If the Environmental Protection Agency (EPA) greatly reduces the amount of arsenic allowed in drinking water, a regulation that is currently under consideration, the public will benefit from the higher standard. Indeed, ingesting high levels of arsenic is linked to various cancers and other illnesses. But depending on how low they set the limit, the EPA's decision could come with a multibillion-dollar price tag. New arsenic-trapping materials developed by researchers at Sandia National Laboratories, however, may help to reduce that cost.

To create arsenic-catching chemicals, the Sandia developers first selected mineral families known to attract negatively charged atom groups, or anions, such as the arsenic-containing compound arsenate. They then employed supercomputer modeling to rapidly assess the arsenic-trapping potential of thousands of variations and combinations of these minerals. The simulations revealed a selection of promising materialsdubbed specific anion nanoengineered sorbents (SANS). The team is now confirming the potential of SANS in the lab, sending arsenic-contaminated water through them and measuring the amount of arsenic in the outflow.

Next the researchers hope to test the materials at a planned city water purification plant in Albuquerque, N.M., as well as in smaller water systems in rural communities. "Municipalities now filter out dirt, silt and sewage," team member Pat Brady remarks, "but pulling out stuff at the parts-per-billion range cheaply is a new and difficult challenge."