Air pollution arguably started when humans first learned how to harness the power of fire, and it became the modern curse of industry, automobiles, and power plants.

Today, in the time of COVID-19, dirty air is even more dangerous to our health. Not only has the pandemic caused the deaths of hundreds of thousands of people in the United States alone, but, according to the National Institute of Environmental Health Sciences (NIEHS), many of the pre-existing conditions that put some segments of the population at greater risk of serious complications from COVID may be linked to long-term exposure to air pollution.

Is there a connection between air pollution and severity of COVID-19?

A study by scientists at Harvard University looked at whether long-term average exposure to fine particulate matter (PM2.5) was associated with a higher risk of dying from COVID-19 in the United States.

By comparing PM2.5 data to the Johns Hopkins University count of COVID-19 deaths in more than 3,000 counties in the spring of 2020, they found long-term average exposure to this type of pollution was associated with worse outcomes from COVID-19.

Air pollution levels by county in the U.S. 2000–2016

Using air pollution data from 2000–2016, FindCare created this map of air pollution by county in the United States.

Using air pollution data from 2000-2016, Findcare created this map of air pollution by county in the United States.

What is particulate matter?

Particulate matter, or particle pollution, is composed of particles mixed with liquid droplets in the air that can be inhaled and that may be detrimental to your health.

Some particles like soot are large, while others, like those 2.5 micrometers or smaller, are not visible to the naked eye. Most originate in pollutants created by cars, industry, and power plants.

Air pollution may be deadly

The findings of the Harvard Study were significant and alarming. They found an association between long-term exposure to PM2.5 air pollution and death from COVID-19.

The United States adopted the Air Pollution Control Act of 1955, the first federal clean air legislation, several years after 20 people died and more than 7,000 others became sick due to extreme air pollution over Donora, Pennsylvania, in 1948.

The Clean Air Act of 1990 in particular regulated the emission of pollutants from industry and motor vehicles. Nevertheless, experts and scientists have worried that over time, low-level exposure to air pollutants could endanger public health—concerns now underscored by the devastation of COVID-19.

For more information, review this chart to see the top 20 worst cities for air quality.

FindCare ranked the top 10 counties according to their average PM2.5 pollution from 2000 to 2016. They also mapped out the average PM2.5 pollution for all available counties. Here are the results.