"A national surveillance system will be launched to monitor the effect on human health of PM 2.5, a senior disease control official said. PM 2.5 is the term for particulate matter in haze and fog measuring 2.5 micrometers in diameter or less. The system, the first of its type, will look at medical and mortality records and compare them to instances of fog and haze to enable targeted intervention, said Xu Dongqun, deputy director of the institute of environmental health ..." (Quoted from article)