title: Evidence for induction of oxidative stress caused by chronic exposure of Chinese residents to arsenic contained in drinking water.
abstract: Exposure of experimental animals or cultured cells to arsenic induces oxidative stress, but, to date, no examination of this phenomenon in humans has been reported. In this study we conducted a cross-sectional study in Wuyuan, Inner Mongolia, China, to explore the relationship between chronic arsenic exposure from drinking water and oxidative stress in humans. Thirty-three inhabitants who had been drinking tube-well water with high concentrations of inorganic arsenic (mean value = 0.41 mg/L) for about 18 years constituted the high-exposure group, and 10 residents who lived nearby but were exposed to much lower concentrations of arsenic in their drinking water (mean value = 0.02 mg/L) were selected as the low-exposure comparison group. Results of the present study indicated that although the activity for superoxide dismutase (SOD) in blood did not differ significantly between the two groups, the mean serum level of lipid peroxides (LPO) was significantly higher among the high-exposed compared with the low-exposed group. Elevated serum LPO concentrations were correlated with blood levels of inorganic arsenic and its methylated metabolites. In addition, they showed an inverse correlation with nonprotein sulfhydryl (NPSH) levels in whole blood. The subjects in the high-arsenic-exposure group had mean blood NPSH levels 57.6% lower than those in the low-exposure group. Blood NPSH levels were inversely correlated with the concentrations of inorganic arsenic and its methylated metabolites in blood and with the ratio of monomethylarsenic to inorganic arsenic. These results provide evidence that chronic exposure to arsenic from drinking water in humans results in induction of oxidative stress, as indicated by the reduction in NPSH and the increase in LPO. Some possible mechanisms for the arsenic-induced oxidative stress are discussed.
authors.affiliation: Graduate School Doctoral Program in Medical Sciences, University of Tsukuba, Ibaraki, Japan.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Pi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamauchi
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Kumagai
authors.forename: Guifan
authors.initials: G
authors.lastname: Sun
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yoshida
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aikawa
authors.forename: Claudia
authors.initials: C
authors.lastname: Hopenhayn-Rich
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Shimojo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001151:Arsenic / Q000009:adverse effects*; D002681:China; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D018570:Risk Assessment; D013438:Sulfhydryl Compounds / Q000097:blood; D014881:Water Supply
chemical_list: D013438:Sulfhydryl Compounds; D001151:Arsenic