Association between blood lead levels and socio-demographic factors among outpatient children in Ningbo, China

Lead exposure is a well-known health concern, affecting children worldwide. We aim to assess children’s blood lead levels (BLLs), and the association of risk factors with elevated BLL in children since the phase-out of leaded gasoline. We enrolled 8085 outpatient children to assess their blood lead levels, and the associations with social-demographic factors. Social-demographic information was obtained by using questionnaires. Multivariable linear and logistic regression models were performed to explore the associations between social-demographic factors and elevated BLLs. The geometric mean BLL was 15.96 μg/L. The prevalence rates of elevated BLLs (≧ 100 μg/L and ≧ 50 μg/L) were 2.0 % and 10.9 %, respectively. BLLs in boys were higher than that in girls (P < 0.001). Girls had a lower risk of BLLs above 50 μg/L than boys (OR = 0.83, 95 % CI 0.71–0.96). Father’s occupation as a skilled laborer or professional worker and living in the suburbs significantly contributed to the elevated BLLs ( ≧ 50 μg/L), with the ORs of 1.39 (1.06–1.81), 1.33 (1.01–1.75) and 1.24 (1.02–1.50), respectively. Our results suggested that children who lived in suburbs and whose fathers were skilled laborers and professional workers were more likely to have BLLs above 50 μg/L.