Environmental forensic files.

If the spate of recent television shows focused on investigating crimes is any indication, forensic science has taken hold of the public consciousness. A standing-room-only crowd at environmental forensics sessions at the 17th Annual International Conference on Soils, Sediments, and Water held in October 2003 in Amherst, Massachusetts, proved the forensics bug has infected scientists, too. In this case, proponents say environmental forensics, which combines approaches from several disciplines to analyze cases of environmental contamination, brings a new level of sophistication to environmental science and the assessment of health risks.

Environmental forensics uses investigative tools from fields as varied as analytical chemistry, isotopic analysis, epidemiology, toxicology, geology, history, and statistics, with technologies ranging from aerial photography to gas chromatography/mass spectrometry and other chemical fingerprinting methods. The aim, often, is to characterize environmental problems and resolve litigation regarding how they occurred.

"Forensics is rekindling the curiosity in environmental science," says Eric Cherry, environmental forensics practice leader with the Ohio-based consulting firm of Hull & Associates. In recent decades, while the legislation of environmental standards has established needed benchmarks, it has also "commodified" the general environmental assessment field, he says; environmental consultants are often asked merely to measure samples against government standards rather than interpret actual risks, pathways, or longterm flare. For Cherry, forensics marks an attempt to strengthen the remediation process by building techniques for identifying appropriate solutions into the diagnosis of a problem.

Experts in environmental forensics have applied its techniques in court cases to establish the source of a pollutant and thus determine who is responsible for paying for remediation. This can require unraveling complex time sequences of when pollutants entered the environment and untangling multiple plumes of contaminants. For instance, chemical fingerprinting can be used to distinguish among different petroleum products in a water sample and determine the contribution of each chemical (and possibly--for example, through the identification of specific additives and other components--different corporations) in a spill.

In one case, Stephen Mudge, a professor of ocean sciences at the University of Wales, Bangor, is studying the effects of the 1989 Exxon Valdez oil spill to assess whether Exxon is liable for ongoing effects on the ocean environment. As part of his assessment, he's testing water samples with chemical fingerprinting to see to what extent the Valdez petroleum is still affecting marine life.

"Environmental forensics is a toolbox of techniques that lets you 'think outside the box,'" Cherry said in a presentation at the Amherst conference. "Forensics helps you select the appropriate tests to acquire the appropriate data in order to make a more informed risk management decision."

Cherry illustrated this with a recent study of historic chemical releases at Cleveland-Hopkins International Airport. The city of Cleveland had asked Hull & Associates to determine the health risks to airport workers and nearby residents of past runoff of jet fuel and de-icing fluid. Former airport employees reported smelling odors that could signal contamination, but conventional analyses could not isolate the source. However, using broad-spectrum analyses of multiple media and a chemical use history of the site, Cherry and colleagues identified 164 chemical compounds, 65% of which would not have appeared either using conventional analysis or on an Environmental Protection Agency checklist of target breakdown compounds to screen for. The study found, however, that only a few chemicals exceeded regulatory standards at certain spots on the site. Further analysis showed that the site did not pose a toxicologic health risk.

The forensic approach has drawn the most attention where it has been used in lawsuits to make polluters pay for damages and remediation, but it is also used to help assess potential liabilities--for example, before purchasing land with an industrial history. Increasingly, companies are commissioning forensic assessments of sites before they buy, to see what legal and health risks may exist.

Robert Morrison, editor-in-chief of the journal Environmental Forensics, expects that, with increasing environmental regulation and costlier litigation, the demand for these skills will grow internationally. One school, at least, is stepping up to meet that demand. In September 2003, the University of Wales, Bangor, announced the world's first degree program in environmental forensics, which was organized by Mudge. Students will study statistics, chemistry, biology, and geology as well as legal strategies for arguing their case in court.