根(gen)據目前對空氣(qi)(qi)中PM2.5來(lai)源的認識,煤炭燃燒(shao)、機動車尾氣(qi)(qi)、工業排放、建(jian)筑和(he)道路揚(yang)塵、區(qu)域傳輸等(deng)來(lai)源,在不(bu)同(tong)(tong)地(di)(di)區(qu)、不(bu)同(tong)(tong)時(shi)段其(qi)(qi)貢獻各不(bu)相同(tong)(tong)。由于PM2.5 在空氣(qi)(qi)中滯留(liu)的時(shi)間(jian)較(jiao)長,所以通(tong)常PM2.5 污染(ran)具(ju)有(you)區(qu)域性特征。對某一地(di)(di)區(qu)而(er)言,除了本地(di)(di)產生的PM2.5外,其(qi)(qi)周邊地(di)(di)區(qu)的影響也是重(zhong)要的來(lai)源。