Methylmercury and Total Mercury in Eels, Anguilla anguilla, from Lakes in Northeastern Poland: Health Risk Assessment.

Abstract

In the aquatic environment, mercury is readily methylated into its most toxic form of methylmercury. In this form, it enters the aquatic food chain and its concentrations increase in subsequent links, which decreases the quality of fish meat and poses risks to consumer health. Concentrations of methylmercury (MeHg) and total mercury (THg) were determined in the muscle tissues of 64 eel specimens measuring from 59 to 95cm in length as functions of specimen size and weight. Risks posed to consumers by eel from different length classes were also assessed. The mean concentration of THg in all of the eel examined was 0.179mgkg-1, but the range was from 0.028 to 0.487mgkg-1. The mean concentration of MeHg was 0.147mgkg-1, and the range was also wide from 0.023 to 0.454mgkg-1. Accumulated MeHg and THg increased with eel body length. The percentage share of MeHg in THg also changed with specimen length, and there was a positive correlation between the concentrations of MeHg and THg. Risk assessment was performed based on the doses of THg and MeHg ingested with fish for several specimen length classes. Consuming the meat of eel measuring 80cm in length increased the estimated weekly intake (EWI) of THg and MeHg twofold in comparison to that from specimens 60cm in length and fourfold in specimens exceeding 90cm in length. The percentage shares of the EWI in the tolerable weekly intake and the target hazard quotient coefficient also increased proportionally. Generally, concentrations of MeHg and THg in eel are below current limits and pose no risk to consumer health as long as the consumption of larger specimens is avoided.