College of Water Sciences, Beijing Normal University, Beijing 100875, China; Research Institute of Solid Waste Management, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Research Institute of Solid Waste Management, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
J Environ Sci (China). 2018 Jun;68:73-82. doi: 10.1016/j.jes.2017.05.018. Epub 2017 May 19.
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 1054.97mg/kg and 0.88 to 46.52μg/kg, respectively. T-Hg concentrations was correlated with total organic carbon (TOC) content (R=0.50, p<0.01) and pH values (R=0.21, p<0.05). A significant linear relationship was observed between MeHg concentrations and the abundance of sulfate-reducing bacteria (SRB) (R=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 24.79-781.02μg/kg and 0.01-0.18μg/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 12.61mg/kg and 0.04 to 0.94mg/kg, respectively, and MeHg concentration in hair positively related to PDI of MeHg via vegetable consumption (R=0.39, p<0.05), suggesting that vegetable may pose health risk to local residents.
在中国中部的一个汞矿区，测量了土壤、蔬菜和人发中的总汞 (T-Hg) 和甲基汞 (MeHg) 浓度。土壤中 T-Hg 和 MeHg 的浓度范围分别为 1.53 至 1054.97mg/kg 和 0.88 至 46.52μg/kg。T-Hg 浓度与总有机碳 (TOC) 含量呈正相关 (R=0.50，p<0.01) 和 pH 值 (R=0.21，p<0.05)。土壤中硫酸盐还原菌 (SRB) 的丰度与 MeHg 浓度呈显著线性关系 (R=0.39，p<0.05)。用特定微生物刺激剂和抑制剂进行的土壤培养实验表明，Hg 甲基化源自 SRB 活性。蔬菜中 T-Hg 和 MeHg 的浓度分别为 24.79-781.02μg/kg 和 0.01-0.18μg/kg；可食用部分的浓度明显高于根部 (T-Hg：p<0.05；MeHg：p<0.01)。根际土壤中 Hg 形态浓度与蔬菜中浓度呈正相关 (p<0.01)，表明土壤是蔬菜中 Hg 的重要来源。风险评估表明，与成人和儿童的暂定可耐受每日摄入量 (PTDI) 相比，食用蔬菜可能会导致更高的每日总汞摄入量 (PDI)。相比之下，甲基汞的 PDI 低于参考剂量。头发样本中 T-Hg 和 MeHg 的浓度范围分别为 1.57 至 12.61mg/kg 和 0.04 至 0.94mg/kg，头发中 MeHg 浓度与通过食用蔬菜摄入的 MeHg 的 PDI 呈正相关 (R=0.39，p<0.05)，这表明蔬菜可能对当地居民构成健康风险。
