The region known as “Cancer Alley” is a roughly 85-mile stretch of the lower Mississippi River between New Orleans and Baton Rouge. Introduced in 1988, the name now describes an industrial corridor that has experienced the multigenerational health impacts of more than 200 industrial facilities along its route—oil refineries and petrochemical plants; and other facilities that produce things like plastics, vinyl chloride, nitrogen fertilizers, chlorine and chloroprene; and account for about 25 percent of the petrochemicals produced in the U.S. 

These facilities proliferated after World War II; NIMBY, along with the political and economic clout of more privileged segments of the population, made sure they were concentrated in poorer and less empowered communities. 

By the 1970s, the newly formed Environmental Protection Agency was documenting toxic pollution adversely affecting drinking water and air quality in Louisiana. Today, around 1.6 million people live with the health impacts of this remarkable concentration of industrial activity.    

The Louisiana Department of Environmental Quality (LDEQ) and a succession of state officials have long resented the “cancer alley” designation, denying both the reality of the pollution and health damage and accusations that the state’s permitting decisions have systematically protected white and affluent communities and sacrificed communities of color and low-income residents.  In 2022 and 2023, researchers with Tulane University’s Environmental Law Clinic published two peer-reviewed studies that demonstrated that the nickname “Cancer Alley” is in fact well-earned. The studies showed that the region does indeed experience higher levels of pollution-related illnesses including cancer, asthma, immune disorders, reproductive problems and heart disease directly related to chemical pollution and elevated levels of particulate matter.

Their conclusions are based on census tract-level data on cancer incidence, which the Louisiana Tumor Registry began collecting and providing to researchers in 2018. This granular data enabled the studies’ authors to correlate cancer incidence to pollution exposure documented by EPA at the neighborhood level. They further refined the data by including relevant factors such as poverty, race, occupation, time spent indoors and outdoors, and incidence of smoking and obesity, and they accounted for the possibility that pollution might affect low-income communities differently compared to those more affluent.  

One recent focus of efforts to address these conditions has been the town of Reserve in St. John the Baptist Parish, home to the nation’s only chloroprene rubber plant, built by DuPont in 1969 and now owned by the Japanese firm Denka. Chloroprene, a chemical that has been shown to cause cancer in mice and rats, is a primary ingredient in neoprene, a synthetic rubber. According to the EPA’s most recent National Air Toxics Assessment (NATA), residents of the census tract closest to the Denka chloroprene plant have a risk of developing cancer from air pollution that is nearly 50 times the national average due to exposure to chloroprene, which the EPA classifies as “a likely human carcinogen.” 

In April 2022, the EPA announced that it would open an investigation of a civil rights complaint regarding the pollution and health problems in Reserve. The complaint is based on EPA rules grounded in “disparate impact,” a provision of Title VI of the 1964 Civil Rights Act that addresses the disproportionate adverse environmental conditions faced by some communities.

The concept of “disparate impact” assesses the consequences of decisions and policies without claiming racist intent. In other words, it looks at the tangible results of such decisions, to ensure that programs “are not administered in a way that perpetuates the repercussions of past discrimination.”  Louisiana’s Attorney General, who has since been elected governor, filed a lawsuit claiming that the EPA was exceeding its authority by using the disparate impact standard rather than providing proof of intentional discrimination. On January 23, 2024, Judge James D. Cain Jr., a Trump administration appointee to the US District Court in the Western District of Louisiana, issued a preliminary injunction barring the EPA and the Department of Justice from enforcing disparate impact-based requirements on Louisiana. 

With the civil rights path temporarily blocked, in April the EPA announced a set of revised national emissions standards, including a significant reduction in the standard for chloroprene so it does not exceed 0.2 micrograms per cubic meter—a level the EPA stated could reduce residents’ cancer risk by as much as 96 percent.

Retaliation was swift. Rather than attempting to refute the classification of chloroprene as a carcinogen, or the official calculations of the volume of omissions, Republican attorneys general from 23 states filed a complaint seeking to overturn the whole concept of environmental justice. Specifically, they demanded that the EPA stop using the concept of disparate impact altogether.  

Using a rationale explicitly borrowed from a college admissions case brought against Harvard and the University of North Carolina last year, the attorneys general argued that the disparate impact standard violates the equal protection clause of the Constitution. They argued it requires states to engage in “racial engineering” in their permitting decisions to redress past environmental wrongs or lessen cumulative impacts of pollution, and that such requirements are in themselves inherently racist.   

On August 22, Judge Cain made his injunction permanent, barring the EPA from imposing or enforcing disparate impact requirements against the State of Louisiana or any other state; or enforcing or imposing any Title VI-based requirements on Louisiana or any other state “unless ratified by the President.” 

The affected communities along the Mississippi fight on.