The link between COVID-19 mortality and air pollution

According to the World Health Organization (WHO), air pollution is responsible for 7 million deaths per year. While poor air quality has been linked to various health issues such as heart disease and respiratory infections, recent studies have also discovered a connection to higher COVID-19 mortality.

Results of current research

It is theorized that chronic respiratory stress resulting from long-term exposure to poor air quality affects the body’s ability to fend off respiratory infections. This is due to pollutants such as particulate matter (PM) and nitrogen dioxide (NO2) inflaming and damaging lung lining over time. In fact, previous research found that SARS patients from moderately polluted areas in China had an 84% increased risk of dying compared to those from regions with low air pollution, while patients from highly polluted areas were twice as likely to die.  Following this, here are some of the discoveries from recent studies:

  • Long-term exposure to NO2 contributes to COVID-19 fatality in a study based on cases from Italy, Spain, France, and Germany
  • Positive associations between short-term exposure to particulate matter, carbon monoxide, nitrogen dioxide, and ozone were found with COVID-19 infection, but a negative association with sulphur dioxide was found in China
  • An increase of 10 μg/m3 in NO2 and PM2.5 was associated with a 22% and 15% increase in COVID-19 cases and a 19% and 9.6% increase in severe infection in China
  • An increase of 1 μg/m3 in PM2.5 pollution was associated with an 15% increase in COVID-19 mortality rate in the States
  • COVID-19 has been detected on particulate matter in Italy, making air pollution a possible carrier for the virus

Limitations of current research

It is important to note that while there appears to be a significant link between COVID-19 mortality and air pollution, correlation does not equate to causation. There are other factors that could have played a role to make it seem as though poor air quality is directly responsible for higher COVID-19 death rates. This includes the fact that areas with high levels of air pollution tend to have a higher population density, which allows for increased spread of disease and thus results in higher COVID-19 mortality. Also, there is potential for severe underreporting of deaths related to COVID-19 in certain areas due to the lack of resources for testing, leading to unreliable numbers used in the studies.

As some of the studies outlined above are still fairly new, they have yet to be peer-reviewed. This means that independent scientists have not yet endorsed the validity of the research and the results, a process which takes between six months to two years. 

Regardless of whether air pollution is directly related to COVID-19 mortality or not, the health impact of poor air quality cannot be denied. Now more than ever, it is imperative to take clean air action for a better, healthier tomorrow.