“Cities in Iran, India, Pakistan and the capital of Mongolia rank among the worst on the planet for air pollution, while those in the United States and Canada are among the best, according to the first global survey released Monday by the World Health Organization,” the Associated Press/San Francisco Chronicle reports. “The list, which relies on country-reported data over the past several years, measures the levels of airborne particles smaller than 10 micrometers — so-called PM10s — for almost 1,100 cities,” the news service writes (9/27).

“Estonia topped the list with the best air quality; Mauritius ranked second; and Canada tied with Australia for third,” according to CBC News (9/26). In a press release, the WHO said it “estimates more than two million people die every year from breathing in tiny particles present in indoor and outdoor air pollution” and called for “greater awareness of health risks caused by urban air pollution, implementation of effective policies and close monitoring of the situation in cities,” steps that would bring “major public health gain[s]” (9/26).