Mercury concentration correlates with the nitrogen stable isotope ratio in the animal food of papuans

Abstract

The relationships among element concentrations (Na, Mg, Al, P, K, Ca, Cr, Fe, Mn, Cu, Zn, Sr, total Hg, organic Hg, inorganic Hg, Pb) and stable carbon and nitrogen isotope ratios ( 13C 12C and 15N 14N ) in animals consumed by the people called Gidra, who inhabit the lowland of Papua New Guinea, were examined. Animals analyzed included mammal, bird, fish, shellfish, reptile, crustacean, and insect. Highly significantly positive correlations were observed between total Hg concentrations and 15N 14N ( r = 0.796), between organic Hg concentrations and 15N 14N ( r = 0.781), and between inorganic Hg concentrations and 15N 14N ( r = 0.739). This was interpreted to indicate that Hg was an element which accumulates in animals along the food chain. Based on the regression function of Hg on δ 15N, the bioconcentration factor for total, organic, and inorganic Hg was estimated to be 5.