Over 800,000 lung cancer patients in China by 2020

Zhong Nanshan, a respiratory expert and academic at the Chinese Academy of Engineering, expects that PM2.5, a major cause of smog, will replace smoking as the top risk factor for lung cancer.

Currently, lung cancer is the top killer among all other cancer variants, causing about 600,000 deaths per year in China. In 2015, roughly 700,000 people were diagnosed in the country.

In response, the Chinese government has launched health initiatives, including efforts to cut down smoking. But the emerging challenge from the smog "should be addressed as well", Zhi said.

According to the National Health and Family Planning Commission, a nationwide network monitoring the impact of air pollution on human health is underway.

More than 40 monitoring sites will be set up in 16 provinces and municipalities that are frequently engulfed by smog to support research on air pollutants in different regions.