University HealthCare Alliance

September 25, 2020

Scope | Why Air Pollution is Linked to Severe Cases of COVID-19

There is growing evidence of increased rates of COVID-19 in areas with high levels of air pollution. Stanford researcher Mary Prunicki, MD, PhD, studies how toxic air can make people chronically ill, and she’s monitoring this apparent connection between the pandemic and polluted air.

I spoke with her for a 1:2:1 podcast about how toxic pollutants can make people more susceptible to COVID-19, why people of color are particularly vulnerable, and how California wildfires could make it all worse. This Q&A is condensed and edited from our conversation.

What is the connection that you’re finding between air pollution and COVID-19?

Studies are coming out that are finding increased rates of COVID-19 in areas of high pollution exposure. For example, a study out of Harvard recently found that someone living in an area of high-particulate pollution is actually 8% more likely to die from COVID than others living in an area just one small unit less pollution.

This study and others have concluded there’s at least a small increase in long-term exposure to pollution causes larger increases in the COVID-19 death rate.

What’s in air pollution that triggers disease, in general, and COVID-19 in particular?

Air pollution is a mixture of solid particles and gas particles. The composition varies depending on the source of the pollution. Our first line of defense when we breathe are cilia, little hair-like structures that line our respiratory tract and keep the airways clear of mucus and dirt.

We know pollution can damage the cilia, and things like smoking can even kill them. Air pollution can cause cellular damage and inflammation throughout the body and has been linked to higher rates of diseases, including cancer, heart disease, stroke, diabetes, asthma, and other co-morbidities. All of these conditions also increase the risk of death in COVID-19 patients.

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