Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA.
Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
Int J Environ Res Public Health. 2021 Dec 18;18(24):13350. doi: 10.3390/ijerph182413350.
Total mercury content (THg) in hair is an accepted biomarker for chronic dietary methylmercury (MeHg) exposure. In artisanal and small-scale gold mining (ASGM) communities, the validity of this biomarker is questioned because of the potential for contamination from inorganic mercury. As mining communities may have both inorganic and organic mercury exposures, the efficacy of the hair-THg biomarker needs to be evaluated, particularly as nations begin population exposure assessments under their commitments to the Minamata Convention. We sought to validate the efficacy of hair THg for public health monitoring of MeHg exposures for populations living in ASGM communities. We quantified both THg and MeHg contents in hair from a representative subset of participants (N = 287) in a large, population-level mercury exposure assessment in the ASGM region in Madre de Dios (MDD), Peru. We compared population MeHg-THg correlations and %MeHg values with demographic variables including community location, sex, occupation, and nativity. We observed that hair MeHg-THg correlations were high (r > 0.7) for all communities, regardless of location or nativity. Specifically, for individuals within ASGM communities, 81% (121 of 150 total) had hair THg predominantly in the form of MeHg (i.e., >66% of THg) and reflective of dietary exposure to mercury. Furthermore, for individuals with hair THg exceeding the U.S. EPA threshold (1.0 μg/g), 88 out of 106 (83%) had MeHg as the predominant form. As a result, had urine THg solely been used for mercury exposure monitoring, approximately 59% of the ASGM population would have been misclassified as having low mercury exposure. Our results support the use of hair THg for monitoring of MeHg exposure of populations in ASGM settings where alternative biomarkers of MeHg exposure are not feasible.
头发中的总汞含量（THg）是衡量慢性膳食甲基汞（MeHg）暴露的公认生物标志物。在手工和小规模采金（ASGM）社区中，由于无机汞的潜在污染，这种生物标志物的有效性受到质疑。由于采金社区可能同时接触无机汞和有机汞，因此需要评估头发-THg 生物标志物的功效，尤其是在各国根据《水俣公约》的承诺开始对人群进行暴露评估时。我们试图验证头发 THg 用于监测 ASGM 社区人群中 MeHg 暴露的公共卫生效果。我们在秘鲁 Madre de Dios（MDD）的一个大型人群汞暴露评估中，从具有代表性的参与者亚组（N = 287）中定量了头发中的 THg 和 MeHg 含量。我们比较了人口 MeHg-THg 相关性和%MeHg 值与人口统计学变量（包括社区位置、性别、职业和出生地）之间的关系。我们观察到，所有社区的头发 MeHg-THg 相关性都很高（r > 0.7），无论其位置或出生地如何。具体而言，对于 ASGM 社区内的个体，81%（150 个个体中有 121 个）的头发 THg 主要以 MeHg 的形式存在（即，>66%的 THg），反映了对汞的饮食暴露。此外，对于头发 THg 超过美国环保署阈值（1.0 μg/g）的个体，106 个个体中有 88 个（83%）的 MeHg 为主要形式。因此，如果仅使用尿 THg 进行汞暴露监测，大约 59%的 ASGM 人群将被错误分类为低汞暴露。我们的结果支持在无法获得 MeHg 暴露替代生物标志物的 ASGM 环境中使用头发 THg 监测人群的 MeHg 暴露。
