[An epidemiologic survey on blood lead levels in preschool children living in towns of Hunan Province].

Objective: To investigate blood lead levels (BLLs) and influencing factors of BLLs among preschool children living in towns of Hunan Province.
Methods: A total of 2 044 preschool children (1,108 boys and 936 girls) from towns of 12 regions in Hunan Province were enrolled by a cluster sampling between September 2008 and June 2009. The average age of the children was 4.4 ± 1.1 years (range 2 to 6 years). BLLs were determined using the atomic absorption spectrographic method. The influencing factors of BLLs were investigated using a standard questionnaire and logistic regression analysis.
Results: The mean BLLs of the children were 81.9 ± 34.5 μg/L. BLLs more than 100 μg/ L were noted in 482 children (23.58%). Of the 482 children, 472 (23.09%) showed BLLs of 100-199 μg/L and 10 (0.49%) showed BLLs ≥ 200 μg/L. There were significant differences in the prevalence of elevated BLLs (≥ 100 μg/L) among different age groups (P < 0.01). The prevalence of elevated BLLs in boys (28.99%) was significantly higher than that in girls (21.98%) (P < 0.01). There were significant differences in the prevalence of elevated BLLs in children from different regions (P < 0.01). The logistic regression analysis showed that the male (OR = 1.449, P < 0.01), father's occupational lead exposure (OR = 1.314, P < 0.01)and maternal frequent use of hair dyes (OR = 1.678, P < 0.05) were risk factor for elevated BLLs.
Conclusions: The prevalence of elevated BLLs is higher in preschool children living in towns of Hunan Province and is associated with a child's region and age. The male, father's occupational lead exposure and maternal frequent use of hair dyes are risk factor for elevated BLLs.