Despite a recent study from Harvard showing strong evidence that people breathing air with more particulate matter have a significantly increased risk of dying from COVID-19, the EPA has chosen to maintain old standards on the national air quality standard.

On April 14 the Environmental Protection Agency (EPA) announced that they would leave unchanged the National Ambient Air Quality Standards (NAAQS) for particulate matter (PM).

Current Air Quality Standards for Particulate Matter

The EPA has two categories of PM, PM10 and PM2.5, referring to the size of less than 10 micrometers in diameter and less 2.5 micrometers in diameter respectively. For comparison, a dust mite would generally be 5 to 20 micrometers and a grain of sand could be about 90 micrometers.

PM can come from a variety of places and be made up of pretty much anything. Per the EPA:

“These particles come in many sizes and shapes and can be made up of hundreds of different chemicals.

Some are emitted directly from a source, such as construction sites, unpaved roads, fields, smokestacks or fires.

Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles.”

Prior to 2013 the allowable concentration of PM2.5 in the air was 15 micrograms per cubic meter, in 2013 it was changed to 12 micrograms per cubic meter.

Under the Clean Air Act the EPA is required to review these standards periodically. The latest review was scheduled to be completed in 2022, but was pushed up to this year by the former head of the EPA Scott Pruitt.

Health and the Air and COVID-19

PM is regulated by the EPA because breathing in tiny particles of assorted chemicals can have serious health consequences. A 2015 Congressional Research Service Report on the 2013 rule explains, “the EPA determined that evidence continued to show associations between particulates in ambient air and numerous significant health problems, including aggravated asthma, chronic bronchitis, nonfatal heart attacks, and premature death. Populations shown to be most at risk include children, older adults, and those with heart and lung disease, and those of lower socioeconomic status.”

Air Quality Guidelines from the World Health Organization published in 2006 call for PM2.5 limits to be set at 10 micrograms per cubic meter. Research into these links has been ongoing and in recent years more has been learned about the dangers of PM. In 2017 researches estimated that thousands of deaths a year could be prevented with lowered PM2.5 standards. Another study done in 2019 also showed that current PM2.5 levels were associated with increased mortality in the U.S.

On April 5, a Harvard University study was published showing with a high degree of certainty that those breathing air with more particulate matter had a significantly increased risk of dying from COVID-19.

Who Opposes Stricter Standards?

While some scientist within the EPA have recommended stricter standards for PM 2.5, they came up with mixed results on whether or not to enact stricter limits during their review of the PM standards the EPA’s Clean Air Scientific Advisory Committee (CASAC), which provided enough justification for the EPA to retain the current standards.

Stricter standards would have also been a major burden for certain businesses that create a lot of PM. In response to the EPA’s decision the American Petroleum Institute (API) issued their approval in a press release title: “API Welcomes EPA Proposal to Maintain Existing Air Quality Standards.”

The makeup of the CASAC recently changed and the current chair Tony Cox previously worked with the API. This, along with the compressed timeline of the rule review has left lingering questions about the scientific integrity of the process and the decision to keep the rule as is.