环境卫生学绪论-临床

1,环境卫生学EnvironmentalHealthScience,周宏伟,教授，博导，环境卫生学系主任国家优秀青年基金获得者教育部新世纪优秀人才广东省千百十工程国家级培养对象办公电话：61648327,Email:811807859,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,2,Overprotectionisasevilasunderprotection,个人所处的小环境（personalenvironment）对人体健康的影响常常大于外界大环境(ambientenvironment)的作用,4,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟biodegradation,一、环境卫生学定义,5,定义1,研究自然环境和生活环境与人群健康的关系，解释环境因素对人群健康影响的发生、发展规律，为充分利用环境有益因素和控制环境有害因素提出卫生要求和预防对策，增进人体健康，提高整体人群健康水平的科学。是预防医学的重要分支学科，也是环境科学不可缺少的重要组成部分。陈学敏，杨克敌,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,6,Definition2,Initsbroadestsense,environmentalhealthisthesegmentofpublichealththatisconcernedwithassessing,understanding,andcontrollingtheimpactsofpeopleontheirenvironmentandtheimpactsoftheenvironmentonthem.-MoellerD.W.EnvironmentalHealth,7,Wikipediadefinition,Environmentalhealthisthatbranchofpublichealththatisconcernedwithallaspectsofthenaturalandbuiltenvironmentthatmayaffecthumanhealth.Otherphrasesthatconcernorrefertothedisciplineofenvironmentalhealthincludeenvironmentalpublichealth,andenvironmentalprotection.Thefieldofenvironmentalhealthiscloselyrelatedtoenvironmentalscienceandpublichealthasenvironmentalhealthisconcernedwithenvironmentalfactorsaffectinghumanhealth.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,8,Environmentalhealthaddressesallthephysical,chemical,andbiologicalfactorsexternaltoaperson,andalltherelatedfactorsimpactingbehaviours.Itencompassestheassessmentandcontrolofthoseenvironmentalfactorsthatcanpotentiallyaffecthealth.Itistargetedtowardspreventingdiseaseandcreatinghealth-supportiveenvironments.Thisdefinitionexcludesbehaviournotrelatedtoenvironment,aswellasbehaviourrelatedtothesocialandculturalenvironment,aswellasgenetics.:1,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,9,EnvironmentalhealthisdefinedbytheWHOas:2Thoseaspectsofthehumanhealthanddiseasethataredeterminedbyfactorsintheenvironment.Italsoreferstothetheoryandpracticeofassessingandcontrollingfactorsintheenvironmentthatcanpotentiallyaffecthealth.EnvironmentalhealthasusedbytheWHORegionalOfficeforEurope,includesboththedirectpathologicaleffectsofchemicals,radiationandsomebiologicalagents,andtheeffects(oftenindirect)onhealthandwellbeingofthebroadphysical,psychological,socialandculturalenvironment,whichincludeshousing,urbandevelopment,landuseandtransport.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,10,EnvironmentalhealthservicesaredefinedbytheWorldHealthOrganizationas:thoseserviceswhichimplementenvironmentalhealthpoliciesthroughmonitoringandcontrolactivities.Theyalsocarryoutthatrolebypromotingtheimprovementofenvironmentalparametersandbyencouragingtheuseofenvironmentallyfriendlyandhealthytechnologiesandbehaviors.Theyalsohavealeadingroleindevelopingandsuggestingnewpolicyareas.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,11,Disciplines,Threebasicdisciplinesgenerallycontributetothefieldofenvironmentalhealth:environmentalepidemiology,toxicology,andexposurescience.Eachofthesedisciplinescontributesdifferentinformationtodescribeproblemsinenvironmentalhealth,butthereissomeoverlapamongthem.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,12,Environmentalepidemiology,studiestherelationshipbetweenenvironmentalexposures(includingexposuretochemicals,radiation,microbiologicalagents,etc.)andhumanhealth.Observationalstudies,whichsimplyobserveexposuresthatpeoplehavealreadyexperienced,arecommoninenvironmentalepidemiologybecausehumanscannotethicallybeexposedtoagentsthatareknownorsuspectedtocausedisease.Whiletheinabilitytouseexperimentalstudydesignsisalimitationofenvironmentalepidemiology,thisdisciplinedirectlyobserveseffectsonhumanhealthratherthanestimatingeffectsfromanimalstudies.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,13,Toxicology,studieshowenvironmentalexposuresleadtospecifichealthoutcomes,generallyinanimals,asameanstounderstandpossiblehealthoutcomesinhumans.Toxicologyhastheadvantageofbeingabletoconductrandomizedcontrolledtrialsandotherexperimentalstudiesbecausetheycanuseanimalsubjects.Howevertherearemanydifferencesinanimalandhumanbiology,andtherecanbealotofuncertaintywheninterpretingtheresultsofanimalstudiesfortheirimplicationsforhumanhealth,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,14,Exposurescience,studieshumanexposuretoenvironmentalcontaminantsbybothidentifyingandquantifyingexposures.Exposuresciencecanbeusedtosupportenvironmentalepidemiologybybetterdescribingenvironmentalexposuresthatmayleadtoaparticularhealthoutcome,identifycommonexposureswhosehealthoutcomesmaybebetterunderstoodthroughatoxicologystudy,orcanbeusedinariskassessmenttodeterminewhethercurrentlevelsofexposuremightexceedrecommendedlevels.Exposuresciencehastheadvantageofbeingabletoveryaccuratelyquantifyexposurestospecificchemicals,butitdoesnotgenerateanyinformationabouthealthoutcomeslikeenvironmentalepidemiologyortoxicology.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,15,16,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,二、通过健康环境预防疾病:对疾病的环境负担的估计,Preventingdiseasethroughhealthyenvironments:Towardsanestimateoftheenvironmentalburdenofdisease,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,17,Executivesummary,Thisglobalassessmentprovidesquantitativeestimatesofburdenofdiseasefromenvironmentalfactorsacrossthemajorcategoriesofreporteddiseasesandinjuries.Theestimates,ineffect,reflecthowmuchdeath,illnessanddisabilitycouldrealisticallybeavoidedeveryyearasaresultofreducedhumanexposurestoenvironmentalhazards.Specificallyconsideredherearemodifiableenvironmentalfactorsrealisticallyamenabletochangeusingavailabletechnologies,policies,andpreventiveandpublichealthmeasures.,18,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,HOWSIGNIFICANTISTHEIMPACTOFENVIRONMENTONHEALTH?,Anestimated24%oftheglobaldiseaseburdenand23%ofalldeathscanbeattributedtoenvironmentalfactors.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,19,在2004年世界卫生报告所涉102类主要疾病、疾病组别和残疾中，环境风险因素在其中85类中导致疾病负担。在不同疾病状况中，可具体归因于环境的疾病比例差别很大。在全球范围，估计24%的疾病负担(健康寿命年损失)和23%的所有死亡(早逝)可归因于环境因素。在0-14岁的儿童中，可归因于环境的死亡比例高达36%。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,20,虽然在疾病总负担中，这已经是一个很大的比例，但估计仍然偏于保守，因为对许多疾病，还有待搜集这方面的证据。同时，在许多情况下，环境危害与疾病结果之间的因果关系很复杂。但在其它情况下，尽管健康影响非常明显，疾病负担也难以量化。例如，与整个生态系统的变化、破坏或耗竭有关的疾病负担就很难量化。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,21,2002年世卫组织分区域环境性疾病负担,疾病负担按每10万人死亡人数衡量。关于世卫组织各分区域的国家名单，见报告正文附件1。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,22,最大绝对负担可归因于可改变的环境因素的疾病包括：腹泻、下呼吸道感染、“其它”意外伤害和疟疾。,估计94%的腹泻疾病负担是由环境造成的，并与不安全饮用水以及环境卫生和个人卫生不良有关。下呼吸道感染与室内空气污染有关，主要涉及家庭固体燃料使用并可能涉及二手烟草烟雾，以及室外空气污染。在发达国家，估计20%的此类感染可归因于环境原因，发展中国家的相应数字则上升到42%。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,23,42%的疟疾是由可改变的环境因素造成的，这与土地使用、毁林、水资源管理、住区选址和修改后的住房设计(例如改进排水系统)方面的政策和做法有关。为本研究目的，使用经杀虫剂处理的蚊帐不视为一项环境管理措施。慢性阻塞性肺病是一种逐渐丧失肺部功能的疾病，据估计此类疾病的42%是由环境风险因素造成的。职业接触粉尘和化学品，以及家庭使用固体燃料导致的室内空气污染，似乎是造成疾病负担环境分值的两个最大因素。但其它形式的室内和室外空气污染，从交通到二手烟草烟雾，也有很大作用。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,24,“其它”意外伤害包括工作场所危害、辐射和工业事故导致的伤害，30%的此类伤害可归因于环境因素。在道路交通事故造成的伤害中，环境因素也占有很大比重(40%)。这主要涉及行人和非机动车基础设施不善等因素，可以通过更好地分隔行人和非机动车流动以及“减缓交通”措施来解决；城市地理和流动模式的较长期变化带来的一些健康影响尚有待加以衡量。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,25,环境因素产生最大影响的疾病,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,26,2、在世界哪些地区环境因素对健康影响最大，以及如何产生影响？,传染病和伤害给发展中地区造成极其沉重的负担世卫组织各个区域之间最大的整体区别在于传染病类。发展中国家由于环境因素人均损失健康寿命年总数是发达国家的15倍。在某些世卫组织发展中国家分区域，腹泻病和下呼吸道感染的环境分值是发达国家分区域的120到150倍。这些差别主要是源于接触环境风险和享有卫生保健方面的差异。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,27,在可归因于环境的非传染病的分值上，发达国家与发展中国家的整体差异不明显然而，在发达国家，可归因于环境的心血管疾病和癌症负担较大。在发达国家，心血管疾病造成的人均健康寿命年损失要比发展中国家高出6倍，癌症高出3倍。缺乏身体活动是导致缺血性心脏病、乳腺癌、结肠癌、直肠癌和糖尿病等各种非传染性疾病的危险因素。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,28,与此同时，发展中国家可归因于环境因素的意外伤害和道路交通伤害带来的疾病负担更沉重。在发展中国家，与环境因素有关的伤害导致的人均健康寿命年损失平均数大体比发达国家高出一倍；就一些疾病，例如疟疾来说，环境性疾病负担将伴随发展而减轻，但其它非传染性疾病，例如慢性阻塞性肺病的负担将加重，接近世界更为发达地区目前的水平。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,29,3哪些人群受环境对健康危害的影响最严重？,儿童承担了过分沉重的环境性健康负担。在全球范围，儿童与总人口相比，因环境风险因素造成的人均健康寿命年损失大约要高4倍。腹泻、疟疾和呼吸道感染均在可归因于环境的疾病中占很大比例，也是5岁以下儿童最大的致命因素。围产期疾病(例如早产和低出生体重)、蛋白质-热能营养不良和意外伤害为儿童其他一些重大致命因素，也明显受环境的影响，尤其是在发展中国家。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,30,平均说来，发展中国家儿童因环境造成的疾病，人均丧失的健康寿命年要比发达国家儿童高出7倍。而在世界某些非常贫困的地区，这一差距还要大得多，因儿童下呼吸道感染丧失的健康寿命年人均达800倍，道路交通伤害，25倍；腹泻，140倍。但即使是这些统计数字也仍未能反映一些接触的较长期效应，这些接触是在幼年时发生的，但直到许多年后才发病。,10factsonchildrensenvironmentalhealth-1,Environmentalfactorsareresponsiblefor88%ofthe1.5millionannualchilddeathsyearduetodiarrhoea.Diarrhoeaisthesecondleadingcauseofdeathamongchildrenunderfiveyearsold,withnearlyoneinfivedeathsduetodiarrhoea.Around88%ofthesedeathsareattributabletounsafewater,inadequatesanitationandpoorhygiene.Treatingandsafestorageofdrinkingwaterandwashinghandscanpreventdiarrhoealdisease.Exclusivebreastfeedingalsohelpspreventdiarrhoealdiseaseamongyoungchildren.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,31,10facts-2,Halfofthetwomillionannualchilddeathsfromacuterespiratoryinfectionsareattributabletoindoorairpollution.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,32,Acuterespiratoryinfectionsinparticularpneumoniaarethebiggestkillerofyoungchildren.Nearlyhalfofthesedeathsareattributabletoindoorsmokefromsolidfuel.Second-handtobaccosmokeisanothermajorriskfactor.Childrenindevelopingcountriesareespeciallyatriskduetopoorhousingconditions.,10facts-3,Asthmaprevalenceisrisingrapidlyinchildren.Asthmaisthemostcommonchronicdiseaseamongchildrenandoccursinallcountries.Itistriggeredbyenvironmentalfactorssuchashousedustmites,second-handsmoke,mouldsandpollens.Asthmacanbecontrolledwithproperdiagnosisandtreatment,andbyreducingexposuretotheenvironmentaltriggers.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,33,10facts-4,Insomedevelopingregionsoftheworld,morethanonethirdofallchildrenareaffectedbyhighlevelsoflead.Leadpoisoningcanalterchildrensbraindevelopment.Itcanincreasetheriskofbehaviouralandlearningproblems,andofcardiovasculardiseaseslaterinlife.Leadisnolongerusedingasolineinmostcountries,butchildrenarestillexposedtoitfromsmelters,lead-basedpaint,recyclingactivities,cosmetics,herbalmedicines,andothersources.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,34,10facts-5,Acutepoisoningfrompesticidescanbelife-threateningtochildren.Unsafeuse,storageanddisposalofpesticidesarethemaincausesofacutepoisoning.Chronic,low-levelexposuretopesticidesislinkedwithneurological,developmental,reproductiveandothereffectsinchildren.Exposuremayresultfromtheuseofpesticidesingardens,homesandschools,agriculturaldrift,orthroughcontaminatedfoodanddrinkingwater.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,35,10facts-6,Mercuryistoxictothenervoussystemofthedevelopingfetus.Thefetus,newbornsandchildrenareespeciallysusceptibletomercuryexposurebecauseofthesensitivityofthedevelopingnervoussystem.Womenofchildbearingageandchildrenshouldavoideatinglargepredatory,non-fattyfish(suchasshark)thatcanhavehighlevelsofmercury.Childrencanalsobeexposedtomercuryfromsomeherbalmedicinesandsometeethingpowders.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,36,10facts-7,ManychildreninAfricaandAsiaareexposedtoaflatoxinsinfoods.Aflatoxinsaretoxiccompoundsproducedbyfungithatcontaminatefood.Maizeandgroundnutsaremajorsourcesofexposure.Acutepoisoningfromaflatoxinscanbelife-threatening.Overthelong-term,childrenwithchronicaflatoxinexposuremaybecomestunted,underweight,andmoresusceptibletoinfectiousdiseasesinchildhoodandlaterlife.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,37,10facts-8,Hundredsofthousandsofchildrenundertheageof15unintentionallyingestpoisonoussubstances,andsome35,000ofthemdieeveryyear.Poisoningmostcommonlyinvolvesfuel,pesticides,medicines,andtoxichouseholdproducts.Storingtheseitemsawayfromchildrenssightandreach,andusingchild-resistantpackagingcansavechildrenslives.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,38,10facts-9,Environmentalfactorsplayaroleinchildhoodcancers.Whilemuchabouttheoriginofchildhoodcancersremainsunknown,environmentalagentssuchasradiation,tobaccoandsecond-handsmoke,aflatoxins,ultravioletlight,andsomepesticidesplayarole.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,39,10facts-10,Climatechangeincreasestheriskofdiseaseespeciallyforchildrenindevelopingcountries.Over85%oftheburdenofdiseaseofclimatechangeisbornebychildrenindevelopingcountries.Childrenfacerisksofinjuriesanddeathfromfloodsandextremetemperatures,asthmaandrespiratorydiseasesthatincreaseinfrequencywithairpollution,anddiarrhoealdiseases,malaria,andmalnutritionrelatedtoclimatechange.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,40,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,41,4.决策者和公众如何应对环境性健康风险？,环境卫生干预措施的公共和预防性卫生战略十分重要。此类干预措施具有成本效益，还可造福于社区的整体福利。例如逐步取消含铅汽油。仍然使用含铅汽油的地区与完全取消含铅汽油的地区相比，前者在整体上因铅接触造成的智力发育迟缓估计比后者高出将近30倍。千年发展目标的一个主要指标是到2015年将无法持续获得安全饮用水和环卫设施的人口减半。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,42,提高经济生产率，节省卫生保健开支，减少尤其是因为腹泻疾病、肠道线虫感染和有关的营养不良而损失的健康寿命年。提供经改善的环卫设施和培养良好的卫生习惯，可以打破水域的粪-口病菌污染整体循环，有利于健康、减贫、福利和经济发展。,43,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,三、环境卫生学发展简史,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,44,环境卫生学形成（EnvironmentalHygiene),19世纪后形成德国MaxvonPenttenkofer(1818-1901)首次提出肠伤寒和霍乱等传染病的流行与空气、水以及食物等生活环境有关；1865年在德国慕尼黑大学开设卫生学讲座，以空气、水、食物、住宅、土壤等为研究对象，采用物理和化学方法，开展了空气中二氧化碳浓度测定方法的研究，称为实验卫生学(experimentalhygiene)。其后，卫生学的发展进入新阶段，实现了专业分化，产生了环境卫生学等多种专门学科。,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,45,环境卫生学发展,近几十年来，环境科学学科蓬勃发展，形成与传统的环境卫生学在研究内容上相互交叉的学科：环境工程学、环境化学、环境生物学、环境管理学、环境毒理学环境卫生学的研究内容从强调hygiene逐渐转变为以健康(health)为核心。EnvironmentalHealthScience环境科学和公共卫生学（PublicHealth)的交叉学科。,环境卫生学关注内容-1/4,Environmentalhealthaddressesallhuman-health-relatedaspectsofboththenaturalenvironmentandthebuiltenvironment.Environmentalhealthconcernsinclude:Airquality,includingbothambientoutdoorairandindoorairquality,whichalsocomprisesconcernsaboutenvironmentaltobaccosmoke.Bodyartsafety,includingtattooing,bodypiercingandpermanentcosmetics.Climatechangeanditseffectsonhealth.Disasterpreparednessandresponse.Foodsafety,includinginagriculture,transportation,foodprocessing,wholesaleandretaildistributionandsale.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,46,环境卫生学关注内容-2/4,Hazardousmaterialsmanagement,includinghazardouswastemanagement,contaminatedsiteremediation,thepreventionofleaksfromundergroundstoragetanksandthepreventionofhazardousmaterialsreleasestotheenvironmentandresponsestoemergencysituationsresultingfromsuchreleases.Housing,includingsubstandardhousingabatementandtheinspectionofjailsandprisons.Childhoodleadpoisoningprevention.Landuseplanning,includingsmartgrowth.Liquidwastedisposal,includingcitywastewatertreatmentplantsandon-sitewastewaterdisposalsystems,suchasseptictanksystemsandchemicaltoilets.,南,47,环境卫生学关注内容-3/4,Medicalwastemanagementanddisposal.Noisepollutioncontrol.Occupationalhealthandindustrialhygiene.Radiologicalhealth,includingexposuretoionizingradiationfromX-raysorradioactiveisotopes.Recreationalwaterillnessprevention,includingfromswimmingpools,spasandoceanandfreshwaterbathingplaces.Safedrinkingwater.Solidwastemanagement,includinglandfills,recyclingfacilities,compostingandsolidwastetransferstations.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,48,环境卫生学关注内容-4/4,Toxicchemicalexposurewhetherinconsumerproducts,housing,workplaces,air,waterorsoil.Vectorcontrol,includingthecontrolofmosquitoes,rodents,flies,cockroachesandotheranimalsthatmaytransmitpathogens.,南方医科大学公共卫生与热带医学学院环境卫生学系周宏伟ehscourse,49,五、环境卫生学核心概念,The5CoreConcepts,毒性评价,急性毒性分级慢性毒性一般慢性毒性特殊毒性,Exposure（暴露）is,Thetotalamountofahazardthatcomesindirectcontactwithyourbody.,The3partsofexposure,TheSourceofthehazard(busexhaust),TheEnvironmentalPathway(air),TheContact(inhaledfumes),Whichroutewillthehazardstake?,Route#1:Inhalation（呼吸）,Hazard!,Inhalation:Breathing.Whenchemicalsenterthebodythroughthisrouteofexposure,theycangetstuckinthelungsand/orbetakenupintothebloodstream.,Route#2:Ingestion（消化道）,Hazard!,Ingestion:Swallowing(usuallybyeatingordrinking).Whenchemicalsente