title: Prenatal exposure to environmental chemical contaminants and asthma and eczema in school-age children.
abstract: BACKGROUND
  Emerging evidence suggests that prenatal or early-life exposures to environmental contaminants may contribute to an increased risk of asthma and allergies in children. We aimed to the explore associations of prenatal exposures to a large set of environmental chemical contaminants with asthma and eczema in school-age children.
  
  
  METHODS
  We studied 1024 mother-child pairs from Greenland and Ukraine from the INUENDO birth cohort. Data were collected by means of an interview-based questionnaire when the children were 5-9 years of age. Questions from the ISAAC study were used to define asthma, eczema, and wheeze. We applied principal components analysis (PCA) to sixteen contaminants in maternal serum sampled during pregnancy, including perfluoroalkyl substances (PFASs), metabolites of diethylhexyl (DEHP) and diisononyl (DiNP) phthalates, PCB-153, and p,p'-DDE. Scores of five principal components (PCs) explaining 70% of the variance were included in multiple logistic regression models.
  
  
  RESULTS
  In a meta-analysis that included both populations, the PC2 score, reflecting exposure to DiNP, was negatively associated with current eczema (OR 0.71, 95% CI 0.52-0.96). Other associations were not consistent between the two populations. In Ukrainian children, the PC3 score (DEHP) was positively associated with current wheeze (adjusted OR 1.56, 95% CI 1.03-2.37), whereas the PC5 score, dominated by perfluorooctanoic acid (PFOA), was inversely associated with current wheeze (OR 0.64, 0.41-0.99). In Greenlandic children, a negative association of PC4 (organochlorines) with ever eczema (OR 0.78, 0.61-0.99) was found.
  
  
  CONCLUSIONS
  We found limited evidence to support a link between prenatal exposure to environmental chemical contaminants and childhood asthma and eczema.
authors.affiliation: IRAS, Division of Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands.
authors.forename: L A M
authors.identifier: http://orcid.org/0000-0003-0292-0946
authors.initials: LA
authors.lastname: Smit
authors.affiliation: IRAS, Division of Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands.
authors.forename: V
authors.initials: V
authors.lastname: Lenters
authors.affiliation: Danish Ramazzini Centre, Department of Occupational Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: B B
authors.initials: BB
authors.lastname: Høyer
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: C H
authors.initials: CH
authors.lastname: Lindh
authors.affiliation: Centre for Arctic Environmental Medicine, Dronning Ingrids Hospital, Nuuk, Greenland.
authors.forename: H S
authors.initials: HS
authors.lastname: Pedersen
authors.affiliation: Department of Social Medicine and Organization of Public Health, Kharkiv National Medical University, Kharkiv, Ukraine.
authors.forename: I
authors.initials: I
authors.lastname: Liermontova
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: B A G
authors.initials: BA
authors.lastname: Jönsson
authors.affiliation: Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
authors.forename: A H
authors.initials: AH
authors.lastname: Piersma
authors.affiliation: Department of Occupational and Environmental Medicine, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: J P
authors.initials: JP
authors.lastname: Bonde
authors.affiliation: Danish Ramazzini Centre, Department of Occupational Medicine, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: G
authors.initials: G
authors.lastname: Toft
authors.affiliation: IRAS, Division of Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Vermeulen
authors.affiliation: IRAS, Division of Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Heederik
mesh_terms: D001249:Asthma / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003633:Dichlorodiphenyl Dichloroethylene; D004051:Diethylhexyl Phthalate; D004485:Eczema / Q000453:epidemiology*; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004785:Environmental Pollutants; D005260:Female; D006116:Greenland / Q000453:epidemiology; D006801:Humans; D006843:Hydrocarbons, Chlorinated; D008297:Male; D010795:Phthalic Acids; D011078:Polychlorinated Biphenyls; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D025341:Principal Component Analysis; D012135:Respiratory Sounds; D014455:Ukraine / Q000453:epidemiology
chemical_list: D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D010795:Phthalic Acids; C012125:diisononyl phthalate; D003633:Dichlorodiphenyl Dichloroethylene; D004051:Diethylhexyl Phthalate; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl
keywords: asthma; birth cohort; eczema; environmental pollutants; multivariate analysis