Internal Monsanto documents reveal a startling campaign to suppress science. Policymakers would be wise to adopt a more precautionary view. Glyphosate, which Monsanto brought to market in 1974, is the most widely used herbicide in the world, applied on farm fields that grow our food, as well as on parks, playgrounds, golf courses, and lawns and gardens. Residues of the weed killer are commonly found in our food and water. The company and chemical industry allies have long asserted its safety, but many independent scientists disagree.