What Is Cancer Alley?

Oil refinery on Mississippi River near New Orleans, Louisiana

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Cancer Alley is an 85-mile long area along an industrial stretch of the Mississippi River known for its abundance of petroleum plants and, as the name implies, cancer cases. 

The area has 45,000 residents and lies in Southeastern Louisiana, between New Orleans and Baton Rouge. Compared to the rest of the state, Cancer Alley has a higher percentage of Black and poor, illiterate residents.

Once the site of cornfields and sugar cane plantations, it is now home to more than 140 petrochemical plants, rampant air pollution, and—some say as a result—an above-average number of cancer cases. This greater-than-expected number of cancer cases within a geographic region over a period of time is called a cancer cluster.

History of Cancer Alley

Before it became what some residents and environmental health experts claim is a hotbed of cancer activity, Cancer Alley was called Chemical Corridor, thanks to many oil refineries and chemical plants that dot its landscape.

Some 50 toxic chemicals—including benzene, formaldehyde, and ethylene oxide—circulate in the air there. In the late 1980s, when residents started noticing clusters of cancer cases and miscarriages on the same street or within blocks of each other, Chemical Corridor took on a new moniker—Cancer Alley. 

Research shows that there are higher-than-normal amounts of lung, stomach, and kidney cancer among certain populations living in Cancer Alley. Anecdotally, residents say there are troubling clusters of several other cancers, including rare ones like neuroblastoma (cancer of the nerve cells) and rhabdomyosarcoma (cancer of the skeletal muscle).

But one of the most concerning and controversial chemicals in Cancer Alley is chloroprene. According to the United States Environmental Protection Agency (EPA), chloroprene is likely to cause cancer in humans.

In 2015, the chemical giant DuPont sold its neoprene plant in LaPlace, Louisiana, an area of Cancer Alley, to Denka Performance Elastomer, headquartered in Tokyo. In the process of manufacturing neoprene, a synthetic rubber used in things like wetsuits, hoses, and orthotic braces, the Denka plant releases chloroprene into the air.

In 2011, the EPA’s National Air Toxic Assessment (NATA) looked at toxic emissions nationwide and released its findings in 2015. When it was found that the air in LaPlace had a higher-than-expected level of chloroprene, the EPA began working with Denka and the Louisiana Department of Environmental Quality to lower its chloroprene emissions by 85%.

The NATA found that the top five census tracts (subdivisions of a county) with the highest estimated cancer risks in the country were in Louisiana. Some say that is, at least in part, due to the Denka plant and its chloroprene emissions.

The state says Denka has now reached that 85% level, but community residents are skeptical. They say that rather than reducing emissions by a certain percentage, the emissions should be on average 0.2 micrograms per cubic meter of air, considered a safe level by the EPA.

What the Research Says

Whether or not cancer rates are truly elevated in the so-called Cancer Alley is hotly debated. The National Cancer Institute notes that actual cancer clusters are rare. Because cancer is a relatively common disease, cases can appear to “cluster” even when there is no concrete connection between them.

True Cancer Clusters

Researchers examined 20 years of data from over 400 cancer cluster investigations and found only one could “unequivocally” be called a cluster.

One study, sponsored in part by Shell Oil, looked at data from 1970 to 1999. It found that those living in Cancer Alley were no more likely to die from cancer than those living in other parts of Louisiana. It even found that white males living in Cancer Alley had significantly lower cancer rates than their counterparts living elsewhere in the state.

For perspective, Louisiana, overall, has higher rates of cancer incidence and deaths (including during the study period) than the national average. When cancer is diagnosed, residents of the state have poorer survival rates than those in other parts of the country.

Cancer Rates in Louisiana

Louisiana has the fifth-highest cancer death rate in the nation. Per 100,000 people in the state, nearly 162 Whites died of cancer in 2018 versus 193 Blacks.

Other research, however, shows a link between living near these petrochemical plants and developing cancer. In 2018, researchers collected health data from residents living within about 1.5 miles of the Denka plant and found that they had a 44% higher cancer prevalence than the national rate.

The report, issued by the University Network for Human Rights, noted that “Our data reveal extremely improbable rates of cancer and other illness among residents surveyed.” And surveyed is the operative word. The researchers noted that their research relies on respondent recall, and memory is not always 100% accurate. 

What’s not really disputed is that cancer seems to strike those who are Black and those who are poor disproportionately. And that holds true for those living in Cancer Alley.

A study from 2012 published in the International Journal of Environmental Research and Public Health found that within Cancer Alley, those living in predominantly Black areas had a 16% higher risk of cancer versus those living in White neighborhoods, and those living in low-income sections had a 12% higher risk than those living in higher-income areas.

Cancer Alley Today

Air pollution steadily declined in the U.S. between 2009 and 2016. In fact, researchers say it decreased by close to 25%. But those same researchers say air pollution is on the upswing, increasing 5.5% from 2016-2018. 

And Cancer Alley still ranks as one of the top-10 most polluted areas of the country. In a report issued in 2018, four of the nation’s “super polluters” were chemical and oil plants, including the Denka one, within Cancer Alley.

While amendments designed to curb toxic emissions were made to the Clean Air Act in 1990, critics say budget and staffing cuts to regulatory agencies and an expansion of industry in the region have limited progress.

Other Cancer Clusters

Cancer Alley isn’t unique. Cancer clusters have been observed—and debated—in other areas of the country besides Southeastern Louisiana. Some examples:

  • The movie “Erin Brockovich” made famous cancer clusters seen in Hinkley, California. Critics say the clusters were due to high chromium levels in the water around the Pacific Gas and Electric Company’s plant.
  • Clusters of ovarian cancer have been observed in parts of Iowa, Wisconsin, New York, Alabama, and Georgia. Researchers say a likely culprit is water pollution from paper and pulp plants. 
  • A cluster of pediatric brain cancer cases has been seen in a rural community in Florida, close to where a rocket and jet company is located.
  • Higher-than-average amounts of breast cancer have been seen in women living on parts of Long Island, New York, and near San Francisco. Experts say this higher risk is probably due to lifestyle factors (e.g., being older, drinking alcohol, using postmenopausal hormones, etc.) rather than any environmental influence.
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