Bio-accumulation of trace metals in Blue Swimmer Crab (Portunus pelagicus) in Sri Lanka

Abstract

In this study, muscle of blue swimmer crab, Portunus pelagicus were analysed for the content of trace metal contaminants. The crabs were collected at the landing sites along the coast of Mannar, Negombo and down south. Totally 60 individuals were collected during the period of May to November, 2014 and the samples were kept in ice and sent to the laboratory. The weight, shell width, gender were determined and brown meat were taken for metal analysis. The concentration of Mercury (Hg), Cadmium (Cd), Arsenic (As), Lead (Pb), Copper (Cu), Ferrous (Fe) and zinc (Zn) were determined after microwave digestion by Atomic Absorption spectrophotometer (AAS). Cd, Pb and Hg concentrations in crab are important in food safety. Results showed that average Cd (ND-0.48 mg/kg), Hg (ND-0.26 mg/kg) and Pb (<0.52 mg/kg) concentration are lower than the maximum permitted level (Cd, Hg, and Pb, 0.5 mg/kg wet weight basis) by the European Union (EU) and Sri Lankan regulation. The EU and Sri Lanka have not set any maximum allowed levels for As in foodstuffs for human consumption. The study highlighted the suitability of P. pelagic living in the studied area as a safe seafood when considering the contents of above trace metals present in their muscles.