The 15 cities with the worst air pollution in the world

China Daily/Reuters Air pollution in urban areas is getting worse. Between 2008 and 2013, global urban air pollution levels rose by 8%.  Some 80% of all urban areas have air pollution levels above what's considered healthy by the World Health Organization, a new report said Thursday. The rate is even more dismal for cities with more than 100,000 people in low- and middle-income countries: The report found that 98% of those areas had unhealthy air.  The most harmful pollutant to human hea...