空气污染可导致精神分裂或自闭症Micestudylinksairpollutiontoautism,schizophreniaAnewresearchdescribeshowthebrainsofmicearedamagedbyexposuretoairpollutioninearlylife.Thebraindamageincludestheenlargementofapartofthebrainthatisseeninhumanswhohaveautismandschizophrenia.ThestudyispublishedinthejournalEnvironmentalHealthPerspectives.Asinautismandschizophrenia,thechangesoccurredpredominatelyinmales.Themicealsoperformedpoorlyintestsofshort-termmemory,learningability,andimpulsivity.Thenewfindingsareconsistentwithseveralrecentstudiesthathaveshownalinkbetweenairpollutionandautisminchildren.Mostnotably,a2013studyinJAMAPsychiatryreportedthatchildrenwholivedinareaswithhighlevelsoftraffic-relatedairpollutionduringtheirfirstyearoflifewerethreetimesaslikelytodevelopautism.“Ourfindingsaddtothegrowingbodyofevidencethatairpollutionmayplayaroleinautism,aswellasinotherneurodevelopmentaldisorders,”saidDeborahCory-Slechta,Ph.D.,professorofenvironmentalmedicineattheUniversityofRochesterandleadauthorofthestudy.Inthreesetsofexperiments,Cory-Slechtaandhercolleaguesexposedmicetolevelsofairpollutiontypicallyfoundinmid-sizedUScitiesduringrushhour.Theexposureswereconductedduringthefirsttwoweeksafterbirth,acriticaltimeinthebrain’sdevelopment.Themicewereexposedtopollutedairforfourhourseachdayfortwofour-dayperiods.Inonegroupofmice,thebrainswereexamined24hoursafterthefinalpollutionexposure.Inallofthosemice,inflammationwasrampantthroughoutthebrain,andthelateralventricles—chambersoneachsideofthebrainthatcontaincerebrospinalfluid—wereenlargedtwotothreetimestheirnormalsize.“Whenwelookedcloselyattheventricles,wecouldseethatthewhitematterthatnormallysurroundsthemhadn’tfullydeveloped,”saidCory-Slechta.“Itappearsthatinflammationhaddamagedthosebraincellsandpreventedthatregionofthebrainfromdeveloping,andtheventriclessimplyexpandedtofillthespace.”Theproblemswerealsoobservedinasecondgroupofmice40daysafterexposureandinanothergroup270daysafterexposure,indicatingthatthedamagetothebrainwaspermanent.Brainsofmiceinallthreegroupsalsohadelevatedlevelsofglutamate,aneurotransmitter,whichisalsoseeninhumanswithautismandschizophrenia.Mostairpollutionismadeupmainlyofcarbonparticlesthatareproducedwhenfuelisburnedbypowerplants,factories,andcars.Fordecades,researchonthehealtheffectsofairpollutionhasfocusedonthepartofthebodywhereitseffectsaremostobvious—thelungs.Thatresearchbegantoshowthatdifferent-sizedparticlesproducedifferenteffects.Largerparticles,theonesregulatedbytheEnvironmentalProtectionAgency(EPA),areactuallytheleastharmfulbecausetheyarecoughedupandexpelled.Butmanyresearchersbelievethatsmallerparticlesknownasultrafineparticles—whicharenotregulatedbytheEPA—aremoredangerous,becausetheyaresmallenoughtotraveldeepintothelungsandbeabsorbedintothebloodstream,wheretheycanproducetoxiceffectsthroughoutthebody.ThatassumptionledCory-Slechtatodesignasetofexperimentsthatwouldshowwhetherultrafineparticleshaveadamagingeffectonthebrain,andifso,torevealthemechanismbywhichtheyinflictharm.Thestudyisthefirstscientificworktodoboth.“Ithinkthesefindingsaregoingtoraisenewquestionsaboutwhetherthecurrentregulatorystandardsforairqualityaresufficienttoprotectourchildren,”saidCory-Slechta.相关内容一项新研究表明，老鼠若在幼年期长期接触污染大气，脑部可能会受损。这种受损包括大脑某一部分变肿大，就人类而言，变肿大的部分常出现在自闭者与精神分裂患者...
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