Methylmercury determination in fish and seafood products and estimated daily intake for the Spanish population

Abstract

The mercury content of 25 samples of fish and seafood products most frequently consumed in Spain was determined. A simple method comprising cold vapour and atomic absorption spectrometry was used to determine separately inorganic and organic mercury. In all samples inorganic mercury content was below 50 µg kg−1. There was wide variability, among not only the mercury levels of different fish species, but also for different samples of the same species — with the methylmercury content ranging from below 54 to 662 µg kg−1. The highest mean methylmercury content was found in fresh tuna. Based on an average total fish consumption of 363 g/person week−1, the methylmercury intake was estimated to be 46.2 µg/person week−1. Therefore, the mercury intake of Spanish people with a body weight ≤ 60 kg is lower than the Joint FAO/WHO Expert Committee on Food Additives (JECFA) provisional tolerable weekly intake (PTWI) of 1.6 µg kg−1 body weight, but exceeds the US National Research Council (NRC) limit of 0.7 µg kg−1 body weight week−1 based on a benchmark dose.