The smog, as the name suggests, is fog and sorrow, and this is the biggest "killer." is composed of particles of dust, sulfuric acid, nitric acid, organic hydrocarbons, etc. in the air, which can make the atmosphere turbid, blurred vision and lead to deterioration of visibility. If the horizontal visibility is less than 10,000 meters, the non-hydrated material is composed. The visual dysfunction caused by the aerosol system is called sputum or ash; and the pollutants and harmful substances in the smog destroy the human tissue cells, causing diseases and cancer. Why is the smog so severe recently? According to the experts of Hunan Meteorological Observatory, the smog process is because the atmosphere enters a static state after the end of the cold air. There is no obvious cold air activity and no precipitation weather. In this case, the pollutants tend to accumulate. If the air diffusion conditions are poor, a haze process will occur.