Sulfur dioxide emissions in China amounted to 21.18 million metric tons in 2012, a fall of 4.52 percent from the previous year, while nitrogen oxide emissions totaled 23.38 million tons, a decline of 2.77 percent, according to a report released by the Ministry of Environmental Protection this month.

In September, the State Council approved the Plan on the Prevention and Control of Air Pollution in Key Regions (2011-15). The plan, which covers 117 cities in 19 provinces, implemented targets to reduce the annual mean concentration of PM10 and sulfur dioxide by 10 percent each, nitrogen dioxide by 7 percent and PM2.5 by 5 percent.

To support the renovation of coal-fired boilers in 15 cities, the central government provided 1.09 billion yuan ($178 million) in subsidies in 2012. The air quality in those cities has improved significantly since the project was launched, according to the report.