Pilot research to determine the mercury content in fish consumed in Marabá, Brazil using the Allegra Method

Background: The objective of this study is to analyze the concentration of mercury in fish consumed in Marabá, Brazil which is located close to the Serra Pelada gold mines.Methods: Fish species which have great economic impact on the city of Marabá were selected for study in a pilot research programme. The species sampled were collected from fish sold at the Feira da 28, were from the species Cichla spp, Mylossoma spp and Pimelodus spp. The samples were processed through the Allegra method.Results: The measured mercury concentrations were Cichla spp.I (0.750 kg) 600 μg/kg, Cichla spp. II (1.254kg) 1000 μg/kg, Cichla spp III (2.750kg) <2000 μg/kg; Mylossoma spp I (1.300kg) 100 μg/kg, Mylossoma spp II (2.100 kg) <300 μg/kg; Pimelodus spp I (0.850 kg) 100 μg/kg, Pimelodus spp II (1.050 kg) <300 μg/kg.Conclusions: The concentrations of mercury in the fish samples analysed exceed the limits for consumption established by the World Health Organization (WHO) and the Brazilian government. The semi quantitative Allegra method for determination of mercury in environmental samples is confirmed as a suitable alternative for environmental monitoring programs which are relevant to public health. More study is needed on the use of mercury and its by-products which can contaminate fish in the Amazon.