Pregnant women exposed to pesticides have high urinary glyphosate concentrations

Key takeaways:

• During spray season, living near agricultural fields led to frequent urinary glyphosate detection at increased concentrations.
• Concentrations did not differ for distance from fields in the non-spray season.

Urinary glyphosate concentrations were significantly increased for pregnant women living near agriculture fields during the pesticide spray season of May to August, according to study results published in Environmental Health Perspectives.

“Pesticide exposure among residents of agricultural regions can occur through inhalation or dermal absorption via spray drift from active applications or through ingestion of pesticide residues in soil or water,” Cynthia L. Curl, PhD, MS, associate professor and co-director at the Center for Excellence in Environmental Health and Safety at the School of Public and Population Health at Boise State University, Boise, Idaho, and colleagues wrote. “A few studies have evaluated the effect of residential location on glyphosate exposure and found higher exposure among those in rural/agricultural locations than those living in urban regions.”

Curl and colleagues quantified glyphosate concentrations in 453 urine samples collected biweekly from 40 pregnant women in southern Idaho from February to December 2021. Researchers estimated glyphosate exposure as the mean concentration measured in all samples with an average of 11 samples per participant and as the mean of samples collected during the pesticide spray season of May to August with an average of five samples per participant. Researchers also evaluated samples from the non-spray season, defined as before May or after August. The samples from 22 women living less than 0.5 km from an actively cultivated agricultural field were compared with 18 women who lived 0.5 km or farther from such areas.

Urinary glyphosate was detected more frequently in samples from women living near agricultural fields (81% vs. 55%) and at significantly increased concentrations (0.228 vs. 0.15 µg/L) during pesticide spray season compared with the non-spray season. Conversely, among women who lived 0.5 km or farther from agricultural fields, there were no differences in urinary glyphosate detection frequency (66% vs. 64%) or concentrations (0.154 vs. 0.165 µg/L) during the spray and non-spray seasons.

In addition, researchers noted that concentrations did not differ between women who lived closer or farther from agricultural fields during the non-spray season.

“Future studies should increase the understanding of specific pathways through which glyphosate exposure occurs during the spray season,” the researchers wrote. “In such future studies, it would be valuable to characterize behaviors potentially associated with exposure, such as frequency of cleaning homes, amount of time spent at home outdoors during the spray season and typical practices around wearing shoes inside the home.”