Long-term exposure to air pollution may be linked to 15 percent of all coronavirus deaths worldwide, according to a new study published in the journal Cardiovascular Research.

The study’s findings—based on analysis of pollution and pandemic data by the Max Planck Institute for Chemistry, Harvard University, and the Cyprus Institute’s Climate and Atmosphere Research Center—revealed that in East Asia, the percentage of coronavirus deaths related to pollution was about 27 percent, while Europe was 19 percent, North America 17 percent, and Australia 3 percent.

“If both long-term exposure to air pollution and infection with the COVID-19 virus come together, then we have an adverse effect on health, particularly with respect to the heart and blood vessels,” the study’s co-author Thomas Munzel, a professor at the University Medical Center of the Johannes Gutenberg University, Mainz, said in a statement.

Specifically, the researchers noted that particulate matter appeared to increase the activity of ACE2 on lung cell surfaces, which acts as the receptor for the SARS-CoV-2 virus (Coronavirus) and allows it to infect the cell.

“So, we have a double hit: Air pollution damages the lungs and increases the activity of ACE2, which in turn leads to enhanced uptake of the virus,” Munzel said.

The study’s authors stressed that attributing coronavirus deaths to air pollution does not mean that only pollution itself was responsible for the fatalities—though they couldn’t completely rule out that possibility.

“The pollution particles are a co-factor in aggravating the disease,” Jos Lelieveld, of the Max Planck Institute for Chemistry, said in a statement.

The researchers stressed that millions of people will continue to die worldwide even after the pandemic if countries don’t make a concerted effort to transition to clean and renewable energy sources.

“The pandemic ends with the vaccination of the population or with herd immunity through extensive infection of the population,” the researchers wrote. “However, there are no vaccines against poor air quality and climate change. The remedy is to mitigate emissions.”

Twenty-one of the world’s thirty cities with the worst air pollution are in India, according to data compiled in IQAir AirVisual’s 2019 World Air Quality Report.

Ghaziabad, a satellite city of the capital New Delhi in northern Uttar Pradesh state, is ranked as the most polluted city on the planet, with an average PM 2.5 concentration measurement of 110.2 in 2019. For perspective, that’s nine times higher than the level that the U.S. Environmental Protection Agency regards as healthy.

According to the World Health Organization, air pollution causes an estimated seven million premature deaths a year globally.

Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek, and Arirang TV. Follow or contact him on LinkedIn.

Image: Reuters