Concentrations of phthalate esters on Indian Ocean silky sharks and their long-term dietary consumption risks

Abstract

ABSTRACT Phthalate esters (PAEs) are emerging pollutants commonly found in plastic products. Thus, increasing plastic pollution in the marine environment amplify their entry and potential impacts on aquatic species. Likewise, pollutants may accumulate in top predators such as sharks and are highly consumed in many countries. Therefore, this study evaluated the concentrations of 10 PAEs plasticizers in commercially important Indian Ocean silky sharks Carcharhinus falciformis and their toxicity risks in children and adults. Results showed the concentrations of ΣPAEs in shark muscle ranging between 5,402–34,577 ng/g ww. PAEs in silky shark muscles appeared to be six times higher in locations near the coasts (islands) with higher anthropogenic impacts. Low molecular weight PAEs like DMP and DnBP dominated PAEs in shark muscle tissues. Moreover, the PAE levels in shark muscles did not significantly increase with length and weight, indicating their relative impacts in all shark sizes. For the estimate of the daily intakes (EDI), the DEHP was 32 μg/kg bw/day in preschool children and 23 μg/kg bw/day in adults (the DEHP Reference Dose (RfD) of 20 μg/kg bw/day). Toxicity risk assessment showed unacceptable levels indicating long-term dietary risks for consumers.