LETTER: Why official theories may hide the true nuclear risks

Sir: Press coverage of last Wednesday's report from the Committee on Medical Aspects of Radiation in the Environment (Comare) gives the impression that radiation has been cleared of blame for the Seascale leukaemia cluster, because doses from Sellafield are too low. Raw sewage, we heard, is a more likely culprit.

However, official perceptions of health hazards from radiation depend crucially upon studies of the long-term effects of a single acute blast of external radiation from the Hiroshima A-bomb. There is now a large body of evidence that these studies are a poor basis for assessing health damage from chronic, low-dose exposure to radiation from man-made fission products, which may be ingested and incorporated into body tissue.

By 1958, the area around Seascale had been plastered with 5,000 becquerels per square metre of the isotope Strontium-90 - that is more than 10 times the levels of Sr-90 from nuclear weapons testing that shocked officialdom into promulgating the 1963 international test-ban treaty.

We are glad to see that the Comare report expresses reservations about "current knowledge" of radiation hazard, and admits there are "uncertainties regarding internal radiation exposures" and an "urgent need ... for improved knowledge".

In the House of Commons two days before the 10th anniversary of the Chernobyl disaster a symposium organised by the Low Level Radiation Campaign and Medact will discuss the health effects of low-dose internal radiation. We are looking for research and funding proposals such as the Comare report also calls for.

Richard Bramall

Low Level Radiation Campaign

Builth Wells, Powys