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 hepatocy tes exposed to sediment extracts obtained in the vicinity of a creosot e-treated wharf. Sediment cores were collected at the intertidal and s ubtidal sections of the wharf at distances of 1, 5, 40 and 50 m. Moreo ver, subsamples were also taken at different depths of the cores rangi ng from 2 to 10 cm below the sediment/water interface, Sediment sample s were air-dried and extracted in dichloromethane followed with an exc hange into dimethylsulfoxide (DMSO). Rainbow trout hepatocytes were ex posed for 24 h at 15 degrees C to several concentrations of the sedime nt extract, Afterwards, the cells were collected, and cell viability w as 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), displa yed genotoxicity and cytotoxicity to hepatocytes. In addition, PAHs, c ytotoxicity and sometimes genotoxicity were detected in all sediment s amples and tended to decrease with distance. Chemical contamination an d (geno)toxic effects were greater in sediment extracts from the inter tidal section than from the subtidal section. However, no evident chan ge in chemical or toxicological characteristics was noted between samp les obtained at different depths. Spearman rank-correlation analysis r evealed some trends between levels of some PAHs and (geno)toxicity in hepatocytes exposed to sediment extracts.