Total mercury determination in bivalves Anadara tuberculosa sold in open markets from Quito, Ecuador

This study aimed to quantify the amount of total mercury in bivalves Anadara tuberculosa supplied from Esmeraldas Province and sold in markets in the Metropolitan District of Quito, Ecuador. The determined total mercury concentration was compared to the permissible limits established by the European Commission and World Health Organization-Food and Agriculture Organization and health risk subsequently assessed. Sampling was conducted in five open markets and involved collecting fifteen specimens from each market. Total mercury was measured through cold vapor atomic fluorescence spectrophotometry. Results showed that samples did not exceed the total mercury threshold value (0.5 mg kg^-1). However, samples of Anadara tuberculosa from the Ofelia market, which receives fresh products from Eloy Alfaro canton, contained the highest mean levels of mercury contamination, 0.055 mg kg^-1. This result could be associated to the influence of illegal mining activity in this area. In addition, methylmercury potential non-carcinogenic risk for consumers exceeded the threshold limit (>1) established by the US Environmental Protection Agency. The daily consumption rate (Rc_lim) was determined to be 26.61-38.50 g for a child weight of 14.5 kg, and 128.44-185.84 g for an adult weight of 70 kg. Thus, consuming a higher amount of Anadara tuberculosa could negatively affect human health.