DNA adducts in Mytilus galloprovincialis and Zosterisessor ophiocephalus collected from PAC-polluted and reference sites of the Venice lagoon.

Mediterranean mussels (Mytilus galloprovincialis) and bottom-dwelling grass gobies (Zosterisessor ophiocephalus) were collected from the Venice lagoon both in front of the open sea and from the industrial area of Porto Marghera. DNA adducts were measured by means of the nuclease P1-enhanced 32P-DNA postlabelling assay. Autoradiograms of gill DNA from animals of the industrial area showed a tract of unresolved adducts along the diagonal radioactive zone. Such adducts were detected at low but significant levels in different sampling periods only in mussels and fish collected at Porto Marghera. The presence of bulky aromatic DNA adducts in native mussels is consistent with previous results on the appearance of a weak adduct in gill DNA of Mytilus galloprovincialis treated with benzo(a)pyrene. However, the mechanisms leading to DNA damage and the fate ofthe initial lesions in marine invertebrates exposed to genotoxic agents are still poorly understood.