Section 1 Environmental Pollution
Because China is now in the stage of rapid development of industrialization and urbanization, the intensity of natural resources development is increasing, and the economic growth mode is extensive, the technical level and management level are relatively backward, and the pollutant discharge is increasing. From the overall situation of the country, China's environmental pollution is still increasing, ecological deterioration is hard to return, and the environmental situation is not optimistic.
I. Air pollution
1. Pollution status
According to the Bulletin on Environmental Status of China, the air quality in China was still at the level of severe pollution during the period of 1997, and the northern cities were more serious than the southern cities (see Figure 3- 1). The average annual concentration of sulfur dioxide ranges from 3 to 248 μ g/m3, and the national average is 66 μ g/m3. More than half of the northern cities and more than one third of the southern cities have an annual average value exceeding the national secondary standard (60 micrograms per cubic meter). The annual average of northern cities is 72 μ g/m3; The annual average of southern cities is 60 micrograms per cubic meter. Yibin, Guiyang, Chongqing and other high-sulfur coal-mining cities in southwest China, as well as cities with high energy consumption such as Shanxi, Shandong, Hebei, Liaoning, Inner Mongolia, Henan and Shaanxi, are seriously polluted by sulfur dioxide.
Figure 3- 1 Comprehensive Index of Urban Air Pollution
The average annual concentration of nitrogen oxides ranges from 4 ~ 140 μ g/m3, and the national average is 45 μ g/m3. The annual average of northern cities is 49 μ g/m3; The annual average of southern cities is 4 1 μ g/m3. 34 cities exceeded the national secondary standard (50 μ g/m3), accounting for 36.2% of the statistical cities. Among them, the pollution of nitrogen oxides in Guangzhou, Beijing and Shanghai is serious, with the average annual concentration exceeding 100 μ g/m3; Cities such as Jinan, Wuhan, Urumqi and Zhengzhou are also heavily polluted.
The average annual concentration of total suspended particles ranges from 32 to 741μ g/m3, and the national average concentration is 29 1 μ g/m3. There are 67 cities that exceed the national secondary standard (200 μ g/m3), accounting for 72% of the total number of cities. The annual average of northern cities is 38 1 μ g/m3; The annual average of southern cities is 200 μ g/m3. In terms of regional distribution, most areas of Beijing, Tianjin, Gansu, Xinjiang, Shaanxi and Shanxi, as well as parts of Henan, Jilin, Qinghai, Ningxia, Inner Mongolia, Shandong, Hebei and Liaoning, are seriously polluted by total suspended particulate matter.
According to the research report of the World Bank, the concentration of air pollutants in some major cities in China far exceeds the international standards, ranking among the best in the world and one of the most polluted cities in the world (see Figure 3 ~ 2).
There are too many things that pollute the environment. ...
primary pollutant
Also known as "primary pollutants". Pollutants directly or indirectly discharged into the environment by pollution sources. Such as chemical poisons and viruses discharged into clean air and water. It is the main source of environmental pollution.
secondary pollutants
Also known as "secondary pollutants". Pollutants discharged by pollution sources (usually called "primary pollutants") evolve into new pollutants in the environment. It is often more harmful to the environment and human body. For example, the sulfuric acid mist produced by the encounter between sulfur dioxide and water vapor in the atmosphere is ten times stronger than sulfur dioxide; When photochemical smog occurs, it will produce secondary pollutants such as ozone, formaldehyde and acrolein, which are harmful to animals, plants and building materials.
air pollution
[Air pollution] There are a lot of pollutants such as dust, smoke, gas, fog, odor, smoke or steam in the outdoor atmosphere, and their characteristics and duration are enough to endanger human health or the lives of animals and plants.
Air pollution When the content of some substances in the air exceeds the normal content, it will harm animals and plants and affect their survival. The normal contents of C0, NH3, SO2, H2S, Cl2, O3 and NO2 in the atmosphere are all below a few parts per million, which has no obvious adverse effects on animals and plants. However, since the19th century, due to the development of industry and transportation, these substances have been discharged into the atmosphere in large quantities, which has made air pollution increasingly serious, affecting the life activities of animals and plants and even human health. Some sources of pollutants come from nature (such as volcanic ash erupted by volcanoes), and some come from human activities, among which the exhaust gas produced by industry and transportation is the main pollution source.
Automobile exhaust pollution
Environmental pollution caused by automobile exhaust. The main pollutants are hydrocarbons, nitrogen oxides, carbon monoxide, sulfur dioxide, lead-containing compounds, phenylpropyl pyrene and solid particles. Will cause photochemical smog and so on.
atmospheric pollution
The phenomenon that pollution leads to the decline of air quality. It is caused by pollutants discharged by human activities or natural processes. It can cause changes in atmospheric physical and chemical conditions, and has adverse effects on human body, animals and plants and other objects. Can be converted into water pollution and soil pollution.
Radioactive contamination
Environmental pollution caused by radioactive substances. The main pollutants are emissions from nuclear industry enterprises, radioactive fallout from nuclear tests, cosmic rays in nature, radioactive deposits and natural radioisotopes. It can harm human body through food chain or directly.
noise pollution
[Noise pollution] Environmental pollution caused by interference or harmful noise (such as the noise of cars or jet planes).
heavy metal contamination
Environmental pollution caused by heavy metals or their compounds. It is mainly caused by human factors such as mining, waste gas emission, sewage irrigation and the use of heavy metal products. For example, Minamata disease and pain in Japan are caused by mercury pollution and cadmium pollution respectively. The degree of harm depends on the concentration and chemical forms of heavy metals in the environment, food and organisms.
exhaust pollution
Air pollution caused by harmful gases emitted by automobiles. The main harmful gases are carbon monoxide, nitrogen oxides, hydrocarbons and sulfur dioxide. Due to the variety of gasoline, vehicle load, engine performance, road conditions, meteorological conditions and other factors, its quantity and types are different. Because the exhaust height of automobile is in the human breathing zone, exhaust pollution is very harmful to human health.
Radio frequency pollution
Radio frequency electromagnetic radiation (emission frequency is 3 kHz to 3× 10? 5 MHz) is caused by environmental pollution. Common pollution sources are high-altitude TV transmission towers, medium-short wave and microwave transmission equipment, high-frequency heating equipment and short-wave or ultrashort wave physiotherapy machines.
soil contamination
The deterioration of soil quality due to pollution. Pollutants mainly come from sewage irrigation, pesticide application, fertilization, waste stacking (or landfill) and atmospheric deposition. It not only hinders the development of agriculture, forestry, fishery and animal husbandry, but also affects human health.
white pollution
The so-called "white pollution" is an image title for people to pollute the environment by plastic waste. It refers to the phenomenon that all kinds of living plastic products made of polystyrene, polypropylene, polyvinyl chloride and other polymer compounds are discarded as solid waste after use, which is difficult to degrade because of littering at will, resulting in serious pollution of the urban environment.
water pollution