Genotoxicity of sediment extracts obtained in the vicinity of a creosote-treated wharf to rainbow trout hepatocytes.

Genotoxicity and cytotoxicity were evaluated in rainbow trout hepatocytes exposed to sediment extracts obtained in the vicinity of a creosote-treated wharf. Sediment cores were collected at the intertidal and subtidal sections of the wharf at distances of 1, 5, 40 and 50 m. Moreover, subsamples were also taken at different depths of the cores ranging from 2 to 10 cm below the sediment/water interface. Sediment samples were air-dried and extracted in dichloromethane followed with an exchange into dimethylsulfoxide (DMSO). Rainbow trout hepatocytes were exposed for 24 h at 15 degrees C to several concentrations of the sediment extract. Afterwards, the cells were collected, and cell viability was assayed along with genotoxicity using the nick translation and the alkaline precipitation assays. Results showed that the wharf contained high concentration of polycyclic aromatic hydrocarbons (PAHs), displayed genotoxicity and cytotoxicity to hepatocytes. In addition, PAHs, cytotoxicity and sometimes genotoxicity were detected in all sediment samples and tended to decrease with distance. Chemical contamination and (geno)toxic effects were greater in sediment extracts from the intertidal section than from the subtidal section. However, no evident change in chemical or toxicological characteristics was noted between samples obtained at different depths. Spearman rank-correlation analysis revealed some trends between levels of some PAHs and (geno)toxicity in hepatocytes exposed to sediment extracts.