Heavy metal concentration in the moss Pleurozium schreberi in the Niepołomice Forest, Poland: changes during 20 years.

The Niepołomice Forest is a large forest complex (110 km2) situated in southern Poland 10 to 30 km to the east of the urban industrial Kraków agglomeration and steelworks, which was built up on the outskirts of the city in 1950. Due to prevailing westerly winds, the forest is affected by pollutants emitted by both the steelworks and the city. The level of heavy metal contamination in the Niepołomice Forest was described using a sensitive bioindicator - the moss Pleurozium schreberi. Mean concentrations of metals in moss collected in the Niepołomice Forest were Cd - 0.71, Cr - 2.4, Cu - 8.6, Fe - 673, Pb - 12.7, and Zn - 61 mg/kg. Concentrations of heavy metals in moss in the Niepołomice Forest decreased in time. As compared with the relatively clean area in north-eastern Poland (Puszcza Białowieska), the concentration of Fe was 2-9 fold and Pb 4-6 fold higher in the Niepołomice Forest in 1975, while in 1998 4 fold and 2 fold, respectively. In both 1975 and 1998 the most polluted by heavy metals was the western part of the Niepołomice Forest (closest to the pollution sources) and the area along the roads inside the forest complex.