Many chemicals that were once commonly used were later found out to be harmful to the environment , to human health, or both. The element lead was once a common additive to gasoline and to paint. Plumbing pipes were once typically made of lead. Only since the 1970s has the danger of lead become apparent. It causes brain damage and small children (who often chewed on objects painted with lead-based paint) are particularly susceptible. The use of lead in gasoline, paint, and plumbing pipes is now banned and new materials are being developed to replace the hazardous lead components.
Asbestos was once used insulation in buildings and in various products such as roofing materials, water supply lines and clutches, brake linings, gaskets and pads for automobiles. Decades later asbestos was linked to cancer but can still be found in old buildings.
Was asbestos always harmful or only recently?