Dr. Brain received his Master of Science and Doctor of Science degrees from Harvard University. He is the Cecil K. and Philip Drinker Professor of Environmental Physiology at Harvard School of Public Health. Dr. Brain’s research emphasizes responses to inhaled gases, particulates, and microbes. His studies extend from the deposition of inhaled particles in the respiratory tract to their clearance by respiratory defense mechanisms. Of particular interest is the role of lung macrophages; this resident cell keeps lung surfaces clean and sterile. The context of these studies on macrophages is the prevention and pathogenesis of environmental lung disease as well as respiratory infection. Dr. Brain’s research has utilized magnetic particles in macrophages throughout the body as a non-invasive tool for measuring cell motility and the response of macrophages to various mediators and toxins. Another area of study is drug delivery to and through the lungs.