title: S100β in heavy metal-related child attention-deficit hyperactivity disorder in an informal e-waste recycling area.
abstract: 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.
authors.affiliation: Laboratory of Environmental Medicine and Developmental Toxicology, and Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, Guangdong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Laboratory of Environmental Medicine and Developmental Toxicology, and Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, Guangdong, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Huo
authors.affiliation: Laboratory of Environmental Medicine and Developmental Toxicology, and Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, Guangdong, China.
authors.forename: Daichun
authors.initials: D
authors.lastname: Liu
authors.affiliation: Laboratory of Environmental Medicine and Developmental Toxicology, and Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen 9700RB, The Netherlands.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Laboratory of Environmental Medicine and Developmental Toxicology, and Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, Guangdong, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Laboratory of Environmental Medicine and Developmental Toxicology, and Provincial Key Laboratory of Infectious Diseases and Molecular Immunopathology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Cell Biology and Genetics, Shantou University Medical College, Shantou 515041, Guangdong, China. Electronic address: xuxj@stu.edu.cn.
authors.forename: Xijin
authors.initials: X
authors.lastname: Xu
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000139:chemically induced*; D002105:Cadmium Poisoning / Q000097:blood; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D020260:Heavy Metal Poisoning, Nervous System / Q000097:blood* / Q000523:psychology*; D006801:Humans; D007855:Lead Poisoning / Q000097:blood; D008297:Male; D020149:Manganese Poisoning / Q000097:blood; D059027:Recycling; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*
chemical_list: D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human
keywords: Attention-deficit/hyperactivity disorder (ADHD); Child behavior; Electronic waste; Heavy metal; Serum S100β