Air pollution causes 350,000 to 500,000 premature deaths on the mainland a year, according to an article co-written by a former health minister.
Chen Zhu, now president of the Chinese Medical Association, and three other authors endorsed the estimate in a commentary published in The Lancet medical journal last month.
The article, titled "China tackles the heath effects of air pollution", cited estimates from the World Bank, the World Health Organisation, the Chinese Academy of Environmental Planning and Fudan University.
The authors said China spewed out more of the main pollutants than any other country, but that "prevention and control of environmental pollution in China is difficult because there are multiple pollution sources and pollutants across cities and regions".
Beijing has committed US$277.5 billion over five years to preventing and controlling air pollution and if targets are met 200,000 fewer people would die prematurely each year, according to The Lancet article. It said the main polluters in the country were industry, coal and vehicles.
However, the estimate the article endorsed - that air pollution causes 350,000 to 500,000 premature deaths each year - was far lower than another estimate in a study published in the same magazine the year before that air pollution was responsible for 1.2 million premature deaths in 2010 alone and the loss of 25 million disability-adjusted life-years.
Chen said the 2012 study was a worst-case scenario and might have overestimated the effects of pollution. The former health chief and his fellow authors said in their commentary the lower estimate used a revised measure of long-term air pollution and real-time air monitoring data in cities, which "better reflect the real situation in the country".
However, Yang Gonghuan, a former deputy director of the Chinese Centre for Disease Control and Prevention and an author of the 2012 study, said: "I don't think it's really appropriate to say we overestimated.
"The Fudan University study only looked at 113 cities, while ours looked at the whole country. The population of the whole country is far greater than the population of 113 cities."
Major Chinese cities have been severely affected by heavy smog in the past few months. Yesterday Guangzhou activated its orange alert and ordered 11 mandatory air pollution emergency measures for the first time, which included taking one-fifth of the 13,000 government vehicles off the roads.
This came two months after the measures were announced.
Local media reported that Guangzhou Mayor Chen Jianhua rode the subway to work to do his small part to combat pollution. Other measures put in place to limit the effects of the pollution included halting dusty construction projects such as mining and demolition.
Schools, kindergartens and childcare facilities were ordered to cancel outdoor activities until the air quality improves.
Additional reporting by Mimi Lau
Watch: A view of Beijing's smog from atop the Forbidden City