PH16 Metals in the Environment: Chemistry and Fate Issues
Exhibit Hall
8:00 AM - Thursday, 13 November 2003
(PH146) Arsenic contamination in groundwater and its toxic evaluation on human health in Cambodia.
Kubota, Reiji1, Kunito, Takashi1, Agusa, Tetsuro1, Monirith, In1, Tanabe, Shinsuke1, Seang Tana, Touch 2, 1 Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime, Japan2 Social and Cultural Observation Unit (OBSES) of the Cabinet of the Council of Ministers, Phnom Penh, Phnom Penh, Cambodia.
ABSTRACT- Recently, chronic arsenic poisoning due to drinking of arsenic-contaminated water has been reported for many countries. Hence, worldwide concern with arsenic and its toxic influence on human health has increased markedly. In case of Cambodia, WHO and UNICEF have suggested a possibility of arsenic contamination in groundwater. However, detailed survey has not been conducted for arsenic contamination in groundwater and also no information is available for toxic effects of arsenic on human health in Cambodia. In this study, we determined the concentrations of total arsenic and individual arsenic compounds in groundwater, human hair, and urine collected from Kandal, Kratie, and Phnom Penh in Cambodia. We also investigated urinary 8-OHdG level to make clear the association of DNA oxidation with arsenic contamination in the residents. Total arsenic concentrations in groundwater from Kratie ranged from <1 to 889 
g/L, and 42.3% of these values exceed the WHO guideline value for arsenic in drinking-water of 10 
g/L. These results indicate that groundwater in Kratie is extremely polluted by arsenic. Total arsenic concentrations in hair of residents in Kratie ranged from 0.05 to 45.7 g/g dry wt and the highest value was comparable to those of Bangladesh and India, suggesting that the residents of Kratie are chronically exposed to arsenic. Chemical speciation of arsenic revealed that dimethylarsinic acid was the major arsenic compound in almost all urine samples of residents in Kratie. Moreover, methylarsonic acid and inorganic arsenic were also detected in the urine samples. The samples were categorized into three groups by urinary total arsenic concentrations (<50 g/L, 50 to 100 g/L, and >100 g/L), and association between arsenic level in urine and 8-OHdG levels was examined for residents of Kratie. Although no significant difference was found in 8-OHdG levels between the three groups, the highest 8-OHdG level was observed in the highest urine-arsenic group (>100 g/L). Hence, residents of Kratie might face the possibility of DNA oxidative damage by high concentration of arsenic from groundwater and might be at risk of toxic effects of arsenic such as carcinogenicity.
Key words: groundwater, arsenic contamination, 8-OHdG, Cambodia