After air pollution, due to the different sources, nature, concentration and duration of pollutants, the differences in meteorological conditions, geographical environment and other factors in polluted areas, and even the differences in people's age and health status, it will do different harm to everyone.
The impact of air pollution on human body is firstly uncomfortable, then the physiological reversible reaction, and then the acute harmful symptoms. The harm of air pollution to people can be roughly divided into three types: acute poisoning, chronic poisoning and carcinogenesis.
(1) acute poisoning
When the concentration of pollutants in the atmosphere is low, it usually does not cause acute poisoning, but under some special conditions, such as special accidents in the production process of factories, a large number of harmful gases leaking out, and sudden changes in external meteorological conditions. It can cause acute poisoning. For example, methyl isocyanate leaked from Pabor pesticide plant in India directly harms human body, with 2,500 people killed and1100,000 injured.
(2) Chronic poisoning
The chronic toxic effect of air pollution on human health is mainly manifested in the increase of morbidity after long-term low-concentration exposure of pollutants to human body. In recent years, the incidence of lung cancer among urban residents in China is very high, the highest of which is Shanghai, and the respiratory diseases of urban residents are significantly higher than those in suburbs.
(3) Carcinogenesis
This is the result of long-term effects, because pollutants act on the body for a long time, destroying the genetic material in the body and leading to variation. If germ cells mutate, all kinds of abnormalities will appear in offspring, which is called teratogenesis. If the genetic material and genetic information of organism cells suddenly change, it is also called mutagenicity; If the tumor is induced, it is called canceration. The "cancer" mentioned here includes benign tumors and malignant tumors. Carcinogens in the environment can be divided into chemical carcinogens, physical carcinogens and biological carcinogens. The canceration process is quite complicated, generally including the initial stage and the growth promotion stage. Factors that can induce tumors are collectively referred to as carcinogenic factors. Tumors caused by long-term exposure to carcinogenic factors in the environment are called environmental tumors. Air pollution will shorten people's life span.
The so-called air pollution means that the normal atmosphere mainly contains nitrogen (78%) which is beneficial to plant growth, oxygen (2 1%) which is needed by human beings and animals, and also contains a small amount of gases such as carbon dioxide < 0.03% >. Air pollution occurs when gases or substances (such as sulfides, nitrogen oxides, dust and organic matter) that are not atmospheric components enter the atmosphere. Air pollution is mainly caused by human activities, and air pollution sources mainly include: factory emissions, automobile exhaust, land reclamation and incineration, forest fires, kitchen smoke (including roadside barbecues), dust (including construction sites) and so on.
Air pollutants are mainly divided into harmful gases (carbon dioxide, nitrogen oxides, hydrocarbons, photochemical smog and halogen elements). ) and particulate matter (dust and acid mist, aerosol, etc.). Their main sources are factory emissions, automobile exhaust, land reclamation, forest fires, kitchen smoke (including roadside barbecues) and dust (including construction sites).
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Second, the harm to industrial and agricultural production.
Air pollution is very harmful to industrial and agricultural production, which will affect economic development and cause a lot of loss of manpower, material resources and financial resources. There are two kinds of hazards of atmospheric pollutants to industry: one is the corrosion of industrial materials, equipment and building facilities by acidic pollutants, sulfur dioxide and nitrogen dioxide in the atmosphere; Second, the increase of floating dust has brought adverse effects on the production, installation, debugging and use of precision instruments and equipment. The harm of air pollution to industrial production, from an economic point of view, is to increase production costs, raise costs and shorten the service life of products.
Air pollution is also very harmful to agricultural production. Acid rain can directly affect the normal growth of plants, and can also cause acidification and dissolution of toxic components in soil and water by infiltrating into soil and water, thus causing toxicity to animals, plants and aquatic organisms. Severe acid rain will make forests decline and fish disappear.
Third, the impact on the atmosphere and climate.
Air pollutants can also affect weather and climate. Particulate matter will reduce atmospheric visibility and reduce the amount of solar radiation reaching the ground. Especially in large industrial cities, the sunshine is 40% less than normal when the smoke and dust are not scattered. The pollutants in the upper atmosphere, such as nitrogen oxides, hydrocarbons and chlorofluorocarbons, decompose ozone in large quantities, resulting in the "ozone hole" problem, which has become the focus of global attention.
Most of the particles discharged into the atmosphere by factories, power stations, automobiles and small domestic coal stoves have the function of condensation nuclei or freezing nuclei of water vapor. These particles can adsorb water vapor in the atmosphere and condense into water droplets or ice crystals, thus changing the original precipitation (rain and snow) in this area. It is found that in the downwind area not far from big industrial cities, the precipitation is more than other surrounding areas, which is the so-called "laporte effect". If acidic pollutants are entrained in the center of particles, they may be attacked by acid rain in the downwind area.
Air pollution not only has a bad influence on the weather, but also on the global climate has gradually attracted people's attention. The greenhouse effect caused by the increase of carbon dioxide concentration in the atmosphere is the most important influence on the global climate. Global warming will bring many adverse effects to human ecological environment, and human beings must fully realize this.
The drying up of rivers, the reduction of forests, the extinction of animals, the destruction of the ozone layer, the greenhouse effect, acid rain and the destruction of the ozone layer are all environmental impacts brought by air pollution. This kind of environmental effect from environmental pollution is lagging behind, and it is often difficult to be detected or predicted when pollution occurs. However, once it happens, it means that environmental pollution has developed to a very serious degree. Of course, the most direct and easily felt consequence of environmental pollution is to reduce the environmental quality of human beings and affect their quality of life, physical health and production activities. For example, urban air pollution causes air pollution, and the incidence of people is rising. Water pollution worsens the quality of water environment, and the quality of drinking water sources generally declines, threatening people's health and causing premature birth or malformation of fetus. Serious pollution incidents not only bring health problems, but also cause social problems. With the intensification of pollution and the improvement of people's awareness of environmental protection, disputes and conflicts between people caused by pollution have increased year by year. At present, environmental pollution problems have appeared in different degrees all over the world, including atmospheric environmental pollution, marine pollution and urban environmental problems. With the globalization of economy and trade, environmental pollution is becoming more and more international. In recent years, the problem of transboundary movement of hazardous wastes is a prominent manifestation in this regard. The adverse effects of the destruction of the earth on human beings are as follows: the ecological environment situation is very severe. First, soil erosion is serious, land desertification is accelerating, forest ecological function is declining, grassland resources are degraded, and water ecological environment system is still deteriorating; Second, the water environment pollution in agriculture and rural areas is serious, and the food safety problem is increasingly prominent; Third, the invasion of harmful alien species, the sharp decline of biodiversity, the loss of genetic resources and the destruction of biological resources are not optimistic; Fourth, due to China's huge population and high natural population growth rate, the per capita possession of important resources related to the national economy and people's livelihood has been declining, resulting in a resource crisis; Fifth, the ecological function continues to decline, ecological security is threatened, the output of industrial solid waste increases sharply, the total amount of air pollution is still at a high level, global warming, ozone layer destruction and so on. The present situation of ecological environment not only brings great destructive power to the ecological environment, but also restricts the coordinated development of economy and society and slows down the socialist process. First of all, the great destruction of the ecological environment has caused us great economic losses. Take the annual flood disaster in China as an example. After a disaster, thousands of people left us forever, a large number of people were homeless, countless beautiful homes were destroyed, countless fertile fields were flooded, and traffic was interrupted by road damage. Let's make a careful estimate. Have we suffered huge economic losses? Secondly, the arbitrary discharge of waste water, waste gas, waste residue and other wastes leads to the pollution of the atmosphere, rivers and land, the serious destruction of the ecological environment, and also seriously damages the physical and mental health of the broad masses of people; Thirdly, due to the serious destruction of vegetation, serious soil erosion and increasingly serious land desertification, many farmers have been forced to leave their homes, and most of them have no fixed place to live, which has aggravated social instability. In fact, there are still many bad consequences caused by destroying the environment. ② Causes of Environmental Pollution Generally speaking, environmental pollution can be the result of human activities, natural activities or the interaction of these two activities. For example, volcanic eruption releases a lot of harmful gases such as dust and sulfur dioxide into the atmosphere, which also pollutes the atmospheric environment. But usually, environmental pollution is more caused by human activities, especially social and economic activities. What we usually refer to is the environmental pollution caused by such human activities. The reason why human activities cause environmental pollution is that there is a fundamental difference between human beings and other creatures: in addition to their own production, human beings also carry out large-scale production, which all other creatures do not have. Because of this, the intensity of human activities is far greater than that of other creatures. For example, in the use of water in the ecosystem, other organisms only use the amount that meets their survival requirements, and humans don't know how many times more water is used than other organisms, so that some local ecosystems are not enough. The emission source of pollutants is called pollution source. The situation of various pollution sources will be described in the fourth section. Environmental pollution can be classified from different angles. According to the type of environmental pollution system or its leading elements, it can be divided into air pollution, water pollution, soil pollution and so on. According to the social field where pollution sources are located, they can be divided into industrial pollution, agricultural pollution and traffic pollution. According to the form or nature of pollutants, they can be divided into waste gas pollution, waste water pollution, solid waste pollution, noise pollution and radiation pollution.