Mercury concentrations and health risk assessment for two fish species, Barbus grypus and Barbus luteus, from the Maroon River, Khuzestan Province, Iran

The purposes of this study are to investigate the concentration of mercury in edible muscle tissues of two popular edible fish species: the Shirbot (Barbus grypus) and Hemri (Barbus luteus), from the Maroon River, Khuzestan Province, Iran, and to assess the risk of their toxicity on human health. We collected 20 samples of each species from the river, and after biometry and determination of their age and sex, concentration of total mercury (assumed to be about 100 % methylmercury) was measured. For B. grypus, mercury averaged 0.16 +/- 0.02 mu g g(-1) wet weight, and for B. luteus, it averaged 0.08 +/- 0.02 mu g g(-1) wet weight. Although mercury has been reported to accumulate with age, length, and trophic level in many studies, we did not find a significant correlation among age, sex, length, and mercury content in either of these omnivorous species. Mercury levels (maximum 0.37 mu g g(-1) wet weight) were below international standards. Consumption of these fish would not pose a serious health hazard to Iranian consumers at the average national consumption of 17.53 g day(-1). However, high-end consumers eating more than 250 g week(-1) and pregnant women should be attentive in choosing fish low in mercury, for example, B. luteus rather than B. grypus.