PM2 5 refers to tiny particles less than 2 5 microns in diameter in the atmosphere  Their size is that the body can reach into the lungs of the human body and cause serious harm to people's respiratory health In recent years, there have been large-scale and long-term haze weather in central and eastern China, and the PM2 5 index in many places has risen in a straight line  A city has introduced traffic restrictions on odd and even vehicle numbers to deal with air pollution However, experts do not approve of this measure of traffic restrictions and believe that this practice has little impact on the decline of the city's PM2
Compared with industrial pollution, the effect of vehicle exhaust on air pollution is small
5 index and cannot fundamentally change the situation of air pollution