Polychlorinated naphthalenes in animal aquatic species and human exposure through the diet: a review

Polychlorinated naphthalenes (PCNs) are a group of environmental pollutants, which contain one to eight chlorine atoms per naphthalene molecule, forming a total of 75 possible congeners. Several of the PCN congeners display toxicity similar to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) through AhR-mediated mechanisms. There are toxicological similarities between PCNs and other well known environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). However, in contrast to these compounds, information on exposure to PCNs for non-occupationally exposed populations is rather scarce. In this article, information on human exposure to PCNs through dietary intake is reviewed. Because this information is very limited and taking into account that most data on PCN levels in potential foods concern to aquatic species, these data are also reviewed. It is concluded that further investigations on dietary intake and potential human health effects of PCNs are clearly necessary.