title: Combined Effects of Prenatal Exposures to Environmental Chemicals on Birth Weight.
abstract: Prenatal chemical exposure has been frequently associated with reduced fetal growth by single pollutant regression models although inconsistent results have been obtained. Our study estimated the effects of exposure to single pollutants and mixtures on birth weight in 248 mother-child pairs. Arsenic, copper, lead, manganese and thallium were measured in cord blood, cadmium in maternal blood, methylmercury in maternal hair, and five organochlorines, two perfluorinated compounds and diethylhexyl phthalate metabolites in cord plasma. Daily exposure to particulate matter was modeled and averaged over the duration of gestation. In single pollutant models, arsenic was significantly associated with reduced birth weight. The effect estimate increased when including cadmium, and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) co-exposure. Combining exposures by principal component analysis generated an exposure factor loaded by cadmium and arsenic that was associated with reduced birth weight. MECPP induced gender specific effects. In girls, the effect estimate was doubled with co-exposure of thallium, PFOS, lead, cadmium, manganese, and mercury, while in boys, the mixture of MECPP with cadmium showed the strongest association with birth weight. In conclusion, birth weight was consistently inversely associated with exposure to pollutant mixtures. Chemicals not showing significant associations at single pollutant level contributed to stronger effects when analyzed as mixtures.
authors.affiliation: Environmental Risk and Health, Flemish Institute for Technological Research (VITO), 2400 Mol, Belgium. eva.govarts@vito.be.
authors.forename: Eva
authors.initials: E
authors.lastname: Govarts
authors.affiliation: Department of Epidemiology and Social Medicine, University of Antwerp, 2610 Wilrijk, Belgium. sylvie.remy@uantwerpen.be.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Remy
authors.affiliation: Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, 3590 Diepenbeek, Belgium. liesbeth.bruckers@uhasselt.be.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Bruckers
authors.affiliation: Environmental Risk and Health, Flemish Institute for Technological Research (VITO), 2400 Mol, Belgium. elly.denhond@wiv-isp.be.
authors.forename: Elly
authors.initials: E
authors.lastname: Den Hond
authors.affiliation: Department of Public Health, Ghent University, Ghent, Belgium; FWO Research Foundation, 1000 Brussels, Belgium. isabelle.sioen@UGent.be.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sioen
authors.affiliation: Department of Health, Provincial Institute for Hygiene, 2000 Antwerp, Belgium. Vera.NELEN@provincieantwerpen.be.
authors.forename: Vera
authors.initials: V
authors.lastname: Nelen
authors.affiliation: Department of Analytical, Environmental and Geochemistry (AEGC), Vrije Universiteit Brussel, 1040 Brussels, Belgium. wbaeyens@vub.ac.be.
authors.forename: Willy
authors.initials: W
authors.lastname: Baeyens
authors.affiliation: Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium. tim.nawrot@uhasselt.be.|Department of Public Health &amp; Primary Care, Leuven University, 3000 Leuven, Belgium. tim.nawrot@uhasselt.be.
authors.forename: Tim S
authors.initials: TS
authors.lastname: Nawrot
authors.affiliation: Department Sociology, Faculty of Political and Social Sciences, University of Antwerp, 2000 Antwerp, Belgium. ilse.loots@uantwerpen.be.
authors.forename: Ilse
authors.initials: I
authors.lastname: Loots
authors.affiliation: Department of Analytical, Environmental and Geochemistry (AEGC), Vrije Universiteit Brussel, 1040 Brussels, Belgium. nicolas.vanlarebeke@ugent.be.
authors.forename: Nick
authors.initials: N
authors.lastname: Van Larebeke
authors.affiliation: Environmental Risk and Health, Flemish Institute for Technological Research (VITO), 2400 Mol, Belgium. greet.schoeters@vito.be.|Department of Biomedical Sciences, University of Antwerp, 2610 Wilrijk, Belgium. greet.schoeters@vito.be.|Department of Environmental Medicine, University of Southern Denmark, 5230 Odense, Denmark. greet.schoeters@vito.be.
authors.forename: Greet
authors.initials: G
authors.lastname: Schoeters
mesh_terms: D000328:Adult; D001151:Arsenic / Q000032:analysis; D001724:Birth Weight; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D047109:Fetal Development; D005466:Fluorocarbons / Q000032:analysis; D006197:Hair / Q000737:chemistry; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D019216:Metals, Heavy / Q000032:analysis; D008767:Methylmercury Compounds / Q000032:analysis; D010795:Phthalic Acids / Q000032:analysis; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects
chemical_list: D004785:Environmental Pollutants; D005466:Fluorocarbons; D006843:Hydrocarbons, Chlorinated; D019216:Metals, Heavy; D008767:Methylmercury Compounds; D010795:Phthalic Acids; D001151:Arsenic
keywords: biomonitoring; birth outcome; cord blood; endocrine disruptors; epidemiology; mixtures; principal component analysis; regression analysis