidance that serves as a global reference for ensuring safety in all areas in the nuclear sector. The standards reflect international consensus on what constitutes a high level of safety for protecting people and the environment.

The application of IAEA safety standards through, inter alia, peer reviews and advisory services at national and international levels are essential to support the development of effective national safety infrastructures. A big part of the IAEA´s statutory mandate is the establishment and promotion of international standards and guides, says, Head of the IAEA´s Publishing Section, IAEA. International standards, however, should not be seen to be in conflict with national regulations.

More than 200 safety standards have been published. They cover nuclear safety, radiation protection, radioactive waste management, the transport of radioactive materials, the safety of nuclear fuel cycle facilities and quality assurance.

"I CARE FOR YOU" WISHES ALL THE BLOGGERS/READERS A VERY HAPPY, HEALTHY AND SAFE NEW YEAR - 2009

Fire at Japan nuclear power plant, no radiation leak

2008-12-10T03:44:00.001-08:00

(Report dated December 8, 2008)
A fire broke out at a nuclear power plant in northern Japan, at the Kashiwazaki-Kariwa nuclear complex and a worker was sickened by smoke inhalation. The plant operator said that there was no release of radioactivity. The fire broke out at a turbine facility during welding of pipes aimed at enhancing quake resistance, Tokyo Electric Power Co (TEPCO) said in a statement. The fire was extinguished within one hour and there was no radiation leak from the incident. The cause of the fire is under investigation, the TEPCO said.

The nuclear power complex, which suffered extensive damage in an earthquake last year, has been out of service and undergoing repairs. The incident occurred just days after a Dec. 1-5 inspection by a team from the United Nations nuclear watchdog. The team of 10 experts from the Vienna-based International Atomic Energy Agency (IAEA) assessed safety measures designed to deal with the continuing threat of earthquakes.

Natural and man-made disasters like larger earthquakes, fire incidents and terrorist attacks can cause serious consequences involving radioactivity leakage and radiation exposure to public. Comprehensive preparedness plans should be in place to respond quickly to such situations with minimum loss to property and human lives.

Indian Association for Radiation Protection – National Conference

2008-12-02T23:08:00.000-08:00

The Indian Association for Radiation Protection (IARP) and Defence Laboratory, Jodhpur organized the National Conference (IARPNC-2008) in Jodhpur during November 19-21, 2008. The focal theme of the conference was “Management of Nuclear & Radiological Emergencies”. Other topics related with the radiation protection and safety, were also covered in the conference by way of Invited talks, and Oral/Poster presentations. The conference was well attended by the top DRDO scientists, scientists from Department of Atomic Energy (DAE)family and a Hon’ble Member, National Disaster Management Authority (NDMA), Delhi. In the end, there was a Panel Discussion on Public awareness regarding safety aspects in peaceful applications of ionising radiations.

The technical proceedings of the conference are brought out as a 464 page, hard-bound volume (Volume 31) of the journal “Radiation Protection and Environment”, published by the IARP. The enquiries for procuring the Proceedings volume may be directed to the Secretary, IARP, C/o, RP&AD, Bhabha Atomic Research Centre (BARC), Mumbai 400085, India (Email: bcbhatt2003@yahoo.com).

IRPA 12 Congress Sets New Attendance Records!

2008-11-14T02:15:00.000-08:00

The highlight of the IRPA International Congress (on radiation protection) opening is always the presentation of the Sievert Lecture. This year’s award winner was Christian Streffer, Germany, who presented an excellent lecture titled Radiological Protection: Challenges and Fascinations of Biological Research. Prof. Streffer began by outlining the limitations faced by epidemiological studies in providing low dose radiation effects information. He went on to provide an excellent review of recent biological studies at the molecular level that are extending dose effects information to lower levels than is currently possible through statistical studies.

The IRPA 12 International Congress in Buenos Aires, October 19 to 24 drew 1,336 radiation protection specialists from 90 countries and 1491 contributed papers. These set IRPA Congress attendance records for both national representation and total attendance. This success is due, in part, to significant support for participation of young scientists, particularly those from developing countries, by the IAEA and several IRPA Associate Societies. The IRPA 12 was opened with a welcome to Buenos Aires by the Vice President for Congress Affairs, Abel Gonzales. The traditional Congress opening was declared by IRPA President, Phil Metcalf with the ringing of the Polvani bell. The opening session concluded with a touching tribute to former ICRP Chairman and Argentina native, Dan Beninson.

Three cheers for the good work done by the IRPA for providing this platform for radiation protection professionals, world-wide.

IARP Conference, Defence Labs, Jodhpur

2008-11-14T01:42:00.000-08:00

The Indian Association for Radiation Protection (IARP) will be organizing its 28th IARP Conference with focal theme of “Management of Nuclear and Radiological Emergencies (IARP NC-2008), being held at Defence Laboratory, Jodhpur during 19-21 November, 2008. The “Proceedings” of the conference is being brought out as a special issue of the journal, Volume 31 (1-4), 2008.

All the thematic areas in radiation protection are covered in the conference. The papers submitted were peer reviewed by experts. In all, 128 papers were accepted for presentation in oral and poster sessions, over the three days. The Proceedings is also being brought out as Compact Disk for distribution to the members of the Association. The information is also available in the IARP website: www.iarp.org.in

What is new in the ICRP site?

2008-11-05T22:55:00.000-08:00

The work of two sub-groups of an ICRP Task Group is nearing completion. The reports of the Task Group will address:

1. Nuclear decay data for dosimetric calculations; and
2. Reference computational phantoms of the adult male and female (a joint ICRP/ICRU Report).

These two drafts, which are interrelated in the sense that they both provide data for dosimetric calculations, are primarily collections of tabulated information, in the first report to describe radionuclide transformations as an extension of ICRP Publication 38, and in the second report to describe the characteristics of the voxel-based reference phantoms referred to in ICRP Publication 103.

Revision of IAEA International Basic Safety Standards (BSS) - draft (1.0)

2008-09-17T04:07:00.000-07:00

International Atomic Energy Agency (IAEA) has been playing a lead role in developing international Basic Safety Standards (BSS) for protection against ionizing radiation and for the safety of radiation sources. The BSS provide guidance for implementing and regulating the all applications involving radiation and radioisotopes, taking cognizance of the basic recommendations of the ICRP. A review of the BSS (SS-115, 1996) was carried out in 2007 in cooperation with the co-sponsors (FAO, ILO, NEA, PAHO and WHO). In a technical meeting involving more than 130 participants from Member States, international organizations and international professional societies, recommendations were made on the revision of the BSS, including that the revised edition should follow the 2007 recommendations of the ICRP (ICRP-103, 2007) to the extent possible.

The first draft 1.0 (DS379) – was thus prepared and is available for comments at the IAEA website. The draft consists of: Introduction, general requirements for protection and safety and requirements for the three exposure situations identified by the ICRP, viz., planned exposure situations, Emergency exposure situations and Existing exposure situations, four Schedules and list of References.

The document emphasizes the responsibilities of government: The government shall establish and maintain an appropriate and effective legal, regulatory and organizational framework for radiation protection and safety. It ensures that the prime responsibility for protection and safety rests with the person/organization responsible for facilities and activities that give rise to radiation risks. The government establishes and maintains a regulatory body with clearly defined functions and responsibilities for regulating radiation protection and safety. It also ensures that the scale of regulatory requirements applied to any exposure situation is commensurate with the associated radiation risks.

It is the government’s responsibility to ensure that the regulatory body is adequately funded and is effectively independent of persons and organizations using or otherwise promoting the use of radiation, so that it is independent of any undue pressure from interested parties and any conflict of interest.

(Some more highlights will be presented in the National Conference of IARP, Defence Labs, Jodpur, India during November 19-21, 2008).

IRPA News Extracts – IRPA 12

2008-09-02T02:04:00.000-07:00

The primary objective of International Radiation Protection Association (IRPA) is to provide a medium whereby those engaged in radiation protection activities in all countries may communicate more readily with each other and through this process advance radiation protection in many parts of the world. This includes relevant aspects of such branches of knowledge as science, medicine, engineering, technology and law, to provide for the protection of man and his environment from the hazards caused by radiation, and thereby to facilitate the safe use of medical, scientific, and industrial radiological practices for the benefit of mankind. For many other related professions it is an excellent opportunity to communicate on the achievements, scientific knowledge and operational experience in radiation protection.

It is a major task for IRPA to provide for and support international meetings for the discussion of radiation protection. The International Congresses of IRPA itself are the most important of these meetings. These have been held about every four years since 1966. For all Associate Societies of IRPA and individual members, it is an important objective to attend the next International IRPA Congress (IRPA 12), to be held in Buenos-Aires, Argentina. Details can be found in www.irpa12.org.ar

IRPA 12 is only 2 months away, and it is shaping up to be an outstanding event! An IRPA Congress record of nearly 1500 abstracts, from more than 80 countries has been submitted!

During the Congress, the 2008 Rolf M. Sievert Award for outstanding contributions to radiation research and radiation protection will be presented to Prof. Christian Streffer of Germany. He is the 10th Sievert award winner, and joins a prestigious group of recipients. Christian Streffer is a leading expert on health effects by irradiation during all stages of pregnancy including the protection of the unborn child. Christian Streffer has been involved with the review of several UNSCEAR reports to the General Assembly of the United Nations. In 1993, Christian was appointed to ICRP Committee 1 (Radiation Effects) and served until 2001 when he was elected as a member of the ICRP Main Commission. Between 2001 and 2007 he chaired ICRP Committee 2 (Doses from radiation exposure).

IRPA 12 will be the most important event of the year for Radiation Protection Professionals!

IAEA Raises Awareness of Radiation Risks Among Heart Doctors

2008-09-01T00:01:00.000-07:00

Patients are not the only ones at risk during cardiac procedures. Doctors performing heart surgery also face health risks, namely to their eyes. The issue of radiation protection for medical personnel is particularly acute in the case of lengthy angioplasty and other cardiac interventions performed under X-ray fluoroscopic guidance. The procedure can cause extensive radiation exposure to cardiologists that could lead to cataracts, alongside other longer term health risks. Fluoroscopy provides X-ray images of a patient that physicians can view on a display screen or monitor in real time. Proper use of tools for radiation protection - like protective screens or barriers - can prevent such radiation exposure problems.

The IAEA is helping the medical community to address this problem through a major international initiative aimed at training cardiologists and other medical professionals in radiation protection. This September in Latin America, the IAEA is organizing a study to test the eyes of interventional cardiologists participating in a regional medical conference. This will allow experts to assess retrospectively what radiation dose these cardiologists received, and then correlate the data with changes in their lens. Hopefully, this will help doctors to protect themselves better in the future and reduce further radiation in their eyes while maintaining the clinical load.

The Cardiology Conference is organized by the Latin American Society of Interventional Cardiologists (SOLACI) in Bogota, Colombia - (IAEA News).

Tests Confirm No Radioactivity Release to Environment from IAEA Seibersdorf Lab, After 3 August Incident

2008-08-30T03:19:00.000-07:00

(Extract from IAEA News)

There was an incident at the International Atomic Energy Agency (IAEA)´s Seibersdorf Laboratory on 3 August, 2008. The Laboratory is located about 35 km southeast of Vienna, Austria. The laboratories provide research and training in applying nuclear science to environmental protection, insect pest control, plant breeding, human and animal health, as well as physical and chemical studies, and nuclear instrumentation.

Tiny amount of plutonium contained in an acid solution spilled from five small glass vials when one of them burst after a build up of pressure in it. The vials were stored in a secure steel safe. In total there was less than one gram of plutonium in the five vials. The material was in the laboratory for scientific reference purposes and virtually all of the contamination was confined within the steel walled safe.

An automatic alarm was triggered when the highly sensitive detectors of the continuous air monitoring system identified minor amounts of radioactive aerosols in the storage room containing the safe. The air contamination was trapped entirely in the filters of the ventilation system. The IAEA emergency response team promptly secured and sealed off the windowless storage room.

An investigation into the circumstances and causes of the incident is still underway. In the meantime the first stage of the clean-up of the storage room was successfully completed on 22 August, 2008. Further independent tests confirmed that there was no release of activity to environment.

According to the IAEA´s nuclear regulator´s assessment of the incident, the lab´s safety systems worked properly and successfully contained the contamination. The incident was rated as level 1 (anomaly) on the Nuclear and Radiological Event Scale (INES) of events. The INES scale has seven categories, the most serious being a "major accident."

An example of good safety culture is set by the IAEA that even small incidents of this type need to be investigated and reported.

New ICRP Draft report for consulting-Rehabilitation

2008-08-19T04:25:00.000-07:00

New ICRP draft report “Application of the Commission’s Recommendations to the Protection of Individuals Living in Long Term Contaminated Territories after a Nuclear Accident or Radiation Emergency”, Version 4 dated 22/7/2008 is available in the ICRP site (www.icrp.org) for public consulting. This is a companion document to the draft report on Emergency Exposure Situations posted earlier for consulting.

The present report provides guidance on the application of the Commission’s recommendations on the above topic. This post-accident (late phase) rehabilitation situation is considered by the Commission as an Existing Exposure Situation. There are six chapters and 3 Annexures. The last date to receive comments is: October 13, 2008.

Bolstering Nuclear Security at China Olympics

2008-08-14T04:52:00.000-07:00

It is reported that China and the IAEA have been working over the last 18 months to bolster the country´s security plan and minimize threats at the Summer Olympics, during 8-24 August, 2008 at Beijing. A radiological dimension was added to their existing security plans so that security for the Olympics is as comprehensive as possible.

The thrust of the IAEA´s work in Beijing is to help integrate radiological planning into existing security arrangements for police, intelligence community and bomb squads based in China. Through advisory missions and training exercises, the IAEA is assisting Chinese authorities with various aspects of radiation detection, physical protection, and emergency response. Efforts to enhance nuclear security arrangements for the Games are largely coordinated with the China Atomic Energy Authority (CAEA).

For several years now, the IAEA has provided specialized technical assistance and expert advice to countries who host major public international events. In addition to its work on the 2008 Summer Games, the IAEA has supported nuclear security measures for the 2004 Olympics in Greece, the 2006 FIFA World Cup in Germany, and the 2007 Pan American Games in Brazil.

Avoid excessive mobile usage

2008-08-01T03:55:00.000-07:00

In spite of repeated news appearing in World Wide Web and in newspapers, little attention is paid to the harmful effects of the radiation emitted by the mobile phones and the cell towers. One can see that the lifestyle change has resulted in usage of mobile phones by almost everybody (2 out of 4) and the children are fascinated by the mobiles. Parents give the mobiles in small children’s hand as a toy, and to school going children as a status symbol.

The radiation levels reported in one of the news papers, Mumbai Mirror, are quite high in many places in Mumbai city and needs urgent response from the government. The radiation dose received depends on the period of exposure. Less time you spend talking, lower is the dose received from the mobile.

A landmark research study carried out in US and Denmark into the use of handsets which may have major public health implications, showed health effects in the children whose mothers have used mobile phones when they were pregnant. The researchers surveyed 13,000 children and found that even less frequent usage was sufficient to increase the health risk to the children.

There is a need for strict regulation to ensure that the manufacturers of the mobile phones and the service providers maintain the radiation emission levels much lower than the stipulated standards. Base stations/towers near schools and crowded areas should be avoided. There should be a dedicated regulatory body for strict regulation of the mobile phone usage. The regulators should also look into the safety of erecting antenna on the residential building tops. The RF radiation levels should periodically monitored in city areas, and around schools. The readings should be displayed for public knowledge and for checking compliance with the set limits by regulators.

38-Hour Simulation of Global Nuclear Accident Concludes: The exercise tests International Nuclear Emergency Response System

2008-07-12T04:43:00.000-07:00

Over two days in July 2008, the IAEA emergency response team coordinated a test of international plans and systems for responding to a potentially serious radiological event. The 38-hour emergency exercise to a simulated accident at a nuclear power plant has successfully concluded. The exercise was coordinated by the IAEA in cooperation with 75 countries and 9 international organizations.

The simulated accident occurred at Mexico´s Laguna Verde nuclear power plant, a two-unit facility along the Gulf of Mexico coast. As the emergency drill progressed, the simulated accident escalated in severity, ultimately rated as a Level 5 "Accident with Wider Consequences" on the International Nuclear Event Scale (INES) because of its potential effects outside the plant site. The event challenged the readiness of nuclear safety, emergency operations, and communications mechanisms to respond to a theoretical radiological or nuclear mishap.

The exercise was a success in that it demonstrated strengths but also the weak points in the international emergency response system, said the IAEA´s Rafael Martincic, who led the preparation and evaluation of the Laguna Verde exercise. Only by identifying weaknesses can we improve the System´s response to large-scale radiological emergencies, he said. A previous simulative exercise took place in Romania in 2005.

The focus now is on evaluating the Laguna Verde exercise, to review findings and identify lessons learned that will further improve the international nuclear emergency response system.

ICRP draft report for comments

2008-06-04T02:52:00.000-07:00

A task Group was formed in November 2006 by the ICRP to develop guidance on the implementation of the new ICRP Recommendations on the principles of optimization of radiation protection in various states of emergency preparedness and response. A report was prepared on the applications of the Commission’s recommendations for the protection of populations in the emergency phase of a nuclear accident or radiological emergency.

The 63 page draft document entitled: Applications of the Commission’s Recommendations for the Protection of People in Emergency Exposure Situations in the ICRP website for public consultation. The document, which can be downloaded, discusses such issues as the setting and use of reference levels, optimization with respect to protective measures, and the interface with the rehabilitation phase following an emergency.

It is reported that ICRP would much appreciate the reader’s views on this draft report. To provide the comments, one can go the Consultation Comments page in the site. The last date for submitting the comments is Friday, August 8, 2008.

Radiation from mobile phones is harmful to children

2008-05-22T04:28:00.000-07:00

One can see that the lifestyle change has resulted in usage of mobile phones by almost everybody (2 out of 4) and the children are fascinated by the mobiles. Parents give the mobiles in small children’s hand as a toy and to school going children as a status symbol.

In spite of repeated news appearing in World Wide Web and in newspapers, little attention is paid to the harmful effects of the radiation emitted by the mobile phones. No body wants to even know about it, neither the users nor the manufacturers.

A landmark research study carried out in US and Denmark into the use of handsets which may have major public health implications, showed health effects in the children whose mothers have used mobile phones when they were pregnant. The researchers surveyed 13,000 children and found that even less frequent usage was sufficient to increase the health risk to the children. These children developed hyperactivity, and difficulties with conduct, emotions and relationships. The health risk in children, below 7 years, using the mobile phone is much greater. Some children are more sensitive than others to the radiation emitted by mobile phones.

There is a need for strict regulation to ensure that the manufacturers of the mobile phones maintain the radiation emission levels of the mobiles much lower than the standards. Base stations near schools and crowded areas should be avoided. There should be a dedicated regulatory body for strict regulation of the mobile phone usage. The regulators should also look into the safety of erecting antenna on the residential building tops. The RF radiation levels should periodically monitored and the readings should be displayed for public knowledge and for checking compliance with the set limits by regulators.

Goiania’s radiation accident – down the memory lane

2008-05-12T03:48:00.000-07:00

In 1987, a scrap yard in Goiânia suffered one of the worst accident involving a radioactive source. Two families live and work at the scrap yard in the Brazilian city. Plastic and metal scrap collected off the streets is sorted out for recycling. Scrap merchants sold a metal canister left at an abandoned medical clinic. It looked harmless but valuable. They had no idea that it contained a powerful radioactive source used to treat cancer. The equipment was opened and the glittering radioactive Caesium chloride powder was shown to the friends and relatives of the junk-yard owner. Small fractions of the powder were gifted as souvenirs.

Thus, unknowingly, the contamination became wide spread over two weeks period. 250 people were contaminated. Four died in the first month. The management of the accident generated 3000 cubic meters of radioactive waste, which was disposed off in near surface repositories on the outskirts of the city.

The incident brought global changes in radiation safety. Lessons drawn from the accident are still helping to shape actions on radiation safety and security decades later. Before the accident, the regulations were weak when it came to controlling radiation used in medicine and industry worldwide. There was no awareness that radioactive sources must be controlled from ´cradle to grave´, and to prevent the public accessing them. Since the accident, the gradual replacement of sealed sources containing the soluble, powdery form of cesium chloride has been considered. The task is not easy. The IAEA has been developing rigorous safety standards for dealing with orphaned sources of this kind in the metal recycling industry. .

Fly-ash waste from thermal power plants

2008-05-10T03:50:00.000-07:00

Coal-based thermal power plants burn train-loads of coal in a day and the percentage of ash generated is of the order of 35-40%. This waste needs disposal, and the target buyers are cement manufacturers and brick makers. The bricks made out of this fly-ash are cheaper as compared to the conventional bricks. The fly ash contains the naturally occurring radionuclides coming from uranium and thorium series of elements and Potassium-40. These radionuclides are present in the coal in parts per million (ppm) levels and get concentrated in the fly ash. A few hundreds of Becquerel (unit to express the quantity of radioactivity) of the radioactivity per kg of the material are likely to be present in the fly-ash.

One of the daughter products in uranium and thorium series is the gaseous radon isotopes. Being gaseous, the radionuclides diffuse out of the bricks/walls made out of the fly ash. These are emitting alpha radiation, and give dose to the lungs when goes inside the lungs as an air contaminant via inhalation route.

From radiation protection considerations, it is suggested that before fly-ash is used for commercial exploitation, an assessment of the materials is made for their radioactive content and the probable dose it is likely to give. If necessary, the material should be processed to remove the radioactivity content as much as possible. Clearance from the appropriate national authorities such as Atomic Energy Regulatory Board in India, may be required before large scale use of the “waste” fly-ash materials in cement or bricks used for construction of residential buildings.

Radioprotectors

2008-04-15T02:40:00.000-07:00

While the radiation therapy is used to effectively to destroy cancerous tissues, it can have devastating side effect on healthy cells. It is desirable to have a drug which can protect some healthy cells without reducing the treatment’s effectiveness? Radio-protectors are drugs that protect normal (non-cancerous) cells from the damage caused by the high radiation dose used in radiation therapy. These agents promote the repair of normal cells that are exposed to radiation.

Amifostine may be the only drug approved by the FDA as a radio-protector. A single dose given to the laboratory animals shortly before receiving radiation therapy significantly reduce the radiation damage.

It is reported that the researchers at the Roswell Park Cancer Institute, USA, have developed a new drug, code-named CBLB502 that can protect healthy cells and bone marrow during anticancer radiation therapy. The drug may even protect against the biological effects such as lethal gastrointestinal (GI) syndrome (as an antidote) which are likely to be caused due to excessive exposures of the full-body in radiation emergencies. However, these are studies involving animals and more research needs to be done in humans.

Everything is more or less radioactive

2008-04-04T04:02:00.000-07:00

When we say radioactive material, we mean the material emits ionizing radiation, capable of producing ion pairs in biological materials. Examples are alpha particles, beta, gamma, X-rays and neutrons. So in all cases, the radiation produces electrical interactions in the absorbing material. X-rays are also produced artificially in machines by rapid slowing down of an electron beam.

Everything around us is radioactive. There is cosmic radiation and terrestrial radiation. Cosmic radiation comes from deep space. Its origin is uncertain and the radiation is highly energetic. It is a mixture of many different types of radiation. All these highly energetic radiation particles interact with the atmosphere and as a result cosmic radiation at ground level becomes primarily muons, neutrons, electrons, positrons and photons. Exposure of humans to this cosmic radiation is unavoidable. The resultant dose is called external dose. Depending upon the elevation from the sea level, the dose rate due to exposure of population is different, and varies considerably. During the interaction, gaseous radioactive isotopes (radionuclides) such as Tritium (H-3) and Carbon-14 are also produced. These gaseous radionuclides get mixed up in the air we are breathing. Over time, they get incorporated in the bio-sphere.

Terrestrial radiation comes from the naturally occurring radioactive material present in rocks, in the ocean, in the atmosphere and in living organisms. Humans are also exposed to the radiation emitted by these terrestrial radioactive materials. Examples of these long-lived radionuclides are: Potassium-40, uranium and thorium series (their decay products such as radioisotopes of radium, polonium and lead). The radionuclides are also found in our diet and they get incorporated in the body. One of the radioactive decay products in the uranium and thorium series is gaseous Radon. The two important radionuclide are Radon-220 (from thorium series) and Radon-222 (from uranium series). Being gaseous, they come out of the solid matrix (like: rock/soil/bricks) and get mixed up in the air we are breathing. These inhaled radionuclides result in internal dose to the body.

The unit of radioactivity is Becquerel (Bq). It represents the quantity of radioactive material that emits one one disintegration per second. The older unit is a Curie (Ci) and 1 Curie is equal to 37 billion Bq. Thus, Bq is a very small unit and prefixes of kilo, mega and giga are use for thousand, million and billion respectively are used to express the amount of radioactive material generally used. Curie is a very big unit and hence prefixes of milli, micro and nano are used to express the amount: one-thousandth, one-millionth and one-billionth of a Curie.

Lead healthy lifestyle with mobile phones

2008-03-03T03:49:00.000-08:00

It is true that mobile phones have brought in revolution in telecommunications industry. The expected mobile phone usage in India is projected to be 500 million (half of the population) within a short period of time. As per the recent reports, of the service providers are planning to erect over 90,000 base stations all over India to meet the ever increasing demand from rural areas! Mobile phone usage is very predominant in the new lifestyle adopted by younger generation. Mobiles are often given to children to play by the ever obliging parents. The scenario is not different in other countries.

Communication between a mobile phone and the nearest base station is achieved by the microwave radiation emissions from the transmitters connected to the antennas mounted at the base stations. These base stations are erected on top of buildings or specially built towers. There is much apprehension worldwide about the long-term health effects due to the exposure of people residing near the base stations and the mobile phone users to the radiofrequency emissions. Health effects such as heating of the exposed tissues, increased risk of malignant tumors (cancers) in the head and ears, genetic effects due to exposure of body cells to the radiofrequency (RF) radiations, etc. are reported in the literature.

Keeping in mind of the above uncertainties, including scanty nature of the studies and the gaps in our knowledge about the health effects of RF radiation, it is advised to keep the exposures much below the prescribed international guidelines. Use mobile phones for messaging only. Hand-free phones are safer. Since children are more sensitive to the radiation, mobile phones should be kept away from children.

There is a need for strict regulation to ensure that the manufacturers of the mobile phones maintain the radiation emission levels of the mobiles much lower than the standards. The base stations should be shared among the service providers to minimize the required number of base stations. Base stations near schools and crowded areas should be avoided.

There should be a dedicated regulatory body for strict regulation of the mobile phone usage. The regulators should periodically monitor the ambient RF levels near the base stations and display the readings for public knowledge and for checking compliance with the set limits by regulators. House insurance/health insurance schemes should also look into the safety of erecting antenna on the residential building tops.

What is dirty bomb?

2008-03-02T04:11:00.000-08:00

A “dirty bomb” is not a nuclear weapon or bomb, the type of which was exploded over Hiroshima and Nagasaki, Japan. Dirty bomb is also called as “radiological dispersal device” (RDD) that combines a conventional explosive, such as dynamite, with radioactive material. Most RDDs would not release enough radiation to kill people or to cause radiation induced severe illness. However, the effects of the conventional explosive itself would be more harmful to individuals than the radioactive material.

Terrorist organizations may use this type of explosion to create panic and fear amongst the target population groups. Making prompt, accurate information available to the public could prevent the panic situation sought by terrorist organizations.

However, depending on the scenario, RDD explosion could create fear and panic due to the radioactive part of the bomb. This is the main motive behind using radioactive material in the conventional bomb. The explosion will contaminate property, may be a few blocks or a few kilometers depending upon the quantity, type of radioactive material used, method used for the dispersal and the weather conditions at that point of time. The clean up of the contamination is potentially costly, need expert’s guidance and time consuming.

Prompt detection of the type of radioactive material used will greatly assist local authorities in advising the community on protective measures, such as sheltering in place, or quickly leaving the immediate area. Radiation can be readily detected with equipment already carried by many emergency responders. There are expert groups identified by the government to respond to such type of emergencies within minutes. Media such as television and mobile messaging system come handy in informing the public as to the protective actions to be taken to minimize the exposure to radiation. The experts also will asess the radiation dose received by the exposed persons and suggest remedial measures, if required.

Thumb rules for the protection are: i) minimize the time spent near the affected area and ii) keep sufficient distance from the site of contamination. The inhalation of the airborne radioactive material can be prevented by using a wet handkerchief over the nose or a respirator normally used by the hospital staff.

Radiation protection of non-human species.

2008-02-01T03:25:00.000-08:00

ICRP Publication 91 (2003) provided the basic framework for assessing the impact of ionizing radiation on non-human species. In order to provide further guidance on the issue, the International Commission on Radiological Protection (ICRP) brought out a draft document, the work of an ICRP Task Group, to address “Environmental Protection: The Concept and Use of Reference Animals and Plants”.

This draft provides the practical basis for consideration of non-human species in radiological protection. The draft report can be downloaded from the ICRP site. It is said that the ICRP would much appreciate receiving comments and suggestions regarding this draft by all concerned not later than Friday 28 March, 2008.

ICRP Publication 103: Recommendations of the ICRP

2007-12-28T00:42:00.001-08:00

Annals of the ICRP Volume 37/2-3
Elsevier, Price: £ 116.00

Abstract- These revised Recommendations for a System of Radiological Protection formally replace the Commission’s previous, 1990, Recommendations, and update, consolidate, and develop the additional guidance on the control of exposure from radiation sources issued since 1990.

The present Recommendations update the radiation and tissue weighting factors in the quantities equivalent and effective dose and update the radiation detriment, based on the latest available scientific information of the biology and physics of radiation exposure. They maintain the Commission’s three fundamental principles of radiological protection, namely justification, optimisation and the application of dose limits, clarifying how they apply to radiation sources delivering exposure and to individuals receiving exposure. The Recommendations evolve from the previous process-based protection approach using practices and interventions by moving to an approach based on the exposure situation. They recognise planned, emergency, and existing exposure situations, and apply the fundamental principles of justification and optimisation of protection to all of these situations. They maintain the Commission’s current individual dose limits for effective dose and equivalent dose from all regulated sources in planned exposure situations. They re-inforce the principle of optimisation of protection, which should be applicable in a similar way to all exposure situations, subject to restrictions on individual doses and risks: dose and risk constraints for planned exposure situations, and reference levels for emergency and existing exposure situations. The Recommendations also include an approach for developing a framework to demonstrate radiological protection of the environment.

(For details: www.icrp.org)

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2007-12-27T23:29:00.000-08:00

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Microwaves for Cancer treatment

2007-12-17T03:04:00.000-08:00

It is reported in Cancer Therapy Journal that large tumors in the breast, treated with a combination of chemotherapy and microwave heat treatment, have shown 50% higher size reduction than the tumors treated with chemotherapy alone. The combination of different cancer treatment techniques has been consistently showing better results than using a single technique such as chemotherapy or surgery.

It is worth mentioning here that radiation, either ionizing radiation such as X-rays and gamma rays or non-ionizing radiation such as microwaves can cause cancers under some conditions, and can also cure (destroy) cancers when the dose and dose rates are sufficiently high to kill the cancer tissues.

Two important precautions, however to be taken from the considerations of radiation protection are i) to ensure that the radiation dosage given should be optimized (not less, not more) and ii) the healthier tissues around the tumor are protected while giving the radiation dose.

International Nuclear Event Scale (INES) is being revised

2007-09-23T04:06:00.000-07:00

A staff reporter of the IAEA reported that the INES scale, originally developed for nuclear power plants in the 1990s, is being revised to make it more versatile and informative tool. Its aim is to consistently communicate the severity of nuclear and radiological incidents and accidents in nuclear industry in the scale 1-3 (incidents) and 4 to 7 (accidents). The scale will now cover all events associated with radiation and radioactive material, including transport related events and human exposure to sources of radiation. The underlying methodology of assessment originally planned for the events rating has not changed. However, the previous procedures were not detailed enough to consistently rate events related to all radiation sources and transportation of the radioactive materials. Over the years, the procedures employed for rating the events have been considerably improved /modified.

The revised scale considers the impact on people and the environment of localized events of exposure of a few people close to the location of the event, or widespread impact, as with the release of radioactive material from an installation. The impact on facilities covers unplanned increased radiation fields due to breach in shielding and spillage of significant quantities of radioactive material resulting from failure of barriers. Degradation in defense-in-depth covers those events without direct impact on people or facilities but for which the measures put in place to prevent accidents did not function as intended.

The revision process has engaged IAEA experts, the INES Advisory Committee and consultants in nuclear safety and radiological protection. The target date for officially issuing the new and improved scale is the end of 2008.

HEALTH CONCERNS OF MOBILE PHONES

2007-08-02T03:45:00.000-07:00

It is true that mobile phones have brought in revolution is telecommunications industry. These devices keep people from anywhere is the world connected. The expected mobile phone usage is projected to be 500 million within a short period of time. As per the recent reports, of the service providers have projected erection of over 90,000 base stations all over India to meet the ever increasing demand from rural areas.

Communication between a mobile phone and the nearest base station is achieved by the microwave emissions from the transmitters connected to the antennas mounted at the base stations, located on top of buildings or specially built towers. The beams from the antennas spread out with distance and tend to reach ground level at distances in the range 50-300 meters from the antennas. With larger capacity base stations having multiple transmitters, the output power can vary over time and with the number of calls being handled. The total radiated power from an antenna could be up to around 100 W with multiple transmitters present.

In view of this exponentially increasing and prolonged usage of the mobile phones, there is much apprehension worldwide about the long term health effects. Some of the health effects of exposure to the microwave radiation can be thermal effects such as heating of the exposed tissues. The exposure is reported to increase the risk of malignant tumors on the side of the head. Many other non-thermal health effects such as cellular genotoxicity are also reported in the literature. Most of the results could not be confirmed due to limited exposure period of 10 to 15 years available. Indirect effect can be just increase in the road accidents due to mobile usage during driving.

Keeping in mind of the above uncertainty, scanty nature of the studies and the gaps in our knowledge about the health effects, it is advised to keep the exposure much below the international guidelines. There is a need for strict regulation with respect to the manufacturers maintaining the limits on the radiation emission levels of the mobiles much lower than the standards. The required numbers of the base stations should be minimized and optimized by way of sharing of the base stations by the different service providers. Regulators should periodically monitor the ambient levels near base stations for compliance of the limits by the service providers.

AN IRRADIATION EVENT

2007-07-30T00:45:00.000-07:00

There was an irradiation incident on June 15, 2007 involving, a radiation therapist at the radiation therapy centre Georges François Leclerc at Dijon, France. This event occurred during the treatment of a patient in radiation therapy. The irradiation of the patient was started as a radiation therapist was still present in the treatment room. The irradiation was interrupted in emergency after around ten seconds. The radiation therapist (occupational worker) who was staying near the accelerator has been exposed to a part of the radiation beam delivered to the patient. An assessment of the dose received by the radiation therapist could confirm that the dose received was in excess of the annual regulatory dose limit allowed for a worker of 20 mSv, the effective dose received was about 30 mSv. No health effects are expected for this person from this exposure. Investigation of the incident is being performed to determine the chronology and causes of the incident and to assess the corrective actions taken by the centre. It has been found that the incident resulted from human errors and a lack of proper procedure.

It is reported that the centre has taken immediate corrective administrative measures and committed itself to perform an in-depth risk identification analysis. Due to the overrun of one of the regulatory exposure limits (effective dose in excess of the yearly limit of 20 mSv), the Nuclear Safety Authority of France (ASN) ASN rates this incident at level 2 on the International Nuclear Event Scale. – Source IAEA News

EARTHQUAKE IN JAPAN TIPPED OVER 100 NUCLEAR WASTE BARRELS

2007-07-21T04:23:00.000-07:00

It was reported that a powerful earthquake of 6.8 magnitude on July 16, 2007 at the Kashiwazaki-Kariwa facility run by Tokyo Electric, Japan caused tipping over of about 100 barrels of low-level nuclear waste at waste storage building of a nuclear power plant. Some of the barrels were found with the lids open. The earthquake also caused some contaminated water from the Tokyo Electric's plant to escape into the sea.

Water which is thought to be from the spent fuel storage pool spread on the operation floors 3 and 3M of the reactor building (non-controlled zone) of unit #6. It was recognized that some leaked water was discharged into sea through draining route. Discharged water activity (after dilution) is reported to be fully less than legislative criteria (0.2Bq/cm^3). It is claimed the discharging had already stopped.
Radionuclides such as I-131, I-133, I-135, Cr-51 and Co-60 were detected on July 17, 2007 in the main ventilation duct (Unit # 7). The ventilation ducts were found bent at the connections to the main stack. The total amount of radioactivity (release?) was estimated to be 3x10^8 Bq. The main stack radiation monitors (units # 1to 6) and monitoring posts in the power station has shown no significant indication of radiation.

Just after the earthquake on July 16th, fire broke out in the unit #3 house transformer that supplies electricity to the reactor facility. It was extinguished at 11:58 AM. The regulator requested licensee to review its fire protection and preparedness system.

The four operating reactors at Kashiwazaki-Kariwa were shut automatically after the earthquake, and the other three had already been halted for routine maintenance, Tokyo Electric said on its Web site. The plant is 9 kilometers (5.6 miles) from the epicenter of the quake. The trade ministry and Kashiwazaki town authorities ordered Tokyo Electric to keep the seven nuclear reactors idle pending safety checks. The government criticized the company for being slow to disclose the radioactive leaks.

The Kashiwazaki-Kariwa plant was not designed to withstand an earthquake as powerful as the magnitude 6.8 tremor. The Trade ministry last year updated regulations to make the nation's nuclear power stations more earthquake resistant. Japan has 55 reactors that generate about one-third of the country's power, making the nation the third-largest nuclear producer in the world. Tokyo Electric operates 17 reactors.

On July 19, Shares of Tokyo Electric Power Co. dropped to a nine-month low on concern that the company's nuclear facility in central Japan, the world's biggest, may be shut for a year after the earthquake caused radioactive leaks.

ICRP PUBLICATION NO. 95

2007-07-16T04:03:00.000-07:00

The International Commission on Radiological Protection (ICRP) has brought out recently a CD containing the ICRP publication no. 95. The publication is a complementary report to other earlier publications which provided age-specific bio-kinetic models and dose coefficients (dose per unit intake of radioactive substance) for members of the public (Publications 56, 67, 69, 71, and 72).

The ICRP-95 provides information on radiation doses to the infant due to intakes of radionuclides in maternal milk. Intakes by female members of the public and female workers are addressed, and dose coefficients per unit intake by the mother (Sv per Bq) are given for radioisotopes of 35 elements including sodium, magnesium, phosphorus, and potassium. The CD provides all the dose coefficients in Publication 95 in a handy electronic format, and includes a considerable amount of additional information. Thus, committed equivalent doses to the various organs and tissues of the offspring are provided. Dose coefficients are also given for inhalation for ten aerosol sizes (0.001, 0.003, 0.01, 0.03, 0.1, 0.3, 1, 3, 5, and 10 µm AMAD) as well as for ingestion. Effective doses and equivalent doses for all important tissues for a range of post-natal integration times (1, 5, 10, and 20 years) are given, together with the dose coefficients to age 70 years. All intake scenarios are considered.

WHAT IS ACCEPTABLE LEVEL OF RISK ?

2007-07-14T04:27:00.000-07:00

The health risk considered here is the fatal cancer, the ultimate end effect of exposure to carcinogens, which is also used as the basis for establishing the radiation dose limits for workers and the public. It is often said that “Nothing is poison but the dose makes it so”. Many substances (such as chemicals) which are toxic at high doses are beneficial to health in small doses, as medicines, to cure diseases. There is no credible scientific evidence that low-dose radiation is harmful. It is also widely reported that low-dose ionizing radiation is harmless and often beneficial to health.

Life is evolved, over millions of years in an environment of ionizing radiation. Even today, there are many radioactive elements existing in the nature. The variation in the background radiation exposures due to these radioactive isotopes is in the range of about 2 to 6 milli-Sievert and more per year in various countries and areas. No adverse health effects are found amongst people living in High Background Radiation Areas (HBRAs).

Public perception of acceptability of risk is based on the benefits that can be derived by taking or accepting the risk. For example, the risk of radiation exposure to much higher levels is accepted by the people in diagnostic and therapeutic radiological procedures. Whereas, the general exposure levels of occupational radiation workers fall in the same range of variation of natural background radiation doses.

For the purpose of regulation of public exposures, a numerical value for the acceptable risk is arrived at in accordance with the principle of protection optimization. In line with the US-Nuclear Regulatory Commission, one can accept a risk of fatality from cancer of one in a million per year, corresponding to the annual public exposure of 0.01 mSv (exposure which can be considered as of below regulatory concern) may be adopted. In case of annual exposures of 1 mSv (dose limit to the public) of small population (like critical group), one can accept a conservative lifetime (75 years) risks to individuals as high as five cancer fatalities in a thousand exposed.

Radiation exposures of the individual members of the public which result in risks below these limits are considered to be safe and acceptable.

USE OF CHEAPER BRICKS - HEALTH CONCERNS

2007-06-18T05:46:00.000-07:00

Construction cost of buildings is increasing by the day. Everybody is familiar with the “red bricks”, which are seen stacked up in any construction site. It is estimated that the cost of construction of a brick wall has gone up from about 500 rupees a square meter in 2003 to over a thousand rupees in 2007!

Cheaper alternatives suggested are: 1) bricks made up of “fly ash”, a waste product from coal-based thermal power plants and 2) gypsum load-bearing panels. The fly ash contains the natural radionuclides which are present in the coal and get concentrated in the fly-ash while burning. Gypsum salt (Phospho-gypsum), obtained as a waste product of the phosphoric acid production process, generally contains significant amount of naturally occurring radioactivity, mainly uranium and its decay products. The radionuclides of concern are: Uranium-238, Radium-226, Thorium-232 and naturally occurring K-40. A few hundreds of Becquerel (unit to express the quantity of radioactivity) of the activity per kg of the materials are likely to be present.

The storage areas of such materials or the houses made by using bricks made out of such materials are potential sites of radioactive radon (Rn-222) gas (decay product of Ra-226) inhalation hazard. From radiation protection considerations, it is suggested that before such materials are used for commercial exploitation, an assessment of the materials is made for their radioactive content. If necessary, the material should be processed to remove the radioactivity content as much as possible. Clearance from the appropriate authorities may be required before large scale use of the “waste” materials.

ICRP APPROVES NEW FUNDAMENTAL RECOMMENDATIONS ON RADIATION PROTECTION

2007-06-10T04:33:00.000-07:00

International Commission on Radiological Protection (ICRP, a non-governmental, independent organization, founded in 1928), in its meeting held at Essen, Germany during 19-21 March, 2007 approved a set of new fundamental recommendations on the protection of man and the environment against ionizing radiation. These recommendations will replace the existing 1990 Recommendations of the ICRP, published in 1991 (ICRP-60, 1991). The new recommendations take into account of new biological and physical information and trends in the setting of radiation standards. For the first time, recommendations were made giving more emphasis to protection of the environment and developing a framework for protection of non-human species.

In brief (as per the final draft): Individual related protection principles remain the same. There are changes in Radiation weighting factors, particularly for protons and neutrons and Tissue weighting factors (reduced for some organs/tissues). There is considerable reduction in the nominal risk coefficient for hereditary effects. However, there is no change in the numerical values in individual-related dose limits applicable for all planned exposure situations.

The recommendations will be published in the Commission’s journal, the Annals of the ICRP, 2007.

SYMBOLS TO WARN OF THE PRESENCE OF RADIOACTIVE MATERIALS

2007-06-10T03:03:00.000-07:00

This new symbol (ISO 21482), a triangular shape with three icons - the trefoil emitting radiation, a skull and a man running away - is meant to warn of the presence of dangerous levels of ionizing radiation on large sealed radioactive sources. The symbol conveys: Danger - Run Away – Do Not Touch. The new symbol does not replace the old one but is in addition to it. IAEA recommends that the symbol may be used on IAEA Category 1, 2 and 3 sealed radiation sources.

The trefoil symbol, the magenta image (Berkeley Lab, US) on a yellow background is being used for decades to denote / warn the presence of radioactive material. The history of the symbol is not very clear, though as it looks today, it originated from Oak Ridge National Lab in late forties. The symbol, however, has little recognition beyond the nuclear community.

RADIATION ACCIDENTS – REDUCE RADIATION EXPOSURE

2007-05-20T01:47:00.000-07:00

With all the terrorist activities on the rise and with availability of nuclear materials not so difficult, it is essential that adequate emergency preparedness is developed and kept in readiness. Assuming that the mass destruction is not in the mind of the terrorists, it is the use Radiological Dispersal Device (RDD), is the likely terrorist act. The RDD is mixing of any radioactive material with conventional explosives and use the same in public domain. The result is large scale contamination of the areas, which is likely to cause panic among the public and disruption of the public utilities such as transport system, food supplies, etc. One should remember that potential health effects may not be alarming in such situations.

There are some simple precautions which the members of the public should take under such situations to reduce the exposures and the health effects. Do not panic. Simply follow the instructions on the protection measures issued by the well identified government agencies responding to such a situation. Some of the simple protective actions can be:

1. Keep away from the affected area. Radiation exposure reduces with distance.
2. Hold a handkerchief, preferably wet, over the nose and mouth. Respiratory protection devices of the type used by medical staff in operation theaters are available in medical stores. This prevents inhalation of the radioactive dust which is likely to get airborne.
3. If you are indoors, remain indoors. Close windows and doors. You may have to close the common ventilation system if the incoming air is not filtered.
4. If one is coming from outside, have change of clothing including shoes, take a shower, clear your nose, wash your mouth and be indoors for further instructions, via Television/Radio from the authorities.

RADIATION HAZARDS OF AIR TRAVEL

2007-05-15T06:11:00.000-07:00

Modern commercial aircrafts operate at altitudes varying from 8 to 16 km from the surface of the earth. Cosmic radiation coming from space is a mixture of many different types of radiation, such as protons, alpha particles, electrons and other high energy particles. The radiation is affected by the earth’s magnetic field and while entering the atmosphere, its intensity reduces due to interaction with the environment. At ground level, the cosmic radiation is mainly consists of muons, neutrons, electrons, positrons and photons. Thus, as the altitude decreases, the cosmic radiation dose also reduces. For example, the dose rate at sea level, at the top of Himalayas, and at 15 km height can be 0.03 micro Sv/h, 1 microSv/h and 10 micro Sv/h. European Commission working group ((EURADOS WG-5) reported typical per flight exposures of 67 microSv and 47.8 microSv to the aircraft crew flying from London to Tokyo and Montreal to London respectively.

This brings into focus the radiation protection aspects of airline crew and of frequently flying airline passengers. The International Commission on Radiological Protection (ICRP) recommends that the airline crew should be treated as radiation workers and for normal flying hours put up by the crew, the expected average annual dose is reported to be of the order of about 2.5 milliSv. This can be compared with the 20 milliSv, the annual average occupational dose limit recommended by the ICRP for all radiation workers. Annual dose limit recommeneded for the members of the public from man-made radiation sources is 1 milliSv.

The number of passengers flying is growing fast, rather exponentially in some countries and if all the doses of the passengers and the crew are added up (collective dose), the statistically estimated health consequences due to the radiation exposure of the group of population is of concern from radiation protection point of view. Now, compares this risk of the health consequences with the risk of potential airline accidents, the radiation exposure risk will work out to be higher!

Any comments?

RADON AT HOME

2007-05-14T01:02:00.000-07:00

Radon-222, a radioactive noble gas isotope, the daughter product of Radium-226 in the naturally occurring Uranium-238 Series has become a centre of attention in radiation protection. Similarly, another isotope of radon, i.e., Radon-220 (called thoron) is the daughter product of Radium-224 in Thorium-232 series. The radon isotopes, Rn-222 and Rn-220 are alpha emitters with half lives of 3.82 days and 55.6 seconds respectively. The decay products of the two isotopes are also short-lived, but they are particulate radionuclides of elements polonium, lead, bismuth and thallium. Official regulatory requirements in some countries call for the measurement of radon indoors before clearance of dwellings for human occupation.

Becquerel (Bq) is the unit used to express the quantity of radioactive material disintegrating at a rate of 1disintegration per second). The radon daughter concentration can also be expressed in terms of working level (WL) units. One WL corresponds to an equilibrium concentration of 3700 Bq / cubic meter of air. Sievert (Sv) is the unit used to express the dose (energy absorbed per kg - effective dose) received due to the exposure to radiation.

Being gaseous, the radon isotopes generated in the underground rocks (about 4 ppm-parts per million), in soil and from the building materials diffuses out and gets mixed up with the air in the environment. The radon gas also comes out from the cracks in the rocks and in hot spring water. Healing property of spring waters is attributed to the presence of radon. Once out in the open, the outside air provides enough dilution. Typical average concentration of radon outdoors is 10 Bq per cubic meter. It varies from place to place. Seasonal variations are seen. In the uranium mines, the concentration can be much higher and it is a potential occupational hazard for the mine workers. However, the radon concentration is much higher indoors due to limited dilution provided for the radon diffusing inside the dwellings from the building materials and the underlying soil (particularly in basement areas). The radon concentration varies with the building material used, the type of the house, quality of construction and ventilation provided. Thus, depending upon the time spent indoors, the exposure of the population can be significant, particularly in cold countries where the ventilation rate provided is low.

On inhalation of the contaminated air, the particulate activity gets deposited in the lung and gives dose to the lung tissues. As compared to the radiation dose resulting from inhalation of unit concentration of the particulate radon daughters, the dose from inhalation of unit concentration of the inert gas is about 50 times lower. Lung cancer is the radon induced malignancy known amongst the mine workers.

Major contribution (70 to 80%) to the average dose of 2.4 milliSv per year to the public from natural sources comes from these radon isotopes and their short-lived daughter products. In some of the high background areas (HBRA), the radon concentration in dwellings may be much higher, which may call for intervention measures, such as relocation to reduce the human exposure.

The International Commission on Radiological Protection (ICRP) recommends Action Levels for regulatory intervention of 200-600 Bq per cubic meter of air with an indoor occupancy of 7000 hours in a year and an equilibrium factor of 0.4 (concentration of radon daughters divided by the concentration of radon gas). This concentration corresponds to an effective dose of 3-10 mSv.

There are various radon measurement techniques / portable monitors are available commercially for the measurement of radon accurately for the estimation of radiation dose and for regulatory compliance. Portable Alpha spectrometry based detection systems, electrets, direct scintillation based radon gas counting systems are employed for the measurement of radon in water, air and for radon exhalation measurements from soil and construction surfaces. Calibration of the systems is one of the important requirements for validation of the system operation and reliability of the data.

FEAR OF RADIATION – UNNECESSARY

2007-05-10T04:53:00.000-07:00

The word RADIATION reminds of dropping of atomic bombs over Japan during the Second World War and the mass destruction of everything in the vicinity of the explosion sites. The effects of the exposures were short term like radiation syndrome and long term, like cancer. That is how the world today came to know about radiation. Since then, there have numerous beneficial effects and peaceful uses of radiation, which has been benefiting the society to a very great extent. Examples are: nuclear power and medical uses of radiation and radioisotopes for diagnosis and therapy. Safety records of such applications are very good as compared to other industries. In fact, other industries should emulate the safety considerations and provisions made in the nuclear industry.

Unlike in other industries, because of the fear of radiation, the effects of radiation exposure on humans are extensively studied and documented. The radioactivity measurement techniques are very well developed and at present a very small amount of radioactive material, in less than nano-gram (one-billionth of a gram) levels can be measured with required accuracy using specially designed electronic instruments. The very data on the health effects of the survivors of the bomb explosion served as the primary database for determination of the radiation exposure risk to the workers and the members of the public. We also have enough data on the health effects of low level radiation exposures of the people living in high radiation background areas (HBRA) in countries like India and China.

The truth is we are all living in this world where there exists natural background radiation, such as cosmic radiation and radiation from the earth consisting of small amounts of radioactive materials like uranium and thorium. This exposure is unavoidable. Public is unawareness of this fact. Nobody really told them or explained to them to be convinced.

However, public reacts to radiation with fear and anxiety. It is the fear of unknown. These indications need to be counterbalanced. How?
1. Two-way open communication between all the stakeholders to be enhanced to break the mutual distrust.
2. Natural background radiation levels can be displayed in public places. Follow one unit to express exposure to radiation. Too many units confuse the public.
3. Use of the term dose limit can be discontinued. It has lost its significance.
4. Improve public familiarity with respect to the effects of radiation and compare the effects with other more familiar environmental pollutants. Use the language which is easily followed by the public, in their language.
5. Educate the public what to do by themselves in case of any release of radioactivity into the environment and high radiation levels.
6. There is no point in highlighting health effects of human exposure to high radiation levels (radiation syndrome) which is likely to occur only during incidents or accidents.
7. Beneficial effects of radiation for health care (medicine) should be projected in schools and collages rather than the biological effects of radiation.
8. In general, public accepts whatever is beneficial or useful to them. Good examples are electricity and use cooking gas. Controllable risk is generally acceptable.

What is radiation hormesis

2007-05-07T06:32:00.000-07:00

It is the hypothesis to explain the lower cancer incidences observed at higher radiation background areas, and inverse correlation observed between lung cancer mortality and indoor radon (a radioactive inert gas – decay product of a naturally occurring uranium -238 radionuclide) levels measured in some US counties. Adaptive response / enhanced immunity of the human biological system at low radiation dose levels are being invoked to explain this effect. This means radiation exposure is beneficial for health, at low doses!

If accepted, the radiation hormesis concept challenges the very basic approach of linear non-threshold model traditionally used by the International Commission for Radiological Protection (ICRP) for the dose-response relationship. The dose limits prescribed are likely to be enhanced from the existing limits of 30 mSv/year and 1 mSv/y for occupational workers and the members of the public respectively. The ICRP recommendations on dose limits are accepted by majority of the nations.

MOBILES DON'T CAUSE CANCER?

2007-01-03T02:14:00.000-08:00

In view of the exponentially increasing usage of mobile phones, there has been much apprehension worldwide about the health concerns of its prolonged use. It is reported in the media that researchers at Danish Institute of Cancer Epidemiology in Copenhagen concluded that “Mobiles don’t cause cancer”. The conclusion was based on their recent study on 420,095 people who had a phone at some point between 1982 and 1995, examined through until 2002. That is occasional radio-frequency (RF) exposures for a period of 13 years.

I strongly recommend that the conclusion should be taken in the proper perspective keeping in mind the following:

1. Cancer is a late-effect. The latent period (since its initiation) for a solid cancer to appear is 30-40 years.
2. The current level of mobile usage is not occasional, but can be quite high, as high as a few hours in day.

Keeping in mind the above uncertainty and the gaps in our knowledge about the health effects, it is not possible to completely rule out adverse health effects even at levels of RF exposures below the international guidelines. Hence, it advisable to have a precautionary approach, such as i) using the phones only occasionally, ii) find out its RF emission levels / SAR Value of the mobiles before it’s purchase, iii) using hand-free types to minimize the exposure to head and neck region and iv) avoid exposure of the mobile to small children.

NUCLEAR ISSUES – NEW YEAR WISHES

2007-01-02T04:33:00.000-08:00

1. No more incidents of detection of Polonium-210 contamination in London or elsewhere. From hazard considerations, it is very mobile and easily dispersed due to its nuclear property. It is one of the daughter products of naturally occurring U-238 series. It has a half life of 138 days and the alpha particle, of energy 5.3 MeV, emission from its nucleus makes it very hazardous if taken internally.

2. Final US Legislation on the Nuclear – deal addresses the concerns of Senior Indian scientists who have been holding Indian Flag high during the harder times of SANCTIONS imposed on India from the west.

3. Full participation of US firms in civilian nuclear power plants, including thorium based reactors in India in the future. The participation shall ensure adequate liability in case of accidents in the reactors.

4. Solve the issue of safe management of spent nuclear fuel from these collaborated reactors. High-value plutonium in the spent fuel should be recovered to exclusively fuel the future Indian fast breeder reactors.

5. Early recovery of the Ash Analizer (if it recovered, it is not well known) belonging to the Central Coal Fields Limited at Hazanbagh, India. The analyzer might have been used to analyze the natural radionuclides in the coal ash. To the best of my knowledge, the natural radioactivity (uranium, thorium) in coal ash in PPM (parts per million) level. As reported in the Press, the instrument can not become radioactive just because it is used to analyze the samples. It only gets contaminated by the use and can be decontaminated easily. I feel, it is over-reaction by the media. However, it needs clarification from the concerned authorities without much delay.