Across 'Cancer Alley', a notorious stretch of industrialised terrain sandwiched between Baton Rouge and New Orleans, residents are growing increasingly alarmed by their daily exposure to toxic air pollution. A joint investigation by Floodlight and The Guardian has unearthed significant gaps in Louisiana's public air monitoring network, leaving many communities in the dark about the hazardous chemicals they breathe every day.
The analysis reveals that public air monitors are frequently sited miles away from major industrial polluters and often fail to test for some of the most noxious substances emitted. For example, ten of Louisiana's top 25 industrial air polluters, as identified by their self-reported emissions to the US Environmental Protection Agency (EPA), operate without a single public air monitor within five miles of their facilities. This includes a Dow Chemical plastics factory in Plaquemine, situated approximately eight miles from its nearest monitoring station, which only measures ozone despite releasing a range of toxic pollutants, including ethylene oxide, a known carcinogen.
More disturbingly still, the analysis highlights that three chemicals identified by researchers as responsible for the majority of cancer risk in the region – ethylene oxide, chloroprene, and formaldehyde – are not monitored by the state at all. Furthermore, despite CF Industries' Donaldsonville plant emitting over 7 million pounds of ammonia annually, according to EPA data, no public monitors measure this hazardous chemical. These omissions leave a critical blind spot in understanding the true extent of air pollution and its potential health impacts on local populations.
Industry groups have reportedly played a significant role in resisting calls for improved monitoring around manufacturing plants. They were also instrumental in drafting a 2024 law that severely limited how data collected through community air monitoring could be utilised in enforcement actions. This legislative move has effectively silenced concerned residents like Kimbrelle Kyereh in St Rose, who, after experiencing symptoms such as headaches, nausea, and insomnia from oily fumes, ceased her own air sampling efforts due to the new restrictions.
The limitations of Louisiana's air monitoring system were starkly exposed during a naphtha leak and subsequent fire at Marathon's Garyville refinery in August 2023. It took over six hours for the Louisiana Department of Environmental Quality to begin air monitoring after the initial leak, and more than 15 hours after the leak began for residents within two miles to be ordered to evacuate. The nearest state monitor only measured ozone, missing the volatile organic compounds released in the fire, and the plant's own monitors tracked only benzene at its fenceline.