HEAVY-METALS IN SURFACE SOILS OF THE WART A RIVER VALLEY IN AN URBAN AREA

In the urban area of the-city of Poznan the contamination with heavy m etals was investigated. From the top.soil: layers of five cross-sectio ns of the valley of the:Warta river 87 samples were collected. Beside common soil characteristics: the contents of a arsenic, barium, cadmiu m, chromium,copper, Iron, lead, manganese, phosphorus and zinc were an alyzed. Predominantly:the level of: contamination:with heavy metals is Ibv in the valley soils:A higher level was found in the area of the o ld city centre. Especially the contents of lead, copper and : zinc wer e raised. Downstream: of the :sewage plant discharge into the river Wa rta: increased contents:of lead: and cadmium were found. The distribut ion of heavy metals in the river Warta sediments indicates that the re ason of the local increase of heavy metal contents is the sewage water discharge, Correlations between the content df different heavy metals and other soil properties (pH, clay and P-content, C/N-ratio) were ca lculated.