Only 8 of China’s 74 largest cities met the country’s new air-quality standards last year, according to the Chinese Environment Ministry. The readings are based on measurements of particulate matter, nitrogen dioxide, carbon monoxide and ozone. In 2013, three cities met the standards. The greatest number of polluted cities was located in northeastern Hebei. Beijing and Shanghai were among the cities failing to meet the standards. The cleanest air was found in the south, in Haikou, Hainan. Last year, China closed 8,000 coal-powered factories as part of an effort to improve air quality.

Source: BBC