Two hundred seventeen tap water samples, from homes in 26 counties of eastern Kentucky, western West Virginia, southeastern Ohio, and northeastern Tennessee, USA, were analyzed for arsenic (As) by Hydride Generation AAS. Nearly half of the 179 samples from private wells had detectable arsenic, and, of these, 43% had 0.5-1.0 ppb, 34%, 1.1-3.0 ppb, 6%, 3.1-5.0 ppb, 11%, 5.1-10.0 ppb, and 6% had As far exceeding the new Maximum Contamination Level (MCL) of 10 ppb recently set by the U.S. Environmental Protection Agency (USEPA). Based on the National Research Council's 2001 report to the USEPA, the lifetime risk of bladder and lung cancer from water arsenic exposure at 10 ppb is about one in 333 individuals, which is much higher than the standard of one in 10,000 individuals set for other carcinogens. Even at 5 ppb, the risk is 1 in 667, at 3 ppb, 1 in 1000, and at 1 ppb, 1 in 3100. The incidence of arsenic-related cancers and other diseases in this coal-mining region is high, and 57% of the well water samples tested in this study had levels over 1 ppb As. Since Central Appalachian families rely heavily on private wells, and the U.S. Federal 2006 compliance edict does not apply to private water sources, more extensive sampling and analysis of well water in the region, using the most sensitive methodology available, is recommended. A public awareness campaign and routine health screening for arsenic exposure is also recommended.
