Summary: In their quest for perfect lawns, homeowners and lawn services are applying vast quantities of pesticides to eliminate weeds and insects. Yet the potentially dangerous consequences of these pesticides--from health and environmental problems to groundwater contamination--are not widely understood by the public. Although the Environmental Protection Agency (EPA) relies on reregistration to bring older pesticides into compliance with current scientific standards, the agency continues to fall behind its schedule to reregister pesticides. EPA's most recent estimates for obtaining required studies for 12 of the 18 major pesticides used in lawn care have slipped by as much as four years. Even after reregistration, the safety of lawn care pesticides is doubtful. EPA has not developed guidelines to assess the health effects of human exposure to pesticides after they are applied to lawns. In light of increasing reports of incidents involving pesticides, EPA is reconsidering its long-held view that pesticides pose no risk to the health of homeowners and their families. EPA is particularly concerned about the pesticides' effect on children, who may play on or around treated lawns. EPA has found 13 lawn care pesticides in groundwater and has identified four potential carcinogens among the 18 major lawn care pesticides.