Project Summary (2000-2005)

The objectives of this study are to quantify carcinogenic risks due to arsenic exposure at levels commonly found in the U.S. Arsenic has been identified as a potent skin carcinogen in highly exposed human populations, but it is uncertain whether these effects occur at low levels. Researchers are extending an epidemiological case-control study of bladder and skin cancers in a US population. This study is resolving the dose-response relationship between low to moderate levels of arsenic exposure and risk of bladder cancer. Arsenic exposure is also being specifically related to intraepidermal carcinomas (including Bowen's disease) and multiple concomitant basal cell carcinomas (BCC) of the skin. Additionally, this study is identifying subgroups of individuals who may be at high risk of arsenic-associated cancers due to co-carcinogen exposure (e.g., cigarette smoking), genetic susceptibility (e.g., polymorphisms in glutathione S-transferases), or dietary factors (e.g., low selenium). Existing biomarkers of arsenic exposure (drinking water, urine, and toenails) are being evaluated and new molecular-genetic markers (based on cDNA arrays) are being explored. This study’s focus in New Hampshire provides a unique opportunity to obtain results directly applicable to tile US population and to help identify those at greatest risk for arsenic-induced malignancies.