The troubling results of this study only add to the growing body of evidence that has linked glyphosate to a host of health problems — including cancer, digestive problems, and reduced fertility.
BUENOS AIRES, ARGENTINA – A new study conducted by Argentinian researchers has found that glyphosate – the controversial herbicide marketed by Monsanto (now Bayer) as RoundUp – causes significant damage to pregnant lab rats and their fetuses at relatively low doses. The study, published in Archives of Toxicology, found that not only was the female fertility of pregnant rats impaired, but fetal growth was retarded and malformations were detected in their second-generation offspring.
Researchers tested the glyphosate-based chemical in pregnant female rats at two different doses. The higher dose (200 mg glyphosate per kg of bodyweight per day) was chosen based on the no-observed adverse effect level (NOAEL) for maternal toxicity of 1000 mg/kg bw/day promoted by the agrochemical industry as safe for mothers and fetuses.
The lower dose, in contrast, was only 2 mg/kg bw/day and was 1 mg higher than the reference dose set for glyphosate by the U.S. Environmental Protection Agency. That EPA-approved reference dose is the level that the government claims is safe to ingest on a daily basis over one’s lifetime. However, the researchers asserted that the 2 mg level in the lower dose tested is consistent with glyphosate residue on soybeans and is in keeping with the level of glyphosate detected throughout Argentina.
While the study did find that the tested glyphosate levels did not result in toxicity to the embryo or abnormal maternal behavior, it did show that female fertility in first-generation offspring was significantly reduced as those females showed a lower number of fertilized egg implantations compared to controls.
The most striking findings, however, were the consequences seen in second-generation offspring, with all rats exposed to glyphosate (low and high doses) showing delayed growth, lower fetal weight and length and a significantly higher rate of abnormally small fetuses.
In the high-dose group – and to the authors’ surprise – severe malformations, such as conjoined fetuses and abnormal limbs, were detected in second-generation offspring, with such fetal abnormalities being found in three out of 117 fetuses. Each of the affected fetuses had a different mother within the first-generation offspring. The study showed a significant statistical correlation between glyphosate exposure and the fetal abnormalities observed.
This result led the authors’ to claim that the industry-declared NOAEL for maternal toxicity is unreliable, given that the high dose that resulted in abnormalities (200 mg) was significantly lower than the NOAEL (1,000 mg). Notably, industry studies that determined the NOAEL did not use glyphosate, but instead aminomethylphosphonic acid (AMPA), a degradation product of glyphosate.
A growing body of evidence, a growing threat to health
The troubling results of this study only add to the growing body of evidence that has linked glyphosate to a host of health problems — including cancer, digestive problems, and reduced fertility. Another recent study, published in May, found that the commonly used herbicide can have major disruptive effects on mammalian sexual development, gene health and the presence of beneficial gut bacteria, even at doses considered safe. That study and this most recent one both come just months after the European Union voted late last year to approve the use of glyphosate for another five years, despite widespread opposition to the chemical’s re-approval.
However, this recent study’s focus on the dangerous multigenerational effects of glyphosate are particularly alarming given that the presence of the chemical — now produced by Bayer Crop Science, after the Bayer/Monsanto merger — is not only increasingly present in the environment, but in our bodies. Indeed, a study published last year in JAMA found that the presence of RoundUp in the blood of southern Californians had spiked by over 1,200 percent since the early 1990s. Given the findings of this latest study on glyphosate, the ever-increasing presence of this toxic chemical in the environment and within our bodies poses not only a major, current health risk but a risk to future generations.