A new study from Harvard's school of public health reveals dirty air in the United States can be linked to higher death rates from COVID-19. These scientists discovered that counties with elevated levels of fine particulate matter known as PM 2.5 in the air were linked to a higher likelihood to die from the virus.
The invisible pollutant commonly known as PM 2.5 is made up of tiny particles (smaller than 2.5 micrometers across) that can seep into human lungs and bloodstream. PM 2.5 is created by automobile exhaust, dirty power plants, and burning wood and coal. This pollutant has been linked to heart disease, chronic bronchitis, diabetes, and other respiratory illness, contributing to 4.2 million deaths worldwide in 2015 alone.
Small increases in this pollutant are what impact COVID-19 death rates, as even a small increase of one microgram per cubic meter of air can increase death rates by 15 percent.
Zuofeng Zhang, a professor of epidemiology at the University of California, Los Angeles explained that polluted air is linked to many of the underlying conditions, such as heart disease, lung disease, and diabetes, that make COVID-19 more fatal.
Because the Harvard study only looks at the relationship between mortality and air pollution at the county level, Zhang cautioned saying "it's hard to show a very solid casual relationship" between the two factors. In order to strengthen the results of the Harvard study, the scientists would need to examine the impact on a more individual level, rather than by county.
But still, scientists have seen this phenomenon before. In 2003 researchers found that regions in China with higher levels of air pollution saw more deaths from SARS, a disease closely related to COVID-19. Recent research from scientists in Italy also found a correlation between atmospheric pollution and higher COVID-19 death rates. Ideally, these findings will continue to encourage policymakers to allocate resources to protect those communities that are hit the hardest by pollution and COVID-19.