Levels and health risk assessment of mercury, cadmium, and lead in green mussel (Perna viridis) and oyster (Crassostrea iredalei) harvested around Manila Bay, Philippines

The coastal provinces of Manila Bay contribute 38% of mussel and oyster's production in the Philippines. However, concerns in the consumers' health are rising due to the possible pollution in the bay waters that may contaminate the bivalves. Thus, the present study determined the level of Hg, Cd, and Pb in green mussel (Perna viridis), oyster (Crassostrea iredalei), seawater as well as the potential health risk. Bivalves and seawater had levels of metals below the regulatory limit established by the country (Bureau of Fisheries and Aquatic Resources; Department of Environment and Natural Resources) and the EU. The maximum estimated daily intake (EDI) of Hg (1.95 x 10-08 mg/kg/day) in mussel was from Seneguelasan (Cavite) during dry season (DS) while maximum EDI of Cd (8.48 x 10-08 mg/kg/day) in oyster was from Tibaguin (Bulacan) during wet season (WS) both in 5-9 years old (yo) male and female, respectively. For maximum EDI of Cd (2.70 x 10-08 mg/kg/day) and Pb (3.54 x 10-08 mg/kg/day) in the mussel, it was found in 10-19 yo male from Wawa (Bataan) during DS and WS. Whereas, maximum EDI of Hg (1.19 x 10-08 mg/kg/day) and Pb (3.30 x 10-08 mg/kg/day) in oyster were found in 40-59 yo male from Timalang Balsahan during DS. However, none of the bivalves showed higher EDI and weekly intake than the reference dose (EPA 1991; EPA IRIS 1989 and 2001) and provisional tolerable weekly intake (FAO/WHO 2000; 2007; 2011). Furthermore, no health risks were associated with the consumption of mussel and oyster as hazard quotients were <1. The possible cancer risks were estimated in four to six individuals out of 1 x 1007. The study recommends to have further risk assessment on other fishery commodities available in the area to secure the consumer's safety.

Automated summary

The study found that levels of mercury, cadmium, and lead in green mussels and oysters from coastal provinces of Manila Bay were below regulatory limits, posing no health risks to consumers. Further risk assessments on other fishery commodities in the area are recommended to ensure consumer safety.