O. A. Dardynskiy, I. V. Dardynskaia, T. M. Belikova, E. M. Bazilevskaya, A. A. Kovshov, N. V. Erastova, A. V. Meltser, V. P. Chashchin, M. V. Chashchin, E. V. Zibarev, and O. G. Khurtsilava
The article presents results of cohort epidemiological studies conducted in the period from 2001 to 2010 among the indigenous population residing in Chukotka (ChAO) and Nenets (NAO) autonomous districts. The aim was to document temporal changes in blood concentrations of persistent contaminants that caused the serious health concern from the first Arctic Monitoring and Assessment Program (AMAP) survey in 2001 “Persistent toxic substances, food security and indigenous peoples of the Russian North”. In monitored indigenous cohorts there have been measured blood concentrations of persistent contaminants including polychlorinated biphenyls (28/31; 52; 99; 101; 105; 118; 128; 138; 153; 156; 170; 180; 183 and 187); hexachlorocyclohexane (α, β, γ - isomers of HCH); oxychlordane (trans chlordane, cis-chlordane); DDT (2,4 DDE; 4,4 DDE; 2,4 DDD; 4,4 DDD; 2,4 DDT; 4,4 DDT); hexachlorobenzene (HCB); heptachlor; dieldrin; mirex; toxaphene (Par 26, the Par 50, the Par 62); PBDEs (28; 47; 100; 99; 153; 154; 183); metals (Cd, Pb, Hg). During 2003-2004 there was implemented a set of measures for the disposal and detoxification of local sources of persistent pollutants and reduction of the risk of associated health effects that had been recommended by the international AMAP expert panel. As a result of 2010 study a significant reduction in the average serum concentrations of DDT and DDE 4.4, as well as blood concentrations of lead was found to occur, they were observed only in men living in NAO. Changes in concentrations of a number of other persistent toxic substances (PTS) although show a tendency to decrease, but these changes failed to reach the level of statistical significance. The mean annual incidence rates of diseases associated with harmful impact of PTS, in particular, cancer, endocrine system diseases, congenital malformations, and immunodeficiency, unlike most of the other classes of diseases in the population showed a clear trend towards to the increase in the period of observation. Conclusion. The results obtained did not allow to confirm the sufficient effectiveness of implemented measures for the rehabilitation of residential areas both in Chukotka and NAO. The period of re-measuring blood concentrations of PTS was assumed not be appropriate due to longer half-life of many PTS studied. The health importance of long-range transboundary transport of PTS is likely to be also underestimated especially due to the observed high contamination of migrating of commercial species of wild birds, fish and marine animals that make up a significant part of the traditional diet of indigenous peoples of the North. There is need for the improvement of national biomonitoring as well as information systems for appropriate assessment, prediction and management of health risks associated with long-range biotransportation of PTS into the arctic food chains.