No abstract

No abstract

Plutonium particles: some like them hot The Medical Research Council's 1975 report The Toxicity of Plutonium (Nature, 253, 385) concludes that "there is no evidence that irradiation by 'hot particles' in the lung is markedly more hazardous than the same acti vity uniformly distributed or that the currently recommended standards for inhalation of plutonium are seriously in error." Report R29 (1974) of the National Radiological Protection Board (NRPB) states that "there is no biological evidence available at present which suggests that 'hot spots' carry a higher risk of cancer induction ." But in the March 20, 1975 New Scientist, Dr A. R. Tamplin warns: "The plutonium exposure standards ... must and will eventually be made more restricti ve by a factor approaching 1,000." Behind this disagreement is a major controversy over the risk of lung cancer from inhaled insoluble particles of intensely radioactive alpha emitters such as plutonium. In that controversy-unresolved by any direct data-lies a source of uncertainty about the future of nuclear power. A report by Amory B. Lovins and Walter C. Patterson of Friends of the Earth. SINCE the late 1960s, many experts-Geesaman, Langham, Long, Morgan among others-have expressed concern about the formidable but highly uncertain toxicity of plutonium (Pu) aerosols. On February 14, 1974, Drs Tamplin and Cochran of the Natural Resources Defense Council (NRDC) took action. They petitioned the United States authorities to reduce the maximum permissible lung burden (MPLB) and maximum permissible concentration in air (MPC a) of insoluble Pu by 115,000 times. Also in 1974, the US Atomic Energy Commission published two defences of present standards, LA-5482-PR and W ASH-1320, and in May and November NRDC published interstitial rebuttals to which the AEC declined to respond in writing or otherwise. The NRDC petition is under review by many US official bodies, and the AEC's successor agency should announce its next move in April. The cancer risk from microscopic inhaled particles of insoluble Pu and similar actinides arises because such

No abstract

No abstract