Assessment of genotoxicity in polluted freshwaters using caged painter's mussel, Unio pictorum.

This study was undertaken to evaluate the applicability of caged painter's mussel, Unio pictorum for freshwater environmental genotoxicity assessment. Mussels in cages were exposed for 3 weeks in 2002-2004 to polluted sites in two large rivers in the Croatia, the Sava and Drava, and on the respective reference sites. DNA damage was assessed in haemocytes of the exposed mussels by the comet and micronucleus assays. Both assays provided good discriminative power between polluted and control sites and showed the same gradation of sites according to their genotoxic properties, with high concordance between investigated years. Background levels of the DNA damage in haemocytes of painter's mussels are defined for both assays for easier detection of contamination-related genotoxicity. U. pictorum is found to be a very suitable sentinel species, sufficiently sensitive to the impact of pollution but at the same time unsusceptible to stress caused by translocation or cage exposure.