Lead and essential trace element levels in school children: a cross-sectional study.
BACKGROUND
Nutritional status is thought to modulate susceptibility to lead (Pb) toxicity. The type and nature of these interactions needs to be investigated.


OBJECTIVE
To assess the prevalence of sub-clinical Pb toxicity (defined by ≥ 10 μ_rm;g/dL blood levels) and trace element deficiencies (Iron (Fe), Zinc (Zn), Copper (Cu) and Magnesium (Mg)) and to find out their possible relationship, if any.


METHODS
A cross-sectional survey was carried out in a total of 195 school children residing in urban (n = 65), urban heavy traffic (n = 65) and urban industrial (n = 65) zones of Hyderabad, India. Blood Pb, trace element levels, haemoglobin and δ-aminolevulinate dehydratase (δ-ALAD) activity was measured.


RESULTS
High blood lead levels ( ≥ 10 μ_rm;g/dL) were observed in 54.3% of children while percentage prevalence of trace element deficiencies such as Fe (16.2%), Zn (68.6%), Mg (41.7%) and Cu (25%) were also high in children included in the study. Higher blood Pb levels and reduced δ-ALAD activity was observed in children residing in heavy traffic and industrial areas. Blood Pb levels but not δ-ALAD activity correlated inversely with serum Fe in heavy traffic and industrial children, respectively. Interestingly, δ-ALAD activity but not blood Pb levels correlated inversely with trace element levels only in urban children.


CONCLUSIONS
These results suggest higher prevalence of sub-clinical Pb toxicity and trace element deficiencies in urban children. Further, high blood Pb levels appear to be correlated with reduced δ-ALAD activity and iron status in Pb exposed children.
Food and Drug Toxicology Research Centre, National Institute of Nutrition (ICMR), Hyderabad, India.
Y
Y
Srinivasa Reddy
Raghu
R
Pullakhandam
K V
KV
Radha Krishna
P
P
Uday Kumar
B
B
Dinesh Kumar
D000293:Adolescent; D000740:Anemia / Q000097:blood / Q000453:epidemiology; D000886:Anthropometry; D002648:Child; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007194:India / Q000453:epidemiology; D007854:Lead / Q000097:blood*; D007855:Lead Poisoning / Q000097:blood; D008297:Male; D000623:Porphobilinogen Synthase / Q000378:metabolism; D015995:Prevalence; D012574:Schools; D014131:Trace Elements / Q000097:blood* / Q000172:deficiency
D006454:Hemoglobins; D014131:Trace Elements; D007854:Lead; D000623:Porphobilinogen Synthase