"Midwestern and Southern states use much higher rates of the potentially harmful pesticide 2,4-D, according to U.S. Geological Survey (USGS) data.

A map by USGS, based on the latest data, collected in 2019, shows that use is most prevalent across Iowa, Missouri, Kansas, Illinois, Indiana, Ohio, Kentucky, with other states also using the herbicide in certain areas.

2,4-D was found to be "possibly carcinogenic to humans" in a 2015 report by International Agency for Research on Cancer (IARC) in the World Health Organization (WHO), although the report states there was "inadequate evidence" at the time to determine the extent of its harm.

But there are justified concerns about potential harm, depending on exposure levels to 2,4-D."

Jasmine Laws reports for Newsweek June 26, 2025. [2]