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

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

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

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

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

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

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

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.