The air quality in some areas of Beijing has declined. Why does haze pollution mostly appear in winter and spring?

Haze pollution mostly occurs in winter and spring. This is because the temperature in these two seasons is relatively low and the air mobility is not strong, which causes tiny particles to be suspended in the air and cannot be blown away by the wind, so haze Days often appear in winter. Haze itself is an aerosol system produced by industrial waste, automobile exhaust, etc. This aerosol system can cause visual obstruction, so haze is also called haze. 1. Fog and haze are not the same thing.

Fog is small water droplets suspended in the air, which reduces the visibility on the ground. Usually, it occurs when there is sufficient water vapor, a breeze or a stable atmosphere, the temperature is around zero, and the relative humidity is relatively high. Under such circumstances, the water vapor in the air will condense into relatively fine water droplets suspended in the air, blocking people's sight. But after the sun comes out, these small water droplets are evaporated, so the fog disappears with the appearance of the sun. Foggy days often appear in spring in February, March and April. The formation of fog requires four conditions, cooling and humidification. 2. Haze is harmful particulate matter.

The difference between haze and fog is quite big. The aerosol system composed of particulate matter such as sulfuric acid and nitric acid in the air causing visual impairment is called haze. The haze is composed of some particulate matter, so these fixed particles will not disappear with the appearance of sunlight. Not only that, compared to fog, haze is harmful to people's health. However, because the appearance of haze and fog will reduce the visibility on the ground, they often appear together. 3. Winter haze cannot be blown away by air flow.

Fog and haze will reduce horizontal visibility, and have a relatively large impact on people's lives, especially in the area of ​​traffic. We must pay attention to driving safety. However, fog is composed of water vapor, generally only appears in the morning before sunrise, and is not harmful to people's health. Haze can form at any time and will not disappear with the appearance of the sun, which is very harmful to people's health. Therefore, you must wear a mask when traveling in haze weather.