Published late October in the journal Cardiovascular Research, the study revealed that roughly 15 percent (or more than 180,000) COVID-19 deaths worldwide can be attributed to long-term exposure to air pollution.
In East Asia, which has some of the highest levels of air pollution on Earth, the researchers estimated that 27 percent of COVID-19 deaths could be attributed to complications from the harmful effects of exposure to air pollution. In Europe, 19 percent of COVID-19 deaths were thought to be associated with air pollution, just two percent higher than the estimate for COVID-19 deaths in North America.
Combined, long-term exposure to air pollution and COVID-19 can have an adverse effect on health, especially on the heart and blood vessels, said study co-author Thomas Munzel, chief of the department of cardiology at the University Medical Center of the Johannes Gutenberg University in Germany.
To estimate the proportion of COVID-19 deaths worldwide that could be attributed to air pollution exposure, the researchers studied health and disease data from the U.S. and China on air pollution and COVID-19. They combined this with satellite data of global exposure to particulate matter, as well as data from ground-based pollution monitoring networks.
Particulate matter is a mixture of microscopic solid particles and liquid droplets in the air. When inhaled, they can affect the heart and lungs, causing adverse health effects.
Overall, the data showed a diverse picture of various countries. For instance, air pollution from anthropogenic sources like combustion is linked to 29 percent of COVID-19 deaths in the Czech Republic, 27 percent in China and 26 percent in Germany.
On the other hand, 15 percent of COVID-19 deaths in Italy can be attributed to air pollution and 14 percent in the U.K. Meanwhile, countries with strict air quality standards and relatively low air pollution levels, like New Zealand and Australia, had the lowest single-figure estimates of all the countries studied.
When inhaling polluted air, those microscopic particles in the air can permeate the lung barrier and enter the bloodstream, causing inflammation and severe oxidative stress explained Munzel. Worse, particulate matter can damage the inner lining of the arteries and the endothelium, causing them to narrow and stiffen.
When the COVID-19 virus infects the lungs, it attacks lung cells and causes similar damage to blood vessels. If the lungs and blood vessels are already weak from exposure to air pollution, then the COVID-19 virus can cause even more extensive damage, creating severe complications.
This suggests that particulate matter is a co-factor in aggravating COVID-19, said co-author Jos Lelieveld of the Max Planck Institute for Chemistry in Germany.
Meanwhile, for people with preexisting conditions like heart disease, the situation can be much worse. When exposed to air pollution and infected with COVID-19, a person with heart disease will likely face an increased risk of heart attacks, heart failure and stroke.
Overall, these findings agree with those of an earlier report that linked air pollution to COVID-19 deaths. In that study, researchers from the Harvard T.H. Chan School of Public Health found that COVID-19 patients from regions in the U.S. with high levels of air pollution were more likely to die from the disease than patients from less polluted regions.
In the first study of its kind, the researchers analyzed levels of fine particulate air pollution before the COVID-19 pandemic in 3,089 U.S. counties, as well as the total COVID-19 deaths in those countries.
Their analysis showed that a small, single-unit increase in particle pollution 15–20 years before the pandemic was associated with a 15 percent increase in the COVID-19 mortality rate. Francesca Domini, who led the analysis, is also part of the latest study published in Cardiovascular Research.
Overall, the findings of the new research suggest that 15 percent of all COVID-19 deaths worldwide could have been avoided if the air were clean. The findings also highlight the need for effective policies that aim to reduce anthropogenic emissions. (Related: Could air pollution be causing the coronavirus to spread more rapidly?)
However, these studies do not show a cause and effect relationship between air pollution and COVID-19. This emphasizes the need for more studies that confirm such a relationship before governments can begin to make and enforce policies for mitigating air pollution.
Learn more about the impact of air pollution on COVID-19 risk and mortality rate at Health.news.