Dr. Guallar is an epidemiologist whose research is focused on the study of cardiovascular disease epidemiology and prevention, with an emphasis on evaluating the role of environmental and nutritional exposures in the development of cardiovascular disease. This research has made critically important and novel contributions to our understanding of risk factors for chronic disease both in the US and globally. He has published seminal articles and is a leading figure in an emerging field highlighting the risks of exposure to levels of metals previously considered safe for cardiovascular health. In addition to his work in toxic metals, Dr. Guallar has made important contributions to understanding the effects of certain micronutrients and vitamin supplements on cardiovascular disease risk and outcomes. Publications in this area were influential in changing consumer habits and attitudes towards these products. Much of this research has been funded by the National Institutes of Health, the Agency for Healthcare Research and Quality, the American Heart Association, the CDC, and other funders.