Louisiana air quality today

Nothing in south Louisiana rises high enough to trap air. What the state supplies instead is what the reaction needs: strong sun, long heat, and a line of refineries and petrochemical plants along the Mississippi between Baton Rouge and New Orleans. Ozone forms in the atmosphere rather than leaving a stack, which is why the worst readings arrive on hot, still afternoons rather than during any particular industrial event.

The five-parish Baton Rouge area — Ascension, East Baton Rouge, Iberville, Livingston and West Baton Rouge — spent decades in ozone nonattainment. In its 2017 and 2018 update to EPA’s Ozone Advance program, LDEQ reported the area meeting an ozone standard for the first time since the Clean Air Act of 1970. The same report describes what changed underneath that: in the early 1980s the area needed a strategy built on cutting volatile organic compounds, and it now runs on cutting nitrogen oxides instead.

Authority over the state’s air is split. The Louisiana Department of Environmental Quality operates the monitors along the industrial corridor and publishes readings by region. Agricultural burning is not its jurisdiction. The sugarcane fields burned off after harvest across the southern parishes fall to the Department of Agriculture and Forestry, which is also the agency that declares statewide burn bans — as it did in 2023, when the commissioner modified the ban to let agricultural burning resume except for standing cane.