The National Library of Medicine is the world's largest medical library, and its Web site does it justice. MedlinePlus is geared toward health professionals and consumers, with information from the National Institutes of Health and other sources on more than 650 diseases and conditions (see http://www.nlm.nih.gov/medlineplus/healthtopics.html). Users can scroll through an alphabetical listing or grouping by topic (i.e., condition, procedure, demographic group, etc.).

Clicking on the Poisoning, Toxicology, Environmental Health (http://www.nlm.nih.gov/medlineplus/poisoningtoxicologyenvironmentalhealth.html) grouping brings a wide range of topics – from air pollution, anthrax, and arsenic to radon, secondhand smoke, and small pox. Click on a subject and a new page has a column on the left listing everything on the page. Some common choices are basic information from NIH, an overview of the topic, specific conditions, prevention/screening, related issues, directories, and organizations. If there are recent news articles on the topic, they are also listed.

MedlinePlus has a medical encyclopedia (http://www.nlm.nih.gov/medlineplus/encyclopedia.html) with more than 4,000 articles about diseases, tests, symptoms, injuries, and surgeries, including photographs and illustrations, and a medical dictionary (http://www.nlm.nih.gov/medlineplus/mplusdictionary.html).

MedlinePlus also has Interactive Tutorials (http://www.nlm.nih.gov/medlineplus/tutorial.html) using animated graphics to explain a procedure or condition in easy-to-read language. The tutorials are available in four different topics: Diseases and Conditions (almost 100); Tests and Diagnostic Procedures (21); Surgery and Treatment Procedures (41); and Prevention and Wellness (8).

Of particular interest to journalists will be the News Section which links to news articles from the past 30 days from the New York Times Syndicate, Reuters Health Information, and others. This section is organized by date, but can also be sorted by topic (i.e., air pollution, asthma, children's health, disaster and emergency preparedness, drinking water, etc.)