For every thousand people alive on earth, 973 are regularly inhaling toxins. Only 27 are not. Which means, almost certainly, you are too.

Last fall, the World Health Organization lowered its global air quality standard from 10 micrograms of particulate matter per cubic meter to five. Those terms and standards can feel abstract, which makes their meaning a bit hard to fathom. But last month the University of Chicago’s Air Quality Life Index project — the gold standard on global air quality research — released a major update

✎ EditSign, incorporating the new guidelines and producing that 973 out of 1,000 (97.3 percent) figure.

The harm is most intense in poorer, still-industrializing places. But the revision was especially dramatic, A.Q.L.I. found, in the wealthier parts of the world. In the United States, before the W.H.O. update, about 8 percent of the country was judged to be breathing dirty air; after, the figure was 93 percent. Across Europe, the revision pushed the numbers from 47 percent to 95.5 percent.

According to […]