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 mu g/L. The prevalence rates of elevated BLLs (>= 100 mu g/L and >= 50 mu g/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 mu g/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 mu g/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 mu g/L.