DNA damage in buccal epithelial cells from individuals chronically exposedto arsenic via drinking water in Inner Mongolia, China

The purpose of this pilot study was to assess DNA damage in buccal cells fr om individuals chronically exposed to arsenic via drinking water in Ba Men, Inner Mongolia. Buccal cells were collected from 19 Ba Men residents expos ed to arsenic at 527.5 +/- 23.7 mug/L (mean +/- SEM) and 13 controls expose d to arsenic at 4.4 +/- 1.0 mug/L. DNA fragmentation by the DNA ladder and TUNEL assay were used to detect DNA damage in buccal cells. In the DNA ladd er assay, 89% (17/19) of the arsenic-exposed group showed <100 bp DNA fragm ents, in contrast to 15% (2/13) of the controls (p<0.0001). For the TUNEL a ssay, the mean frequencies of positive cells were higher in the exposed gro up (15.1%) than in the controls (2.0%) (p<0.0001). The study showed that hi gh arsenic exposure via drinking water resulted in DNA damage and DNA fragm entation in buccal cells thus may be an appropriate biomarker for assessing chronic effects of arsenic in humans. A study investigating DNA fragmentat ion from the individuals with low levels of arsenic exposure in this popula tion is in progress.