PREVALENCE OF BLOOD LEAD
LEVEL IN BANGKOK CHILDREN
Ruangkanchanasetr S, Suepiantham J.
Department of Pediatrics, Faculty of
Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Objective: To evaluate the lead
problem in Bangkok children and identify risk factors and impact associated
with high lead level (>10
mg/dL)
Methods: The longitudinal study
(N = 84) followed blood lead levels at birth, 6,12,18,24 and 78 months of
age. Also multiple cross-sectional studies comprising of children under 15
years of age attending the outpatient clinic, Ramathibodi Hospital (N=511),
kindergartens (N=60) and secondary school students (N=377) in Bangkok were
conducted. The control for under 2 year-old children (N=188) were those
attending Metapracharak Hospital, Nakornprathom Province. Physical
examinations were performed by pediatricians. Blood lead levels were
assessed by Atomic Absorption Spectrometry. Questionnaires to identify risk
factors were completed by parents of under 2 year-old children. IQ tests
were assessed by psychologists in the longitudinal group at 2 and 6 years
of age.
Results: The mean blood lead
levels were increasing with age from 5.57+2.31 mg/dL at birth, 5.03+2.21 mg/dL at 6 years of
age, in the cohort study, to 6.74+2.02 mg/dL in kindergartens, and 9.03+3.65 mg/dL in secondary school students. They were all in the acceptable
range. However, the proportion of blood lead higher than 10 mg/dL were increasing from 1 to 6, 10% at birth to 6% at 2 years of
age, 10% in kindergartens and 35% in secondary school. The mean lead level
in Bangkok children under 2 years of age was higher than those of the
control group, but not statistically singificant. The high lead group had a
higher mean age and larger family size than those in the low lead group. In
the kindergartens and secondary school, males had higher lead levels than
females in the same age group.
Conclusion:
The blood lead levels in Bangkok children were
not as high as expected. On the contrary, they tended to decrease following
the reduction of ambient lead levels because of unleaded gasoline usage.