Pollution of the coastal bottom sediments at the Middle Primorie (Russia) due to mining activity

The contents and geochemical forms of Mn, Zn, Cu, Pb and Cd were studied in the coastal sediments at the Sea of Japan, an area adjacent to the watershed with a developed mining industry (Rudnaya River basin, middle Sikhote-Aline). Solid discharge into the Rudnaya River has abnormally high metal contents that are in leachable forms, including sulfides. Metal levels in the coastal sediments were elevated as a result of this polluted matter dissipation. Sediment pollution by Pb, Cd, Cu and Zn (normalized Clark Concentration measure) exceeds 20–50 within Rudnaya Bight and varies from 5 to 10 within a 25-km plume southward of the bight due to current action. An alteration of the metal forms also occurred, due to mechanic decomposition of the sulfide minerals and dissipation of all river-derived forms.