BEIJING, Oct 28 (Reuters) - China's Health Ministry will set up a national network within five years to provide a way of monitoring the long-term impact of chronic air pollution on human health, state media said on Monday.
The network will gather data on PM2.5, or particulate matter with a diameter of 2.5 micrometers, in different locations around the country, the report said, citing a ministry statement.
"The document noted that the absence of a long-term, systematic monitoring system has prevented the country from uncovering the link between air pollution and human health," the report said.
The network will first cover cities where smog is most prevalent, it added.
"The evaluation will be based on the integrated and long-term analysis of PM2.5 data, weather information and cases of local residents' diseases and deaths," Xinhua said.
An international study published in July showed that air pollution is shortening the lives of people in northern China by about 5.5 years compared to the south, a legacy of a policy that provided free coal for heating in the north.
Air quality is of increasing concern to China's stability-obsessed leaders, anxious to douse potential unrest as a more affluent, urban population turns against a growth-at-all-costs economic model that has besmirched much of the country's air, water and soil.
The government has announced many plans to fight pollution over the years, but has made little apparent progress, especially in the north and northeast.
Last week, the PM2.5 index reached a reading of 1,000 in some parts of Harbin, the gritty capital of northeastern Heilongjiang province and home to some 11 million people, virtually shutting it down.
A level above 300 is considered hazardous, while the World Health Organisation recommends a daily level of no more than 20. (Reporting by Ben Blanchard; Editing by Ron Popeski)