TWN Info Service on Biosafety
2 April 2025
Third World Network
www.twn.my
Dear Friends and Colleagues
Glyphosate exposure linked to GM crop cultivation decreased perinatal health unequally
In the two decades following the introduction of GM crops, the volume of glyphosate applied in the US increased by more than 750%. A large study found that the introduction of GM seeds and glyphosate significantly reduced average birthweight and gestational length in babies. The study suggests that glyphosate exposure caused previously undocumented health costs for rural US communities over the last 20 years, with historically disadvantaged groups disproportionately bearing these.
The researchers analyzed data on gestation time and birthweight of more than 10 million babies born between 1990 and 2013 in rural US counties. Between 1990 and 1996, there was no difference in birthweight or pregnancy length between counties. However, following the introduction of GM crops, birthweight began to drop in counties where more GM crops are grown and sprayed with glyphosate. By 2005, babies born in counties dominated by GM corn, soy and cotton weighed on average about 30 grams less than those born in rural counties that mostly grow other kinds of crops on which glyphosate is not used. Babies were also born 1.5 days earlier in places where glyphosate spraying was common. Children of Black or unmarried parents were more than 60 times as likely to have low or very low birthweight, with nearly twice as much decrease in weight.
These results suggest that current regulations are inadequate, and highlight the need to improve pesticide use and exposure monitoring. If not, the public will likely continue to bear the health burden of glyphosate and GM crops inefficiently and unequally.
See also the following article in Science: Common weed killer may be harming infants
With best wishes,
Third World Network
_____________________________________________________________
GLYPHOSATE EXPOSURE AND GM SEED ROLLOUT UNEQUALLY REDUCED PERINATAL HEALTH
Reynier, E., & Rubin, E.
Proceedings of the National Academy of Sciences, 122(3), e2413013121
https://www.pnas.org/doi/10.1073/pnas.2413013121
14 Jan 2025
Significance
While the herbicide glyphosate is the most commonly used herbicide globally, the effects of glyphosate exposure on human health and the environment remain unclear—particularly in more developed countries, where glyphosate exposure is often considered low. Using spatiotemporal variation in the adoption of glyphosate-resistant crops, we document significant adverse perinatal health effects due to increased glyphosate exposure in the rural United States. Further, historically disadvantaged groups disproportionately bear these health effects. These results conflict with current regulatory guidance, suggest current regulations may be inadequate, and highlight the need to improve pesticide use and exposure monitoring.
Abstract
The advent of herbicide-tolerant genetically modified (GM) crops spurred rapid and widespread use of the herbicide glyphosate throughout US agriculture. In the two decades following GM-seeds’ introduction, the volume of glyphosate applied in the United States increased by more than 750%. Despite this breadth and scale, science and policy remain unresolved regarding the effects of glyphosate on human health. We identify the causal effect of glyphosate exposure on perinatal health by combining 1) county-level variation in glyphosate use driven by 2) the timing of the GM technology and 3) differential geographic suitability for GM crops. Our results suggest the introduction of GM seeds and glyphosate significantly reduced average birthweight and gestational length. While we find effects throughout the birthweight distribution, low expected-weight births experienced the largest reductions: Glyphosate’s birthweight effect for births in the lowest decile is 12 times larger than that in the highest decile. Together, these estimates suggest that glyphosate exposure caused previously undocumented and unequal health costs for rural US communities over the last 20 years.