Made by the Monsanto Corporation, Roundup is one of the world’s most widely used herbicides. Almost a billion kilograms of it and its chemically-similar relatives are applied annually on crops, gardens, sidewalks and lawns by farmers and homeowners alike.

It is also used by drug enforcement agents globally in the fight against illegal crops like marijuana and coca, and even by some environmental groups for invasive species eradication and habitat restoration. In addition, many of the genetically-modified crops that are grown commercially are specifically engineered to resist Roundup; nine-tenths of the corn, cotton, and soybeans produced in the US are “Roundup Ready” (i.e. herbicide resistant) strains created and patented by Monsanto scientists. Monsanto makes an estimated $5 billion annual from the sale of Roundup and Roundup Ready-plants.

When glyphosate, the active ingredient in Roundup and similar herbicides, was first discovered in 1970 it was called a “virtually ideal” herbicide. The…