Pollution level in China's 3 metropolitan areas dropped nearly 40%: Govt

China has made a remarkable achievement by reducing the pollution level by nearly 40 per cent in the three main metropolitan areas, including Beijing, by putting in place the world's largest clean coal-fired power generation system, according to Minister of Environmental Protection Li Ganjie.

Li said Beijing had seen many blue days in December, something less common during winter, which is usually the worst period of the year for air quality due to the operation of central heating, which is generally fuelled by coal.

China, the world's biggest polluter, has a four-tier colour-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.

Li said China has put in place the world's largest clean coal-fired power generation system over the past five years by completing the "ultra-low emission" transformation of coal- fired power plants with combined capacity of 640 million kilowatts, 68 per cent of the country's total installed capacity of coal-fired generating units.

The transformation has resulted in 83 per cent decrease in sulfur dioxide emission, 50 per cent cut in nitrogen oxides, and 67 per cent reduction in smoke dust, Li said.

From January to November, 338 Chinese cities saw a combined 20.4-per cent reduction in particulate matter (PM) 10, compared to that in 2013, Li was quoted as saying by state-run Xinhua news agency.

Li called the achievements remarkable, and said they were made possible by putting in place the world's largest clean coal-fired power generation system over the past five years.

The PM2.5 levels in three main metropolitan areas: Beijing-Tianjin-Hebei, Yangtze River Delta and Pearl River Delta were down 38.2 per cent, 31.7 per cent and 25.6 per cent respectively, Li said.

Beijing and northern cities suffered smog and heavy pollution specially in winter for several years as they went through heavy industrialisation. The government has been cracking down heavily in the last few years by removing coal- fired industries.

The central government unveiled a five-year national clean air action plan in 2013, aiming to improve air quality through measures such as closing factories, limiting cars and replacing coal with clean energy.

For the period, the density of PM2.5 in Beijing declined 25.6 to about 60 micrograms per cubic meter, he added.

The government also took effective actions in other fields, Li said.

In 2015, the country released its action plan for water pollution prevention and control, aiming to reduce pollutants, improve drinking water and promote water conservation by the end of 2020.

In 2016, an action plan on tackling soil pollution in China was released by the China's Cabinet, aiming to improve soil quality and ensure safe agricultural products and a healthy living.