More than 10 million people die each year from air pollution, according to a new study — far more than the estimated 2.6 million people who have died from Covid-19 since it was detected more than a year ago. And while Covid is headline news, ordinary air pollution remains a side issue for policy wonks and technocrats. You might wonder whether the estimate of 10.2 million excess deaths from pollution is accurate. The study, which specifically examines global mortality from particulate matter generated by the combustion of fossil fuels, does deploy some complex measurement techniques. Still, if you believe that smoking is bad for people and sometimes kills them — a well-established fact — it stands to reason that air pollution is also bad.

I have been a frequent visitor to China and India over the years, and it was not unusual for the air pollution to be so terrible that I wanted to stay in my hotel room all day. As a relatively well-to-do visitor, I had this luxury — but many of the city’s residents do not. When they go outside, the air damages their respiratory and circulatory systems, shortening their lives.

The 10.2 million estimate draws upon 2012 data, and since 2012 China has cut its emissions considerably. Yet many other countries have seen more economic growth and more pollution over that time, so the inaccuracies from the limited data can cut in both directions.

If you are still skeptical, note that earlier World Health Organization estimates for annual deaths from air pollution typically range between 6 million and 7 million. To repeat: That is per year.

Why aren’t these deaths a bigger issue in U.S. political and policy discourse? One reason may be that 62% of those deaths are in China and India. The number of premature deaths due to particulate matter in North America was 483,000, just slightly lower than the number of measured deaths from Covid to date. An estimated 876 of those deaths were of children under the age of 4.

Another reason for the weak political salience of the issue may be its invisibility. Air pollution causes many deaths. But it is rare to see or read about a person dying directly from air pollution. Lung cancer and cardiac disease are frequently cited as causes of death, even though they may stem from air pollution.

Another problem is that the question of how to better fight air pollution does not fit neatly into current ideological battles. You might think Democrats would emphasize this issue, but much of the economic burden of tougher action would fall on the Northeast, a largely Democratic-leaning area.

Or you might ask why there isn’t more focus on how many people die each year from global warming, either directly or indirectly. It is difficult to find an accurate estimate of that number, although it is almost certainly nowhere close to 10 million.