Current regulations are too much stringent?

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

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

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)

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

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

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.

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.