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2
AIRANDCLIMATE
1.Airpollution
Warm-up
Thinkofanywordsyoucanassociatewithairpollution,notethemdownandthencompareyourlist
withyourpartner’s.
Thinkofanypossiblesourcesofairpollutionandwritethemdownontheblackboard.
Exercise1
Matchthewordstothedefinitions,thenreadthetextandunderlinethem.
1.liquid
2.remote
3.exhaust
4.dilute
5.digestion
6.abrasive
7.aby-product
8.soot
9.trace
10.persistent
a.fumesfromanengine
b.aprocessofchangingfoodbyanorganism
c.rough
d.anotplannedproductorresult
e.asubstancethatcanflow
f.continuing
g.averysmallamount
h.distant
i.blackpowderleftafterburning
j.containingmorewater
Airpollutioncanbedescribedasanyharmfulmaterialthatispresentintheatmosphere,andthereforeits
causesarenumerousandhighlyvaried.Someofitssources,likevolcaniceruptions,arenatural,othersare
causedbyhumanactivities,forexamplebytheburningoffossilfuels.Pollutantscanappearintheformof
solidparticles,liquiddroplets,orgases.Becausetheycantravelonwindanddonotrespectpolitical
borders,theyarenotonlyconcentratedoverindustrializedareaswhichgeneratedthembuttheycanalso
befoundinremotelocations.
Pollutantscanbeclassifiedaseitherprimaryorsecondary.Usually,primarypollutantsaresubstances
directlyemittedfromaprocess,suchasashfromavolcaniceruption,carbonmonoxidefromcarexhausts
orsulphurdioxidereleasedfromfactories.Secondarypollutantsformintheairwhenprimarypollutants
reactorinteractcreating,forexample,diluteacids,whichfallasacidrain.
Naturalsourcesofairpollutioncanbequitedangerousattimes.Theymayincludedustpickedupbywind
fromlargeareaswithlittleornovegetation,suchasdesertsandsemi-deserts;theemissionofmethane
resultingfromthedigestionoffoodbyanimalssuchascattle;smokeandcarbonmonoxidefromwildfires
causedbynaturalreasons.Volcanicactivitiesareperhapsthelargestsinglesourcesofnaturalair
pollution.Thesecanproducecloudsofabrasiveashparticulatesandotherharmfulchemicalsubstances
suchaschlorineandsulphur.
Yet,themostwell-knownandseriouscausesofairpollutionareman-made.Theburningofoilproducts
andotherfossilfuelsisacommoncauseofpollution,especiallyincities.Whenpetrolisburned,it
producescarbondioxideormonoxide.Smallparticlesofsootarealsoreleasedintotheatmosphere,along
withtraceamountsofotherharmfulsubstances.Allthat,togetherwithairborneparticles,mightcreate
persistentsmog,whichplaguescities.
Otherman-madecausesofairpollutionincludesmokefromindustryandpowerstations.Thesubstances
emittedatthesesourcescancontainsulphurdioxideandnitrogendioxide,whichareresponsibleforthe
formationofacidrain.Chlorofluorocarbons(CFCs)aretheozonelayer-destroyingchemicalsemitted
fromcoolingsystemsinoldrefrigerators,buttheyhavebeenbannedfromuseinnewones.
Airpollutioninfluencestheworldandpeopleinanumberofways.Theprimaryproblemsarediseasesof
theheartandlungs.Asthmaandrespiratoryallergiesareontherise,duetoirritationbychemicalsand
particulates.Somepollutantsaredamagingtheatmosphere,exposingtheearthtoharmfulultraviolet
radiationandgivewaytosecondaryproblems,suchasacidrainanddeathofvegetation.
