Harvard University researchers study reveals strong link between Air pollution and higher COVID-19 death rates

In a recent nationwide research study from Harvard T.H. Chan School of Public Health, researchers found that people with COVID-19 who resides in US regions with significant levels of air pollution (metric: PM2.5) are more likely to die from the disease in comparison with people who reside in less polluted areas. This study sheds light on the long-term exposure of air pollution and COVID-19 mortality in the United States.

The study has been peer-reviewed and has been accepted by Science Advances journal, and earlier it was first published on medRxiv, the preprint archive server for health sciences. As we know, fine particulate matter pollution PM2.5 is the major cause of air pollution worldwide and is produced mainly from fuel combustion of automobiles, refineries, factories, and power plants. The researchers in their study look at the correlation between long-term exposure to PM2.5 and increased risk of death from COVID-19 in the US.

To account for almost whole population span, the study considered data for 3,000 counties across the US, and compared the levels of PM2.5 pollution with COVID-19 death counts for each area. The researchers took into account several parameters to find the conclusions: adjusting for population size, hospital beds, number of people tested for COVID-19, weather, socioeconomic and behavioral variables (obesity, smoking). They found that a small increase in long-term exposure to PM2.5 particulate matter leads to a large increase in the COVI9-19 death rate.

The research study also revealed that for someone living in a county with long-term exposure to high-levels of fine particulate pollution is 8% more likely to die from COVID-19 disease than someone who lives in a region that has just one unit ( one µg/m3) less of such pollution. In an April 7, 2020 New York Times article, Francesca Dominici, senior author commented, how their study suggests that counties with higher pollution levels will be the ones having higher numbers of hospitalizations and deaths and accordingly at these places resources should be concentrated.

While, it is already known the strong link between PM2.5 exposure and higher chances of death from cardiovascular and respiratory illnesses. The new results from the study strongly relates with the former findings. The authors wrote the following conclusions in their journal paper, “Despite the inherent limitations of the ecological study design, our results underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis”.

References:

1. Wu, X., Nethery, R. C., Sabath, M. B., Braun, D. and Dominici, F., 2020. Air pollution and COVID-19 mortality in the United States: Strengths and limitations of an ecological regression analysis. Science advances, 6(45), p.eabd4049.

2. A pre-print version can be found at: Exposure to air pollution and COVID-19 mortality in the United States. Xiao Wu, Rachel C. Nethery, Benjamin M. Sabath, Danielle Braun, Francesca Dominici. medRxiv 2020.04.05.20054502; doi: https://doi.org/10.1101/2020.04.05.20054502