Is the cause of smog really related to the environment?

There are many sources of smog, such as automobile exhaust, industrial emissions, building dust, garbage incineration, and even volcanic eruption. Hazy weather is usually formed by the mixed action of various pollution sources. However, in the smog weather in different regions, the role of different pollution sources is different.

Haze weather has existed since ancient times, and human activities or natural phenomena such as slash-and-burn and volcanic eruption may lead to haze weather. However, after mankind entered the era of fossil fuels, the smog weather really threatened the living environment and health of mankind. Rapid industrialization and urbanization lead to rapid energy consumption, high concentration of population and destruction of ecological environment, which have laid the groundwork for the formation of haze weather.

The formation of smog has both "source" and "accomplice", which is the meteorological condition that is not conducive to the spread of pollutants. Once pollutants accumulate for a long time under static meteorological conditions, it is easy to form haze weather. The formation of smoke has three elements:

The first is the physical basic source of particulate matter. China has the largest loess plateau in the world, and its soil texture is the easiest to produce granular dust particles.

Second, poor exercise leads to dust. For example, the mud in the garden in the middle of the road and the soil on the roadside stones will flow to the road after raining or splashing water, which will produce a lot of dust after one hour of drying. Even if these particles fall back to the ground, they will be thrown over the city again because of the continuous passing of cars.

Thirdly, the basic source of dust and the process of movement difference gather in a certain spatial range, and particles finally gather with water molecules to form haze. At present, in more than 350 cities in the Loess Plateau of China, the three elements of smog structure are quite rich.

In addition to meteorological conditions, the increase of atmospheric particulate matter (including coarse particulate matter PM 10 and fine particulate matter PM2.5) caused by industrial production, vehicle exhaust emissions and coal burning in winter 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 the 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 immediately.

There are several reasons for the smog weather.

1. The main factor when the atmospheric pressure is low and the air does not flow. Because the air does not flow, the tiny particles in the air gather together and float in the air.

2. The ground is dusty and the air humidity is low. People and vehicles on the ground stir up dust.

3. Automobile exhaust is the main pollutant emission. In recent years, there are more and more cars in cities, and automobile exhaust is a factor of smog.

4. Secondary pollution produced by factories.

5. CO2 and other pollutants emitted by heating in winter.