Steve MacLellan

Dirty air in the United States is linked to higher death rates from COVID-19, according to a new study from researchers at Harvard’s school of public health. Scientists found that people who lived in counties in with elevated levels of fine particulate matter known as PM 2.5 in the air were more likely to die from the virus.

PM 2.5 is one of the world’s most dangerous invisible pollutants. It’s made up of tiny particles (smaller than 2.5 micrometers across) that can seep into human lungs and bloodstreams. It comes from automobile exhaust and dirty power plants, as well as from burning wood and coal. Many studies have linked high levels of PM 2.5 to heart disease, chronic bronchitis, diabetes, and other respiratory illnesses. Researchers have estimated that PM 2.5 contributed to 4.2 million deaths worldwide in 2015 alone.

According to the Harvard analysis, which has yet to be peer reviewed, just a small increase in long-term levels of PM 2.5 — even one microgram per cubic meter of air — could increase COVID-19 death rates by 15 percent.