the Institute of Medicine Roundtable on Environmental Health Science, Research, and Medicine held a regional workshop in Pittsburgh, Pennsylvania, on March 13, 2003. This workshop was a continued outgrowth from the Roundtable's first workshop when its members realized that the challenges facing those in the field of environmental health could not be addressed without a new definition of environmental health-one that incorporates the natural, built, and social environment. The Roundtable realized that the industrial legacy is not unique to Pittsburgh. Other cities around the world have seen their industries disappear, and it is only a matter of time before some of the Pittsburghs of today, such as Wuhan, China, (a sister city) will need to address similar problems. One goal for this IOM Environmental Health Roundtable Workshop is to extract lessons from Pittsburgh's experience in addressing the post-industrial challenge, distilling lessons that might be useful elsewhere.