英译汉!谢绝机器入内
Passengersintaxis,buses,andcarsallbreathemorepollutionthancyclistsandpedestrians,anewstudyshows.Researchersmeasuredlevelsoflevelsofultra-fine(极细微的),traffic-producedpollutionparticles(粒子的)onbusyLondonstreetsusinganewlydevelopedparticlecounterfittedwithavideorecorder.
Theequipmentallowedthemtomatchparticlelevelswitheachofthefivemodesoftransport.Theyalsocouldidentifywhatactivitiesandbehaviorsleadtothehighestexposures(暴露).Onaverage,taxipassengerswereexposedtojustunder100,000andpeopleincarsabout40,000.
Pedestriansandbicyclists,meanwhile,wereexposedtocountsofjust5,000and8,000,respectively.Ultra-fineparticlesaresosmallthatlargeamountscanbebreathedinasinglebreath,afterwhichtheycansettleinthelungsanddamagecells.
WouldtheresultsholdtrueinNewYorkCityorelsewhere?Wegenerallyfoundthatthetrendssuchaspedestrianshavingthelowestexposuresandthein-vehicleexposuresbeingmuchhighertobecommonacrossdifferentcountries,”studyco-authorSurbjitKaurofImperialCollegeLondonsaid,“However,theconcentrations(浓度)dovaryduetodifferentlocalconditions,suchastraffic,meteorology,buildinglayout,andconfiguration.“
Peoplesittinginavehicleinthemiddleofheavytrafficaredirectlyinthepathofthepollutantsource---othervehicle’smufflers.Pollutionincarsislessthaninothervehiclesmostlikelybecausecarsgenerallyspendlesstimeintrafficthantaxisandbuses,Also,privatecarstendtobecleanertobeginwith.
Bikersstickmostlytotheouteredgesofthestreet,wherepollutionlevelsarelower.Peopleonthesidewalkareevenfurtheraway.