COVID-19 pandemic is saving many more lives around the world than its taking by reducing harmful air pollution, according to estimates by a group of French and Hong Kong scientists.

Writing in the journal Environmental Pollution, Frédéric Dutheil and Valentin Navel from Université Clermont Auvergne in Clermont-Ferrand, France and Julien S. Baker from Hong Kong Baptist University, Kowloon Tong, Hong Kong point out that “NASA scientists have commented that the reduction in NO2 pollution was first apparent near Wuhan, but spread across the rest of the country, and eventually worldwide” .

In Central China, NO2 emissions were reduced by as much as 30%, while CO2 emissions, another common tracer of air pollution, decreased by 25% in China and by 6% worldwide due to the coronavirus pandemic, according to the researchers.

The reduction in air pollution is a result of the measures introduced by authorities to curb the spread of the disease, including restrictions on transportation, reduction in local business travel, and the shutdown of schools, universities and other establishments, the scientists argue.

Air pollution kills 4.6 million people annual, World Health Organization estimates.

Air pollution associated deaths include but are not limited to aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies, the researchers point out.

“China, where the COVID-19 epidemic started, is also a country severely affected by air pollution,” Dutheil, Baker and Navel write. “Air pollution in China was responsible for 4000 preventable deaths each day i.e. 1.6 million fatalities in 2016.”

Even as China reported 3,158 deaths due to COVID-19, the scientists estimate that the reduction in air pollution saved at least 100,000 lives in China based on models that predict deaths from air pollution.

“Considering the huge decrease in air pollution following the quarantine (China’s CO2 emissions decreased by a quarter), the COVID-19 pandemic might paradoxically have decreased the total number of deaths during this period, by drastically decreasing the number of fatalities due to air pollution,” the researchers conclude. “Moreover, in addition to the reduced number of deaths due to air pollution, the reduction in air pollution itself could also have positive benefits in reducing preventable non communicable diseases.”