Abstract: In recent years, heavy and persistent haze/fog events in China have aroused serious public concerns. These events were mainly caused by high levels of air pollutants (typically particulate matter with an aerodynamic diameter less than 2.5 μm, PM2.5). The authors reviewed the recent scientific developments about the health effects of PM2.5 and its chemical compositions on the respiratory, cardiovascular, reproductive and neurological system and cancers. Then, the potential susceptible subpopulations were summarized. Several suggestions were provided to allievate and avoid the hazardous health effects of haze/fog events.

Key words:  haze/fog, PM_2.5, health