Food safety aspects of toxic element accumulation in fish from wastewater-fed ponds in Hanoi, Vietnam

Objective: To evaluate the food safety of fish from production systems in Hanoi feed with domestic and industrial wastewater with respect to the potentially toxic elements such as arsenic (As), cadmium (Cd) and lead (Pb). Methods: Common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix) and tilapia (Oreochromis niloticus) were sampled from wastewater-fed ponds, and total concentrations of As, Cd and Pb were determined in skin, liver and muscle. Results: Arsenic, Cd and Pd concentrations were generally low and for many samples below the detection limit. The highest concentrations of Cd and Pb were found in the liver of tilapia, and the highest As concentration in the skin of tilapia. Maximum concentrations in muscle tissue were 0.120, 0.079 and 0.082 mg/kg fresh weight (f.w.) for As, Cd and Pb, respectively. Consumption of fish with maximum muscle tissue concentration will result in a human intake corresponding to 6.2%, 8.7% and 2.5% of the tolerable intake of these elements set by Codex Alimentarious Commission. Conclusion: The consumption of common carp, silver carp and tilapia produced in wastewater-fed ponds of Hanoi seems not to constitute a food safety problem with respect to As, Cd and Pb.