How is the persistent smog in Shijiazhuang formed?

Haze is a combination of fog and haze. Because of the deterioration of air quality, cloudy days have increased and the harm has increased. In many areas of our country, the smog weather phenomenon is combined with fog as an early warning and forecast of disastrous weather. Collectively referred to as "haze weather".

First, the formation reason:

The similarity between fog and haze is sight distance obstacle. However, the reasons and conditions for the formation of fog and haze are quite different. Fog is a large number of tiny water droplets or ice crystals floating in the air, and the formation conditions should have a high water vapor saturation coefficient. When fog appears, the relative humidity of air often reaches 100% or approaches 100%. With the daily change of air humidity, fog is more common or thicker in the morning and evening, and it becomes lighter or even disappears during the day. The effective horizontal visibility is less than 1KM in fog. When the effective horizontal visibility is 1- 10km, it is called light fog.

"There is actually a difference between fog and haze." Sun Leng, a senior engineer in the Climate System Monitoring Office of the National Climate Center, pointed out that fog refers to the weather phenomenon when the visibility is lower than 1 km due to the condensation of suspended water vapor in the atmosphere. The formation of smog is mainly the result of a large number of suspended particles in the air and meteorological conditions. There are three reasons:

-The phenomenon of static wind in the horizontal direction has increased. The higher the buildings are built in the city, the obstruction and friction of airflow passing through the urban area will be obviously weakened. The increase of static wind phenomenon is not conducive to the diffusion and dilution of suspended particles in the atmosphere, and it is easy to accumulate around urban areas and suburbs;

-There is an inversion in the vertical direction. The inversion layer is like a pot cover over a city. This inversion phenomenon that the upper air temperature is higher than the lower air temperature limits the vertical movement of the lower air, making it difficult for suspended particles in the air to drift to the upper air and be blocked at the lower air and near the ground.

The increase of suspended particles in the air. 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.

With the deterioration of air quality, cloudy days are increasing and the harm is increasing. In many areas of our country, the smog weather phenomenon is combined with fog as an early warning and forecast of disastrous weather. Collectively referred to as "haze weather". In fact, fog and haze are completely different to some extent. For example, when fog appears, the air is humid; When smog occurs, the air is relatively dry and the relative humidity of the air is usually below 60%. The reason is that a large number of extremely fine dust particles, smoke particles and salt particles float in the air evenly, so that the air with effective horizontal visibility less than 10KM is mixed together. The symbol is "∞". The diurnal variation of haze is generally not obvious. When the air mass changes little and is stable, it lasts for a long time, sometimes exceeding 10 days. Due to weather phenomena such as haze, light fog, sandstorm, sand blowing, floating dust and smoke, the effective horizontal visibility is less than 10KM due to a large number of extremely fine dust particles or smoke particles floating in the air. Sometimes it is difficult for meteorological professionals to tell the difference. It is necessary to comprehensively analyze and judge the weather background, sky conditions, air humidity, color and smell, satellite monitoring and other factors in order to draw a correct conclusion. The weather phenomena of fog and haze can sometimes be converted to each other.

Haze is harmful to the human body after being inhaled into the human respiratory tract, and long-term severe inhalation will lead to death.

Second, the influence of smog.

Speaking of the impact of air pollution on newborn health, a recent large-scale international study confirmed that pregnant women exposed to some high-concentration air pollutants are more likely to give birth to underweight babies, while low-birth-weight babies are likely to increase the risk of child death and illness, which has a great relationship with the future development and health of babies. [4]

This study combines the data of 3 million newborn babies provided by 14 research center in 9 countries and regions including the United States, South Korea and Brazil. Emphasis is placed on two kinds of harmful air pollutants, inhalable particles with diameters less than 2.5 microns and less than 10 microns, namely, PM2.5 and PM 10. These particles come from burning fossil fuels and firewood in industry and transportation. But it also includes dust and sea salt particles. According to the researchers' calculation, every increase of 10 micrograms per cubic meter of PM 10 will increase the probability of underweight by 3% and reduce the total average weight by 3 grams. The median value of PM 10 varies between 14 centers, from 12.5 micrograms per cubic meter in Vancouver, Canada. 66.5 micrograms per cubic meter to Seoul, South Korea, combined with the exposure information of PM2.5, with the increase of the exposure level of inhalable particulate matter in each center, the probability of low birth weight of infants increased by 10%.

Third, protect yourself.

1, open the window less in foggy days.

It is not recommended to open the window for ventilation in the morning and evening in foggy weather. It's best to wait until the sun comes out before opening the window for ventilation.

Step 2 wear a mask when you go out

You can wear a mask when you go out, which can effectively prevent dust particles from entering the body. Cotton masks are the best because some people are allergic to non-woven fabrics, while cotton masks are generally not allergic and easy to clean. When you come back from going out, you should wash your face and expose your skin immediately.

3. Drink more Tonghua Platycodon grandiflorum tea

Tongplatycodon grandiflorum tea has the functions of clearing fire and filtering lung dust, and can effectively assist the human body to discharge harmful substances such as PM2.5 particles accumulated in the body. For details, please refer to Baidu Encyclopedia for Platycodon grandiflorum Tea.

4, the right amount of vitamin D.

In winter, there is more fog and less sunshine. Due to insufficient ultraviolet radiation and insufficient vitamin D in the human body, some people will experience mental laziness and depression. If necessary, you can add some vitamin D.

5. Eat lightly and drink plenty of water

The diet in foggy days should choose light and digestible foods rich in vitamins, drink plenty of water and eat more fresh vegetables and fruits, which can not only supplement various vitamins and inorganic salts, but also play a role in moistening the lungs, resolving phlegm, relieving cough, strengthening the spleen and tonifying the kidney. Eat less irritating food and eat more pears, loquats, oranges, oranges and other foods.

6, easy to cause cardiovascular disease.

Smog weather is a "health killer" for patients with cardiovascular diseases, especially the elderly with respiratory diseases and cardiovascular diseases. It is best not to go out in foggy days, and it is not suitable for morning exercise, otherwise it may induce diseases and even heart attacks, which may be life-threatening. Experts pointed out that foggy days are the "dangerous period" for patients with cardiovascular diseases because foggy days are depressed and the oxygen content in the air drops, which makes people feel chest tightness easily. The wet and cold fog in the morning can also cause cold stimulation, which can easily lead to vasospasm, blood pressure fluctuation and increased heart load. At the same time, some pathogens in fog can cause headaches and even induce diseases such as hypertension and cerebral hemorrhage. Therefore, people with cardiovascular diseases, especially the elderly and infirm, should not go out in foggy days, let alone do morning exercises in foggy days to avoid danger.

7. Deep cleaning

The skin on the surface of human body is in direct contact with the outside air, which is very vulnerable to smog weather. Especially in busy and noisy cities, in addition to dealing with the "muscles" of smog at any time, there are many suspended particles produced by construction, automobile exhaust, industrial fuel combustion, fireworks, candles, etc., which will inevitably block pores and form blackheads, resulting in skin problems such as pore blockage, keratin accumulation and skin peeling. Therefore, the primary measure for self-protection is to deeply clean the skin surface and clean pores. Because the whole body of the water-colored Turkish bath is exposed to the continuous high-heat steam, the capillaries of the skin are fully expanded through a large amount of perspiration and heat dissipation, the blood circulation is accelerated, and the excessive fat waste and lactic acid accumulated in the body are quickly discharged from the body, effectively preventing smog particles and fine substances generated by sulfur dioxide and nitrogen dioxide from adhering to the deep skin.