RODALE NEWS, EMMAUS, PA—If you ever turn over a bottle of Roundup, one of the most popular chemical weed killers in the world, you’ll see glyphosate listed as the active ingredient. What you won’t see is a list of inactive ingredients. And that’s problematic. Because researchers who recently tested the product’s active ingredient in combination with certain inert ones found the combo makes this weed killer much more toxic than previously disclosed. “It’s not as benign as people are led to believe,” says Greg Bowman, editor of the Rodale Institute’s New Farm online publication, which focuses on nontoxic farming methods. And even the listed ingredient may be more dangerous than was previously thought. “More and more studies by medical and agricultural specialists are revealing the subtle, low-level impact that Roundup’s main ingredient, glyphosate, has on wildlife, soil life, and—directly and indirectly—people themselves,” Bowman says.
THE DETAILS: Researchers tested four combinations of Roundup on cultured human cells, and found that one inert ingredient in particular, polyethoxylated tallowamine, or POEA, significantly boosted the toxic effects of the main ingredient, glyphosate. In the study, the combination of the two killed or damaged many more of the cells than glyphosate alone. The study was published in the journal Chemical Research in Toxicology.
WHAT IT MEANS: In the U.S. alone, farmers and homeowners use an estimated 100 million pounds of the Roundup herbicide a year. The problem is, weeds are becoming resistant to the chemical, so farmers are forced to apply more and more of it. Between 1994 and 2005, the use of glyphosate increased 1,500 percent. And while the manufacturer and the U.S. Environmental Protection Agency say the product is safe, a growing body of nonindustry-funded scientific research suggests otherwise. When the active ingredient alone is tested—which is standard procedure in toxicology testing—the product may seem relatively safe. But when all the chemicals in the product are tested together, which provides a realistic snapshot of the product’s safety, the results suggest much more toxicity.