The United States Department of Justice is suing the two corporations responsible for the worst cancer-causing air pollution in the country.

A southeastern region in Louisiana colloquially known as "cancer alley" is home to the Denka Performance Elastomer synthetic rubber plant and Pontchartrain Works facility. Last year, ProPublica estimated that the cancer risk for residents near the plant was 1 in 210, which is 47 times what the EPA deems acceptable chloroprene exposure.

Chloroprene is a mutagen classified by the EPA as a "likely human carcinogen." Mutagens can cause cancer by mutating DNA, meaning children are at a higher risk due to their cells dividing more rapidly than those of adults. In Louisiana, a local elementary school sits just 1,500 feet from the Denka plant. Of students at the school, 75 percent are Black.

Filed Tuesday, the lawsuit from the DOJ claims that the Pontchartrain Works facility is in violation of the Clean Air Act and “presents an imminent and substantial endangerment to public health and welfare." On behalf of the Environmental Protection Agency, the DOJ also compels the Denka plant to “immediately take all necessary measures” to curb chloroprene emissions.

The EPA's civil rights division previously issued citations for the plant and town of St. John the Baptist Parish in October, 2022 for failing to take action against the harm done to residents. This week's lawsuit marks the next step in the agency's pushback against environmental racism.

Robert Taylor, executive director and founder of Concerned Citizens of St. John, helped file the initial civil rights violation complaint with the EPA that led to citations. He recently told The Guardian that the agency's actions "will have a tremendous impact on our struggle here."

"Over the six years we have been fighting this fight we haven’t had anything as great as this to happen in terms of getting concrete action on emissions," Taylor said, adding, “The state government has totally ignored us – marches on the capitol, rallying – they wouldn’t even give us an audience. And for the administration to come in and do this, it just validates our efforts.”

EPA administrator Michael Regan previously promised “strong action” against air pollution in cancer alley, and said in a statement that the "complaint filed against Denka delivers on that promise."

“The company has not moved far enough or fast enough to reduce emissions or ensure the safety of the surrounding community," he said. "This action is not the first step we have taken to reduce risks to the people living in St John the Baptist Parish, and it will not be the last.”