The corridor holds nearly 150 oil refineries, plastics plants and chemical facilities, many built on or near former plantation land. Some of the most affected towns were founded by formerly enslaved people after emancipation. Today those descendants live beside industrial fence lines.
In 2015, an Environmental Protection Agency air toxics assessment found that census tracts near the Denka plant in St. John the Baptist Parish had the highest estimated cancer risk from air pollution in the nation, driven by chloroprene emissions. In 2021, United Nations human rights experts called continued industrial expansion in the region a form of environmental racism.
Local groups such as RISE St. James and Concerned Citizens of St. John have fought new permits, including a proposed Formosa Plastics complex. Cancer Alley has become the clearest US example of how zoning, permitting and land history combine to place pollution in Black communities.