Childhood mortality in the city located near the nuclear complex ''Mayak''

The purpose of the study is to assess possible health effects associated with technogenic radiation exposure due to residence near a nuclear complex. The study cohort includes 10,478 children born between 1974 and 1981 and living in the city of Ozyorsk, which is located near the nuclear complex Mayak''. The comparison cohort includes 6,217 children born in the same period and living in the city of Snezhinsk, which is similar to Ozyorsk with respect to its infrastructure and the quality of medical care, and differs from Ozyorsk with respect to the level of radiation exposure to the population. Average value of accumulated effective dose resulted from Mayak operation in the children of Ozyorsk is 2.2 mSv (from 0.05 to 3.4 mSv), and in the children of Snezhinsk - 1.3 mSv (from 0.07 to 2.0 mSv). This difference in doses is related to larger distance of Snezhinsk from Mayak. The number of person-years of follow-up is 135,778 in the study cohort and 82,232 in the comparison cohort. The mortality rate between 1 and 15 years of age is 44.9±5.7 deaths per 105 person-years (PY) in Ozyorsk and 29.2±6.0 deaths per 105 PY in Snezhinsk. The difference is not statistically significant. The structure of mortality is similar in the study and comparison cohorts. Major causes of deaths in both cities are external causes, neoplasms and respiratory diseases. Mortality from all malignant neoplasms is 9.6 deaths per 105 PY (Ozyorsk) and 4.9 deaths per 105 PY (Snezhinsk), including leukemia mortality 3.7 deaths per 105 PY and 2.4 deaths per 105 PY in Ozyorsk and Snezhinsk respectively (the differences are not statistically significant). Comparison of age-specific childhood mortality rates in the study cohort with those in the urban population of Russia shows, that cancer mortality in the study cohort is on the level of national average values almost in all age groups, whereas mortality from non-cancer diseases, external causes and respiratory diseases is considerably lower, than in the general population of Russia. It suggests, that social factors, such as the level of medical care, are of more importance for prevention and treatment of non-cancer diseases than cancer. (author)