Airpollutionisoneofthemajorproblemsofthemodernworld.Agreatdealofenergyisneededtorunthefactoriesofmodernindustrialnations.Automobile,trains,planesandbussesneedenergy,too.Nearlyallofthisenergyisproducedbyburningfuels.Theburningproduceswastes,someofwhichremainintheair,causingairpollution. 　　Scientistsarefindingwaystostopairpollutionespeciallyinbigindustrialareasanddensely-populatedcities.Theyarestudyingnewwaysofgeneratingelectricitythatmaybelessdamagingtotheenvironment.Inthemeantime,manypowerplantsarebeingmodernizedtogiveofflesspollutedmaterial.Also,engineerstrytodesignandlocatenewpowerplantstodominimumdamagetotheenvironment. 　　However,itmaybethatwestillhavealong 　　beforewehavea"clean"world.Nearlyallofthecountriesaretryinghardtopreventandcontrolairpollution.Thereindeedseemstobenoendtotasksthatenvironmentalistswillberequiredtodo.Peoplewillcontinuallyfindnewwaystocontrolpollution.