Shreveport fog

Fog obscures downtown Shreveport’s Regions Tower, on Jan. 26, 2024.?Caddo Parish is likely to be the only parish in the state in violation of new EPA regulations requiring reductions in the release of fine particulate matter that were announced on Wednesday. It remains unclear when or if industrial facilities in the parish might be required to reduce particulate emissions. (Staff photo by Brendan Heffernan)?

The Shreveport area is likely the only part of Louisiana in violation of new, tougher federal standards for deadly soot pollution -- microscopic particles that can penetrate deep into the lungs, harming people's health.

The standards were rolled out by the Biden administration's Environmental Protection Agency on Wednesday. But it likely will be at least two years before the parish is declared a "non-attainment" area under the new procedures, and it could be several more years before a state plan to address the higher pollution levels are in place.?

EPA contends the reduction will prevent up to 4,500 premature deaths and 290,000 lost workdays, and will create between $22 billion and $46 billion in net health benefits in 2032, when the rule is supposed to be fully implemented. It will cost the economy about $590 million to implement, based on annualized costs using a 7% interest rate, EPA estimates.?

State Department of Environmental Quality officials declined to comment on the new rules, saying it was still evaluating them. Attorney General Liz Murrill's office also declined comment on whether the state would challenge them.

They have already been criticized by national business organizations, including the American Chemistry Council.

"EPA’s revised standard will only serve to exacerbate current permitting gridlock issues at a time when domestic economic performance is critical to national interests," the council said in a statement released Wednesday. "These impacts will hinder our nation’s ability to build new infrastructure, expand manufacturing, and grow our economy."

The new rules also were denounced by U.S. Sen. Bill Cassidy, R-Baton Rouge.

“The U.S. has made major strides in improving air quality while growing and powering our economy,” Cassidy said. “Today’s final rule ignores this progress and incentivizes manufacturing to move their jobs to China away from Louisiana.”

Environmental groups and the American Lung Association, which has pushed for reduced particulate levels for years, praised the EPA action.?

“The new, stronger particle pollution standards will save lives," said Paul Billings, the association's senior vice president for public policy. "Despite what polluting industries are saying about the new air pollution standards, the sky will not fall and the world will not come to end."

Earthjustice's Patrice Simms said the new standards will "help address unjust disparities in air quality for communities of color and low-income communities.”

The new rules reduce the amount of fine particulate matter, labeled PM2.5, that can be measured in the air on average during a year, using a three-year average, from 12 micrograms per liter to only 9.

In rolling out the rule, EPA agreed with Cassidy that the nation has dramatically reduced many forms of air pollution, including a 42% reduction in particulate matter since 2000. But it said the new rules were needed to result in health improvements in exposed communities.?

According to EPA documents, Caddo Parish, where most of Shreveport is located, averaged 9.9 micrograms per cubic meter at its official monitoring stations between 2020 and 2022, meaning that it would be 0.9 micrograms higher than the new standard.?

A state listing of 162 daily average measurements in Caddo Parish for 2021 showed that half were above the 9 microgram standard, with the highest, measured at an average 19.3 micrograms on July 27, 2021, more than twice the new standard.?

The American Lung Association also listed Caddo at the top of its list of parishes for particulate matter in its 2023 air quality report card for Louisiana, pointing out that the parish had 4,790 pediatric asthma, 17,256 adult asthma, and 16,060 chronic obstructive pulmonary disease cases.?

The state has official monitoring stations measuring PM2.5 levels in only 13 of 64 parishes. The 2020-2022 levels for those parishes are:

  • West Baton Rouge, 8.8
  • East Baton Rouge Parish, 8.5?
  • St. Bernard, 8
  • Lafayette, 7.9
  • Orleans, 7.8
  • Jefferson, 7.7
  • Iberville, 7.7
  • Ouachita, 7.5
  • Tangipahoa, 7.5
  • Calcasieu, 7.4
  • Rapides, 7.4
  • Terrebonne, 7.2

The lower soot limit also will result in a change to EPA's colorful Air Quality Index warning system, to better represent the increased risk from particulate matter, and will be rolled out 60 days after the new rules are published in the Federal Register.?

Air Quality Index changes

This graphic shows how the EPA Air Quality Index, at?, will change to reflect the reduction in particulate matter required by the agency's new regulation. The changes will go into effect 60 days after the rule is officially published.? (EPA)

Louisiana index numbers are based on readings at monitoring stations operated by the state DEQ.

The index now lists air as good, or green, when the particle levels are below 12 micrograms per cubic meter. The top of that category will be adjusted downward to 9.?

The moderate, or yellow, category will be for 9.1 to 35 micrograms, and the number of yellow days is likely to increase in many areas, according to EPA officials.

The next level, unhealthy for sensitive groups, or orange, will remain the same, topping off at 55.4 micrograms. But the next higher level, unhealthy, which applies to all exposed to particles, will have its upper limit reduced to 125.4 micrograms.?

The very unhealthy category, or purple, also gets adjusted downward, with its highest exposure level set at 225.4 micrograms. And the hazardous level, or maroon, for worst exposure, will be anything above that, and will no longer be divided into two layers.?

Last year, there were a few locations in Louisiana that saw very unhealthy or even hazardous levels of soot, largely the result of wildfires either within the state, or smoke drifting into the state from Canada or the West Coast.?

EPA officials say they don't expect an increase in the number of days where very unhealthy or hazardous warnings will be posted.

The rule changes also include requirements that states adjust the location of air monitors measuring particulate matter to include "an environmental justice factor."?

"This factor will account for proximity of populations at increased risk of PM2.5-related health effects to air pollution sources of concern," says an EPA monitoring fact sheet.

The new rules don't require states to add more monitors to their monitoring network, but may require changes to where existing monitors are located.

The previous rules required at least one monitor to be located near the site of the highest particulate concentration, with an additional monitor to be placed near a road in metropolitan statistical areas with populations over 1 million. A third monitor could be required in areas known for poor air quality.?

The new rule requires the monitor to be sited in an at-risk community, "particularly where there are anticipated effects from sources of air pollution in the area."

States will have another year after the EPA designates an area out of compliance to submit a plan to address it. Six years after the rules go in place is the deadline for that area to reach the requirements.?

EPA estimates there are as many as 200 major source permits issued each year that might fall under the new rules. If a facility already had a final permit before the new rule was put in place, no new permits are required.?

Email Mark Schleifstein at or follow him on Twitter, @MSchleifstein. His work is supported with a grant funded by the Walton Family Foundation and administered by the Society of Environmental Journalists.