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FYI
----- Original Message -----
From: Jim
Muckerheide
Sent: Wednesday, January 16, 2002 5:11 PM
Subject: [rad-sci-l] Nucl Week on French Acad of Med statement on
LNT & "Disinformation" FYI, Nucleonics Week on the French Academy of Medicine statement re the LNT and "Disinformation": Regards, Jim Muckerheide =================== Copyright 2001 The McGraw-Hill Companies, Inc. Nucleonics Week December 13, 2001 SECTION: Vol. 42, No. 50; Pg. 1 HEADLINE: FRENCH ACADEMY DENOUNCES NEW LIMITS, RADIATION MISINFORMATION BYLINE: By Ann MacLachlan, Paris BODY: France's Academy of Medicine has renewed its opposition to a 20-milliSievert (2 rem) annual dose limit for professional exposures, saying such a regulation would ''bring no health benefit while hampering operation of medical radiology departments by making it more difficult to develop new techniques.'' The Academy, in a new opinion issued Dec. 4, said France should adopt without modification the Euratom radiation protection directive, which sets a professional dose limit of 100 mSv averaged over five years and doesn't change the current annual exposure limit of 50 mSv. The French administration is in the final throes of drafting decrees to enact the 1996 Euratom general directive, as well as a 1997 directive covering rad protection in medical practices. The French nuclear industry, too, has railed against the current draft which stipulates a strict 12-month dose limit of 20 mSv (see related story, page 11). The Academy also ''denounces'' the use of the linear non-threshold (LNT) theory to estimate the health effect of doses below a few milliSieverts, the order of magnitude of the variation in natural background radiation among French regions. It also condemns the use of the collective dose concept to estimate health effects, saying ''these procedures have no scientific validity, even if they appear convenient for administrative reasons.'' The Academy's statement, entitled ''Medical Irradiation, Radioactive Waste, and Disinformation,'' was signed by Guy de The, chairman of its public health commission, and Maurice Tubiana, a renowned cancer specialist. Other drafters were Andre Aurengo, another well-known radiotherapist, and Roland Masse, a former director of rad protection agency OPRI. They are in the forefront of French scientists combating what they see as the misuse of international radiation protection recommendations to fan public concern about the health effects of low doses. Within the French system, the Academy scientists are often considered to represent an extreme view and they have clashed on occasion with radiation protection professionals who appreciate the current system, including the use of the LNT hypothesis and collective dose, because it simplifies their lives. The full Academy adopted the opinion in a unanimous vote Dec. 4. The statement supplements one issued in October 2000 and goes into more detail on medical irradiation. In particular, the Academy says that radiation protection efforts should be increased for medical X-rays to reduce doses for certain exams, such as scans for young people, and recommends further measures, such as more training for radiology personnel. The scientists say it is ''unacceptable'' that while medical irradiation represents 95% of artificial irradiation received by a typical Frenchman, ''so few resources'' are devoted to reducing medical doses compared to the ''high funding'' given to rad protection in power industry. X-rays represent an effective dose of about 1 mSv/year in France, compared to 2-4 mSv from natural sources. The Academy makes several recommendations about how to optimize medical doses and how to justify them, two principles required under the Euratom directive 97/43 that will be enacted into national regulations next year. 'Disinformation' But the Academy goes further to address what it considers ''disinformation'' that has been circulating recently about the radiological risks from nuclear waste and the health effects of the Chernobyl accident. Concerning radwaste, the Academy says that risk studies should give priority to isotopes not on the basis of collective dose, but on the basis of potential individual doses, ''since collective doses calculated from individual doses below a few microSieverts can have no health significance.'' Besides supporting more epidemiological studies of people living in naturally high-radiation areas like India's Kerala state and of ex-USSR populations exposed to relatively high doses of nuclear and other contaminants over long periods, the doctors call for a ''significant national effort'' in France, similar to that underway in the U.S., to study biological mechanisms implicated in cellular response below 100 mSv. The Academy scientists assert that it is ''legitimate'' to evaluate risks from nuclear plant dismantling and waste transport, storage and disposal programs on the basis of what is known about millions of people living in high-background areas, since the dose levels are lower in the case of industrial activities and there's no difference in biological impact of natural or artificial radiation. They noted that no adverse health effects have been detected in Kerala or other high-background areas in studies so far. The doctors also say the LNT theory of dose-effect relation is disproven by numerous experimental and epidemiological data. No increase in cancer has been shown in Hiroshima and Nagasaki survivors at doses below 200 mSv for adults and 100 mSv for children, they asserted, the only ''doubt'' being for in-utero exposure where 10 mSv could be the limit. The Academy railed in particular against the use of the LNT hypothesis to evaluate risks from Chernobyl fallout outside the ex-USSR. It said high doses to thyroids of children in areas near Chernobyl (1-3 Gray average in the most-exposed regions) have led to about 2,000 cancers, with about 10 deaths so far. But ''no increase in thyroid affections that can be attributed to Chernobyl fallout has been shown outside of the USSR, for example in Poland or other adjacent states,'' it says. <snip> _______________________________________________ rad-sci-l mailing list rad-sci-l@ans.ep.wisc.edu http://ans.ep.wisc.edu/mailman/listinfo/rad-sci-l |