Concentration of total mercury on king mackerel, Scomberomorus cavalla, and Brazilian mackerel, Scomberomorus brasiliensis, from the Mucuripe fi sh market, Fortaleza, Ceará State

Abstract

Mercury (Hg) biomagnifi cation through aquatic food chains increases Hg exposure to human consumers. In the present study we determined Hg concentrations and potential human exposure doses for two carnivorous fi sh Scomberomorus cavalla and Scomberomorus brasiliensis, from the Mucuripe fi sh market, and frequently consumed by the local population. We analyzed 13 individuals of S. cavalla (0.7 – 12.0 kg; 59 – 126.6 cm) and 10 individuals of S. brasiliensis (0.7 – 3.8 kg; 53 - 88 cm). Mercury concentrations in fi sh muscle varied from 36.0 to 1736.5 ng.g-1 in S. cavalla and from 87 to 497,0 ng.g-1 in S. brasiliensis. In liver tissues Hg concentrations varied from 81.7 to 3901.9 ng.g-1 and 48.9 to 699.1 ng.g-1, whereas in skin from 8.7 to 173.5 ng.g-1 and 10.5 to 331.1 ng.g-1, in S. cavalla and S. brasiliensis, respectively. Mercury concentrations in all analyzed tissues of the two species were signifi cantly correlated with fi sh size. Large (>110 cm) individuals of S. cavalla presented Hg concentrations higher than the maximum allowed concentration for nhuman consumption. This result, however, was not observed for S. brasiliensis. Maximum estimated human exposure under local consumption conditions was much lower than the legal limit exposure to humans.