Male rats exposed before birth to low doses of the weedkiller atrazine are more likely to develop prostate inflammation and to go through puberty later than non-exposed animals, finds a new study conducted by federal government scientists.

One of the most common agricultural herbicides in the United States, some 80 million pounds of atrazine are applied across the country every year to control broadleaf and grassy weeds in crops such as corn and sugar cane. It is the main ingredient in about 40 name-brand herbicides.

“Atrazine is a staple product for producers, who use it as a critical tool for weed control in growing the vast majority of corn, sorghum and sugarcane in the United States. Use of atrazine fights weed resistance, reduces soil erosion and increases crop yield,” according to the Triazine Network, an association of growers and researchers. Atrazine is sprayed on an Iowa cornfield. (Photo credit unknown)

But atrazine and its byproducts are known to be endocrine disrupters that are persistent in the environment, making their way into both surface water and groundwater supplies.

This study on how atrazine affects male rats was led by Suzanne Fenton, PhD, and Jason Stanko, PhD, of the National Institute of Environmental Health Sciences, part of the National Institutes of Health. The scientists tested male rats using atrazine concentrations close to the regulated levels in drinking water sources.