LOW LEVEL RADIATION--HOW CONTROVERSIAL

Medical experts tell us that smoking is linked to lung cancer, and that the more cigarettes a smoker has smoked in the past, the higher his probability of contracting it. What, then, is the probability of contracting lung cancer due to having smoked half a cigarette in a lifetime? (How many lung cancers in a million of such tried-it-only-once smokers?) Nobody knows for sure, because it can only be inferred by extrapolation; direct observation is virtually impossible (background too high, no cause-effect link). Quacks would therefore call this "an unsolved problem," and until the exact figure is known they would assume "for safety's sake" that this half cigarette may be lethal and requires all kinds of foolproof safeguards. When told that a lot of problems are unsolved for the simple reason that they are not worth solving, they will regard the problem as "controversial."

The National Academy of Sciences' BEIR (Biological Effects of Ionizing Radiation) Committee has now issued a final report, reducing its previous (1972) estimates of cancer risks by about half. The report has been endorsed by all but two of the 21 committee members; the two are holding out on mutually opposing sides.

[A short and easily understood report can be found in Science, 22 Aug 80, p.887. Related and highly interesting papers are "Radiation risks from nuclear power exaggerated," New England J. Medicine, 22 May 80, pp. 1205-1206, and "Low-dose radiation and leukemia" by a team of 8 physicians from the Mayo Clinic, New Engl. J. Med., 15 May 80, pp. 1101-1105 (no statistically significant dependency found). An unusual contribution comes from high-altitude, strong background radiation areas in Mainland China, Science, 22 Aug 80, pp.877-880 (no health effects differing from control areas found).]