Today, in modern civilization, the car has become an indispensable means of transport. Since the birth of the first vehicle since 1886, it brought to people's lives and greatly facilitated the work, but also has become one of the pillars of modern material. However, we should also note that the rapid development in the automobile industry, and maintain the continuous increase in the production of motor vehicles, the air pollution has brought automobile, automobile exhaust pollution. The main hazard is automobile exhaust to form smog. 1943, Los Angeles, California in the United States, 2.5 million cars burning off 1,100 tons of gasoline per day. After the combustion of hydrocarbons, such as gasoline ultraviolet rays of the sun under a chemical reaction, forming a light blue smoke, most people suffering from the city jealous, headache disease. Later, it was known as photochemical smog of this pollution. Los Angeles twice in 1955 and 1970 occurred photochemical smog, and more than 400 former featured poisoning, respiratory failure and death, the latter a city of three-quarters of the sick. This is the history to be called "the world's eight major hazard" and "20th Century 10 environmental hazards," Los Angeles smog in one of the incidents. It is a profound understanding of these incidents to the people of the dangers of automobile exhaust. 200 vehicle emissions of organic compounds, including benzene, a highly carcinogenic polycyclic aromatic ingredients, the human body is a long-term cumulative effects. Medical studies have revealed that a large number of benzene vapor inhalation a short period of time can cause life-threatening acute poisoning, the long-term repeated exposure to low levels of benzene can cause chronic poisoning. Data show that PM10 concentrations increased with a series of negative effects on human health closely. American scientists have done in Utah Valley epidemiological studies found that the PM10 air to have a significant impact on human health can lead to cardiovascular disease, respiratory disease and other diseases in patients with sensitive physical death. It is estimated that 60,000 PM10 lead of the United States and the United Kingdom each year 10,000 people died. Through screening and comprehensive analysis of childhood lead poisoning caused by automobile exhaust pollution is the main factor, as automobile exhaust lead dust accumulation in more than one meter above the ground, and that is exactly the children's activities with the breathing zone of pollution caused by it has become one of the major causes of childhood lead poisoning. Include automobile exhaust pollutants : carbon monoxide, hydrocarbons, nitrogen oxides, sulfur dioxide and soot particles (some heavy metal compounds, lead compounds, smoke and oil mist), smell (formaldehyde). According to statistics, about 1,000 vehicles a day 3/hm emit carbon monoxide, hydrocarbons 200-400kg and nitrogen oxides 50-150kg; Los Angeles and other mobile sources of pollutants emitted by motor vehicles accounted for 90% of total atmospheric pollutants. According to the State Environmental Protection Administration predicted that in 2005 China's vehicle emissions in urban air pollution will reach 79% of the share of air pollution in automobile exhaust is the "culprit." Automobile exhaust the highest level of carbon monoxide, it can enter through the respiratory tract of gestation, the blood was absorbed, combined with hemoglobin to form carboxyhemoglobin, lowering blood oxygen, blood weaken the oxygen supply of human tissues, resulting in tissue hypoxia, which led to headaches and other symptoms, or suffocation. The content of nitrogen oxides from automobile exhaust smaller, but highly toxic, toxicity is three times the sulfur oxides. Alveolar oxygen into nitrogen compounds, lead to the formation of nitrite and nitrate, a sharp stimulus to the lung tissue, increased pulmonary capillary permeability, leading to emphysema. Nitrite with hemoglobin, forming ferrihemoglobin caused tissue hypoxia. 200 species of hydrocarbons from automobile exhaust, C2H4 concentration in the atmosphere indicated to (1%), to enable some plants dysplasia. Automobile exhaust also found 32 species of polycyclic aromatic hydrocarbons, including 3,4 - benzopyrene and other carcinogenic substances. When the concentration reaches 0.012ug/m3 benzopyrene in the air, residents will have a marked increase in the number of lung cancer. More nearly away from the road, the greater the traffic flow on the highway, the higher the mortality rate of lung cancer. 回答者: lynice - 助理 二级 10-8 14:04