Trace metals in Noah’s Ark shells (Arca noae Linnaeus, 1758) – impact of tourist season and human health risk

Commercially important bivalve Noah’s Ark shell (Arca noae Linnaeus, 1758) represents a high quality seafood product, but the data on levels of metal contaminants that could pose a human health risk and also on some essential elements that are important for health protection are lacking. This study examines the concentrations of Cd, Pb, Cr, Ni, Cu, Co and Zn in the soft tissue of A. noae from harvesting area in the central Adriatic Sea, to survey whether heavy metals are within the acceptable limits for public health and whether tourism could have an impact on them. The concentrations of analysed metals varied for Cd: 0.15-0.74, Pb: 0.06-0.26, Cr: 0.11-0.34, Ni: 0.09-0.22, Cu: 0.65-1.95, Co: 0.04-0.09 and Zn: 18.3-74.7 mg/kg wet weight. These levels were lower than the permissible limits for safe consummation of seafood, and only for Cd, some precautions should be taken into account if older shellfish were consumed. Increase of Cd, Cr and Cu in shell tissue was observed during the tourist season at the site closest to the marine traffic routes, indicating that metal levels in shellfish tissue should be especially carefully monitored during the peak tourist season, to prevent eventual toxic effects due to increased intake of metals, specifically of Cd