Descripción
It is commonly stated that "any radiation dose, no matter how small, can cause cancer." The basis for that statement is the linear-no threshold theory (LNT)--which might more appropriately be called "linear-no threshold hypothesis"--of radiation carcinogenesis. According to LNT, if a 1 Gy (100 rad) dose gives a cancer risk R, the risk from a dose of 0.01 Gy (1 rad) is R/ 100, the risk from 0.00001 Gy (1 millirad) is R/100,000, and so on. Thus the cancer risk is not zero regardless of how small the dose. However, over the past several years, many radiation health scientists have come to regard risk estimates in the low-dose region based on LNT as exaggerated or completely negligible. For example, the 6,000-member Health Physics Society, the principal organization for radiation protection scientists, issued a position paper (1) stating: "Below 10 rad... risks of health effects are either too small to be observed or are nonexistent." A similar position statement was issued by the American Nuclear Society. When the Health Physics Society Newsletter asked for submission of comments on validity of LNT, there were about 20 negative comments submitted and only a single comment supportive of LNT. In a worldwide poll conducted by the principal on-line discussion group of radiation protection professionals (RADSAFE), the vote was 118 to 12 against LNT. A 2001 Report by the French Academy of Medicine concluded that LNT is "without any scientific validity," and an elaborate joint study by the French Academy of Medicine and the French Academy of Sciences (2) strongly condemned the use of LNT.
