title: Maternal exposure to metals and persistent pollutants and cord blood immune system biomarkers.
abstract: BACKGROUND
  The fetal time period is a critical window of immune system development and resulting heightened susceptibility to the adverse effects of environmental exposures. Epidemiologists and toxicologists have hypothesized that persistent organic pollutants, pesticides and metals have immunotoxic properties. Immunotoxic effects may manifest as an altered immune system profile at birth. Immunoglobulin E, thymic stromal lymphopoietin (TSLP), and interleukin-33 (IL-33) may be implicated in the etiology of childhood allergy and are detectable at birth. The objective of this study was to examine the potential relationship between maternal concentrations of metals, persistent organic pollutants, and pesticides and elevated umbilical cord blood concentrations of IgE, TSLP, and IL-33 in a Canadian birth cohort.
  
  
  METHODS
  This study utilized data collected in the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a trans-Canada cohort study of 2,001 pregnant women. Of these women, 1258 had a singleton, term birth and cord blood sample. Logistic regression was used to determine associations between log-transformed continuous variables and immune system biomarkers.
  
  
  RESULTS
  Inverse relationships were observed between lead, DDE, PCB-118, and a summary index of organophosphorous metabolites and jointly elevated concentrations of IL-33 and TSLP. None of the environmental contaminants were associated with increased odds of a high cord blood immune system biomarker concentration.
  
  
  CONCLUSIONS
  In this primarily urban Canadian population of pregnant women and their newborns, maternal blood or urine concentrations of persistent organic pollutants, pesticides, and metals were not associated with immunotoxic effects that manifest as increased odds of elevated concentrations of IgE, TSLP or IL-33.
authors.affiliation: Interdisciplinary PhD Program, Dalhousie University, IDPhD c/o Faculty of Graduate Studies Room 314 Henry Hicks Building 6299 South St Halifax, Halifax, NS, B3H 4H6, Canada. jillian.ashley-martin@dal.ca.
authors.forename: Jillian
authors.initials: J
authors.lastname: Ashley-Martin
authors.affiliation: Department of Community Health & Epidemiology, Dalhousie University, Centre for Clinical Research, 5790 University Avenue, Halifax, NS, B3H 1 V7, Canada. Adrian.levy@dal.ca.
authors.forename: Adrian R
authors.initials: AR
authors.lastname: Levy
authors.affiliation: Population Studies Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Dr., AL 0801A, Ottawa, ON, K1A 0 K9, Canada. Tye.Arbuckle@hc-sc.gc.ca.
authors.forename: Tye E
authors.initials: TE
authors.lastname: Arbuckle
authors.affiliation: Department of Epidemiology and Biostatistics, McGill University, Purvis Hall 1020 Pine Ave. West, Montreal, H3A 1A2, QC, Canada. robert.platt@mcgill.ca.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Platt
authors.affiliation: Department of Microbiology & Immunology, Dalhousie University Sir Charles Tupper Medical Building, Room 7-C5850 College Street, Halifax, NS, Canada. jean.marshall@dal.ca.
authors.forename: Jean S
authors.initials: JS
authors.lastname: Marshall
authors.affiliation: Department of Obstetrics & Gynaecology and Paediatrics, Dalhousie University, Perinatal Epidemiology Research Unit, 7th Floor Women's Site, IWK Health Centre, 5980 University Ave, PO Box 9700, Halifax, NS, B3H 6R8, Canada. l.dodds@dal.ca.
authors.forename: Linda
authors.initials: L
authors.lastname: Dodds
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D002170:Canada; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D015386:Hazardous Substances / Q000097:blood; D006801:Humans; D007155:Immunologic Factors / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D018811:Maternal Exposure / Q000009:adverse effects*; D008670:Metals / Q000097:blood*; D011247:Pregnancy; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D015386:Hazardous Substances; D007155:Immunologic Factors; D008670:Metals