Air pollution in Beijing

Main air pollution sources: coal burning, motor vehicle exhaust, factory exhaust gas and dust.

China is the largest producer and consumer of coal in the world. About 78% of electricity, 60% of civil commodity energy and 70% of chemical raw materials depend on coal. The direct combustion of coal is the most important man-made air pollution source in China.

China ranks first in the world in motorcycle production and first in automobile production 1 1. Although the number of cars used is much lower than that of developed countries, the air pollutants emitted by domestic cars per kilometer are three to five times that of European cars. China's urban speed is much lower than that of developed countries because of poor road system facilities. Road area accounts for only 3.6% of Shanghai's total area, while Tokyo accounts for 14438+0% of the total area.

The number of cars in China will quadruple in the next fifteen years, so smart cars with the latest technology will be the key to solve the air pollution and energy problems in China.

According to the data of the State Environmental Protection Administration of China, the number of cars on the road is expected to increase to 33 million by 2006, and will jump to 1.3 1 100 million by 2020, which may cause air pollution and energy shortage.

During the period of 1997, China's industrial smoke and dust emissions reached 6.846 million tons, and industrial dust emissions reached 5.484 million tons, of which township enterprises accounted for a large proportion.

Road dust carried by construction sites, demolition sites and motor vehicles is an important source of dust. Sandstorm caused by vegetation destruction (including deforestation, reclamation and overgrazing) in northern China is also a pollution source that cannot be ignored, especially in spring.

The incineration of urban garbage and suburban agricultural waste is also a potential source of air pollution, which will emit carcinogens such as dioxins and polycyclic aromatic hydrocarbons.

Air pollution caused a lot of losses.

The losses caused by urban air pollution in China mainly include: the health loss caused by indoor and outdoor air pollution (especially chronic bronchitis), the loss of crops and forests caused by acidic precipitation, the corrosion of materials, and the high lead content in particulate matter, which leads to the nervous system damage and mental decline of children. According to the results published by the World Bank 1997, air pollution in China leads to a high daily mortality rate. The losses caused by excessive air pollution-including premature death, diseases, loss of means of production and urban buildings-are estimated to account for 2.9% of GDP according to the algorithm of human resources.

The Ministry of Health of China has identified chronic obstructive respiratory diseases as one of the main causes of death in China, accounting for more than 65,438+0/4 of all deaths.

Main measures to slow down air pollution

The measures to alleviate air pollution are mainly changing from coal to gas (including natural gas, gas and liquefied petroleum gas), central heating and hydropower generation. In China, 654.38+47 million residents have used gas for cooking, and the urban gas penetration rate has reached 75.7%.

The technical measures to reduce motor vehicle pollution mainly include prohibiting the use of leaded gasoline, installing catalytic converter boxes on cars and installing EFI systems on new cars. Beijing, Shanghai, Chongqing and Harbin have modified 300 to 5,000 buses, using natural gas or liquefied petroleum gas as fuel. Many taxis in Beijing have switched to dual-purpose fuel. The Ministry of Science and Technology and the United Nations Development Programme also support the demonstration of fuel cell vehicles.

A big city like Beijing must control its population.

Most notably, the sudden increase in urban population has aggravated urban air pollution, which requires additional energy consumption, including consuming more coal to generate electricity and providing more oil for motor vehicles. Urbanization brings an average annual population growth rate of 6% ~ 7%, which leads to the emergence of new residential areas, new coal-fired heating boilers and numerous construction sites in the suburbs. These construction sites lack effective dust/dust control measures. These human activities offset the environmental improvement brought by changing household energy from coal to gas fuel. In the past two years, the Beijing Municipal Government has invested a lot of money and manpower and taken 93 emergency measures, further changing coal to natural gas, heating to central heating, and moving factories to suburban counties. However, the total coal consumption in Beijing has not decreased much. 1999, the whole city of Beijing including suburban counties still consumes coal160,000 tons. There are many new pollution sources in the lower level of urban-rural fringe. Due to atmospheric diffusion and heat island effect, sulfur dioxide and fine particles can still spread to urban areas, affecting urban air quality. 1999 The number of migrants living in Beijing for a long time has reached1800,000, and most of the working population lives in the urban-rural fringe. They have no gas and natural gas for cooking and no coal stoves for heating, and a large number of small coal stoves have not been eliminated. It is necessary to control the urban population.

In order to achieve the goal of better air, bluer sky and greener water, Beijing has carried out five aspects of work in general. First, improve Beijing's energy structure, from burning coal to burning natural gas, and the second pipeline to introduce Shaanxi-Gansu natural gas is being laid; Second, heavily polluting enterprises are determined to relocate and carry out technological transformation in the process of relocation. For example, Shougang has moved a considerable number of factories to Hebei Province, and carried out technical transformation in the process to reduce pollution; Third, Beijing's automobile exhaust emission standards are stricter than the national standards. At present, Euro II standard is implemented, and Euro III standard will be implemented next year. Fourth, replace all coal-fired stoves within the Fourth Ring Road in Beijing with electricity and gas to reduce pollution; Fifth, carry out large-scale greening, beautification and afforestation to make Beijing's ecological environment better and improve the quality of life of Beijing residents.

In addition, adjust the price of energy charges to curb the use of inferior coal; Adjust sewage charges to improve the enthusiasm of enterprises for pollution control; It is necessary to raise public awareness of air quality, especially officials, and strengthen environmental and economic training.

Although China is slowing down the deterioration of air quality by controlling industrial pollution, its enthusiasm for cars is preventing further improvement of pollution. Li Xinmin, deputy director of the Pollution Control Department of the State Environmental Protection Administration of China, said that there are currently 27 million cars on the roads in China, and 4-5 million new cars or trucks join the ranks every year. In the past 20 years, the average annual economic growth in China has reached 9.4%. In order to meet the demand for electricity in industrial production, the coal supply needs to grow steadily. 67% of China's energy comes from coal. In order to keep up with the demand, the quality of coal provided by coal producers in China is declining, and the pollution is becoming more and more serious. He said that the sulfur content of coal currently produced in China has reached 1%, and more sulfur has been released into the air. Sulfur dioxide is a major pollutant and one of the greenhouse gases that cause global warming. According to the current trend, by 2025, China will surpass the United States and become the largest emitter of greenhouse gases in the world.

Air pollution sources can be divided into natural and man-made two categories. Natural pollution sources are formed due to natural causes (such as volcanic eruptions, forest fires, etc.). ), and man-made pollution sources are formed because people are engaged in production and life activities. Among man-made pollution sources, it can be divided into fixed (such as chimneys and industrial exhaust pipes) and mobile (such as cars, trains, planes and ships). Due to the prevalence and frequency of man-made pollution sources, people pay more attention to them than natural pollution sources. The main sources of air pollution are: (1) industrial enterprises, which are the main sources of air pollution and one of the key points of air health protection. With the rapid development of industry, the types and quantities of air pollutants are increasing. Due to the different nature, scale, technological process, raw materials and product types of industrial enterprises, the degree of air pollution is also different. (2) Living stoves and heating boilers in residential areas, with the concentration of population, a large number of civil living stoves and heating boilers also need to consume a lot of coal, especially in winter heating time, which often makes the polluted areas filled with smoke, which is also an air pollution source that cannot be ignored. (3) Transportation In recent decades, due to the development of transportation, more and more cars are driving in the city, and passenger and cargo transportation such as trains, ships and planes is frequent, which has added new air pollution sources to the city. Of great significance is the exhaust gas emitted by cars. The characteristic of automobile air pollution is that the pollutants discharged are close to people's breathing zone and can be directly inhaled by people. The exhaust gas from automobile internal combustion engines mainly contains carbon monoxide, nitrogen oxides, hydrocarbons (hydrocarbons), lead compounds and so on. (II) Harm and influence of air pollution The harm and influence of air pollution on human beings and their living environment have been gradually recognized by people, which can be summarized as follows: ① Harm to human health. There are three ways for human body to suffer, that is, inhaling polluted air, skin contact with polluted air, and eating food containing atmospheric pollutants, which will not only cause respiratory and lung diseases, but also harm cardiovascular system and liver, and even seriously endanger people's lives. ② Harm to living things. Animals get sick or die from inhaling polluted air or eating food containing pollutants. Air pollutants will reduce the disease resistance of plants, affect their growth and development, and cause leaf spot or wither and die. ③ Damage to articles. Such as textiles and clothing, leather, metal products, building materials, cultural works of art, etc. , causing chemical damage and pollution damage. ④ Causing acid rain, which has adverse effects on agriculture, forestry and freshwater aquaculture. ⑤ Destroy the upper ozone layer and form an ozone hole, which is harmful to the living environment of human beings and organisms. ⑥ It has an impact on the global climate. For example, the increase of greenhouse gases such as carbon dioxide will lead to the warming of the earth's atmosphere and the increase of global weather disasters. For example, the increase of aerosol particles such as smoke and dust will increase atmospheric turbidity, weaken solar radiation, affect the long-wave radiation of the earth, and may lead to abnormal weather and climate. How to prevent and control air pollution and reduce its harm and influence has become a major and urgent research topic. (3) Prevention and control of air pollution Prevention and control of air pollution is a huge systematic project, which requires the joint efforts of individuals, collectives, countries and even countries around the world. The following measures can be considered: ① Reduce pollutant emissions. Pollution-free energy (such as solar energy, wind energy, hydropower generation), energy structure reform, low-pollution energy (such as natural gas), fuel pretreatment (such as desulfurization before burning coal), and improved combustion technology can all reduce pollutant emissions. In addition, before pollutants enter the atmosphere, some pollutants in waste gas can be eliminated by dust removal and smoke elimination technology, condensation technology, liquid absorption technology and recycling technology, so as to reduce the amount of pollutants entering the atmosphere. ② Control emissions and make full use of the self-purification ability of the atmosphere. Different meteorological conditions have different atmospheric capacity of pollutants, and the same pollutant discharge will cause different pollutant concentrations. For areas and time periods with strong wind, good ventilation, strong turbulence and strong convection, the atmospheric diffusion and dilution ability is strong, and it can accept more areas and time periods where the temperature of factories and mines is reversed. If the atmospheric diffusion and dilution ability is weak, it can't accept more pollutants, otherwise it will cause serious air pollution. Therefore, effective emission control should be carried out in different regions and different time periods. (3) The site selection, chimney design, urban and industrial planning should be reasonable to avoid excessive concentration of large emitters and repeated pollution, resulting in serious local pollution incidents. (4) Planting trees to allow more plants to absorb pollutants and reduce the degree of air pollution.