(1) Harm to human health: People need to breathe air to maintain their lives. An adult breathes about 20,000 times a day and inhales 1.5 ~ 20 cubic meters of air. Therefore, polluted air has a direct impact on human health.
The harm of air pollutants to human body is various, mainly manifested in respiratory diseases and physiological dysfunction, as well as the irritation of mucosal tissues such as eyes and nose.
For example,1February 5-8, 952, the soot incident in London, England, killed 4000 people. People call the smoke of this disaster "the smoke of killing people". According to the analysis, this is because there was no wind and fog in London, and the smoke and dust generated by factory chimneys and residents' heating permeated the urban area of London for a long time. The highest concentration of smoke and dust reaches 4.46 mg/m3, and the daily average concentration of sulfur dioxide reaches 3.83 ml/m3. Sulfuric acid droplets produced by chemical reaction of sulfur dioxide attach to smoke or condense on fog droplets, and enter organs with breathing, which makes people sick or accelerates the death of patients with chronic diseases.
As can be seen from the above example, when the concentration of pollutants in the air is high, it will cause acute pollution poisoning, or aggravate the symptoms, and even kill thousands of people within a few days. In fact, even if the concentration of pollutants in the atmosphere is not high, breathing this polluted air all the year round will cause chronic bronchitis, bronchial asthma, emphysema, lung cancer and other diseases.
There are many prevention and control measures, but the most fundamental thing is to reduce pollution sources. The following measures are usually taken:
(1) Reasonable industrial layout: This is an important measure to solve air pollution. Factories should not be too concentrated to reduce pollutant emissions in an area. In addition, chemical plants with raw material supply relations should be put together to reduce waste gas emissions through comprehensive utilization of waste gas.
(2) District heating and central heating: stoves scattered in thousands of households and short chimneys as dense as trees in cities are the main pollution sources of soot dust pollution. It is an important measure to eliminate soot by central heating and district heating, that is, to replace the stoves of thousands of households in several large thermal power plants with efficient dust removal equipment set in the suburbs.
(3) Reduce the pollution of traffic exhaust: The key to reduce the pollution of automobile exhaust is to improve the combustion design of the engine, improve the combustion quality of gasoline, and make the engine oil burn fully, thus reducing harmful exhaust.
(4) Changing fuel composition: changing coal into gas, and stepping up research and development of other new energy sources, such as solar energy, hydrogen fuel and geothermal energy. In this way, the pollution of smoke can be greatly reduced.
(5) Afforestation: Dense forests can reduce wind speed and a lot of dust carried in the air. The surface of leaves is rough, some have fluff, and some can secrete mucus and oil, so they can absorb a lot of floating dust. Dusty leaves can continue to absorb dust after being washed by rain. Such reciprocating blocking and adsorption of dust can purify the air.
(6) Adjust the energy structure, rationally plan the layout of industrial development and urban construction, reduce pollutant discharge, increase urban green area, plant trees and make full use of the self-purification ability of the environment. At the same time, it is necessary to formulate standards, strengthen monitoring and forecasting, and cultivate environmental awareness.