President Trump recently signed an Executive Order that expands U.S. production of glyphosate, a herbicide contained in commercial and domestic weed killers, such as Roundup. Glyphosate has been rigorously tested in more than 2,000 studies, including the U.S. National Cancer Institute’s large Agricultural Health Study, and has been used by farmers and home gardeners for more than 50 years. Yet some environmental advocates and other groups contend it causes cancer, specifically non-Hodgkins Lymphoma. This outcry stems primarily from a 2015 hazard assessment by the International Agency for Research on Cancer’s (IARC), a semi-autonomous agency of the World Health Organization, which...