A new long-term animal study is reigniting debate over the safety of glyphosate, the world’s most widely used weed killer, after researchers found a significantly increased risk of cancer—including early-life leukemia—even at levels currently deemed safe by regulators.
The study, published this month in Environmental Health, tracked more than 1,000 rats over two years and found that glyphosate and its commercial herbicide formulations triggered a higher incidence of benign and malignant tumors. Notably, the researchers observed early-life leukemia in rats exposed prenatally—raising fresh concerns about the compound’s effects on developing organisms.
“This study provides independent scientific evidence that both glyphosate and glyphosate-based herbicides can contribute to carcinogenic outcomes,” said Dr. Daniele Mandrioli, director of the Cesare Maltoni Cancer Research Center at the Ramazzini Institute in Italy and the study’s principal investigator.