Exposure to lead even at low levels correlates with
attention-deficit/hyperactivity disorder (
ADHD). However, lead-contaminated environments are often contaminated with other
heavy metals that could exacerbate lead-induced
ADHD. We conducted this study to evaluate the relationship between multiple
heavy metals and child behaviors, and the involvement of S100
calcium-binding protein β (S100β) expression in child
ADHD in Guiyu, an internationally-known e-waste contaminated recycling town. Two hundred and forty kindergarten children, 3- to 7-years of age, who lived in Guiyu, were recruited for this study. Child behavioral assessment was derived from parent and teacher ratings. Serum S100β was assayed by an
enzyme-linked
immunosorbent assay (ELISA). Lead (Pb),
cadmium (Cd) and
manganese (Mn) levels in whole blood were measured using
graphite furnace atomic absorption spectrometry (GFAAS). The prevalence of children with
ADHD symptoms in Guiyu was 18.6%, with the percentage of children suspected to have behavior problems being 46.2% or 46.5%, based on the Rutter parents' or teachers' scale scores, respectively. Child blood levels of Pb, Cd, and Mn correlated with certain behavioral abnormalities, such as conduct problems and
antisocial behavior. Serum S100β levels were associated with
heavy metal levels in blood, and certain behavioral abnormalities. These findings suggest that exposure to various environmental
heavy metals in Guiyu might result in
child behavior disorders. Results also indicate that S100β may provide information for laboratory evaluation of neurotoxicity.