CONTENTS •Source & Uses •Body stores & Distribution •Lead poisoning •Clinical features •Diagnosis •Management •Prevention
SOURCE & USES•Lead(Pb) is a heavy metal•Occupational & Non-occupational sources•Main source of environmental(non-occupational)source of Pb is Gasoline•Also through drinking water from lead pipes, chewinglead paints on toys etc..
Contd…Pb is used in various industries due to:- low B.P anticorrosive easily oxidised mixes with other metals easily to form alloys.It is used in:- Storage batteries, glass manufacture,ship building, printing and potteries, rubber industryetc..
Body Stores & DistributionBody store:- 150 to 400mg(blood level- 25µg/100ml)Clinical symptoms- >70µg/100ml in bloodNormal adult ingest-0.2 to 0.3mg of lead/day
characteristic finding of leadpoisoning, dense metaphyseallines.
LEAD POISONING(PLUMBISM)All lead compounds are toxicMOST Dangerous- lead arsenate,lead oxide,leadcarbonate.Least toxic-lead sulphide.Plumbism occur in 3 ways-INHALATION(most common), INGESTION, throughSKIN.
PATHOLOGYPb + essential SH-groups of certain enzymes Increase in permeability Potassium leakage
CLINICAL FEATURESINORGANIC Pb exposure:- Abd. Colic obstinate constipation loss of appetite blue lines on gums stippling of red cells anaemia wrist drop foot drop
DIAGNOSISHistoryClinical featuresLaboratory diagnosis a)Coproporphyrin in urine(CPU) Normal- <150µg/L b)Amino levulinic acid in urine(ALAU) >5mg/L
c)Pb in blood and urine (In urine Nl is 0.2-0.8mg) In urine- >0.8mg/L Indicates In blood- >70µg/100ml Pb absorptiond)Basophilic stippling of RBC
MANAGEMENTAima) To prevent further absorptionb) To remove lead from soft tissuesc) To prevent recurrence TREATMENT Saline purge (remove lead from the gut) d-penicillamine(promote Pb excretion in urine)
PREVENTIVE MEASURESa)Substitution Pb compounds should be substituted by less toxicmaterials.b)Isolation Pb dust or fumes should be enclosed and segregatedc)Local exhaust ventillation To remove dust & fumes
Contd…d)Personal protection By approved respiratorse)Good housekeepingf)In working atmosphere Pb conc. Should be kept <2mg per 10cu.m of airg)Periodic medical examination of workersh)Personal hygiene (Hand washing)i)Health education
WHO states that in the case of exposure to lead, itis not only the average level of lead in the bloodthat is important, but also the number of subjectswhose blood level exceeds a certain value.Pb poisoning is a notifiable and compensatable diseasein India since 1924.