Figure 9.10: China’s most polluted and least polluted cities in terms of air quality. Based on a 2011 report from the WHO, the map shows the 20 cities in China that have the most air pollution and the 10 cities with the least air pollution, as measured by the number of PM10 particles per cubic meter. PM10 particles are microscopic; by definition, they are less than 10 micrometers in diameter. These tiny particles can get into people’s lungs and potentially cause serious health problems. The cities of northern and central China suffer from higher levels of air pollution than those in the south.
[Sources consulted: “China’s Most Polluted Cities—WHO Index,” China Briefing, September 28, 2011, at http://www.china-briefing.com/news/2011/09/28/chinas-most-polluted-cities-who-index.html; “Particle Pollution and Your Health,” AirNow, at http://cfpub.epa.gov/airnow/index.cfm?action=particle_health.index]