This review summarizes publications on medical and biological effects of low-dose radiation. Potential bias in epidemiological research is analyzed. Consequences of Chernobyl accident and radiocontamination in the Urals are discussed in some detail. Thyroid cancer was rarely diagnosed in children and adolescents in the former Soviet Union prior to the accident. The mass screening after the accident found not only small tumors but also advanced neglected cancers misinterpreted as aggressive radiogenic malignancies. The latter gave rise to the concept that cancer in exposed individuals is more aggressive than in the general population, which caused overtreatment. Children at schools and preschools were easily available for screening; mass examinations were performed under conditions of high expectancy of thyroid cancer, which resulted in overdiagnosis. Some patients from non-contaminated areas were registered as Chernobyl victims. After the accident, numerous poorly substantiated publications appeared, whereas spontaneous diseases in clean-up workers or residents of contaminated areas were a priori regarded to be radiogenic. The accident has been exploited to strangle the worldwide development of atomic energy for boosting of fossil fuel prices. Later on, consequences of contaminations in the Urals have been overestimated as well. Radiation safety standards are exceedingly restrictive and should be revised to become more realistic and workable. Elevation of the limits must be accompanied by measures guaranteeing their observance. Strictly observed realistic safety norms will bring more benefit for the public health than excessive restrictions that would be neglected in countries with prevailing disrespect for laws and regulations. Of note, negligence and disregard of written instructions was among the causes of the Chernobyl catastrophe. In conclusion, consequences of the Chernobyl accident are still felt: some countries continue dismantling nuclear power plants, thus strengthening their economic dependence on Russia.