By Dr. Muawia Eltayeb Ahmed Pr. Zein Karrar BLOOD LEAD LEVELS AND LEAD TOXICITY IN HIGH-RISK GROUPS OF SUDANESE CHILDREN By Dr. Muawia Eltayeb Ahmed Pr. Zein Karrar

INTRODUCTION Lead is the commonest of the heavy metals: 13mg/Kg of the earth’s crust Extremely toxic___ not natural constituent of the human body Popular in industry Sources: found naturally in soil, water, and air Most abundant contaminating sources are: paints and gasoline

Industries: car batteries solder alloys and cable sheathings Pigments and colours Rust inhibitors Ammunition Plastic stabilizers Glazes in cookware Insecticides, pesticides, and rodenticides Plumbing fittings and lead pipes in water systems

Some folk medicines and cosmetics e.g. Alkohl Toys, curtain weights, and clothing accessories ingested by children with pica Placental transfer and breast milk in mothers with high lead burden

ROUTES OF EXPOSURE Inhalation: motor vehicle exhaust and gasoline sniffing practiced by street children in Sudan and some adolescent ins many parts of the world Ingestion: from water transmitted in lead pipes, food canned or cooked in lead glazed cookware, or children with pica Direct contact: traditional medications for skin or eyes__ pellets retained in the body

POPULATIONS AT RISK Preschool-age children Nutritional deficiencies of iron and calcium Children with habits like pica and gasoline sniffing 2-3 years Children whose parents’ occupation involve lead Close residence to industrial areas

EPIDEMIOLOGY AAP statement in 1987: (Lead levels > 25mcg/dl are unacceptable for children) Impairment of cognitive function occurs at levels > 10mcg/dl In Western hemisphere decline due to elimination and screening In Sudan only environmental studies

CLINCAL PICTURE Nonspecific Recurrent symptomatic episodes Irritability, anorexia, decreased play activity Lead colic: sporadic vomiting, intermittent abdominal pain, constipation, loss of developmental skills, anaemia Encephalopathy: persistent vomiting, ataxia, impaired consciousness, coma, seizures

CLINICAL PICTURE Subtle effects: neurobehavioural and cognitive performance IQ deficits, behavioural disorders, hearing defects, slowed growth For every 10mcg/dl increase in BPb there is a decrease of 4-7 points in mean IQ Children with high BPb are 7 times more likely not to graduate from school, 6 times more likely to have reading difficulties

CLINICAL PICTURE Renal: chronic nephropathy, Fanconi syndrome Impaired vit D and calcium metabolism Neuro-psychiatric disturbances Preterm delivery, LBW Lead poisoning should be suspected in: mental retardation, behavioural changes, recurrent abdominal pain, unexplained refractory anaemias, persistent vomiting, uncontrolled seizures

LABORATORY DIAGNOSIS Blood lead level Microcytic anaemia Basophilic stippling of erythrocytes  erythrocyte protoporphyrin  urinary coproporphyrin Lead lines on radiology Radiopaque flecks on abdominal radiograph

BPb and recommended treatment Environ intervention Aggressive environ intervention Chelation therapy Medical emergency and aggressive therapy < 25mcg/dl 25- 45mcg/dl 40- 70 mcg/dl > 70mcg/dl

JUSTIFICATION No study in Sudan Recent trend of urbanization and industrialization besides discovery of petroleum→ an era of environmental health problems The need for workers on the health and environment field to increase awareness of the clinical and environmental impact of lead poisoning

OBJECTIVES The purpose of this study is to: determine blood lead levels and prevalence of lead poisoning in two high-risk groups: street children and children residing in industrial areas compare the findings to a non-risk control group assess the clinical and other laboratory findings and correlation to BPb

OBJECTIVES 4. Relate the findings to demographic variables, family background, abnormal habits, nutritional state, and common childhood illnesses

MATERIAL AND METHODS Cross-sectional community-based comparative study April to July 2001 Study populations and areas: Study group 1: street children from their gathering places in many parts of Khartoum Study group 2: children in industrial areas of Khartoum North, Omdurman, and Khartoum Control group: children from Elfitehab and Salha village south of Omdurman

355 children were studied:118 for group 1, 100 for group 2, and 137 for the control group Cluster sampling was used for houses or gathering places and simple random sampling for the study units A structured questionnaire was used to record clinical findings Investigations: BPb level, Hb, peripheral blood picture

Consent Official authorities permission Counseling and advice Inclusion Exclusion Data analysis

RESULTS Street children were almost all males (3 females out of 118) 111 street children (94.1%) sniff gasoline and 96 (81.4%) sniff glue 40 children (40%) residing in industrial areas had pica or a history of pica, while 52 children of the control group (38.2%) had this habit

RESULTS Blood lead levels BPb mcg/dl Group 1 Group 2 Control No. % < 10 16 66 48.2 10-<25 39 33.1 53 56 40.9 25-<40 44.9 23 15 10.9 40-<70 26 22 8 >70 Total 118 100 137

RESULTS BPb in mcg/dl Age groups in years <1 1-<5 5-<10 10-<15 >15 No. % <10 13 76.5 26 29.9 27 21.3 15 14.6 1 4.8 10-<25 4 23.5 50 57.5 55 43.3 34 33 5 23.8 25-<40 9 10.3 38 35 42.9 40-<70 2 2.3 7 5.5 19 18.4 6 28.6 total 17 87 24.5 127 35.8 103 29 21 5.9

Relation of BPb to age groups

Relation of BPb to bowel habits mcg/dl Normal Diarrhoea Constipation No. % <10 70 32.7 10 31.3 2 1.9 10-<25 105 49.1 11 34.4 29 27.6 25-<40 34 15.9 8 25 48 45.7 40-<70 5 2.3 3 9.4 26 24.8 Total 214 61 32 9.1 29.9

Relation of BPb to convulsions Mcg/dl Convulsions No convulsions no. % No. <10 82 23.8 10-<25 2 18.2 146 42.4 25-<40 4 36.4 87 25.3 40-<70 5 45.5 29 8.4 Total 11 3.1 344 96.6

Relation of BPb to pica BPb mcg/dl Children with pica No pica No. % <10 12 11.2 68 28.7 10-<25 52 48.6 89 37.6 25-<40 34 31.8 55 23.2 40-<70 9 8.4 25 10.5 Total 107 31.1 237 68.9

Relation of BPb to behaviour mcg/dl Abnormal behaviour Normal behaviour No. % <10 82 27.2 10-<25 6 11.1 142 47.2 25-<40 23 42.6 68 22.6 40-<70 25 46.3 9 3 Total 54 15.2 301 84.8

Relation of BPb to the degree of anemia

CONCLUSION Prevalence of lead poisoning using the minimum accepted level is as follows: All street children are lead poisoned- 66.9% had moderate to high levels 84% of children in industrial areas had levels >10mcg/dl, 31% had moderate to high levels 48.2% of the control group had safe levels, 40.9% in the safe but unacceptable level,

CONCLUSION and 10.9% had mild to moderate levels BPb increases with age Pica is a strong positive determining factor for BPb level  BPb levels were positively associated with many CNS complaints, constipation, abnormal behaviour, and convulsions

CONCLUSION Anaemia is prevalent in the three groups Haemoglobin levels were inversely related to BPb Peripheral blood picture findings tend to be microcytic hypochromic with increased lead with a considerable proportion of normocytic normochromic picture

RECOMMENDATIONS Screening of children and families at risk Health education offered to risk populations and occupations Screening offered for children with refractory anaemias, difficult to control seizures, behavioural changes, unexplained encephalopathy, and mental retardation Children with pica supplemented with iron and calcium

RECOMMENDATIONS Environmental surveys Industrial facilities should be placed away from residential areas Use of unleaded gasoline Provision of better lab facilities and drugs

THANKS DR. MEA IDRIS email: muawiatayeb@hotmail.com