20
Feb
Exposure to Glyphosate Herbicide Adversely Affects Perinatal Health, Study Finds
(Beyond Pesticides, February 20, 2024) Researchers at the University of Oregon found that the rollout of genetically engineered corn in the early 2000s, followed by exponential increases in glyphosate-based herbicides, “caused previously undocumented and unequal health costs for rural U.S. communities over the last 20 years.†Their results “suggest the introduction of GM [genetically modified] seeds and glyphosate significantly reduced average birthweight and gestational length.â€
The conclusions of this study emerge as fossil fuel advocates, including President Donald Trump, are mobilizing to pioneer “energy dominance†despite the market movement toward renewable energy. Just as chemical-intensive farmers and land managers continue to spray synthetic fertilizers and pesticides, a successful rollout of alternatives must rely on feeding the soil rather than the plant.
Advocates continue to demand that elected officials and regulators embody the precautionary principle and scientific integrity in decision-making. Given the hostile federal climate on anything relating to holistic solutions, communities are coming together to move beyond input-dependent land management systems and adopt organic criteria of allowed and prohibited substances, mandatory public comment process, independent third-party certification, and a federal advisory board (National Organic Standards Board) consisting of farmers, environmentalists, consumers, scientists, economists, researchers, and other stakeholders, with binding recommendations to the U.S. Department of Agriculture (USDA) Secretary.
Background and Methodology
The authors of this study, Edwin Rubin, PhD, and Emmett Reynier, are researchers at the University of Oregon Department of Economics. Mr. Reynier is a current PhD candidate in environmental economics and a Fellow at the Oak Ridge Institute for Science and Education Research. Dr. Rubin is an assistant professor with degrees in agricultural and resource economics, statistics, agricultural economics, and mathematics.
“Our primary analyses focus on the over 10 million births that occurred between 1990 and 2013 in rural U.S. counties or involved mothers residing in rural counties—as defined by the US Department of Agriculture (USDA),†says Dr. Rubin and Mr. Reynier. “We focus on this subset as it represents the births most likely to be impacted by the increase in glyphosate intensity and exposure induced by the release of GM seeds.”
The birth data consists of over 10 million infants from the National Vital Statistics System, an intergovernmental database sponsored by the National Center for Health Statistics under the Centers for Disease Control and Prevention (CDC). The glyphosate use data originated from the U.S. Geological Survey (USGS) National Pesticide Synthesis Project, which tracked glyphosate intensity at the county level between 1992 and 2017. The suitability of genetically engineered crops (the quantity of yield) for corn, wheat, and soybeans was measured based on the Global Agro-Ecological Zones modeling framework (GAEZ) developed by the United Nations Food and Agriculture Organization (UN-FAO).
The researchers use two empirical approaches: The reduced form difference-in-differences (DID) approach and the two-stage approach. The DID approach identifies the policy impact, and the two-stage approach captures the direct impact of glyphosate, given the number of variables in play. Both approaches attempt to identify differences in external factors (“exogenous variationâ€) that may be contributing to differences in perinatal (the weeks preceding and proceeding birth) health outcomes at the county-to-county level. For more information on the methodology and empirical approaches, see here.
Results
The first method (DID approach) compared counties with higher and lower suitability ratings for growing GE crops. Before 1996, both types of counties had similar quantities of glyphosate residues and similar baby weights. After 1996, counties with higher crop suitability had significantly higher glyphosate use, and the babies in these areas weighed less on average.
The second method (two-stage approach) looked at the actual impact of glyphosate use. At the average amount used in 2012, the study found that glyphosate exposure reduced baby birthweights by about 29–30 grams and shortened pregnancies by about 1 to 1.5 days. There were also more cases of babies being born with very low weights and prematurely.
The study also found that not all babies were affected in the same way. When the researchers grouped babies by normal birth weight, they saw that the most vulnerable babies (first decile) lost up to 75 grams relative to the 6 grams lost for the least vulnerable babies. In addition, babies born to Black mothers, female babies, and those born to unmarried parents were at higher risk of adverse developmental effects.
Overall, the study strongly suggests that the rollout of glyphosate-tolerant seeds contributed to the exponential increase in glyphosate use, which in turn led to poorer health outcomes for infants in rural areas. This finding builds on decades of serious concerns raised by independent scientists, public health professionals, farmers, farmworkers, and concerned parents on the trajectory of the U.S. public health and food systems.
Existing Literature
There are decades of peer-reviewed studies and scientific literature pointing to linkages between severe health impacts and exposure to glyphosate-based herbicides.
A study published in the Journal of Ecotoxicology and Environmental Safety in 2024 documented, for the first time, the presence of the herbicide glyphosate in human sperm. The study looked at 128 French men with an average age of 36 years who tested positive for glyphosate in their blood. Seventy-three out of the 128 men were found also to have glyphosate in their seminal plasma. Not only that, the amount of glyphosate in seminal plasma was nearly four times higher than what was detected in the blood. Glyphosate has also been linked to toxicity to pollinators and birds, as well as links to cancer (Non-Hodgkin’s Lymphoma), endocrine disruption, reproductive harms, kidney and liver damage, neurotoxicity, birth and developmental effects, among other adverse health effects. See the Gateway on Pesticide Hazards and Safe Pest Management entry for glyphosate to learn more.
See glyphosate and genetic engineering sections in the Daily News for further analysis. For more resources on genetic engineering and risks to public health, see here.
Call to Action
There is a bipartisan push this year in state legislatures across the nation looking to prohibit glyphosate use or restrict its use to some degree, including bills in California, Connecticut, Hawai’i, Illinois, Massachusetts, Missouri, New York, Rhode Island, and Texas. Advocates welcome the introduction of legislation as communities have urged for decades and continue to demand action to address issues around glyphosate, given the known risks. However, they also acknowledge past battles on individual active ingredients (e.g., chlorpyrifos, dicamba, paraquat) or groups of active ingredients (e.g., organophosphates, neonicotinoids) have not necessarily succeeded in eliminating toxic chemical use.
On the brink of the second Trump administration, a legal victory in early December overturned a rule issued under the first Trump administration to “practically eliminate oversight of novel GE technology and instead let industry self-regulate,†as characterized by the Center for Food Safety (CFS). (See Daily News here.)
You can act now by calling on Congress to ensure the integrity of federal agencies through the appointment of independent Inspectors General. (See the Action of the Week here.)
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: PNAS
