ABSTRACT
Arsenic (As) is a widely distributed element within the earth’s crust with an average abundance of approximately 2 mg per kg and may occur in drinking water due to contact between the groundwater and As-rich sediments and rocks (Greenwood and Earnshaw 1984). The consumption of drinking water containing even relatively low levels of As over long periods of time has been shown to be deleterious to human health (Kapaj et al. 2006, Steinmaus et al. 2000, Smith et al. 1999). A range of diseases have been linked to As exposure via drinking water and include cancers, dermal lesions, and skin diseases. This has been particularly acute in Bangladesh and West Bengal, India where well waters may contain As concentrations as high as several hundred micrograms per liter. This link between As exposure due to the consumption of contaminated water and human health has prompted the USA Environmental Protection Agency (EPA) to lower the Maximum Contaminant Level (MCL) for As in drinking water from 50 µg L−1 to 10 µg L−1. This lower level came into force in January, 2006 and affected an estimated 4000 municipal authorities and several million private wells in the United States. Although private domestic wells are not covered by federal regulations, local laws governing the water quality are starting to appear in some states (e.g., New Hampshire) which often mandate that during real estate transactions, the quality of the water must meet federal regulations. These local laws and a growing consumer awareness of the adverse health effects associated with the consumption of As-tainted water have spurred sales of water treatment systems among residential and small business customers.
