外文翻译水污染和社会的关系

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1、外文文献英文资料WATERPOLLUTIONANDSOCIETYByDavidKrantzandBradKifferstein INTRODUCTION    Comprisingover70%oftheEarth’ssurface,waterisundoubtedlythemostpreciousnaturalresourcethatexistsonourplanet. Withouttheseeminglyinvaluablecompoundcomprisedofhydrogenandoxygen,lifeonEarthwouldbenon-existent:

2、itisessentialforeverythingonourplanettogrowandprosper. Althoughweashumansrecognizethisfact,wedisregarditbypollutingourrivers,lakes,andoceans.Subsequently,weareslowlybutsurelyharmingourplanettothepointwhereorganismsaredyingataveryalarmingrate. Inadditiontoinnocentorganismsdyingoff,ourd

3、rinkingwaterhasbecomegreatlyaffectedasisourabilitytousewaterforrecreationalpurposes. Inordertocombatwaterpollution,wemustunderstandtheproblemsandbecomepartofthesolution.POINTANDNONPOINTSOURCES   AccordingtotheAmericanCollegeDictionary,pollutionisdefinedas: “tomakefoulorunclean;dirty.”

4、 Waterpollutionoccurswhenabodyofwaterisadverselyaffectedduetotheadditionoflargeamountsofmaterialstothewater. Whenitisunfitforitsintendeduse,waterisconsideredpolluted. Twotypesofwaterpollutantsexist;pointsourceandnonpointsource. Pointsourcesofpollutionoccurwhenharmfulsubstancesareemitt

5、eddirectlyintoabodyofwater. TheExxonValdezoilspillbestillustratesapointsourcewaterpollution. Anonpointsourcedeliverspollutantsindirectlythroughenvironmentalchanges. Anexampleofthistypeofwaterpollutioniswhenfertilizerfromafieldiscarriedintoastreambyrain,intheformofrun-offwhichinturneff

6、ectsaquaticlife. Thetechnologyexistsforpointsourcesofpollutiontobemonitoredandregulated,althoughpoliticalfactorsmaycomplicatematters.Nonpointsourcesaremuchmoredifficulttocontrol. Pollutionarisingfromnonpointsourcesaccountsforamajorityofthecontaminantsinstreamsandlakes.CAUSESOFPOLLUTIO

7、N    Manycausesofpollutionincludingsewageandfertilizerscontainnutrientssuchasnitratesandphosphates. Inexcesslevels,nutrientsoverstimulatethegrowthofaquaticplantsandalgae. Excessivegrowthofthesetypesoforganismsconsequentlyclogsourwaterways,useupdissolvedoxygenastheydecompose,andblockli

8、ghtto