The haze weather is a state of air pollution, haze is to exceed the standard content of suspended particles in the atmosphere of the general formulation, especially PM2.5 (aerodynamic equivalent diameter less than or equal to 2.5 micron particles) are thought to be caused by fog and haze culprit; PM2.5 refers to the atmosphere in diameter less than or equal to 2.5 micron particles, sometimes referred to as particulate matter into the lungs, PM2.5 may cause respiratory disease, cardiovascular disease, toxic substances poisoning, high carcinogenic, lack of infant development with the deterioration of air quality, the haze weather phenomenon increased harm. Many areas of the China haze Weather phenomena are incorporated into fog as a warning and forecasting of disastrous weather, collectively referred to as "fog and haze".