Here are some links that are worth checking out. Most of them are government sites, but these sites are huge and contain links to just about anywhere you might want to go on the web. If there are any inactive links, or if you know of a link that should be added, please email the webmaster.
U.S. Department of Health and Human Services
Agency for Health Care Policy & Research
Environmental Protection Agency
US Consumer Product Safety Commission
National Center for Biotech Info-Human Gene Map
National Institute of Allergy and
Infectious Diseases
National Food Safety Database Home Page
American Public Health Association
American Journal of Epidemiology