Epidemiological Research with Special Reference to Nuclear Worker Studies: Commentary

Limitations of some epidemiological studies on low-dose lowrate exposures to ionizing radiation include dose comparisons disregarding natural radiation background, unfounded classification of sporadic diseases as radiogenic and conclusions about causality of dose-effect relationships. Other bias, confounders and inter-study heterogeneity have been pointed out. Some dose-effect correlations can be explained by a dose-dependent selection, self-selection and recall bias. It can be reasonably assumed that individuals knowing their higher doses would be more motivated to undergo medical examinations being at the same time given more attention. Reported dose-effect relationships between low-dose low-rate exposures and non-neoplastic diseases call in question the causality of such relationships for cancer detected by the same researchers. Reliable evidence in regard to biological effects of low radiation doses can be obtained in large-scale animal experiments with registration of life duration. The monitoring of human populations exposed to low-dose radiation is important but conclusions should be made with caution considering potential bias and economical motives to strangulate nuclear energy production in accordance with the interests of fossil fuel producers. Of note, health burdens are the greatest for power stations based on coal and oil; the burdens are smaller for natural gas and still lower for the nuclear power. The same ranking applies for the greenhouse gas emissions