WASHINGTON — The Trump administration on Monday rejected setting tougher standards on soot, the nation’s most widespread deadly air pollutant, saying the existing regulations remain sufficient even though some public health experts and environmental justice organizations had pleaded for stricter limits.

The Environmental Protection Agency retained the current thresholds for fine-particle pollution for another five years, despite mounting evidence linking air pollution to lethal outcomes in respiratory illnesses, including covid-19, the disease caused by the coronavirus. Documents obtained by The Washington Post show that the EPA has disregarded concerns raised by some administration officials that several of its air policy rollbacks would disproportionately affect minority and low-income communities.

In its decision announced Monday, the EPA maintained that the Obama-era levels, set in 2012, are adequately protective of human health. Agency scientists had recommended lowering the annual particulate matter standard to between 8 and 10 micrograms per cubic meter in a draft report last year, citing estimates that reducing the limit to 9 could save between 9,050 and 34,600 lives a year.

The current national standards limit annual concentrations of soot and other chemicals to 12 micrograms per cubic meter of air. Emissions on specific days are allowed to be as high as 35 per cubic meter, a standard set 14 years ago. These fine particles – which measure less than 2.5 micrometers in diameter, or one-thirtieth the width of a human hair – can enter the lungs and bloodstream, causing inflammation that can lead to asthma, heart attacks and other illnesses.

During a call with reporters Monday, EPA Administrator Andrew Wheeler said the agency’s decision “comes after careful review of the most rigorous scientific evidence,” as well as consultation with the agency’s outside scientific advisers, consideration of tens of thousands of official comments and input from five public meetings.

“I got multiple recommendations,” he said, referring to the standards. “Every scientist can take a look a this and reach a different conclusion.”

Wheeler also said that particulate matter pollution has decreased during the Trump administration, and that the nation’s levels remain one-fifth of the global average and are lower than levels in France, Germany and the United Kingdom.

“The U.S. now has some of the lowest fine particulate matter in the world,” he said.

Still, Monday’s news came as a gut punch to people like Bridgette Murray, whose neighbors in the historically Black neighborhood of Pleasantville in downtown Houston have long struggled with air polluted by nearby petrochemical manufacturing and a bustling highway. The community erected six of its own monitors starting last fall to cover the neighborhood’s three square miles and detect pollutants spewing into the air.

A year of data, gathered with the support of the Environmental Defense Fund and Texas Southern University, brought worrisome results: The concentration in the air of fine particle pollution, known as soot, was close to the upper annual limit.

Murray has suffered headaches when the air quality worsens, permissible under federal standards that allow daily concentrations to spike up to 35 micrograms per cubic meter. Other residents have endured various lung ailments and cancer. So, they went looking for answers. “We wanted to move from that kind of anecdotal posture to actually collect some data,” said Murray, executive director of a community-based organization called Achieving Community Tasks Successfully.

To Murray, the rejection of stricter standards offers fresh evidence that the Trump administration is not doing enough to protect disadvantaged communities.

“It is an artificially high standard that is supportive of industry,” she said. “But very little is being done to help those who are exposed to that pollution on a day-to-day basis.”

An EPA advisory committee made up of outside experts split on the question, with some members calling for tighter standards and others arguing the current rules are sufficient. Ultimately, Wheeler decided this spring to maintain the existing standards for fine particulate matter.

“The United States has some of the cleanest air in the world, and we’re going to keep it that way,” Wheeler told reporters at the time. “We believe the current standard is protective of public health.”

Soot comes from a variety of sources. Among them: industrial operations, incinerators, car and truck exhaust, power plants, smokestacks, and burning wood. Low-income and minority communities in the United States tend to be exposed to greater air pollution, including soot, often because they are located close to highways and industrial facilities.

A 2019 study by the Union of Concerned Scientists found that on average, communities of color in the Northeast and Mid-Atlantic breathe 66% more air pollution from vehicles than White residents. A separate study published last year in the Proceedings of the National Academies of Sciences found that Black and Hispanic communities in the United States bear a “pollution burden” that far exceeds any air pollution they produce.

Long-term exposure to polluted air has increased the risks Americans of color face when it comes to heart and respiratory illness, including covid-19, which is disproportionately killing African Americans.

“This flies in the face of good science and good public health. It is outrageous,” said Dominique Browning, co-founder and the head of Moms Clean Air Force, an advocacy group that pushes for robust air and climate oversight around the country.

“It builds in years more of assaults on the human body, especially in places where people are breathing the worst of it,” she added.

But several major business groups, including the U.S. Chamber of Commerce and the American Petroleum Institute, backed the administration, noting that annual concentrations of fine particulate matter are down by 39% since 2000.

Douglas Buffington, West Virginia’s senior deputy attorney general, called Monday’s announcement a major win for coal. Had the EPA tightened the air-quality standards, he said on a call with Wheeler, “it could have been a huge blow to the coal industry.” Instead, he said, the decision shows that “evidence-based regulations can protect the environment and still leave room for industries to thrive.”

The rule marks the Trump administration’s latest move in a long-running effort to ease industrial regulation. The White House has rolled back more than 125 environmental safeguards during Trump’s time in office, according to a Post analysis, with plans to finish nearly a dozen more by mid-January. Those rollbacks include scaling back automobile fuel-efficiency standards and emissions limits for coal-burning plants, as well as lifting Obama-era methane limits on new oil and gas wells.

In most instances, federal agencies are required to conduct an “environmental justice” analysis to determine how these actions will affect vulnerable communities. But on multiple occasions, the Trump administration has downplayed the impact on poor and minority communities.

The EPA recently finalized changes to a rule known as “Once In, Always In,” which requires facilities to always operate the most advanced pollution controls if they annually emit 10 tons or more of a single hazardous air pollutant or 25 tons or more of at least two such pollutants. The updated rule exempts all facilities that have already cut their hazardous air emissions below these levels, which could potentially allow some companies to pollute more as long as they don’t reach the legal threshold again.

In the interagency analysis, according to documents posted online, one White House Office of Information and Regulatory Affairs official noted that the change “raises the potential for an increase in overall hazardous air pollutant emissions and consequent health effects, especially for populations near area sources. It has previously been noted that the burden of cancer risk for hazardous air pollutants falls disproportionately on racially segregated metropolitan areas, contributing to health disparities.”

The staffer said the EPA should conduct a thorough analysis to best inform the public of the potential harms of the rule.

The Environmental Integrity Project did conduct such an analysis, examining the potential impact on 12 plants in Illinois, Indiana, Michigan, Ohio and Minnesota. It found that they could more than quadruple their emissions of toxic air pollution, from 121,082 pounds in 2018 to as much as 540,000 pounds each year.

In a separate rollback, the agency scrapped limits on leaks of methane – a potent greenhouse gas – from oil and gas operations. During the interagency review, one administration official noted in the margins: “Implementing this rule will have adverse human health and environmental effects on racial and ethic minorities, low-income and rural populations.”

In another section, a Department of Health and Human Services official noted that the rule could cause more ozone, and “ozone pollution exposure may be an important risk factor that increases susceptibility to and severity of infectious diseases, including COVID-19.”

“The Trump administration’s EPA has repeatedly and deliberately hid the harmful impacts of its rollbacks to environmental justice communities, meaning low-income and minority populations,” said Amit Narang, Public Citizen’s regulatory policy advocate.

In the case of the national soot standards, critics are already gearing up to challenge them in court. Most areas of the country have met the annual standards, with the exception of portions of Southern and Central California and parts of Pennsylvania and Idaho – though Elena Craft, the Environmental Defense Fund’s senior director for climate and health, noted that inadequate air monitoring may account for those results.

Craft and her colleagues found that roughly 10% of the Houston area had concentrations of fine-particle pollution above 12 micrograms per cubic meter in 2015, meaning that the area failed to meet the current standards. “The case is strong that the administration used flawed science in keeping the standards, and ultimately that will be borne out in court,” she said, noting that policymakers lack critical data because there is not a single federal air monitor in all of west Houston.

But even if opponents of the decision eventually prevail in court, or if the Biden administration pursues stricter national standards, the reality is that residents in many places will have to live with dirtier air for longer, said Michele Roberts, national co-coordinator for the Environmental Justice Health Alliance.

“It’s not just a quick fix overnight. These communities are going to be breathing the same air for some time,” Roberts said. “People of color and the poor – that is who gets hit the hardest by this.”