David Christiani, MD, MPH, is medical director of the Christiani Lab in the Division of Pulmonary and Critical Care Medicine at Massachusetts General Hospital. A staff physician in the Mass General Pulmonary and Critical Care Unit, Dr. Christiani is also a professor of medicine at Harvard Medical School and the Elkan Blout Professor of Environmental Genetics at the Harvard School of Public Health. In addition, he directs the environmental and occupational medicine section of the Mass General Division of Pulmonary and Critical Care Medicine. br> His major research interests are gene-environment interactions in acute and chronic illness. He has been active in developing new methods for assessing health effects after exposure to pollutants, incorporating genetic studies in environmental health and introducing genetic studies into the critical-care setting. His interest in global environmental health dates back 30 years, and he has led or co-led international collaborative studies in Asia, Africa and Latin America.