Causes and harm of smog

The causes of smog and its harmful pictures. Hazy weather is a state of air pollution. The smog we often talk about is actually the combination of fog and haze, which is harmful to the body. Introduce the causes and harm pictures of smog for everyone.

Haze and the Causes of Haze Picture 1 Causes of Haze Weather Formation

1, human reason

① Automobile exhaust. Automobile exhaust is the main component of smog particles.

(2) Waste gas generated by burning coal for heating in winter in the north.

(3) Waste gas discharged from industrial production. For example, metallurgy, kilns and boilers, electromechanical manufacturing, automobile repair and paint and building materials production produce a lot of waste gas from kiln combustion.

④ Dust from construction sites and road traffic.

⑤ Particles can grow. The particle size of bacteria and viruses is equivalent to PM0,1~ PM2,5. When the humidity and temperature in the air are appropriate, microorganisms will attach to particles, especially oil fume particles. After absorbing oil droplets, microorganisms will be transformed into more microorganisms, which will increase the number of biological toxic substances in smog.

⑥ Dust "smog" will also be produced in home decoration. 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 also brings many hidden dangers to the decoration project.

2. Climatic reasons

① The phenomenon of static wind in the horizontal direction increases. 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.

② The inversion temperature appears 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.

③ The increase of suspended particles and organic pollutants in the air. With the growth of urban population and industrial development, the number of motor vehicles has surged, resulting in a large increase in pollutant emissions and suspended solids.

Haze weather hazard

1, harm to human body

Haze can affect people's respiratory system, causing acute rhinitis and acute bronchitis. For patients with chronic respiratory diseases such as bronchial asthma, chronic bronchitis, obstructive emphysema, and chronic obstructive pulmonary disease, smog weather will make the condition acute or acute.

② Haze days have a serious impact on cardiovascular and cerebrovascular diseases, which will hinder normal blood circulation and lead to cardiovascular diseases, hypertension and coronary heart disease.

(3) Hazy weather will also lead to the weakening of ultraviolet rays in the surface layer, which can enhance the activity of infectious bacteria in the air and increase infectious diseases.

4 smog is not conducive to children's growth. In foggy days, due to the decrease of sunshine, insufficient ultraviolet radiation for children, insufficient production of vitamin D in the body, and greatly reduced absorption of calcium, rickets in infants and young children will be seriously caused, which will slow down the growth and development of children.

2. Impact on ecological environment and traffic.

① In foggy days, traffic jams and traffic accidents are easily caused due to poor air quality and low visibility. In daily driving, you should observe the road conditions to avoid danger.

② In foggy weather, the light is seriously insufficient, and the ultraviolet rays near the bottom are obviously weakened, so it is difficult to kill the bacteria in the air, thus greatly increasing the probability of suffering from infectious diseases.

③ Haze weather has an important impact on roads, railways, aviation, shipping, power supply system and crop growth. Fog and haze will cause air quality decline, affect the ecological environment and bring great harm to human health.

Cause and harm of haze Picture 2 Causes of haze weather formation

Increasingly serious air pollution is the main cause of smog formation. A large number of polluting enterprises that do not meet the national environmental standards, such as the traditional steel industry, are still using a large number of outdated equipment. Waste gas and waste residue are discharged into the atmosphere before discharge, including sulfur dioxide, nitrogen oxides and inhalable particles, which are the initiators of smog and are extremely harmful to human body.

With the prevalence of private cars, traditional cars can only use gasoline fuel, and a large number of automobile exhaust gases contain many toxic particles, which is an important reason for smog.

The urban planning and construction are unreasonable and the greening degree is low. Flowers and trees are important media for absorbing, decomposing and treating air pollutants, especially carbon dioxide and dust particles. But the present situation is that our greening level is still relatively low, and we need more green messengers to protect our homes.

Hazards of smog

The first is the harm to the respiratory system. Dust particles, hydrogen sulfide and hydrosulfide in smog are directly inhaled through the nose and mouth, attached to the human respiratory mucosa, deposited and stimulated the respiratory tract and alveoli, causing respiratory diseases such as bronchial asthma and lung diseases. Some researchers pointed out that walking for half an hour in foggy weather is more harmful than smoking a box of cigarettes!

Hazy weather will also lead to the widespread spread of various infectious viruses with the aggravation of smog. Therefore, wear a mask when going out in foggy days to minimize outdoor activities.

Affect our happy mood and mental health. Severe smog weather is easy to make people fidgety and depressed.

The cause and harm of smog. Figure 3 What are the components of smog?

I. Sulfur dioxide

Sulfur dioxide is the most common sulfur oxide, a colorless gas with a strong pungent smell, and it is also one of the main pollutants in the atmosphere. Both coal and oil contain sulfides, so sulfur dioxide will be produced when burning. Sulfur dioxide is easily soluble in water after being inhaled into the respiratory tract, so most of it is blocked in the upper respiratory tract. Corrosive sulfurous acid is generated on wet mucosa, and part of it is further oxidized into sulfuric acid, which enhances the stimulation. If the human body inhales sulfur dioxide with the concentration of 100 ppm every day, after 8 hours, there will be obvious irritation symptoms in the bronchi and lungs, which will damage the lung tissue.

If sulfur dioxide enters the deep layer of human lungs with airborne particles, its toxicity will increase by 3 ~ 4 times, leading to fibrous hyperplasia of alveolar wall. If the proliferation range spreads widely, it will form pulmonary fibrosis, which will break the pulmonary fibers and form emphysema. Sulfur dioxide can also be absorbed into the blood by the human body, which has a toxic effect on the whole body. It can destroy the activity of enzymes, affect human metabolism and do some damage to the liver.

Second, nitrogen oxides

Nitrogen oxides refer to compounds composed of nitrogen and oxygen, such as nitric oxide, nitrogen dioxide, nitrous oxide, nitrous oxide and so on. As air pollutants, nitrogen oxides generally refer to nitric oxide and nitrogen dioxide. In addition to natural circulation, most nitrogen oxides in the atmosphere come from the combustion of fossil fuels, such as automobiles, airplanes and industrial boilers. Fertilizer plants and metal smelters also emit this gas.

Nitrogen oxides can stimulate the lungs, reduce people's resistance to respiratory diseases such as colds, and also cause damage to children's lung development. In addition, nitrogen oxides, mainly nitric oxide and nitrogen dioxide, will react with hydrocarbons under ultraviolet irradiation to form toxic smog, that is, photochemical smog and photochemical smog have special smells, which irritate eyes, harm plants and reduce atmospheric visibility. 65438-0943, photochemical pollution occurred in Los Angeles, USA, killing more than 800 people. Many people have symptoms of eye pain, headache and difficulty breathing. In addition, 1970 photochemical smog incident in Tokyo, Japan also caused 20,000 people to suffer from pinkeye.

Third, inhalable particulate matter.

When it comes to inhalable particulate matter, you will definitely think of PM2 and PM5, which are suspended in the atmosphere like PM 10, but with different particle sizes. PM2 and PM5 are part of PM 10, that is, particles with diameters below 2 and 5 microns. Because the particle size of PM2 and PM5 is very small, the nasal cavity and throat of human body are unstoppable. They can descend all the way, enter bronchioles and alveoli, then enter capillaries through alveolar walls, and then enter the whole blood circulation system. Damage to human respiratory system and cardiovascular system.

PM2 and PM5 mainly come from man-made emissions, including primary emissions and secondary transformation. Primary emission mainly comes from combustion process and dust. Secondary conversion refers to the formation of gaseous precursors such as sulfur dioxide, ammonia, nitrogen oxides and volatile organic compounds through chemical reactions in the atmosphere.