The causes of haze weather and harmful haze weather are introduced.

1, there are three reasons for the smog weather: the phenomenon of increasing static wind in the horizontal direction. There is an inversion in the vertical direction. The increase of suspended particles in the air.

2. With the growth of urban population and industrial development, the number of motor vehicles has soared, and the emissions of pollutants and suspended solids have increased greatly, which directly leads to the decline of visibility. In fact, dust "smog" will also occur in home decoration, and indoor dust is pervasive, which is not only harmful to the health of staff and users, but also increases the cleaning burden. When the dust is serious, it will also bring many hidden dangers to the decoration project.

3. In addition to meteorological conditions, industrial production in winter, motor vehicle exhaust emissions and coal combustion lead to the increase of atmospheric particulate matter (including coarse particulate matter PM 10 and fine particulate matter PM2.5) concentration, which is an important factor of smog. At present, the level of pollutant discharge in many cities is at a critical point, which is very sensitive to meteorological conditions. When diffusion conditions are good, the air quality can reach the standard, and once adverse weather conditions are encountered, the air quality and visibility will drop rapidly.

4, affecting life. Haze weather has an important impact on roads, railways, aviation, shipping, power supply systems and crop growth. Fog and haze will cause air quality decline, affect the ecological environment and bring great harm to human health.

5. Affect traffic. Due to poor air quality and low visibility in foggy days, rear-end collision accidents are prone to occur, which will affect the normal traffic order and have no change in everyone's travel. We should observe the road conditions more during daily driving to avoid danger.