1 930 65438+February15 o'clock, it is the middle of winter, and the fog covers the whole land of Belgium. The fog over the industrial area of the Maas Valley in the west of Liege, Belgium is particularly thick. On the third day, under the combined effect of sulfur dioxide (SO2), other harmful gases and dust pollution, thousands of people in the valley industrial zone developed respiratory diseases, including chest pain, cough, tears, sore throat, hoarseness, nausea, vomiting and dyspnea.

2. Los Angeles photochemical smog incident

The photochemical smog event in Los Angeles, USA, was an event in which toxic smog polluted the atmosphere of Los Angeles from 1940 to 1960, and it was one of the world-famous public hazards.

Photochemical smog is a toxic gas produced by the chemical reaction of hydrocarbons in automobile exhaust with other components in the air under the action of sunlight. These toxic gases include ozone, nitrogen oxides, aldehydes, ketones, peroxides and so on.

3. Donora Smoke Incident

1948 10 10/October 26th -3 1, located in the small town of Donora, Pennsylvania, USA. Because the gas and metal particles containing toxic and harmful substances such as sulfur dioxide discharged from factories in the town gather in the valley in abnormal climate, these toxic substances are attached to suspended particles, which seriously pollutes the atmosphere.

Extended data:

air pollution control

International measures

1979165438+10 At the meeting of environment ministers of the United Nations Economic Commission for Europe held in Geneva in October, the Convention on the Control of Long-range Transboundary Air Pollution was adopted and came into force in 1983. According to the convention, by the end of 1993, the contracting parties must reduce the sulfur dioxide emissions to 70% of the emissions of 1980. Thirty-two countries, including Europe and North America (including the United States and Canada), signed the Convention.

According to the acid rain law of the United States, the emission of sulfur dioxide east of the Mississippi River will be reduced from 20 million tons/year in 1983 to100000 tons/year; The emission of sulfur dioxide in Canada decreased from 4.7 million tons/year in 1983 to 2.3 million tons/year in 1994.

Main measures to reduce sulfur dioxide emissions in countries around the world;

1, raw coal desulfurization technology.

2. Improve coal-burning technology.

3. Lime process is mainly used to remove 85%-90% of sulfur dioxide gas from flue gas. However, although the desulfurization effect is good, it is very expensive.

4. Develop new energy sources, such as solar energy, wind energy, nuclear energy and combustible ice. But the technology is not mature enough. If used improperly, it will cause new pollution, and consumption cost is very high.

The harm of air pollution to human body is mainly manifested in respiratory diseases; It can inhibit the physiological mechanism of plants, leading to poor growth, weakened disease and insect resistance and even death.

Air pollution will also have adverse effects on the climate, such as reducing visibility and solar radiation (data show that the intensity of solar radiation and ultraviolet radiation in cities is lower than that in rural areas 10 ~ 30% and 10 ~ 25% respectively), leading to an increase in the incidence of rickets in cities; Air pollutants will corrode articles and affect product quality.

In recent ten years, acid rain has appeared in many countries, and the acidity in rain and snow has increased, which has made rivers and lakes, soil acidification, fish reduction and even extinction, affecting forest development, which is closely related to air pollution.

Baidu Encyclopedia-Mas Valley Smoke Event

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