Via Quartz, a vivid and startling comparison: Here are the world’s worst cities for air pollution, and they’re not the ones you’d expect. Click through for the chart and very useful links. Excerpt:
Exposure to air pollution is getting worse in parts of the world, especially industrializing countries, according to the WHO. The WHO’s key announcement yesterday was that it has included outdoor air pollution on its definitive list of the world’s known carcinogens—an addition that, it hopes, will get governments to do something about it. Air pollution is the world’s worst environmental carcinogen and more dangerous than second-hand smoke, for instance, the health body said.
As the chart above shows, the cities with the worst air are often not big capitals, but provincial places with heavy industry in them or nearby. Ahwaz, for instance, in southwestern Iran, far outstrips infamously polluted cities like New Delhi or Beijing, with 372 parts per million of particles smaller than 10 micrometers (PM10), compared to the world average of 71. Life expectancy for the city of 1.2 million residents is the lowest in Iran.