SALT LAKE CITY — Environmental advocates who have long sounded the alarm about the health problems associated with air pollution — including asthma, dementia, heart attacks and cancer — now have another bullet point to add to the list: COVID-19.

A handful of studies from around the world, including a U.S. analysis from Harvard University that has not yet been peer-reviewed, indicate that exposure to air pollution may increase the severity of the disease and ultimately lead to more deaths.

But the scientists behind these studies have found themselves at odds with the Trump administration as leaders at the Environmental Protection Agency have questioned their preliminary findings and taken steps to relax pollution controls in the midst of the pandemic, said Vijay Limaye, climate and health scientist with the Natural Resources Defense Council, a nonprofit based in New York.

“They are hoping to undermine the people making the link between environmental regulation and human health,” Limaye said. “As a scientist who’s been following the research for years and years, I can say that it’s not just one preliminary study from Harvard. There are mountains of scientific evidence pointing to causal links between air pollution and heart and lung disease.”

Since 2017, the Trump administration has worked to reverse 100 environmental rules, including 54 rules related to air pollution and emissions, The New York Times reported. At the end of March, EPA Administrator Andrew Wheeler announced the suspension of emissions reporting requirements because of COVID-19, just days after relief was requested by the American Petroleum Institute, according to Inside Climate News. And in recent weeks, the EPA finalized the rollback of methane pollutant controls and took steps to change clean car standards.

“Scientists at EPA, NOAA, and NASA are using the opportunity available during the COVID-19 outbreak to further enhance our understanding of how human activity potentially impacts air quality,” an EPA spokesperson told the Deseret News in an email.

The spokesperson also noted that air pollution levels have decreased substantially over the past decade. Average fine particle pollution (also known as PM 2.5) fell by 39% between 2000 and 2018 and overall criteria air pollutant emissions have dropped 7% since 2017.

Advocates like Limaye say that millions of people in the U.S. are still exposed to dangerous levels of air pollution every year and claim the Trump administration is taking advantage of a public distracted by the coronavirus to dismantle environmental protections — which could ultimately make the pandemic worse.

“Without a doubt, there has been an acceleration of the deregulatory agenda in the past five months,” Limaye said. “We’ve been tracking all sorts of dangerous rollbacks that have real implications in terms of damage to human health across this country.”

Inside the lungs

Pollutants like PM 2.5 and ozone irritate the lungs and can worsen a person’s reaction to a respiratory disease like COVID-19, said Elena Craft, who lives in Austin, Texas, and works as the senior director of climate and health with the Environmental Defense Fund. These pollutants are also linked to underlying conditions like asthma, heart disease, ARDS and COPD that are known to make death from the coronavirus more likely, she said.

PM 2.5 consists of particles, smaller than the diameter of a human hair that can enter the tiny air sacs of the lungs called alveoli and then pass through into the blood stream. Ozone can cause scarring in the lungs, almost like an internal sunburn, Craft explained. Both pollutants can limit oxygen exchange and cause respiratory distress.

“With a COVID infection, we see these strong inflammatory responses, if already exacerbated by exposure to higher concentration of air pollution, it’s adding insult to injury,” said Craft. “Your lungs are essentially overwhelmed.”

John Balmes, a professor of medicine at UC Berkeley and UC San Francisco as well as a spokesperson for the American Lung Association, said there is “literally several decades of research” showing that air pollution damages the heart and lungs. He believes one of the reasons the nation is seeing higher coronavirus death rates among minority and lower income communities is that those people are more likely to live near pollution sources.

While air pollution decreased at the beginning of the COVID-19 pandemic when states enacted lockdown rules, traffic has since returned to near-normal levels. In Utah for example, current traffic is about 90% of what it was in 2019, according to Department of Transportation data. In addition, with record temperatures, western states are experiencing familiar summer spikes in ozone and are bracing for the effects of wildfire season, said Logan Mitchell, research assistant professor with the department of atmospheric sciences at the University of Utah.

A controversial study

Studies abound showing that air pollution is generally bad for human health, but evidence is sparser when it comes to a direct link between dirty air and the coronavirus.

The Harvard study, posted online in April, is the best nationwide analysis that exists so far, said Balmes. It shows that there is an 8% increase in risk of COVID-19 death for every one microgram per meter cubed of PM 2.5.

“That is very strong effect, it’s almost hard to believe,” said Balmes who is working on further research on this subject. “But I’ve looked at their data pretty carefully, and I think the analysis is solid.”

The study, led by biostatistician Francesca Dominici, was posted without being peer-reviewed, a practice that has become increasingly common during the pandemic, according to Craft. The authors have made changes in response to critiques from other scientists.

“Our results underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis,” the study reads.

The EPA’s Wheeler has dismissed the study as preliminary, saying he looks forward to reading it once it has been completed and peer-reviewed, Inside Climate News reported.

“I have to say, at least in the press, that the scientists seem to have a bias,” Wheeler said in April, the same day he announced the decision not to strengthen the air quality standard for PM 2.5.

Craft said her organization has steered away from relying on that particular study because it is based on county-level data instead of individual-level data and therefore cannot be used to prove causality.

“There are a lot of confounding variables that may factor into trying to understand the results,” Craft said. Instead, she focuses on air pollution’s more established links to underlying health conditions that make it harder for people to survive the coronavirus.

Tony Cox, a Denver-based statistician who serves as the chairman of the EPA’s Clean Air Science Advisory Committee, had a harsher take. He said the Harvard study is totally hypothetical and unreliable.

“The results are based on a hypothetical model that makes dramatically false assumptions, such as that higher levels of air pollution cause more expected deaths even in locations without people to die,” Cox said.

Cox, who has worked as a consultant for the American Petroleum Institute and other industry groups, as well as national and international agencies, is known for calling for rigorous standards when it comes to establishing the health risks of certain pollutants.

But he admits that air pollution could be harmful. “It seems plausible to me on biological grounds that sufficiently high and prolonged exposures to air pollution causing chronic inflammation of the lung could increase risk of respiratory diseases and infections,” he said.

While much is still unknown about the specifics of COVID-19, similar studies from the Netherlands, Italy, China and California have found the same association: people who live in more polluted areas are more likely to die from the coronavirus.

Rolling back enforcement

Claudia Persico, an economist and professor of policy at American University, studied the effects of the EPA’s March suspension of environmental law enforcement and found that EPA policies led to an increase in pollution around toxic release inventory sites which was associated with a 53.1% increase in coronavirus cases and 10.5% increase in deaths. She estimated that between 7,000 and 10,000 people who might have lived otherwise died because they were exposed to pollution. Persico’s study, co-authored with graduate student Kathryn Johnson, has not been peer-reviewed.

While it may seem like there are benefits to rolling back environmental regulation during the pandemic in terms of industry and the economy, that comes with a high cost to human lives, Persico said.

An EPA spokesperson said that the temporary rollback of enforcement, set to expire at the end of this month, has been misunderstood.

“EPA’s temporary enforcement guidance is not a blanket waiver of enforcement. All regulated entities are expected to comply with all applicable requirements,” the spokesperson said.

Still, the NRDC along with 14 other environmental groups, in addition to nine states led by New York, have sued the Trump administration over its lack of environmental enforcement over the past few months.

“It seems like we are going to be living with the consequences of the waiver for some time,” said Limaye. “It will be difficult to understand the implications for a while, potentially months or years to come as we uncover the data.”

“People are dying potentially because of this. It’s pretty serious, and there needs to be more forethought in terms of trying to think through what the research says before agreeing to roll back environmental regulation, especially considering the effects on vulnerable communities,” said Persico. “This is a time when we need to be strengthening environmental regulations instead of rolling them back.”