The work is timely as researchers and public officials become increasingly concerned about pharmaceuticals and personal care products detected in soil and water. Environmental engineers are seeking better ways to track these emerging pollutants, which tend to be more complex and water-soluble than previous contaminants of concern, such as chlorinated solvents and petroleum byproducts.

The new modeling approach is expected to assist environmental regulators and cleanup consultants in determining the extent to which hazardous contaminants will linger on a piece of land and the rate at which they will migrate toward critical water resources and supplies. The tool also will help them decide whether the pollutants need to be removed and how best to accomplish this, researchers say.

The tool is based on a breakthrough by chemists who study how medications move from the bloodstream into human tissue. See Thanh Nguyen's website at http://myweb.jhu.edu/thn and John Hopkins' Department of Geography and Environmental Engineering at www.jhu.edu/~dogee.