BIOINDICATORS OF POLLUTANT EXPOSURE IN THE NORTHWESTERN MEDITERRANEAN-SEA

Several bioindicators were used to evaluate the biological and genotox ic effects of marine pollutants near large coastal cities in the north western part of the Mediterranean Sea. Three target species of teleost s were selected: red mullet Mullus barbatus and 2 types of comber (Ser ranus hepatus and S. cabrilla). Induction of ethoxyresorufin-O-deethyl ase (EROD) activity specific for polycyclic aromatic hydrocarbons (PAH ) and polychlorinated biphenyls (PCB) was measured in the livers of th e fish, and inhibition of acetylcholinesterase (AChE) by organophospho rus insecticides and carbamates was measured in their muscle tissues. Maximal EROD activities (16.8 +/- 2.7 to 19.4 +/- 4.2 pmol min(-1) mg protein(-1)) recorded in red muller near Barcelona (Spain), Milazzo (S icily) and Ostia (Italy) indicated exposure to high pollutant concentr ations. Inhibitions of AChE activity were low in areas remote from agr icultural and industrial activity. The highest inhibitions were measur ed at sites of heavy industrial and domestic waste, such as Genoa and Naples (Italy), Rio Ter (Spain), Barcelona, and Cortiou (France). Inhi bition of AChE activity was higher at a given station for younger indi viduals 120 to 140 mm in length than for those 160 to 180 mm long. Ant ioxidant enzyme activities (catalase, superoxide dismutase, glutathion e peroxidase and DT-diaphorase) were measured in red mullet livers at 5 stations along the French and Spanish coasts. Catalase activity was highest al Cortiou, consistent with higher levels of pollution, and lo wer at Mallorca (Balearic Islands). Varying responses were obtained fo r the other antioxidant enzymes. Glutathione S-transferase (GST), a de toxification enzyme, was also measured in the livers of red mullet fis h and found to be significantly higher at Cortiou than at the other lo cations studied. Chemical measurement of PAH in surface sediment indic ated the pyrolytic origin of this contaminant for all stations except Milazzo (petroleum origin). Detection of DNA adducts as a bioindicator of exposure to carcinogenic substances was tested according to 2 comp lementary assay techniques: enzyme-linked immunosorbent assay (ELISA) and P-32-postlabeling. ELISA revealed maximal quantities of PAH-DNA at Barcelona (15 adducts per 10(8) nucleotides), Cap Finale (Corsica) (2 0.8) and Milazzo (15.5). The richest adduct profiles were detected by the P-32 method at Antibes (France), Santa Ponza (Balearic Islands), M ilazzo and Cap Finale, with a maximum of 6.2 adducts per 10(8) nucleot ides at Milazzo. This multimarker approach showed that pollutant expos ure levels varied according to site. With a sedimentary PAH profile ap parently resulting from petroleum pollution, the Milazzo station had t he greatest quantity of DNA adducts and the highest inductions of EROD activity and AChE inhibitions in M. barbalus and S. hepatus.