Mercury in soil, vegetable and human hair in a typical mining area in China: Implication for human exposure

• Published in: Journal of environmental sciences (China) Vol. 68; pp. 73 - 82
• Main Authors: Jia, Qin, Zhu, Xuemei, Hao, Yaqiong, Yang, Ziliang, Wang, Qi, Fu, Haihui, Yu, Hongjin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2018
• Subjects: Adult; Child; Environmental Exposure - analysis; Environmental Exposure - statistics & numerical data; Environmental Monitoring; Environmental Pollutants - analysis; Food Contamination; Hair - chemistry; Human hair; Humans; Mercury; Mercury - analysis; Methylmercury; Methylmercury Compounds - analysis; Mining; Soil; Soil - chemistry; Vegetable; Vegetables - chemistry; Soil; Mercury; Human hair; Vegetable; Methylmercury
• ISSN: 1001-0742; 1878-7320
• DOI: 10.1016/j.jes.2017.05.018

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 (R2=0.50, p<0.01) and pH values (R2=0.21, p<0.05). A significant linear relationship was observed between MeHg concentrations and the abundance of sulfate-reducing bacteria (SRB) (R2=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 (R2=0.39, p<0.05), suggesting that vegetable may pose health risk to local residents. [Display omitted]