Automobile exhaust mainly refers to

Automobile exhaust mainly refers to the exhaust gas discharged from the exhaust pipe. The exhaust gas contains 150 to 200 different compounds, among which carbon monoxide, hydrocarbons, nitrogen oxides, lead compounds and particulate matter are the most harmful. The diffusion of harmful gases into the air causes air pollution. The particulate matter of automobile exhaust contains strong carcinogen benzo (a) pyrene. In general, one gram of particulate matter contains about 70 micrograms of benzo pyrene, which can produce 30 mg of benzo pyrene per kilogram of gasoline. When the concentration of benzopyrene in the air reaches 0.012 microgram/cubic meter, the number of lung cancer in residents will increase significantly. Automobile exhaust not only harms people, but also poisons plants. Ozone and peroxyethyl nitrate, the secondary pollutants in exhaust, can cause necrosis and blight of plant leaves. Ethylene can affect the flowering and bearing of plants. Vehicle exhaust is more harmful to beet, spinach, tomato and tobacco. The crop yield reduction on both sides of the highway is obviously related to the pollution of automobile exhaust.