Organochlorines in edible fish from the Gulf of Naples, Southern Italy.

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, which tend to bioaccumulate in lipid tissues of living organisms and eventually become hazards for wildlife and humans. Ingestion of fish and seefood from contaminated areas is the main source of human exposure to organochlorines, and several studies have recently demostrated a clear correlation between the frequency of fish consumption and levels of these chemicals in human tissues, serum and milk. Concentrations of hexachlorobenzene (HCB), DDTs and 20 polychorinated biphenyl congeners were determined in edible tissues of ten edible marine species collected from the Gulf of Naples off Campania region (Southern Italy) in order to acquire data on contamination status of the area and to assess potential risks from these chemicals for the human consumers. Homogenized samples were extracted by light petroleum/acetone, cleaned up by n-hexane/acetonitrile repartition and separated into two fractions by passing through a glass column packed with Florisil. The cleaned extracts were analysed using a gas chromatograph equipped with an electron capture detector (63Ni ECD) on two fused silica capillary columns at different polarity. OCPs and PCBs were identified by comparison of retention times with those of the standards on the two columns and quantified from individually resolved peak areas based on the peak areas of corresponding standards. All data were analysed using one way ANOVA test and Tukey-Kramer Multiple Comparisons Test. Residue levels of PCBs as the sum of all the determined congeners were the highest, followed by DDTs and HCB. Marked differences in residue levels of DDTs and PCBs were found between the various investigated species (from P<0.05 to P< 0.001). In particular, the presence of the highest levels of OCPs and PCBs in coastal and strictly resident species such as sea bass (Dicentrarchus labrax) and grey mullet (Mugil cephalus) clearly suggests that the contamination of the Gulf of Naples by these compounds is mainly due to local agricultural, industrial and municipal sources. Concentrations of DDTs and PCBs detected in this study turn out to be generally comparable or higher then those found in similar species from other Mediterranean and non-Mediterranean regions subjected to high anthropogenic impact. From the human health point of view, residue levels of HCB and DDTs detected in this study are well below the Italian Maximum Residue Limits in some foods of animal origin. However, concentrations of PCBs (as the sum of the seven target congeners IUPAC nos. 28, 52, 101, 118, 138, 153 and 180) detected in all the analysed samples far exceed the limit recommended by the European Union for meat, eggs, poultry and related products. Therefore, we suggest that fish consumption patterns for the study area and vicinities be determined im order to allow a more accurate risk assessment for consumers and to protect human health. Moreover, as soon as possible European Commission should set up Maximum Residue Limits also for PCBs in fish, crustaceans and molluscs. The implementation of measures to control industrial waste discharges and to avoid dispersal in the environment of these persistent and toxic contaminants is necessary. Finally, additional studies to monitor level of organochlorine pollutants in edible fish from the Gulf of Naples, particularly in the marine species turned out to be more contaminated in this study, should be carried out.