Until now, most health studies have focused on the safety of glyphosate, rather than the mixture of ingredients found in Roundup. But in the new study, scientists found that Roundup’s inert ingredients amplified the toxic effect on human cells—even at concentrations much more diluted than those used on farms and lawns. The new findings intensify a debate about so-called “inerts” — the solvents, preservatives, surfactants and other substances that manufacturers add to pesticides. Nearly 4,000 inert ingredients are approved for use by the U.S. Environmental Protection Agency. The French team, led by Gilles-Eric Seralini, a University of Caen molecular biologist, said its results highlight the need for health agencies to reconsider the safety of Roundup. “The authorizations for using these Roundup herbicides must now clearly be revised since their toxic effects depend on, and are multiplied by, other compounds used in the mixtures,” Seralini’s team wrote. The research team suspects that Roundup might cause pregnancy problems by interfering with hormone production, possibly leading to abnormal fetal development, low birth weights or miscarriages.
Controversy about the safety of the weed killer recently erupted in Argentina, one of the world’s largest exporters of soy. Last month, an environmental group petitioned Argentina’s Supreme Court, seeking a temporary ban on glyphosate use after an Argentine scientist and local activists reported a high incidence of birth defects and cancers in people living near crop-spraying areas. Scientists there also linked genetic malformations in amphibians to glysophate. In addition, last year in Sweden, a scientific team found that exposure is a risk factor for people developing non-Hodgkin lymphoma.
In the French study, researchers tested four different Roundup formulations. They also tested one specific inert ingredient, polyethoxylated tallowamine (POEA) and glyphosate separately to determine which caused more damage to embryonic, placental and umbilical cord cells. POEA was more deadly to human embryonic, placental and umbilical cord cells than the herbicide itself – a finding the researchers call “astonishing.” Glyphosate, POEA and all four Roundup formulations damaged all three cell types. Umbilical cord cells were especially sensitive to POEA. Glyphosate became more harmful when combined with POEA, and POEA alone was more deadly to cells than glyphosate. It is added to Roundup and other herbicides to help them penetrate plants' surfaces, making the weed killer more effective. The research appears in the January issue of the journal Chemical Research in Toxicology.
Sources: Scientific American, June 23, 2009
http://www.scientificamerican.com/article.cfm?id=weed-whacking-herbicid…
Environmental Health News, June 22, 2009
http://www.environmentalhealthnews.org/ehs/news/roundup-weed-killer-is-…
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