Some types of oat cereals, oatmeal, granola and snack bars contain higher levels of a chemical found in the weed killer Roundup than what the Environmental Working Group considers safe, according to a report released Wednesday by the advocacy group. Almost three-quarters of food samples tested showed higher glyphosate levels than what the group’s scientists believe to be “protective of children’s health,” the report indicates. Last week, a jury at the Superior Court of California in San Francisco awarded $289 million in damages to a groundskeeper whose attorney argued that Roundup, a weed killer made by Monsanto, caused his terminal cancer. “We will appeal this decision and continue to vigorously defend this product, which has a 40-year history of safe use and continues to be a vital, effective and safe tool for farmers and others,” Monsanto Vice President Scott Partridge said in a statement at the time. “More than 800 scientific studies, the US EPA, the National Institutes of Health and regulators around the world have concluded that glyphosate is safe for use and does not cause cancer,” Partridge said. However, the human health effects of glyphosate remain uncertain, because the product has additional chemical ingredients that, individually or combined, might be carcinogenic, among other reasons.