Fish intake from different ecosystems and exposure in family fisheries in the Brazilian amazon

Evidence of human exposure to mercury through fish consumption is restricted to the riparian areas of Madeira and Tapajós. Little is known about exposure to populations that regularly consume fish from other Amazonian ecosystems. Mercury exposure levels were compared in fishermen and relatives living in different geographic regions, in the State of Pará, considering the weekly frequency of fish intake and fish ecosystem (river or estuarine). The study included 407 residents of fishermen villages in three different regions (Tapajós, Tocantins and Caeté) and different species of fish from each region. High weekly frequency of fish intake was observed in all studied communities. The median concentrations Total mercury were 4,6µg/g (0,0-30,1µg/g), 8,9µg/g (1,2-50,6µg/g), 0,7µg/g (0,0-6,2µg/g) e 1,8µg/g (0,1-20,7µg/g), respectively in the villages A and B (Tapajós), village C (Tocantins) and D (Caeté), with differences in the observed concentrations between the studied communities. Fish with higher Total mercury concentrations were found in the Tapajós region, 0.160±0.000μg/g in the Leporinus friderici species and the lowest in the Tocantins species 0.004±0.003μg/g in Mugil curema. Riparians from Tocantins are less exposed and consume fish with lower concentrations of mercury. The herbivorous and detritus species of the estuarine area are safe species for human consumption.