Francesca Pellizzato

Imposex in Hexaplex trunculus at some sites on the North Mediterranean Coast as a base-line for future evaluation of the effectiveness of the total ban on organotin based antifouling paints

Imposex — the superimposition of male sexual organs (penis and vas deferens) onto female Neogastropods such as Hexaplex trunculus (Linne , 1758) — is used world-wide as a biomarker of ecological impact of organotin based antifouling biocides (TBT and TPhT). To limit the impact of organotin pollution, since January 1, 2003, the International Maritime Organization (IMO) has enacted a global ban on the use of organotin compounds in antifouling systems. It is important to record imposex levels and organotin contamination before the implementation of the ban, in order to assess the current situation and be able, in the future, to verify the effects of the International Protocol. In this paper, recent imposex data measured in populations of Hexaplex trunculus from three different Mediterranean regions are compared: the Ligurian Sea (Italy), the Lagoon of Venice (Italy) and the western coast of Istria (Croatia). In the two former locations, a partial ban on TBT has been in force for vessels less than 25 m since 1982, while in the latter region no restrictions on organotin antifouling paints have been applied yet. Gastropod samples collected from the Venice lagoon were analysed with an acid extraction followed by Grignard derivatisation, clean up and GC-MS determination, in order to relate the levels of TBT, TPhT and their metabolites with the imposex degree detected. Biological data show that the levels of imposex were very high (VDS from 4.3 to 5) in all the sampling sites considered, particularly in the Croatian coast stations. The concentrations of organotin compounds — butyltins and phenyltins — measured in the samples from the lagoon of Venice were found to partition differently in the visceral coil and in the rest of the soft body of the analysed organisms.

Organochlorine compounds (polychlorinated biphenyls and pesticides) and polycyclic aromatic hydrocarbons in populations of Hexaplex trunculus affected by imposex in the Lagoon of Venice, Italy

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides, and polycyclic aromatic hydrocarbons (PAHs) were measured in gastropods from the Lagoon of Venice, Italy. The visceral coil and the rest of the soft body of organisms (Hexaplex trunculus) sampled at two stations inside the lagoon and three stations on the seaward side were analyzed to evaluate their contamination levels. Preferential accumulation of PCBs and pesticides in the visceral coil (>80%) compared with the rest of the soft body was observed, whereas on average, PAHs showed no preferential partitioning. Differences between levels of organochlorine contaminants in the gastropods highlighted a gradient of pollution from the stations inside the lagoon (PCBs, 45-363 ng/g; pesticides, 4-51 ng/g) to the sea (PCBs, 13-131 ng/g; pesticides, 2-29 ng/g). The possible role of the three classes of contaminants, in addition to that of organotin compounds (OTCs), previously analyzed in the same samples, in causing one of the anatomic modifications because of imposex in this gastropod also was studied. A modeling approach by partial least squares (PLS) in latent variables was applied to explain the penis length of imposex-affected females with concentrations of organic pollutants. The synergistic role of PCBs, pesticides, and OTCs was evidenced, whereas the contribution of PAHs appeared to be very low.

CONTAMINATION IN MYTILUS GALLOPROVINCIALIS BY CHLORINATED HYDROCARBONS (PCBS AND PESTICIDES), PAHS AND HEAVY METALS IN THE LAGOON OF VENICE

Polychlorobiphenyls, chlorinated pesticides, polycyclic aromatic hydrocarbons and heavy metals (Cd, Pb, Cr, Ni, Hg, Cu, Fe, Zn) were measured in the entire tissue of the mussel Mytilus galloprovincialis, collected at five sites in the Lagoon of Venice and one reference site outside the Lagoon, in the Adriatic Sea. Total concentrations ranged from 57.5 ± 0.2 to 779 ± 11 ng g−1 d.w. for PAHs, from 52 ± 4 to 286 ± 1 ng g−1 d.w. for PCBs, and from 2.6 ± 0.8 to 37 ± 4 ng g−1 d.w. for pesticides, indicating significantly higher contamination in the central part of the Lagoon with respect to the northern and southern ones. As regards heavy metals, only Cd presented a pattern similar to that of organic compounds. The other metals showed peculiar distribution in the six sites of the Lagoon in relation to their sources. The risk to human health as a result of eating these mussels was evaluated by comparison of daily dietary intake with toxicological threshold limits. In mussels from Porto Marghera, Cd, hexachlorobenzene and pyrene had concentrations potentially harmful to human health.