Abstract. The research was applied to 17 spiecies of freshwater molluscs, for 14 spiecies the concentration of heavy metals (Cu, Zn, Pb, Co, Cd i Hg) was marked in soft tissues, and for 16 spiecies the concetration of these metals was marked in shells. This study is based on the analysis of 110 sampels of soft tissues and 119 sampels of shells. The species that the best react to the changes in the concentration of the heavy metals in water and sediments are: Anodonta anatina, Dreissena polymorpha, Lymnaea stagnalis, Pseudoanodonta complanata i Viviparus contectus. The second group that is less related with the enviroment are four species: V. viviparus, Sphaerium solidum, Unio pictorum oraz U. tumidus. The species most related with the enviroment in individual arrangements are: (1) tissues-water: V. contectus, A. anatina and V. viviparus, (2) tissues-sediments: A. anatina, P. complanata and V. contectus, (3) shells-water: D. polymorpha, U. pictorum and Lymnaea stagnalis, (4) shells-sedimetns: V. viviparus, D. polymorpha i S. solidum. In the surface water we can control all six analyzed metals through the shell analysis of D. polymorpha, and in the bottom sediments we can control the concentration of Cu, Zn, Pb, Cd i Hg by soft tissues analysis and Co by shell analysis of A. anatina. Those two spiecies are crucial for the future research. Two other species are considered as supplementary. Those are: L. stagnalis (in water we can control the concentration of Cu, Zn, Pb, Cd by shell analysis, and in sediments we can control Cu, Pb, Cd by shell analysis and Zn by soft tissue analysis), V. contectus (in water we can control the concentration of Cu, Co, Cd by tissues analysis and Pb by shell analysis, and in sediments we can control Cu, Zn, Co i Cd by tissues analysis). In the futur research one should resigned from using five species that are under protection in Poland since 2001. Those are: S. rivicola, S. solidum, U. crassus, P. complanata and A. cygnea.
Key words: the Odra river estuary, lakes of Western Pomerania, Poland, freshwater molluscs, soft tissues, shells, water, bottom sediment, heavy metals