My Blogs : First Opinion ; Radiation Protection Issues ; My Voice

My Website : www.radsafetyinfo.com

Monday, October 17, 2011

Tritium exposure - Kalpakkam

This has reference to the news item in the Times of India dt. 17 October, 2011: “Staff exposed to nuclear radiation – Tritium risk for some Kalpakkam workers”.

The news item states that some workers are exposed to nuclear radiation above permissible levels.

By going by the report, none was exposed to doses above permissible. Exposure to Investigation Levels which are 3/10th of the permissible levels is not an issue at all. In fact, tritium is the least radiotoxic radioisotope and hence least harmful. As a matter of abundant precaution, these levels of exposures are also investigated and corrective actions taken.

It is unfair to the nuclear industry to misquote the report and raise hue and cry on this normal exposure situation in any nuclear reactor.

Saturday, October 1, 2011

Suppression of experimental evidence against LNT

This has reference to the article “Will the LNT Controversy ever be solved?” appeared in the July issue of the Express Healthcare. The following information appeared in HINDU (dated 22nd Sept. 2011) supports the view expressed in the article.

American geneticist Hermann J. Muller was awarded the 1946 Nobel Prize in medicine for his discovery that X-rays induce genetic mutations. In his Nobel Prize Lecture of December 12, 1946, Muller argued that the dose–response for radiation-induced germ cell mutations was linear and that there was “no escape from the conclusion that there is no threshold”. Muller and Curt Stern (the other geneticist) had done many of the key experiments. The fruit fly germ cell mutations experimental results at the University of Rochester failed to support the linear dose-response model at low exposure levels. However, in Muller's speech, he insisted there was "no escape from the conclusion that there is no threshold." Stern raised no objection. It is reported that the two successfully suppressed last-minute evidence against the LNT from the fruit fly experiments.

According to the Edward J. Calabrese, a Professor of Toxicology at the University of Massachusetts, School of Public Health, Amherst, uncovered the correspondence between Muller and Stern. He said, Muller’s decision not to mention the key scientific evidence against his position has had a far-reaching impact on our approach to regulating radiation and chemical exposure. In fact, Calabrese’s career research shows that low doses of some chemicals and radiation are benign or even helpful.

Within a year, National Academy of Sciences (NAS) was forced to accept the linear model for gonadal mutations, the practice was extrapolated to somatic cells and cancer. Twenty years later, NAS adopted the linear approach for chemicals. Soon thereafter, the U.S. Environmental Protection Agency announced it would use the linear model for risk assessment. The International Commission of Radiological protection also assumed the LNT as the basis for giving the recommendations for radiological protection.

If the truth was to be told, probably the nuclear industry could have drastically different exposure standards today, and far less fear about exposures to radiation. The resources, world-wide, spent on over-protection could have been better spent on healthcare in under-developed countries.