PM2.5英文介绍

PM2 5 PM anabbreviationforParticulateMatter referstoliquidorsolidparticlessuspendedintheair Dependingontheiroriginandvisualappearance aerosolshaveacquireddifferentnamesintheeverydaylanguage Dustreferstosolidairbornematerial dispersedintoaerosolfromgrainypowderssuchassoil Combustionprocessesproducesmokeparticles buttheincombustibleresiduesofcoalarecalledflyash Intheearlydays airpollutionhadtheappearanceofbothsmokeandfog sothetermsmogwascreated Intheopenatmosphere thevisibilitymayoftenbereducedbyregionalhaze originatingfromvariousnaturaloranthropogenicsources Neitherwaterdropletsoffogandclouds snow rain sleet hydrometors nordustparticleslargerthan100um blowingsand areconsideredtobeparticulatematter Whatis WhatisPM2 5 ThenamePM2 5denotesthatitincludesallparticulatematterthathasanaerodynamicdiameterof2 5micronsorsmaller 2 5micrometersisapproximately1 30thesizeofahumanhair PM2 5alsocalledfineparticulatelodgesdeeplyintothetissueofthelungandisnoteasilydispelled Itcausesbothrespiratoryandcardiacillness andhasbeenlinkedtoprematuremortalityeveninhealthyindividuals PMFormationintheAtmosphere ThesourcesofPM2 5includefuelcombustionfromautomobiles powerplants woodburning industrialprocesses anddiesel poweredvehiclessuchasbusesandtrucks Thesefineparticlesarealsoformedintheatmospherewhengasessuchassulfurdioxide nitrogenoxides andvolatileorganiccompounds allofwhicharealsoproductsoffuelcombustion aretransformedintheairbychemicalreactions PM2 5HealthEffect Increasedlevelsoffineparticlesintheairasaresultofanthropogenicparticulateairpollution isconsistentlyandindependentlyrelatedtothemostseriouseffects includinglungcancerandothercardiopulmonarymortality Thelargenumberofdeathsandotherhealthproblemsassociatedwithparticulatepollutionwasfirstdemonstratedintheearly1970sandhasbeenreproducedmanytimessince PMpollutionisestimatedtocause22 000 52 000deathsperyearintheUnitedStates from2000 and200 000deathsperyearinEurope Whoneedstotakestepstoreduceexposure Everyoneneedstotakestepstoprotectthemselveswhenpollutionlevelsare hazardous andabove SomepeopleareathigherriskfromPM2 5exposure Peoplemostatriskfromparticlepollutionexposureincludethosewithheartorlungdisease includingasthmaandchronicobstructivepulmonarydisease COPD olderadults andchildren Researchindicatesthatpregnantwomen newborns andpeoplewithcertainhealthconditions suchasobesityordiabetes alsomaybemoresusceptibletoPM relatedeffects TheGlobalPM2 5pollutionindexmapwasdrawnbyCanadianscientistsaccordingtoNASAsatellitedata Inthemap colorschangefromdarkbluetolightblue yellowanddarkred whichrepresentsthattheconcentrationofPM2 5becomesmoreandmorehigh FromthemapwecanseethatairpollutionhasbeenanunusuallyaustereprobleminChina especiallyinthenorthandeast Noteasytomonitor Althoughtightermonitoringstandardswillsoonbeintroducednationwide itwillnotbeeasyforBeijingandothercitiestomeetacceptedPM2 5standardsandthenfurthercontrolpollution Thebiggestproblemformonitorisfinancing PM2 5monitoringequipmentusuallycosts80 000 380 000yuan 12 710 60 370 Apreliminaryestimateshowsthatmorethan338prefecture levelcitieswillhavetoinvestmorethan2billionyuan 318million onthenewequipment Hardtocontrol Asamulti sourcepollutant PM2 5istrickytotechnicallycontrol ResearchshowsthatoverhalfofPM2 5emissionsarenotdirectlyemitted butareoxidationsofotherairpollutants Slowthe