As North America enters its peak summer growing season, gardeners are planting and weeding, and groundskeepers are mowing parks and playing fields. Many are using the popular weedkiller Roundup, which is widely available at stores like Home Depot and Target.

In the past two years, three U.S. juries have awarded multimillion-dollar verdicts to plaintiffs who asserted that glyphosate, the active ingredient in Roundup, gave them non-Hodgkin lymphoma, a cancer of the immune system.

Bayer, a German chemical company, bought Roundup's inventor, Monsanto, in 2018 and inherited some 125,000 pending lawsuits, of which it has settled all but about 30,000. The company is now considering ending U.S. retail sales of Roundup to reduce the risk of further lawsuits from residential users, who have been the main source of legal claims.