Whole-body scanners at airports

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

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

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

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

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

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

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.