Living near farmland can significantly increase people’s exposure to glyphosate, the active ingredient in the widely used herbicide Roundup, new research shows. This chemical has been connected to health concerns, including non-Hodgkin lymphoma and a higher risk of preterm birth.
We are environmental health scientists who study pesticide exposures in human populations, including exposures to herbicides. In our newly published research, we tracked glyphosate levels in pregnant women for 10 months.
We found that those who were living within about a third of a mile (500 meters) of an agricultural field had significantly higher levels of glyphosate in their urine than those who lived farther away. Importantly, we only saw those differences during the time of year when farmers spray glyphosate on their fields, further suggesting agricultural spray as the source of this exposure.
Our research also found that eating organic food, produced without the use of synthetic pesticides, could reduce glyphosate levels in women living far from farm fields – but not in women who lived near farm fields.
Together, the results provide new insight into how people are exposed to this common and potentially harmful chemical.
Why it matters
Glyphosate is the single most heavily used agricultural pesticide in the world. Its use grew dramatically over the past two decades with the increase in production of genetically modified, herbicide-resistant crops. These crops are engineered to withstand the weed-killing effects of herbicides like glyphosate, which means that an entire field can be sprayed with these chemicals, eliminating the weeds without harm to the crop itself. This is a change from previous practices, where herbicide applications had to be more targeted.
While herbicides like dicamba and 2,4-D are known to become airborne, glyphosate is not volatile, so there has been less concern over its potential to drift when it is sprayed on crops.
However, our research provides evidence for the first time that agricultural use of glyphosate still reaches people living nearby.