National Institute of Environmental Health Sciences
conducts basic research on environmental health and environment-related diseases. Links to information on programs, grants, research, events, contracts, employment, training, outreach events, public information.
http://www.niehs.nih.gov/

Children's Environmental Health Network
The CEHN is a national multidisciplinary project whose purpose is to protect the health of children as it relates to environmental hazards.
http://www.cehn.org/

National Environmental Health Association
NEHA offers a variety of programs, education, employment opportunities, and various other products and services to those in the environmental field.
http://www.neha.org/

Environmental Health Information Service
EHIS is an on-line service of the National Institute of Environmental Health Sciences. The EHIS provides the most accurate and timely information on environmental health, toxicology, and cancer.
http://ehis.niehs.nih.gov/

National Safety Council (U.S.)
Site provides information on many safety, health and environmental topics; training resources (worker safety, DDC, FAI, CPR); products; publications; news; programs; and home safety. NSC is a membership organization.
http://www.nsc.org/