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US EPA reapproves atrazine

Agency allows continued use of common herbicide with new requirements

by Britt E. Erickson
September 26, 2020 | A version of this story appeared in Volume 98, Issue 37


Young corn plants growing in rows in a field.
Credit: Shutterstock
Atrazine is commonly sprayed on young corn plants to control grasses and broadleaf weeds.

After reviewing the risks of atrazine for more than 7 years, the US Environmental Protection Agency says the widely used herbicide can stay on the market with some new restrictions. EPA administrator Andrew Wheeler announced this final decision Sept. 18 during an event in Missouri attended by farm-group leaders and local lawmakers.

Chemical structure of atrazine.

Atrazine is one of the most commonly used herbicides in the US. Farmers spray it on crops such as corn, sorghum, and sugarcane to control grasses and broadleaf weeds. Consumers apply it to residential lawns to kill weeds. Atrazine persists in the environment and is a widespread contaminant in drinking water. The herbicide and its breakdown products are linked to developmental and reproductive toxicity in people and aquatic organisms.

The EPA concluded in 2018 that combined exposure to atrazine from food, drinking water, and residential lawns poses developmental risks to children. In 2016, the agency had found reproductive risks to wildlife.

To address the risks to children, the EPA is lowering the amount of atrazine that can be applied to residential lawns. The agency is also requiring workers who apply the herbicide to wear respirators.

To reduce the herbicide’s drift into bodies of water, the EPA is placing restrictions on spraying. For example, spraying is prohibited during temperature inversions and when wind speeds exceed 24 km/h. Manufacturers must update the language on atrazine product labels to reflect the new restrictions.

Environmental and consumer advocacy groups claim that the EPA’s decision will lead to increases in atrazine in US water bodies and leave children unprotected. “EPA’s decision to reapprove atrazine continues an unlawful pattern by the Trump administration of approving toxic pesticides without rigorously analyzing or accounting for their harmful effects,” Sylvia Wu, a senior attorney at the Center for Food Safety, says in a statement.

Farmers welcome an end to the uncertainty over the use of atrazine in the US. The decision “provides much needed regulatory certainty for farmers during a time when few things are certain,” Gary Marshall, CEO of the Missouri Corn Growers Association, says in a statement released by the EPA.

The agency is imposing the new restrictions while it reviews the risks of atrazine on endangered species. It expects to complete that work in 2021. Anticipating future restrictions related to risks to endangered species, pesticide manufacturer Syngenta is canceling use of atrazine in Hawaii, Puerto Rico, and US territories, as well as all uses of the herbicide on conifers and roadsides.



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