Mercury Exposure in Children of the Wanshan Mercury Mining Area, Guizhou, China.

Buyun Du,Xinbin Feng,Jun Zhou,Ping Li,Laurence Maurice,Guangle Qiu

doi:10.3390/ijerph13111107

Abstract

To evaluate the mercury (Hg) exposure level of children located in a Hg mining area, total Hg concentrations and speciation were determined in hair and urine samples of children in the Wanshan Hg mining area, Guizhou Province, China. Rice samples consumed by these same children were also collected for total mercury (THg) and methyl-mercury (MeHg) analysis. The geometric mean concentrations of THg and MeHg in the hair samples were 1.4 (range 0.50–6.0) μg/g and 1.1 (range 0.35–4.2) μg/g, respectively, while the geometric mean concentration of urine Hg (UHg) was 1.4 (range 0.09–26) μg/g Creatinine (Cr). The average of the probable daily intake (PDI) of MeHg via rice consumption was 0.052 (0.0033–0.39) µg/kg/day, which significantly correlated with the hair MeHg concentrations (r = 0.55, p < 0.01), indicating that ingestion of rice is the main pathway of MeHg exposure for children in this area. Furthermore, 18% (26/141) of the PDIs of MeHg exceeded the USEPA Reference Dose (RfD) of 0.10 µg/kg/day, indicating that children in this area are at a high MeHg exposure level. This paper for the first time evaluates the co-exposure levels of IHg and MeHg of children living in Wanshan mining area, and revealed the difference in exposure patterns between children and adults in this area.

Highlights

Mercury (Hg) is a toxic metal that has harmful effects on human health
This paper for the first time evaluates the co-exposure levels of inorganic Hg (IHg) and methyl Hg (MeHg) of children living in Wanshan mining area, and revealed the difference in exposure patterns between children and adults in this area
Hg exposure levels in the children were the highest in region A, two kilometers downstream of the Hg mine sites, which were seriously contaminated by mining activities

Summary

Introduction

Mercury (Hg) is a toxic metal that has harmful effects on human health. The toxicity depends on its chemical forms, among which inorganic Hg (IHg) and methyl Hg (MeHg) are the most important chemical forms. IHg may cause a variety of adverse effects, with damage to the central nervous system and kidneys being the most prominent [1,2]. The most important routes of human exposure to IHg are inhalation of Hg vapor and accidental ingestion of Hg2+ [1]. Hg in bloodstream is distributed to the tissues around the body including the central nervous system [5,6]. The major elimination routes of IHg are urinary and fecal excretion [7]

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