Association Between Urinary Heavy Metals and Developmental Disorders in Children Aged 6–15 Years: A Study Based on the NHANES Database

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) collected between 1999 and 2018, enrolling a total of 4525 children and adolescents aged 6-15 years. Weighted logistic regression, weighted quantile sum (WQS) regression and quantile g-computation (qgcomp) models were applied to explore the associations between nine urinary heavy metals (UHMs) and developmental disorders (DDs). After full covariate adjustment, urinary lead (Pb) (OR = 1.30, 95% CI: 1.10-1.54) and urinary antimony (Sb) (OR = 1.41, 95% CI: 1.18-1.69) were found to be positively correlated with DDs. Combined exposure models further identified a positive joint relationship between the mixture of UHMs and DDs, with Pb and Sb serving as the major contributing components. Sensitivity analyses that defined DDs solely based on receipt of special education or early intervention services yielded consistent findings. Given the limitations inherent to the cross-sectional design, single-spot urine sampling and heterogeneous outcome definitions, the present findings can only demonstrate correlational relationships, and further longitudinal investigations are required for conclusive validation.