Thedepletionoftheozonelayer(臭氧层的衰退)

Thedepletionoftheozonelayer（臭氧层损耗）ABSTRACTOzone(O3)isastratospheric(平流层的)layer（层）thatplaysimportantroleinprovidingsupporttohumansfortheirsurvival.Itisanessentialfactorformanyglobal,biological（生物的）andenvironmentalphenomena.Butvariousanthropogenic(人为的)activitiessuchasemissions（排放）ofCFCs（氟氯烃）,HCFCs（氢氯氟烃）andotherorgano-halogens（有机卤素污染物）leadtothedepletionofozone.Theozonedepletionresultedinsecondaryproductionofanozonelayerneartheground(terrestrialozonelayer),whichisresponsibleforadverseeffectsonplants,humansandenvironmentwithincreasednumberofbronchialdiseasesinhumans.ThemutationscausedbyUVraysresultinvariationinmorphogenictraitsofplantswhichultimatelydecreasescropproductivity.However,UVradiation(紫外线、紫外辐射)isrequiredinoptimumintensityforbothplantsandanimals.Thisreviewtakesintoanaccountthewiderangingeffectsofozonedepletionwithamajorityofthembeingdetrimentaltotheplantsystem.一、Whatisit?Theozonelayerisfoundintheupperstratosphereanditsprimaryfunctionistofilterultravioletshort-waveraditionthatcomesfromthesun.Ozonegas(臭氧)absorbsUVradiation.The'hole'intheozonelayerwasfirstnotedinthe1980's,andisofconcernasincreasedlevelsofUVradiationcanleadstoincreasedlevelsofskincancerandeyecataracts(白内障).AtfirsttheozoneholewasonlyfoundoverAntarctica（南极洲）,butithasbeenbecominglargeratarapidrate,andnowaffectspartsofChile（智利）andAustralia.Theproblemisworsened（恶化）asCFC'sareaprimarycauseofthedamageandtheyremaininthestratosphereforupto100years.二、CausesOfOzoneDepletion1、CFC'sTheincreaseinthesizeoftheholeintheozonelayerisdirectlylinkedtoincreasedproductionofCFC'ssincethe1950'sinaerosols（气溶胶、喷雾器）,plasticfoam（泡沫塑料）,fastfoodpackaging(包装、包装业)andfridges（电冰箱）.Chlorine（氯）isproducedbyCFC'Sandreactsstronglywithozoneinthestratosphere（同温层、最上层）,breakingdowntheozonelayer.2、NaturalCausesVolcaniceruptions(火山喷发),astheyrelease（释放）carbonmonoxide（一氧化物）anddecreasenitrogenoxides（氮氧化合物）intheatmosphere.Methane（沼气、甲烷）fromrotting（腐败）vegetation（植被）.三、EffectsOfOzoneDepletionSuchas:threatenourhealth、globalwarming、increasedisease四、SolutionsToOzoneDepletion1、EducationAdvisepeopletocoverupwhenoutinthesunshinetoreducethedamagecausedbyUVradiation.2、GovernmentlegislationBanproductionofimportandmanufactureofallCFC's.3、RemovalOfCFC'sGovernmentlegislationcombineswithdevelopmentofalternativestoCFC's.Pumpactionspraysinsteadofaerosols.4、InternationalAgreementsVariously,beginningwiththeMontrealProtocolin1987,wheremeasureshavebeentakentoreduceCFCproduction.1992EUcountriesagreetohaltCFCproductionby1995.