摘要
Concentrations of total mercury（T-Hg） and methylmercury（MeHg） in soil, vegetables, and human hair were measured in a mercury mining area in central China. T-Hg and MeHg concentrations in soil ranged from 1.53 to 1054.97 mg/kg and 0.88 to 46.52 μg/kg, respectively.T-Hg concentrations was correlated with total organic carbon（TOC） content（R^2= 0.50, p〈0.01）and pH values（R^2= 0.21, p〈0.05）. A significant linear relationship was observed between MeHg concentrations and the abundance of sulfate-reducing bacteria（SRB）（R^2= 0.39, p〈0.05） in soil.Soil incubation experiments amended with specific microbial stimulants and inhibitors showed that Hg methylation was derived from SRB activity. T-Hg and MeHg concentrations in vegetables were 24.79 – 781.02 μg/kg and 0.01 – 0.18 μg/kg, respectively; levels in the edible parts were significantly higher than in the roots（T-Hg： p〈0.05; MeHg： p〈0.01）. Hg species concentrations in rhizosphere soil were positively correlated to those in vegetables（p〈0.01）, indicating that soil was an important source of Hg in vegetables. Risk assessment indicated that the consumption of vegetables could result in higher probable daily intake（PDI） of T-Hg than the provisional tolerable daily intake（PTDI） for both adults and children. In contrast, the PDI of MeHg was lower than the reference dose. T-Hg and MeHg concentrations in hair samples ranged from 1.57 to 12.61 mg/kg and 0.04 to 0.94 mg/kg, respectively, and MeHg concentration in hair positively related to PDI of MeHg via vegetable consumption（R^2= 0.39, p〈0.05）, suggesting that vegetable may pose health risk to local residents.
Concentrations of total mercury（T-Hg） and methylmercury（MeHg） in soil, vegetables, and human hair were measured in a mercury mining area in central China. T-Hg and MeHg concentrations in soil ranged from 1.53 to 1054.97 mg/kg and 0.88 to 46.52 μg/kg, respectively.T-Hg concentrations was correlated with total organic carbon（TOC） content（R^2= 0.50, p〈0.01）and pH values（R^2= 0.21, p〈0.05）. A significant linear relationship was observed between MeHg concentrations and the abundance of sulfate-reducing bacteria（SRB）（R^2= 0.39, p〈0.05） in soil.Soil incubation experiments amended with specific microbial stimulants and inhibitors showed that Hg methylation was derived from SRB activity. T-Hg and MeHg concentrations in vegetables were 24.79 – 781.02 μg/kg and 0.01 – 0.18 μg/kg, respectively; levels in the edible parts were significantly higher than in the roots（T-Hg： p〈0.05; MeHg： p〈0.01）. Hg species concentrations in rhizosphere soil were positively correlated to those in vegetables（p〈0.01）, indicating that soil was an important source of Hg in vegetables. Risk assessment indicated that the consumption of vegetables could result in higher probable daily intake（PDI） of T-Hg than the provisional tolerable daily intake（PTDI） for both adults and children. In contrast, the PDI of MeHg was lower than the reference dose. T-Hg and MeHg concentrations in hair samples ranged from 1.57 to 12.61 mg/kg and 0.04 to 0.94 mg/kg, respectively, and MeHg concentration in hair positively related to PDI of MeHg via vegetable consumption（R^2= 0.39, p〈0.05）, suggesting that vegetable may pose health risk to local residents.
基金
provided by Sino-Norwegian Cooperative Project on Mercury-capacity building for implementing the Minamata Convention
