職業(yè)衛(wèi)生與職業(yè)醫(yī)學(xué)-鉛中毒

鉛中毒（Leadpoisoning）勞動衛(wèi)生與職業(yè)病學(xué)教研室

12toysporcelaincosmeticsfoodTraditionalChinesemedicine密陀僧黑錫丹二味黑錫丹34Physicalandchemicalproperties理化特性O(shè)ccupationalexposure接觸機(jī)會Toxicity毒理Clinicalmanifestation臨床表現(xiàn)Diagnosis診斷Therapy治療prevention預(yù)防Leadpoinsing5PhysicalandchemicalpropertiesColorlightgraytoaslightbluishgreycolorTenacitymalleable,ductileandsectile（延展性，柔軟性和可切割性）Density11.34g/cm3Specificgravity11.3Atomicweight207.20Meltingpoint327℃Boilingpoint1525℃6PhysicalandchemicalpropertiesLeaddustisthegeneralexistingstateintheindustrialproductionDifferentleadoxideshowsdifferentcolors(leadsuboxide,leadmono-oxide,dileadtrioxide,leadtetraoxide)7400~500℃氧化亞鉛氧化鉛四氧化三鉛三氧化二鉛8選礦采礦提煉冶煉精煉Leadminersandleadsmeltersandrefiners鉛礦破碎鉛礦研磨Occupationalexposure910OccupationalexposureAccumulatorbatterymanufacturing11OccupationalexposurePrintindustrypaint12ToxicityAbsorption:therearemainlythreeinvasivewaysenterthebody.Respiratorytractisprobablythemostsignificantrouteofabsorptioninmostoccupationalcases.Andthengastrointestinaltract.Skinisthelast.Leadasafumeorveryfineparticulateisreadilydepositedinandabsorbedthroughthelungs.Largerparticlesthatareinhaledwillusuallybetrappedbythemucociliarydefensivesystem;unfortunately,mostleadthatisclearedfromthetracheobronchialtreeisswallowed.Leaddustthatcontaminateshands,clothing,food,andtobaccoproductsmayalsobeingested.Absorptionfromthegastrointestinaltractisparticularlyefficientinchildren.Althoughorganicleadcompounds,suchastetraethyllead,canbeabsorbedthroughtheskin,inorganicleadcannot.13呼吸道（主要）迅速40%的氧化鉛入血循環(huán)

（肺泡的彌散作用及吞噬細(xì)胞的吞噬）消化道（其次）較慢5%-10%經(jīng)肝靜脈入肝（由膽汁排入腸內(nèi)，隨糞便排出）皮膚：無機(jī)鉛化合物不能通過完整的皮膚。有機(jī)鉛化合物能通過皮膚和粘膜（四乙基鉛）毒理---吸收14ToxicityDistribution:Onceleadisabsorbedintoblood,themajorityleaddustisbindingtohumanerythrocyte.Andthenitisdistributedtosofttissuesandbones,soft-tissueconcentrationsarehighestintheliverandkidneys鉛肝、腎、脾、肺、皮膚血循環(huán)大部分與紅細(xì)胞結(jié)合小部分在血漿初期后期血漿蛋白結(jié)合鉛可溶性PbHPO4骨（90-95%）毛發(fā)牙齒難溶磷酸鉛15ToxicityExcretion:Leadislargelyexcretedduringtheurine,andtoasmallextent,inthefeces,excretionisslow,withestimatesofahalf-lifeaslongas10years.Leadalsocrossestheblood-brainbarrierandtheplacenta.主要途徑：腎臟20－80g/天次要途徑：糞便、膽汁、乳汁、汗液、月經(jīng)母體胎盤

胎兒嬰兒乳汁

為什么妊娠及哺乳期的婦女要脫離鉛作業(yè)？16Toxicity--toxicologicalmechanism影響卟啉代謝，導(dǎo)致鉛毒性貧血血管痙攣紅細(xì)胞脆性增加，毛細(xì)血管通透性增加對神經(jīng)鞘細(xì)胞的直接毒作用，引起神經(jīng)纖維節(jié)段性脫髓鞘Leadiscapableofrestrainingsomeenzymesinporphyrinmetabolismandcausinganincreaseofitsmetabolitesinurineorblood,suchasALA,FEP,etcLeadcancausevasospasmItcanincreaseerythrocytefragilityandcapillarypermeabilityItcanrusultinnervefibersegmentaldemyelinationduetoitsdirecttoxicactiononneurilemmacell17Toxicity--toxicologicalmechanism血紅素的生物合成及鉛對合成過程的影響★18Clinicalmanifestation急性鉛中毒：多由經(jīng)口攝入大量鉛化合物引起，多表現(xiàn)為胃腸道癥狀，少數(shù)出現(xiàn)中毒性腦病。生產(chǎn)過程中急性中毒已少見，職業(yè)性中毒多為慢性中毒。19慢性鉛中毒：（chronicleadpoisoning）神經(jīng)系統(tǒng)：主要表現(xiàn)為類神經(jīng)征，外周神經(jīng)炎，嚴(yán)重者出現(xiàn)中毒性腦病Nervoussystem:LeadmaycauseSimilarityNeuroticSymptom,peripheralneuropathyandtoxicencephacopathyClinicalmanifestation表現(xiàn)為頭昏、頭痛、全身無力、記憶力減退、睡眠障礙、多夢等可分為感覺型、運(yùn)動型和混合型。感覺型的表現(xiàn)為肢端麻木，四肢末端呈手套襪子型感覺障礙。運(yùn)動型:Usuallymanifestedbymotorweaknessand,inseverecases,bywristdroporfootdrop.表現(xiàn)為頭痛、惡心、嘔吐、高熱、煩躁、抽搐、嗜睡、精神障礙，昏迷等癥狀，類似癲癇發(fā)作或局部腦損害等綜合征。

20腕下垂21Clinicalmanifestation消化系統(tǒng)：食欲不振、惡心、隱性腹痛、腹脹、腹瀉或便秘。重者出現(xiàn)腹絞痛(abdominalangina)Digestivesystem:gastrointestinalsymptomscanoccur,includinganepithymia,nausea,abdominalpain,abdominaldistension,diarrheaorconstipation.22ClinicalmanifestationHematopoieticsystem:Leadcausesanormochromicnormocyticanemia.Inwhichredcellsmayshowcharacteristicbasophilicstippling.Evenwhenpatientsarenotfranklyanemic,theirhemoglobinvaluesareusuallydepressedandtypicallyriseslightlyduringrecovery.Whenpatientsarefranklyanemic,itisoftendue,inpart,tohemolysisrelatedtoleadeffectsontheredcellmembrane.血液和造血系統(tǒng)：低色素性的正常紅細(xì)胞性貧血，呈現(xiàn)特征性的嗜堿性點(diǎn)彩細(xì)胞。病人貧血時(shí)，部分原因是由于鉛對紅細(xì)胞膜產(chǎn)生影響而發(fā)生溶血。23點(diǎn)彩紅細(xì)胞24Clinicalmanifestation其它：齒齦邊鉛線（Pb+H2SPbS+H2

），F(xiàn)anconi綜合征，對生殖系統(tǒng)的損傷。鉛線25ClinicalmanifestationTherenaleffectsoflead:Leadprincipallyaffectstherenaltubularcells.Aminoaciduriamaydevelop,andabnormalitiesofuricacidexcretionmayleadtoepisodesofgout.Withseverepoisoning,end-stagerenaldiseasemayoccurInmen,leadisassociatedwithareductiononspermcountandanincreaseinthenumberofabnormalsperm.Inwomen,leadexposurehasbeenassociatedwithspontaneousabortionandstillbirth.26Diagnosisprinciple血鉛、尿鉛、驅(qū)鉛試驗(yàn)、鋅卟啉（ZPP)、尿ALA驅(qū)鉛試驗(yàn)：對于工齡長，車間內(nèi)Pb濃度高，有Pb中毒的臨床表現(xiàn)，但血、尿Pb含量無異常的職業(yè)人群，在服EDTA后留24小時(shí)尿，再測尿中Pb含量。尿Pb>=3.84μmol/L者為中毒。

271.觀察對象（鉛吸收）：有密切鉛接觸史，無鉛中毒臨床表現(xiàn)，具有下列表現(xiàn)之一者：尿鉛≥0.34μmol/L或0.48μmol/24h血鉛≥1.9μmol/L診斷性驅(qū)鉛實(shí)驗(yàn)后尿鉛≥1.45μmol/L而＜3.86

μmol/LDiagnosiscriteriaObservationobjects（Leadabsorption）：Personhasnoleadpoisioningclinicalmanifestation,butwhenhehasthehistoryofclosecontactwithleadaswellasoneofthefollowingfeaturescanbediagnosisasleadabsorption.Urinelead≥0.34μmol/L

or0.48μmol/24hBloodlead≥1.9μmol/LAfterdiagnosticleadexpellingtest,urinelead≥1.45μmol/L

and＜3.86

μmol/L28DiagnosiscriteriaMildpoinsing：Thereisoneofthefollowingfeaturesuponbloodlead≥2.9μmol/L

orurinelead≥0.58μmol/LALAinurine≥61.0μmol/L；Freeerythrocyteprotoporphyrin

（FEP）≥3.56μmol/L；Zincprotoporphyrin

（ZPP）≥2.91μmol/L；TherearesomesymptomssuchasabdominalpaindistensionandconstipationDiagnosticleadexpellingtest:urinelead≥3.86μmol/Lor4.82μmol/24h29Diagnosiscriteria2.輕度中毒：血鉛≥2.9μmol/L或尿鉛≥0.58μmol/L；且具有下列一項(xiàng)表現(xiàn)者，可診斷為輕度中毒：尿δ-氨基－γ－酮戊酸≥61.0μmol/L；紅細(xì)胞游離原卟啉（FEP）≥3.56μmol/L；紅細(xì)胞鋅原卟啉（ZPP）≥2.91μmol/L；有腹部隱痛、腹脹、便秘等癥狀。診斷性驅(qū)鉛試驗(yàn)，尿鉛≥3.86μmol/L或4.82μmol/24h者，可診斷為輕度鉛中毒。30DiagnosiscriteriaModeratepoisoning:patienthasoneofthefollowingfeaturesuponmildpoisoning①abdomianlangina②anemia③toxicperpheralneuropathy3.中度中毒：在輕度中毒的基礎(chǔ)上，具有下列一項(xiàng)表現(xiàn)者：①腹絞痛；②貧血；③中毒性周圍神經(jīng)??；31DiagnosiscriteriaSeverepoisoning:Patientatleasthasoneofthefollowingfeatures,suchasleadparalysisortoxicencephalopathy4.重度中毒：具有下列表現(xiàn)之一者：①鉛麻痹；②鉛腦病。32Treatment--principles鉛吸收：可繼續(xù)原工作，3～6個(gè)月復(fù)查一次。輕度中毒：驅(qū)鉛治療后可恢復(fù)工作，一般不必調(diào)離鉛作業(yè)。中度中毒：驅(qū)鉛治療后原則上調(diào)離鉛作業(yè)。重度中毒：必須調(diào)離鉛作業(yè)，給予治療和休息。33治療：驅(qū)鉛療法：依地酸二鈉鈣（CaNa2-EDTA），靜注或靜滴；二巰基丁二酸鈉（NaDMS），靜注；二巰基丁二酸（DMSA），可口服。對癥療法：如有類神經(jīng)征者給以鎮(zhèn)靜劑，腹絞痛發(fā)作者可靜脈注射葡萄糖酸鈣或皮下注射阿托品。Treatment34Prevention

加強(qiáng)個(gè)人防護(hù)：穿工作服，戴濾過式防塵防煙口罩嚴(yán)禁在車間內(nèi)進(jìn)食、吸煙定期檢測車間空氣中鉛濃度和設(shè)備維修上崗前及定期體檢，排除職業(yè)禁忌癥降低鉛濃度：用無鉛或低毒物代替鉛加強(qiáng)工藝改革：機(jī)械化、自動化、密閉化加強(qiáng)通風(fēng)控制熔鉛溫度，減少鉛蒸氣逸出35Questions

Femaleworkerswhoexposedleadduringgestationandlactationshouldtakeofftheirjobs,why?Whataretheimplicationofleadabsorption?Whataremainclinicalmanifestationsofchronicleadpoisoning?361.生產(chǎn)條件下，鉛及其化合物主要經(jīng)（）進(jìn)入人體A呼吸道B消化道C皮膚D血液2.慢性鉛中毒可出現(xiàn)（）A白細(xì)胞減少B腹絞痛C齒輪樣肌張力增高D化學(xué)性肺水腫3.鉛中毒的特效療法是（）A用金屬絡(luò)合劑B吸氧C使用小劑量美蘭D限制靜脈補(bǔ)液4.鉛可抑制血中（）酶的活性Aδ-氨基-γ-酮戊酸脫水酶B膽堿酯酶C乳酸脫氫酶D堿性磷酸酶E血紅素合成酶習(xí)題375.慢性鉛中毒可出現(xiàn)（）A再生障礙性貧血B鉛麻痹C中毒性腦病D溶血E化學(xué)性肺水腫6.鉛對造血系統(tǒng)的影響可見到（）A再生障礙性貧血B卟啉代謝障礙C低色素正常細(xì)胞性貧血D點(diǎn)彩紅細(xì)胞增多E白血病7.鉛對神經(jīng)系統(tǒng)的影響主要表現(xiàn)是（）A類神經(jīng)癥B腦缺氧C外周神經(jīng)炎D中毒性腦病E腦水腫習(xí)題38典型案例：患者黃某，男性，40歲，2003年入某金屬加工廠工作。5個(gè)月后，感頭痛、失眠、記憶力減退，手足麻木，出現(xiàn)腹痛，食欲不振等不適感，不伴有嘔吐、腹瀉，體溫正常，經(jīng)醫(yī)療部門對癥治療后，癥狀反復(fù)。當(dāng)你遇到腹痛患者時(shí)，應(yīng)考慮哪些病癥？上述材料中，你認(rèn)為病史還應(yīng)補(bǔ)充什么內(nèi)容？以上資料中無明確的職業(yè)史，一般會考慮急性闌尾炎、潰瘍腸穿孔、胰腺炎、急性胃炎等?？紤]職業(yè)史，治療史。確診為什么病，治療過程中所用藥物，治療效果如何等。39進(jìn)一步追問患者職業(yè)史，發(fā)現(xiàn)該人工作的金屬廠主要生產(chǎn)流程是以廢蓄電池為原料，經(jīng)拆件、溶解等土煉方法提煉鉛錠，生產(chǎn)過程大量鉛蒸氣逸出，在空氣中形成鉛煙(塵)污染環(huán)境，通過呼吸道或消化道進(jìn)入人體，疑似鉛中毒。根據(jù)患者的職業(yè)接觸史和臨床表現(xiàn)，隨即轉(zhuǎn)至職業(yè)病院進(jìn)行診治。要證實(shí)患者是鉛中毒