The heavily industrialized and populated regions of Northern Italy, particularly Lombardy, have the highest rates of air pollution in the country. They also have had the country’s highest rates of COVID-19 deaths.
A new study led by Eric Coker, Ph.D., an assistant professor in the department of environmental and global health at the University of Florida College of Public Health and Health Professions, along with colleagues at the UF One Health Center of Excellence and the Fondazione Eni Enrico Mattei in Italy, finds that long-term exposure to outdoor fine particulate matter (PM2.5) is strongly related to excess COVID-19-related deaths in Northern Italy. The findings appear in the Journal of Environmental and Resource Economics.
Previous studies have linked fine particulate matter to cardiovascular and respiratory morbidity and mortality, and a recent position paper by the Italian Society of Environmental Medicine argues that particulate matter may act as both a carrier and substrate of the new coronavirus.
In the new study, Coker and colleagues examined whether higher average long-term exposure to PM2.5 is positively associated with the current extraordinarily high death toll in Northern Italy. They found that a one-unit increase in PM2.5 concentration is associated with a 9% increase in COVID-19 related mortality.
“I think what surprised me the most was just how robust the findings were with respect to different model specifications and different PM2.5 exposure assessment estimation methods,” Coker said. “The relationship was quite strong and unambiguous. Another surprising finding, but that actually matches up with some work done in the U.S., is that population density was not an important factor in COVID-19 mortality.”
Coker said the next steps in this line of research include investigating the effects of short-term particulate matter exposure as well as the multifactorial nature of severe COVID-19 and mortality.
“And of course more studies are needed using data at the individual level as well research into the underlying biological mechanism,” he said.
While the study focused exclusively on Italy, the findings are relevant to the U.S. as well, Coker said.
“I think the most important implications relate to how we have seen such disproportionate impacts of COVID-19 in black and brown communities,” he said. “Environmental pollution and air pollution, in particular, may well be playing an important role since we know these same communities are disproportionately exposed to air pollution and many other environmental contaminants.”