In 2018, scientists published a study showing that doctor visits for respiratory infections increased with the air pollution that periodically settled into the urban valleys of northern Utah—research that could prove relevant as researchers try to unlock the mysteries of Covid-19.

But if the Trump administration succeeds in finalizing a new rule that would place limits on the science used by the Environmental Protection Agency, the Utah study is exactly the kind of research that would be given less weight—or possibly ignored—in future U.S. environmental decision-making.

To many in the scientific community, the Covid-19 crisis is driving home the potential consequences of the proposal, which is now on a fast track. The proposed rule is called "Strengthening Transparency in Regulatory Science"—a name that has an Orwellian ring in the view of agency critics, who argue that it treats protection of patient confidentiality as if it were secrecy that undercut the value of the science. By eliminating from environmental decision-making studies that rely on patients' anonymous medical data they say, the rule would knock out some of the most valuable human health science. And the Trump EPA is pushing forward with the plan at a time when the entire health science field is at the front line of what the president himself has called a "wartime" effort to control the coronavirus.

The EPA has now set a deadline of May 18 for public comment on the latest revision of the proposal; the EPA extended the original 30-day comment period, which would have ended April 17, by an additional month after an outcry from the public health community over the short deadline amid the crisis.

Of particular relevance to future EPA decision-making is research on whether air pollution increases susceptibility to the ravages of Covid-19. A study released this week by Harvard researchers indicates that the death rate from the new coronavirus is higher in counties with higher levels of fine particulate matter pollution.

The findings have been submitted for publication in a leading journal and are under peer review. They are consistent with a 2003 study on the SARS outbreak in China, which showed infected patients from regions with higher air pollution were 84 percent more likely to die than those in less-polluted areas.

After northern Italy, which has that nation's worst fine particle air pollution, tallied the largest number of Covid-19 casualties in the country, European public health groups warned of the potential that air pollution could increase the risk of the virus.

"This is a whole area of research that's going to continue to develop, and we want EPA to be able to consider those scientific studies in any future protections," said Gretchen Goldman, research director at the Union of Concerned Scientists' Center for Science and Democracy. "But under this rule any kind of study that looked at people with coronavirus and how they are affected would probably not be able to be used, since they would rely on health data from individuals."

An Old Tactic Retooled for a New Attack

EPA Administrator Andrew Wheeler has characterized the proposed rule as an effort to improve openness. "When finalized, the science transparency rule will ensure that all important studies underlying significant regulatory actions at the EPA, regardless of their source, are available for a transparent review by qualified scientists," he said in a prepared statement.

In the scientific world, studies already are critiqued by outside experts in peer review prior to publication in leading scientific journals. Moreover, scientists continually test the reproducibility and validity of each other's research—not simply by trying to reproduce the same results with the same data—but by asking if the conclusions hold up in different studies.

By asserting that the scientific process is insufficient and produces suspect results, the Trump EPA is taking up an argument that industry groups have been making for two decades, ever since studies by the American Cancer Society and researchers at Harvard established the connection between exposure to fine particulate matter pollution (PM 2.5) and premature death.

As early as 1996, Christopher Horner, a lawyer-consultant for the tobacco industry, suggested a tactic to use against the EPA: attack the science by employing a buzzword like "transparency" and raise doubts about whether studies were "able to be reproduced," according to documents made public in litigation against the industry.

Big Tobacco at that time was facing the prospect of EPA second-hand smoke regulation, but Horner suggested that challenging the EPA science process would be a more winning strategy than engaging in a fight over the substance of the science. Horner, who more recently has worked for groups funded by the fossil fuel industry, served on the Trump transition team at EPA.

If the EPA goes forward with a plan to limit its reliance on studies that include confidential data, it could force the agency to discount the ACS and Harvard studies, which are widely viewed as seminal research on the health impacts of air pollution. Those studies have served as the underpinning of the cost-benefit analysis for most of the agency's current air pollution regulations over the past two decades, including those related to climate change.

Some studies would still pass muster under the proposed EPA transparency rule. For example, the new Harvard coronavirus study—which looks at pollution and deaths at the county level—relies on all publicly available data. But the proposal could result in the EPA discounting future Covid-19 research that delves more deeply into personal medical history and uses home addresses of patients for more precise measurement of air pollution exposure, experts say.

"The best possible studies are where you know where the person lives, how much money that person makes, whether or not this person has cancer, whether or not this person has been diagnosed for heart disease," said Francesca Dominici, co-director of Harvard's data science initiative and a co-author of the COVID-19 study. "That's all individual-level highly, highly confidential information."

C. Arden Pope, an economist at Brigham Young University, who was a co-author of the pioneering American Cancer Society and Harvard studies, has been engaged in such research in Utah for decades. The geography of the Wasatch Front—the chain of cities between the mountains and the Great Salt Lake in northern Utah—has been an ideal study site, in his view, because of the variable air quality caused by frequent temperature inversions that drive out clear mountain air and trap pollution in the valley.

But research on whether the waves of air pollution affect health is only possible because of his partnership with Utah's Intermountain Healthcare System. "You have a large well-run health care system that keeps very good records," Pope said.

In the 2018 respiratory infection study, for instance, Pope and his colleagues were able to analyze clinical data from more than 100,000 doctor and emergency room visits over 17 years, including patient health history and home addresses. But the researchers' agreement with Intermountain Health Care requires that they maintain the confidentiality of that information. Pope thinks it would be a mistake for the EPA to discount or give less weight to such studies by claiming that patient confidentiality somehow makes the aggregate data off limits. .

"Research that uses carefully collected, well defined, well understood clinical data, why would you want to say that's second-tier or third-tier evidence, because it uses data we decide as a society to allow to remain private?" Pope asked. "In fact, some of the very best studies available use data that cannot be shared widely."

Pope said he doesn't know if the 2018 Utah study will prove to be relevant to the question of whether there is an association between air pollution and Covid-19. He and his fellow researchers were looking at lower respiratory infections caused by different viruses, including RSV, or Respiratory Syncytial Virus, and flu viruses. "In the end, I'm sure that somebody will retrospectively go back and look at the data" to see if there are associations between air pollution and Covid-19, Pope said. "And much of that data will be clinical data that is not able to be able to be released publicly."

Pope declined to speculate how ruling out such data would affect future regulation at EPA. "I'm hoping public policy folks ultimately will be reasonable," he said. But he argued that in one sense, it won't matter what the science ultimately says on whether air pollution worsens the effects of COVID-19. "As a matter of public policy, whether it does or doesn't, we already know the public health need to reduce air pollution is overwhelming," Pope said.