Put down the Raid and back away slowly: Scientists are growing more confident that long-term exposure to toxic substances, notably pesticides, is implicated in most cases of Parkinson’s disease, according to a new story in the Los Angeles Times. Researchers first made a link between Parkinson’s and paraquat, a weedkiller long popular around the world, in the early 1980s.

Since then, hundreds of studies of animals, at least 40 of human patients, and three of human brain tissue have found “a relatively consistent relationship between pesticide exposure and Parkinson’s,” according to British scientists whose research was published in a recent issue of the journal Environmental Health Perspectives.

Without these environmental exposures, researchers think, people would still get Parkinson’s, but in smaller numbers and later in life. Over 1 billion pounds of pesticides are used in U.S. farms, gardens, and households every year. Syndicated from Grist.org.

Image credit: Los Angeles Times