LEAD POISONING. Dr. S.B. Lall. Head, Poison Control Centre DIRECTORATE OF ENVIRONMENTAL HEALTH & MALARIA ERADICATION

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1 LEAD POISONING Dr. S.B. Lall Head, Poison Control Centre DIRECTORATE OF ENVIRONMENTAL HEALTH & MALARIA ERADICATION

2 Lead Poisoning A Case Report Poison Control Centre received a blood sample for estimation of lead in a 2- month old male baby admitted in Rustaq hospital, with history of : delayed passage of meconium and constipation for one month passed stools only after use of glycerine suppository baby had been given orally a local medicine ( Bint al dahab ) for constipation, 2 weeks back Baby FTND, 2.7 kg, breast fed On examination: weight 5 kg, active, NAD, except mild distension of abdomen PR examination NAD empty rectum X-Ray abdomen showed -abdomen loaded with stool and scattered radio opaque speckles

3 Blood Lead Levels 83.3 µg/dl Diagnosis---LEAD POISONING History of administration of Bint al dahab X-ray abdomen showing lead speckles BLL 83.3 µg/dl Referred to The Royal Hospital for Chelation therapy After chelation therapy---bll 49.9 µg/dl Lead levels in local medicine 20.0% lead by weight / gm of sample

4 Two reports from Oman on lead poisoning in infants Woolf DA. Aetiology of acute lead encephalopathy in Omani infants J Tropical Pediatrics 36, , 1990 Sharma RR, Chandy MJ and Lad SD Br J Neurosurg 4, , 1990

5 A WHO study by Poison Control Centre-2003 Prevalence and Potential Risk Factors for Elevated BLL Among School Children, Antenatal Cases and Some Industrial Workers

6 Blood Lead Levels in all children Total Number of blood samples 334 Range µg / dl Mean ± SD 4.46 ± 3.7 µg / dl Number of Samples 10 µg / dl 22 ( 6.58 % ) Number of Samples > 20 µg / dl 3

7 Frequency in different blood lead categories % frequency % n % 0.9 % 0 < < <20 20 BLL µg/dl

8 Prevalence of lead poisoning in School Children 6.58% (BLL 10µg/dl). 25 % of total children had BLL between 5 10 µg/dl. Prevalence of elevated BLL among girls > boys but Mean BLL levels similar Inverse correlation between elevated BLL and age ( r=-0.07) Association of exposure with (i) habit of not washing hands before eating and (ii) playing in home garages (P<0.05) Possible sources Soil, Wall paint, Traditional remedies, Al kohl, Glazed pottery, Tinned food, Painted toys, Water, Industrial Lead battery and radiator repair workers 60-80% workers highly exposed (BLL 60µg/dl) p<0.001 Antenatal cases BLL < 10 µg/dl in all cases studied (p>0.05 vs controls)

9 Why lead is a cause for concern? Lead is a toxic heavy metal and is cumulative Widely present in earth s crust and its extensive use ( industrial, petrol/diesel, paints etc.) has resulted in environmental contamination worldwide Lead sources exist in Oman Traditional remedies, Kohl, Past use of leaded gasoline and wall paints, Leaded water pipes, Refineries, Lead soldered cans, Glazed ceramic ware, Glass, Rubber, Plastic & Battery manufacturing industries, Car radiator repair units, Welding and Construction

10 Sources of Exposure for Small Children Wall paint chippings Contaminated household soil and dust Water from lead soldered pipes Contaminated food (lead soldered cans, glazed ceramic) Painted toys and miniature models Some traditional remedies ( Bint al dahab, Kohl ) Contaminated air ( petrol / diesel exhaust, industrial) Major Pathways of Exposure HOUSEHOLD SOIL AND DUST WATER FOOD

11 Major Routes of Exposure Ingestion Inhalation Toxicity depends on : Age Nutritional status Route of exposure Duration of exposure Amount of lead in the source

12 Health effects correlate with the lead levels blood

13 Children below six years at greatest risk Behavioral characteristics (outdoor activity, less hygiene, more hand-to-mouth activity, pica) Eat and drink more per unit body weight than adults Lead absorption substantially higher than adults More prevalence of nutritional deficiencies Blood brain barrier incompletely developed Developing brain and nervous system more sensitive to damage

14 Substantial evidence to show strong link between lead exposure and IQ loss Loss of 1.3 IQ points for each 5µg/dl interval of BLL between 5 and 20µg/dl.

15 Mild mental retardation (MMR) from Lead-related IQ loss MMR = IQ between 70-50

16 Lead causes growth retardation Adjusted height (Cm) ADJUSTED WEIGHT (Kg) BLL µg /dl BLL BLL µg /dl

17 Effects of low level lead exposure in early childhood (BLL 10µg/dl ) Decreased IQ Learning & reading difficulties and poor school performance Behavioral problems (aggressive, hyperactive, social maladjustments) Decreased hearing Growth retardation

18 Clinical Presentations Chronic low dose exposure ( BLL ug/dl) Frequent abdominal pain ( colic) Fatigue. Malaise Irritability Impaired concentration, headache Loss of appetite Nausea, vomiting Constipation or diarrhoea Pallor Weight loss & growth retardation Acute large dose exposure (severe poisoning and encephalopathy, BLL >80 ug/dl) Abdominal colic, Vomiting Ataxia Convulsions Coma

19 Lead poisoning to be suspected History of pica, Traditional remedy administered Multi-system findings ( GIT : Self limited episodes of abdominal pain and vomiting, anorexia, constipation or diarrhea ) CNS: Headache, neuro-behavioral deficits, developmental delays BLOOD: Microcytic hypochromic anemia NEUROMUSCULAR: Muscle weakness RENAL: Gout Behavioral disorders, Attention deficit hyperactivity syndrome Growth retardation Consider lead encephalopathy in a child with: Consider lead encephalopathy in a child with: delirium convulsions coma

20 Investigations Blood Lead Levels ( BLL ) Free Erythrocyte Protoporphyrin Levels (ZnEP) Hemoglobin and Peripheral blood film X-Ray Abdomen and Long bones Hearing, IQ, Cognitive evaluation BLL most sensitive and diagnostic <10 µg/dl ---No poisoning (<0.48µmol/L) 10 µg/dl --- indicates lead poisoning in children Interventions µg/dl Find source, Prevent exposure, Nutritional & Educational Intervention > 45µg/dl Chelation ( Calcium Di Sodium EDTA or DMSA ) > 80µg/dl Admit, Treat as emergency for chelation therapy

21 Estimation of blood lead levels Anodal Stripping Voltametery (ASV) Only 2 ml blood sample required No extraction procedure needed Sensitivity o.1 ug/dl Internal and External Quality control

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27 The Proper blood collection method for Lead analysis Venous blood after thoroughly cleaning the venepuncture site with spirit swabs ( to avoid contamination of sample with lead in the dust deposited on the skin ) 2.0 ml of whole blood in BD vaccutainer containing 3.6 mg of EDTA ( purple cap ) lead free containers preferred Discard clotted or hemolysed sample

28 Keep the sample in refrigerator ( DO NOT FREEZ ) Fill request form ( hematology form ) including full details of patient : Name, Age, Sex.clinical history,clinical featuress, date&time of sample collection, doctor s name & stamp with Telephone & Fax number Send the sample within hrs in cool box to the Toxicology laboratory from 7:00 to 13:00 pm (Saturday to Tuesday) Directorate of Environmental Health & Malaria Eradication Poison Control Centre Wattayah, Muscat Telephone Fax or Conact persons : Dr.Lall or Mr.Mohammed Al Habsi

29 NORMAL CUT OFF RANGE CHILD 10 µg / dl PREGNANT WOMEN 10 µg / dl ADULTS 40 µg / dl

30 PRIMARY PREVENTION Proactive approach at controlling, reducing or eliminating sources of lead in child s environment Phasing out leaded gasoline Generate data on population blood lead levels specially in children <6 years Enforcement of health safety standards Raising public awareness Evaluation of home environment Nutritional and educational interventions Follow-up of all children with lead levels >10µg/dl

31 Prevent Exposure of children to lead أطفال يا آلون شيبس ملون تشققات صبغة الجدران العاب السيارات أطفال يلعبون باللعب المطلية الا واني والا آواب المطلية أطفال يلعبون في تربة(طين) حديقة المنزل دخان عادم السيارات BINT AL DAHAB AL KOHL

32 Community Advice Check your home for chipping, cracking of paints and immediately repair it. Mop floor & windows with wet cloth Do not give cheap painted toys to children Make children wash hands after playing outside. Advise children not to play in garages or near roads Give healthy food rich in Iron and Calcium (milk and milk products, green vegetables) Do not use newspaper sheet for packing food Be careful when using traditional remedies If you are in doubt about the risk of lead exposure to your child, contact your doctor and get blood lead levels, if advised. For more details, contact Poison Control Centre, Telephone

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