The integrated use of chemical analysis, cytochrome P450 and stress proteins in mussels to assess pollution along the Galician coast (NW Spain)

Aliphatic and polycyclic aromatic hydrocarbons (PAHs) as well as biochemical markers, such as cytochrome P450, benzo(a)pyrene hydroxylase (BPH) and stress-70 proteins, were determined in mussels (Mytilus galloprovincialis) collected in October 1995 from several locations along the Galician coast (NW Spain). The survey proved the existence of a pollution gradient among sampling sites and a chronic exposure to petrogenic and pyrolitic hydrocarbons. This was reflected in mussel tissue levels of PAHs which ranged from 22 to 562 ng/g wet weight. High levels of total cytochrome P450 were detected in mussels from the most polluted sites, but differences were not statistically significant. BPH activity did not show either differences among sampling sites. Conversely, stress-70 proteins were significantly induced in the most polluted locations, and levels of the 72-kDa band correlated well (r2 = 0.854) with the sum of the PAHs from four to six rings accumulated by mussels.