Riverine fluxes of the persistent organochlorine pesticides hexachlorcyclohexane and DDT in the Russian Federation

The contribution of gross riverine organochlorine pesticide (OCP) transport to estuaries of Russian seas and Lake Baikal was determined to help unders tand OCP transboundary transfer and to provide a basis for estimating Russi a's contribution to global pollution by these pesticides. The official OGSN K/GSN data ranks sea/ocean/lake basins in the following order based upon th e amounts of total OCPs received from agricultural use: Eastern Arctic>West ern Arctic>Pacific>Baltic>Caspian>Azov/Black>Baikal A similar ranking was o btained using an independent set of data: Eastern Arctic>Pacific>Caspian>We stern Arctic>Baltic>Azov/Black. In terms of riverine flow-associated discha rge of HCH isomers (i.e., sum of alpha-, beta- and gamma-HCH) estuaries of the Kara, Okhotsk and Beloye (White)/Barents seas received more pesticides than other seas. No HCH was discharged to estuaries of the Eastern Siberian and Bering seas. For DDT and its derivative (DDE), estuaries of the Kara, Caspian, Okhotsk and Baltic seas received the greatest amounts. During our study period (1988-1996), HCH transport was more prevalent in the majority of rivers reflecting both the official ban on the use of DDT in the former Soviet Union and the greater popularity of HCH as a pesticide. In general, it appears that Russian rivers play a significant role in OCP contamination of some estuaries of regional seas, especially those of the eastern Arctic basin, such as the Kara Sea. (C) 2000 Elsevier Science Ltd. All rights res erved.