It is generally acknowledged that the Mediterranean Sea represents a geological hot spot for mercury (Hg): about half the world’s Hg resources are located in this area, with abundant deposits in sites facing the Italian seas (Covelli et al., 2012, Grassi and Netti, 2000, Martinez-Frias et al., 1998, Moldenhauer et al., 2008). Because of the natural presence of mercury and the development of related industrial and anthropogenic activities since ancient times, the release of mercury into the marine environment is recognized as the main determinant of the bio-magnification of its predominant organic form – methyl mercury (MeHg) – in Mediterranean seafood from different trophic levels (TLs) (UNEP, 2002, FAO/WHO, 2011). A previous evaluation by the (US) National Research Council established an intake limit of 0.7 μg/kg body weight per week (NRC, 2000). Very recently, the European Food Safety Authority revised its former opinion on mercury and methylmercury in food: A Tolerable Weekly Intake (TWI) of 1.3 μg/kg body weight (bw) for MeHg is now proposed lower than the former one of 1.6 (EFSA, 2012a), on the basis of multiple epidemiological studies that observed adverse effects in children as consequence of maternal exposures. Other Agencies, in Japan, USA, New Zealand, Australia, UK, and Canada, have proposed MeHg Reference Doses (RfD) ranging from 0.1 to 0.47 μg/kg/day, based on multiple end-points (Mahaffey et al., 2011). Recent papers have focused on biota sampled from Mediterranean industrial hot spots in Southern Italy, such as the gulf of Taranto (Di Leo et al., 2010, Spada et al., 2012) and the Augusta basin (Gabellini et al., 2011). The findings indicate that the presence of MeHg in local seafood of a low trophic level (TL) may represent a potential health concern for the population. A detailed biomonitoring study of fishermen and their families in a Northern Africa Mediterranean coastal village (Elhamri et al., 2007) found a correlation between the number of seafood meals based on anchovies and pilchards and methyl-mercury levels in hair. The same correlation with fish consumption was described by Dıez et al. (2008) in a study carried out on 237 subjects recruited in the urban population of Neaples (I); Freire et al. (2010) reported a possible association between fish consumption and cognitive development in a Spanish cohort of prescholar children. When extrapolated to dietary intakes, the Hg levels in hair indicated potential overexposure with respect to the oral reference dose. Plenty of data are available on HgTOT and MeHg levels for Italian marine species; however, some of the investigations were restricted to few species of seafood, or limited geo-referenced areas (Perugini et al., 2009, Storelli et al., 2002, Storelli et al., 2003, Storelli et al., 2005a, Copat et al., 2012). In some cases, the reported contamination data were biased by being expressed only on a dry basis (Ipolyi et al., 2004). In other studies, the sampling was affected by a strict environmental approach: this is the case for species that are not of commercial size and/or interest (Storelli et al., 2005b) or for fish as bioindicators of the environmental status in known highly polluted sites (Corsi et al., 2002). In this study, we aim to give a more comprehensive picture of the occurrence of HgTOT and MeHg in seafood recovered from fishing and aquaculture activities in areas of Italy presumed to be not impacted. Together with a better definition of MeHg levels on a geo-referenced basis, the final aim is to give a first ranking of the contributions of commercial fish and seafood species to MeHg exposure in the coastal populations, as already done in other countries (Groth, 2010, Lambert et al., 2012). The information will be then translated into intake advice for sensitive groups, without compromising the nutritional benefits of seafood-based diets (FAO/WHO, 2011).
Dining and Cooking