Risk Profiling of Methylmercury in the Consumption of Dried Tamban (Sardinella lemuru) by the Filipino Consuming Population

Abstract

Methylmercury (MeHg) is one of the most toxic forms of mercury (Hg) produced via methylation of its inorganic form from natural and anthropogenic sources. Fish that feed on phytoplankton, such as sardines, serve as the entry points of MeHg in the aquatic food web. Dietary exposure (DE) to MeHg leads to varying health risks such as ataxia, neurodevelopmental delays, and blindness in newborns and infants. The study aimed to develop a risk profile on the potential risk associated with the consumption of Philippine dried tamban (Sardinella lemuru) through 1) conceptualization of the risk profile, 2) review of related literature, 3) formulation of assumptions (i.e. identification of variabilities and establishment of uncertainties or data gaps), 4) exposure pathway assessment, and 5) risk characterization. The risk of MeHg was estimated using the total mercury (THg) concentrations in dried tamban samples collected from the major fishing grounds of sardines in the Philippines, consumption data of the adult Filipino consuming population, and the assumed average body weights of Asian adults. The estimated DEs ranged from 0.000043-0.008724 μg/kg bw (bodyweight)/wk, which is equivalent to about 0.003-0.545% of the provisional tolerable weekly intake (PTWI) of 1.6 μg/kg bw for MeHg established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 2007. Our findings imply that dried tamban does not pose a major health risk to the adult Filipino consuming population. However, it is also essential to note that aside from dried tamban, there are other potential sources of MeHg in the diet such as other fish and seafood.