title: Prenatal airborne polycyclic aromatic hydrocarbon exposure, LINE1 methylation and child development in a Chinese cohort.
abstract: Polycyclic aromatic hydrocarbons (PAH) are carcinogenic, neurotoxic environmental pollutants generated during incomplete combustion of fossil fuel and other organic material. PAH exposure has been associated with adverse fetal development and epigenetic alterations in cord blood. Several molecular epidemiology studies have established PAH-DNA adducts as biomarkers of PAH exposure.
  
  
  
  We investigated the relationship between LINE1 DNA methylation and PAH-DNA adduct levels in cord blood, and with neurodevelopmental outcomes.
  
  
  
  In Tongliang County, China, the current study enrolled two population-based cohorts of nonsmoking pregnant women before (2002) and after (2005) the closure of a local coal-fired power plant in May 2004. We analyzed cord blood samples collected from mothers in the two cohorts (n=110 from 2002 cohort and n=107 from 2005 cohort) for PAH-DNA adducts and genomic LINE1 DNA methylation. Neurodevelopmental data on children were collected using the Gesell Developmental Scales (GDS) at age 2 and using the Wechsler Intelligence Scale for Children (WISC) at age 5.
  
  
  
  A significant inverse relationship was observed between PAH-DNA adducts and LINE1 DNA methylation (β=-0.010, p<0.038). A significant, positive association between LINE1 methylation and scores on WISC full scale and verbal (β=85.31, p<0.005; β=94.36, p<0.003) but not on the GDS. Mediation analysis did not find LINE1 to be a direct mediator between PAH-DNA adducts and IQ score.
  
  
  
  LINE1 methylation in cord blood DNA was a positive predictor of IQ at age 5 and was decreased at higher levels of prenatal PAH exposure measured by PAH-DNA adducts in cord blood. However, the adverse effects of prenatal exposure to PAH on IQ scores did not appear to be directly mediated by altered LINE1 methylation.
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States.
authors.forename: Joan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States.
authors.forename: Vrinda
authors.initials: V
authors.lastname: Kalia
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States.
authors.forename: Frederica
authors.initials: F
authors.lastname: Perera
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States.
authors.forename: Julie
authors.initials: J
authors.lastname: Herbstman
authors.affiliation: Chirdren's Hospital, Chongqing Medical University, Chongqing, China.
authors.forename: Tingyu
authors.initials: T
authors.lastname: Li
authors.affiliation: Shanxi Medical University, Taiyuan, China.
authors.forename: Jisheng
authors.initials: J
authors.lastname: Nie
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States.
authors.forename: L R
authors.initials: LR
authors.lastname: Qu
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Environmental Health Sciences, Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, NY, United States. Electronic address: dt14@columbia.edu.
authors.forename: Deliang
authors.initials: D
authors.lastname: Tang
mesh_terms: D000328:Adult; D002657:Child Development; D002675:Child, Preschool; D002681:China; D015331:Cohort Studies; D018736:DNA Adducts / Q000378:metabolism*; D019175:DNA Methylation; D004785:Environmental Pollutants / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D020084:Long Interspersed Nucleotide Elements; D018811:Maternal Exposure; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D014888:Wechsler Scales; D055815:Young Adult
chemical_list: D018736:DNA Adducts; D004785:Environmental Pollutants; D011084:Polycyclic Aromatic Hydrocarbons; C095911:polycyclic aromatic hydrocarbons-DNA adduct
keywords: Global methylation; LINE1 methylation; Neurodevelopment; Polycyclic aromatic hydrocarbons; Prenatal exposure