Quantitation of total arsenic (tAs) in water and iAs, monomethylarsenic (MMeAs), and dimethylarsenic (DMeAs) in blood, urine, and hair was performed as reported previously (26).
Table 1 shows that the mean blood concentrations of iAs, MMeAs, and DMeAs of the high-arsenic-exposed group were about 3.0, 9.9, and 5.1 times higher, respectively, than those of the low-arsenic-exposed group, and the urinary levels of iAs, MMeAs, and DMeAs of the high-arsenic-exposed group were about 5.1, 11.7, and 10.3 times higher than those of the low-arsenic-exposed controls.
As shown in Figure 1, the serum LPO levels were significantly correlated with the concentrations of iAs, MMeAs, DMeAs, and total arsenic in blood.
Both blood and urine levels of iAs, MMeAs, and DMeAs were significantly higher in the high-exposure group compared with the low-exposure controls.
DMeAs, a metabolite of iAs, induced DNA damage via formation of *[O.sub.2.sup.-] and dimethylarsenic peroxyl radical (39,40).