Human exposure to methylmercury through rice intake in mercury mining areas, Guizhou province, China.
The toxicity of methylmercury (Me-Hg) has caused widespread public human concern as a result of several widely publicized disasters. Me-Hg is highly toxic, and the nervous system is its principal target tissue for humans. Although the general population is primarily exposed to Me-Hg through contaminated fish and marine mammals, in Hg mining areas a long history of mining activities can produce serious Hg pollution to the local environment In a study of 98 persons from the Wanshan Hg mining area, hair Me-Hg levels indicated Me-Hg exposure. Rice, the staple food of the local inhabitants also showed high total Hg (T-Hg) and Me-Hg levels. The geometric mean concentration of T-Hg and mean concentration of Me-Hg in rice samples collected from 3 villages in Wanshan Hg mining area were 36.2 (ranging from 4.9 to 214.7), and 8.5 (ranging from 1.9 to 27.6) microg/kg, respectively, which were significantly elevated compared to the rice samples collected from a reference area, where the mean T-Hg and Me-Hg concentrations were 7.0 (3.2-15.1) and 2.5 (0.8-4.3) microg/kg, respectively. Pork meat, vegetable, and drinking water samples collected in Wanshan Hg mining area contained highly elevated T-Hg, but very low levels of Me-Hg. The relationships between the estimated rice Me-Hg intake and hair Me-Hg levels (r = 0.65, p < 0.001) confirmed rice with high Me-Hg levels indeed was the main route of Me-Hg exposure for the local residents in the Wanshan Hg mining area. From our study, we can conclude that the main human exposure to Me-Hg via food consumption is not restricted to fish, but in some cases in mining areas of China to frequent rice meals.
Feng
Xinbin
X
State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China. fengxinbin@vip.skleg.cn
Li
Ping
P
Qiu
Guangle
G
Wang
Shaofeng
S
Li
Guanghui
G
Shang
Lihai
L
Meng
Bo
B
Jiang
Hongmei
H
Bai
Weiyang
W
Li
Zhonggen
Z
Fu
Xuewu
X
D000328:Adult; D001937:Brassica / Q000378:metabolism; D002681:China; D018552:Daucus carota / Q000378:metabolism; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000378:metabolism*; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D006197:Hair / Q000737:chemistry; D006801:Humans; D008297:Male; D008460:Meat / Q000032:analysis; D008628:Mercury / Q000032:analysis / Q000378:metabolism; D008767:Methylmercury Compounds / Q000032:analysis* / Q000378:metabolism*; D008875:Middle Aged; D008906:Mining; D012275:Oryza / Q000378:metabolism*; D014881:Water Supply / Q000032:analysis
D004785:Environmental Pollutants; D008767:Methylmercury Compounds; D008628:Mercury