Mercury accumulation in fish species from the Persian Gulf and in human hair from fishermen

Total and methylmercury concentrations were assessed in muscle and liver of 141 fish samples from the northern part of the Persian Gulf. All fish samples belonged to five different species: grunt, flathead, greasy grouper, tiger-tooth croaker, and silver pomfret. In addition, Hg and methylmercury were analyzed in scalp hair of 19 fishermen living in the same coastal stations of the Persian Gulf and consuming several fish meals a week. Total mercury concentrations in fish muscle and liver ranged from 0.01 to 1.35 mu g g (-aEuro parts per thousand 1) w.w. and from 0.02 to 1.30 mu g g (-aEuro parts per thousand 1) w.w., respectively. In fish muscle, 3% of the Hg concentrations were higher than 0.5 mu g g (-aEuro parts per thousand 1) w.w., which corresponds to the maximum acceptable WHO level, while 9% were in the range of polluted fish (between 0.3 and 0.5 mu g g (-aEuro parts per thousand 1) w.w.). The highest mercury concentrations in fish muscle were observed in flathead fish at Abadan (average of 0.68 mu g g (-aEuro parts per thousand 1) w.w.). Methylmercury fractions in fish muscle and liver amount to 34-99% (median 64%) and 24-70% (median 43%), respectively. The mean total Hg concentration in the fishermen's scalp hair amounted to 2.9 +/- 2.2 mu g g (-aEuro parts per thousand 1), with 68% in the form of methylmercury. Ninety-five percent of the Hg levels in the fishermen's hair were below 10 mu g g (-aEuro parts per thousand 1), which is the WHO warning limit. In addition, relationships between the mercury levels in hair, on the one hand, and exposure-related factors such as Hg levels in specific fish species, regional differences, and number of fish meals, on the other hand, are discussed. It appears that a significant correlation for example exists between Hg levels human hair and fish muscle or human hair and age and that mean mercury levels in fish muscle and human hair decreased from western (Abadan) to eastern (Abbas port) coastal sites.