18. Jefferson County, KY
> Number of facilities contributing to toxic air: 10
> Avg daily PM2.5 concentration: 10.3 micrograms per cubic meter– #76 highest out of all counties
> Population: 768,419 — #83 largest out of all counties
> Population density: 1,969.22 people per square mile — #63 highest out of all counties
The historic “Rubbertown” district of Jefferson County is an industrial stretch along the OH River in southwestern Louisville dating back to the early 20th century. There are currently multiple chemical plants in Rubbertown and beyond, including Clariant Specialty Chemicals, which has been fined multiple times in the last decade for nitrogen oxide emissions. The broader Jefferson County area is home to multiple Ford plants, metal fabrication factories, and a weapons manufacturer called BAE Systems.
17. Iberville Parish, LA
> Number of facilities contributing to toxic air: 10
> Avg daily PM2.5 concentration: 8.3 micrograms per cubic meter– #1,261 highest out of all counties
> Population: 32,626 — #1,367 largest out of all counties
> Population density: 46.31 people per square mile — #1,480 highest out of all counties
St. Gabriel, Plaquemine, and the surrounding areas along the Mississippi River are home to numerous chemical manufacturers, including plants that make ammonia-derived compounds for agricultural markets. Pockets of high-risk zones surround BPC Ingredients, Shintech PVC producer, PCS Nitrogen Fertilizers, Honeywell, and Taminco U.S. LLC. Leaks at multiple Iberville factories in recent years have released ammonia, fluorocarbons, and sulfuric acid into the air.
16. Nueces County, TX
> Number of facilities contributing to toxic air: 10
> Avg daily PM2.5 concentration: 9.2 micrograms per cubic meter– #422 highest out of all counties
> Population: 362,151 — #196 largest out of all counties
> Population density: 303.04 people per square mile — #376 highest out of all counties
This South Texas county comprises Corpus Christi and the surrounding area, including the Mustang barrier island. A center of the oil and chemical industries, the port area is home to multiple refineries and chemical outfits including Valero, Citgo, Flint Hills, and American Chrome and Chemicals. Citgo’s Corpus Christi Refinery has been cited and fined by the EPA multiple times in the last decade, including for exceeding benzene emissions standards in 2020.
15. Shelby County, TN
> Number of facilities contributing to toxic air: 10
> Avg daily PM2.5 concentration: 7.8 micrograms per cubic meter– #1,595 highest out of all counties
> Population: 936,611 — #55 largest out of all counties
> Population density: 1,191.42 people per square mile — #106 highest out of all counties
Shelby County, which includes Memphis and the surrounding area along the Mississippi River, scored an F for ozone pollution in the American Lung Association’s 2021 State of the Air Report, although it scored slightly better for particle pollution. A pocket of polluting industry around McKellar Lake includes Stella Jones, a manufacturer of pressure-treated wood, as well as a Valero refinery, and Owens Corning Asphalt plant.
14. Sedgwick County, KS
> Number of facilities contributing to toxic air: 11
> Avg daily PM2.5 concentration: 7.4 micrograms per cubic meter– #1,850 highest out of all counties
> Population: 515,416 — #136 largest out of all counties
> Population density: 519.09 people per square mile — #233 highest out of all counties
Wichita is the county seat of Sedgwick, which is home to multiple aerospace manufacturers including Globe Engineering and Spirit Aerosystems, as well as metal manufacturers including 3P Processing Inc. and Koch-Glitsch LP. The 3P factory, which releases trichloroethylene and chromium compounds, is responsible for a wide swath of excess cancer risk. Another area of heightened risk in the county surrounds the chemical companies Evonik Corp. and Occidental Chemical Corporation.