By Faradis Lindblom
A common herbicide used by eastern Iowa corn farmers may have potential chronic risk to both aquatic and terrestrial life as well as the surrounding environments, according to an EPA study.
The EPA termed atrazine, a popular herbicide used on corn, a risk to most living things in an ecological risk assessment earlier this month.
The release read: “Aquatic plant communities are impacted in many areas where atrazine use is heaviest, and there is potential chronic risks to fish, amphibians, and aquatic invertebrate in these same locations. In the terrestrial environment, there are risk concerns for mammals, birds, reptiles, plants, and plant communities across the country for many of the atrazine uses.”
Atrazine is a restricted-use product — meaning there are limits to how much an applicator can use because of the potential for groundwater contamination, said Meaghan Anderson, a field agronomist with Iowa State Extension and Outreach.
“It can be applied alone for weed control, tank-mixed with other herbicides, or as a part of a pre-mix product,” Anderson wrote in an email. “It is not as commonly used in some other areas of the state.”
Anderson said atrazine is especially prevalent in southeastern and eastern Iowa.
Currently, atrazine is undergoing registration review, the EPA’s periodic evaluation program.
All herbicides are reviewed at least every 15 years to make sure they meet standards for use and do not pose extreme health or environmental risks.
As part of this process, the EPA released a draft risk assessment in April detailing the risk atrazine poses to animals and the environment. In creating the assessment, the EPA collected information from various sources such as companies, academic sources, and scientific literature.
Cathy Milbourn, an EPA official, said the draft risk assessment is open for public comment, in which people may voice their opinions or present more research in favor of or against the reregistration of atrazine.
Milbourn said the assessment will not yet affect farmers and consumers.
After the assessment is completed, including public comments, the EPA will talk about “potential mitigation measures,” according to an email from the agency.
Organizations dedicated to environmental and public-health protection, such as Beyond Pesticides of Washington, D.C., are committed to ending the use of atrazine during the re-registration cycle.
However, not everyone, including Russell Meade, a local farmer who works near Tiffin, agrees that eliminating atrazine is a good idea.
“If we end up getting down to just a couple chemicals that we have available, and we have widespread weed resistance, then it’s going to cost the agriculture industry billions of dollars,” Meade said. “… [That] is going to translate to food-price increases of significant proportion, let alone the ability to produce the large amounts of foods that we are able to using the tools that we have.”
In addition to the potential economic downfalls that could occur, Meade said, the concentration of atrazine that farmers are allowed to use is necessary to prevent weed resistance.
“We are consciously aware of not overusing chemicals, but occasionally, when you have a weed outbreak, sometimes you need to be able to use a higher concentration to take care of something before it gets out of hand,” Meade said.
The complete registration review for atrazine may take at least a couple more years to complete. Once the ecological and human health risk assessments have been peer reviewed and allowed for public comment, the EPA will publish a proposed decision on the future of atrazine.
