The overestimation of medical consequences of low-dose exposures: Cui bono?

Abstract

After the Chernobyl disaster appeared papers overestimating medical consequences of low-dose radiation exposures. Examples have been discussed previously; an updated overview of selected studies is provided here. Various kinds of bias can be found in the epidemiological research reporting elevated health risks from low doses of ionizing radiation: Interpretation of spontaneous conditions as radiation-induced, dose comparisons disregarding the natural background, publication bias, etc. Admittedly, all relevant parameters cannot always be taken into account in epidemiological research. Several examples of potentially biased reports on Mayak Production Association workers and Techa river valley residents are analyzed here. Doubtful correlations between exposures to low radiation doses and nonmalignant conditions, discussed in this commentary, call into question the cause-effect character of such correlations for malignancies revealed by the same scientists. Correlations can be caused or influenced by dose-dependent selection and self-selection. Individuals with higher doses were probably more motivated to undergo medical checkups and given more attention. The medical surveillance of exposed populations is important; but more consideration should be given to potential bias. A promising approach to the study of dose-response relationships are lifelong experiments in different animal species that can reveal the net harm or potential benefit (within a certain range according to the concept of hormesis) from low-dose exposures to ionizing radiation.