Despite a noticeable improvement in China's air quality in 2015, the issue on air pollution still remains a "major health hazard" to the citizens as 366 cities in the country still do not pass the air quality standard of the World Health Organization (WHO) , reported NBC News on Wednesday.
"None of these 366 cities meet the World Health Organization air quality standard," noted Dong Liansai, a climate and energy campaigner for Greenpeace. "That is to say 100 percent of Chinese cities studied fail to meet the WHO's standard."
The yearly average levels of particulate matter of 2.5 micrometers in diameter (PM2.5), which is capable of infiltrating the human lungs, has reportedly decreased by 10.3 percent in 2015, as compared to the previous year.
The areas of Beijing, Yangtze River Delta and Pearl River Delta were also noted to have a remarkable improvement in air quality.
However, despite these improvements, the PM2.5 concentration in China remained at 50.2 parts per cubic meter, which is significantly high compared to the annual average of less than 10 micrograms of WHO's guideline.
According to Huffington Post on Jan. 7, the improvement on China's air quality is attributed to the country's decreased coal production and consumption, investment in renewable energy sources and a tighter policy on imposing punishments on polluters.
"It seems very clear that [the improved air quality] coincided quite perfectly with a fall in industrial coal consumption and improvements in emissions standards and enforcement for power plants and industry," said Lauri Myllyvirta of Greenpeace.
"The government has not just done the typical shutting down of smaller and more inefficient facilities, but it's also making plans for overall capacity in certain sectors," noted Anders Hove, associate director of research at the Paulson Institute.
Despite the hazardous air pollution in China, Greenpeace included Beijing in the 90 percent of the cities that showed improvement in overall air quality last year.