Agency for Toxic Substances and Disease Registry (ATSDR): The ATSDR is a federal agency within the United States Department of Health and Human Services. Their mission is to protect communities from harmful environmental exposures and related health effects. They conduct research, provide education and outreach, and offer resources on various environmental health topics. Their website provides access to extensive information on toxic substances, hazardous waste sites, chemical exposures, and related health effects. Website: ATSDR