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ASSESSING ARSENIC EXPOSURE AND SKIN HYPERKERATOSIS IN INNER MONGOLIA, CHINA
Citation:
Mumford, J. L., M Schmitt, R K. Kwok, R L. Calderon, Y. Xia, H. Ma, X. E. Le, AND X. Lu. ASSESSING ARSENIC EXPOSURE AND SKIN HYPERKERATOSIS IN INNER MONGOLIA, CHINA. Presented at American Association for Cancer Research Annual Meeting, New Orleans, LA, March 24-28, 2001.
Description:
Arsenic is a known human carcinogen. The inorganic forms, especially arsenite (As+3), are believed to be the most toxic species. Methylation is often considered to be the
detoxification pathway for the metabolism of inorganic arsenic. The ground water in Ba
Men, Inner Mongolia is naturally contaminated with arsenic, ranging from <50 ?g/L to 1.8
mg/L. A pilot study was conducted in Ba Men to (1) characterize arsenic exposure and
(2) link the arsenic exposure and urinary metabolites to skin hyperkeratosis which has
been suggested as a potential biomarker for assessing arsenic exposure and the associated
skin cancer risk. Water and urine samples were collected from 19 Ba Men residents
exposed to arsenic at 528 ?24 ?g/L (mean ? SEM) and 13 residents exposed to arsenic at
4?1.0 ?g/L as controls/low exposed. Sixteen of the high As-exposed individuals showed
hyperkeratosis with varying degrees of severity. Water samples collected from wells and after storage in tanks in homes prior to consumption were analyzed for As+3, As+5, and particulate arsenic by hydride generation/atomic fluorescence spectrometry (HG/AFS). Urine samples were collected from each subject and analyzed for inorganic As, MMA (methylarsonate), and DMA (dimethylarsinate) by HPLC/HG/AFS. The results showed that the well water contained mostly As+3 (averaging 63%) and the tank water contained mostly As+5 (64%). In urine, DMA (57%)
was the major metabolite, followed by MMA (19%), As+3 (17%), and As+5 (7%). The
relationships among arsenic concentrations in drinking water, urinary metabolites and
hyperkeratosis are being evaluated and the results will be reported. (This abstract does
not reflect EPA policy.)