求大神帮翻译一下,救急啊!!!
Astudysuggeststhatdirtyaircanreducelungdevelopment.ResearchersattheUniversityofSouthernCaliforniainLosAngelespublishedtheirworkinthe"NewEnglandJournalofMedicine".AboutonethousandsevenhundredchildrenfromdifferentcommunitiesinSouthernCaliforniatookpartinthestudy.Thescientiststestedthechildreneveryyearforeightyears,startingatageten.Theysaythisisthelongeststudyeverdoneonairpollutionandthehealthofchildren.Thescientistsfoundthatchildrenwholivedinareaswiththedirtiestairwerefivetimesmorelikelytogrowupwithweaklungs.Manywereusinglessthaneightypercentofnormallungstrengthtobreathe.Thedamagefromdirtyairwasasbadasthatfoundinchildrenwithparentswhosmoke.Childrenwithreducedlungpowermaysuffermoresevereeffectsfromacommoncold,forexample.Buttheresearchersexpressgreaterconcernsaboutlong-termeffects.Theysayadultsnormallybegintoloseonepercentoftheirlungpowereachyearafteragetwenty.Thedoctorsnotethatweaklungactivityisthesecondleadingcauseofearlydeathsamongadults.Thefirstissmoking.Bythetimepeopleareeighteen,theirlungsarefullydeveloped,orclosetoit.Thedoctorssayitisimpossibletorecoverfromanydamage.Researcherssaytheyarestillnotsurehowairpollutionaffectslungdevelopment.Theybelievethatpollutionaffectsthetinyairspaceswhereoxygenandcarbondioxide(二氧化碳)areexchanged.ArdenPopeisaneconomicsprofessoratBrighamYoungUniversityinProvo,Utah.ProfessorPopewroteacommentaryaboutthestudy.HenotedthatairqualityinSouthernCaliforniahasimprovedsincethestudybeganintheearlynineteen-nineties.Clean-airlawshavereducedpollutionfromvehicles,industryandothercauses.ButdirtyairisstillaprobleminareasofCaliforniaandotherplaces.ProfessorPopesayscontinuedeffortstoimproveairqualityarelikelytoprovideadditionalimprovementsinhealth.