[Hair Mercury Concentrations in Residents of Fuling and Zhongxian in the Three Gorges Reservoir Region and Their Influence Factors]

Abstract

To evaluate the mercury (Hg) exposure risk for residents of the Three Gorges Reservoir Region (TGRR), hair samples were collected from 238 local residents within the central regions of the TGRR (Fuling District and Zhongxian County) in this study. Subsequently, total mercury (THg) and methylmercury (MeHg) concentrations were determined. The results obtained showed that the average THg and MeHg concentrations in hair samples of the residents within these two areas were (0.50±0.54) μg·g^-1 and(0.35±0.25) μg·g^-1, respectively. Specifically, the average THg and MeHg concentrations in hair samples of Fuling residents were(0.71±0.87) μg·g^-1 and(0.53±0.46) μg·g^-1, respectively. Both these values were higher than those in hair samples of Zhongxian County residents [THg(0.41±0.36) μg·g^-1 and MeHg (0.28±0.26) μg·g^-1]. It is noteworthy that the hair Hg levels in residents of these two areas are both well below the U.S. Environmental Protection Agency's reference dose (1 μg·g^-1). Hair Hg levels varied slightly among different age groups; higher Hg levels were detected in residents in the age group of 40-50 years(P<0.05). However, there was no significant difference between the hair Hg levels among genders(P>0.05). Hair Hg levels in females were slightly above those in males. Hair Hg levels were significantly correlated with the frequency of fish consumption. Furthermore, hair Hg levels in non-fishermen were significantly lower than those in fishermen. An elevated mean value of (1.44±0.79) μg·g^-1(P<0.01), which exceeds the RfD of 1 μg·g^-1, was detected in fishermen. Moreover, hair Hg levels in smokers of Fuling and Zhongxian County[(0.55±0.24) μg·g^-1 and (0.58±0.54) μg·g^-1, respectively] were both markedly higher than those in non-smokers[(0.51±0.30) μg·g^-1 and (0.36±0.26) μg·g^-1respectively]. In conclusion, the risk of Hg exposure to residents of the TGRR was lower. However, in this study, it was determined that fishermen are at significant risk of Hg exposure.

Keywords: Three Gorges Reservoir Region; concentration; hair mercury levels; influencing factors; risk of mercury exposure.