title: Tea consumption in pregnancy as a predictor of pesticide exposure and adverse birth outcomes: The MIREC Study.
abstract: BACKGROUND
  Pesticide residues in tea may contribute to exposure during pregnancy; however, the impact on maternal and infant health is not well understood. The aim of this study was to determine whether tea intake in the first trimester was associated with elevated concentrations of various pesticides in maternal blood or urine. Further, we examined the relationship between tea consumption and adverse birth outcomes.
  
  
  METHODS
  Data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canada pregnancy cohort, were used. All singleton, live births (n=1898) with available biomarkers were included in the analyses. Descriptive statistics were used to characterize the population. The geometric means (GM) of organochlorine (OC) pesticide constituents or metabolites in maternal plasma (lipid adjusted) and organophosphate (OP) pesticide metabolites (adjusted for specific gravity) in maternal urine were calculated for participants who drank regular, green or herbal tea in the first trimester and for those who did not. Differences between groups were examined using chi-square or t-tests. Associations between frequency of drinking tea and adverse birth outcomes were examined using logistic regression (preterm birth and small-for-gestational-age) or generalized linear models (birthweight decile and head circumference).
  
  
  RESULTS
  The GM of the OC pesticide constituent trans-nonachlor was 2.74 mg/g lipid, and for metabolites oxychlordane and p,p'-DDE this was 1.94 ng/g lipid and 55.8 ng/g lipid, respectively. OP pesticide metabolite concentrations adjusted for specific gravity, were dimethylphosphate (GM: 3.19 µg/L), dimethylthiophosphate (GM: 3.29 µg/L), dimethyldithiophosphate (GM: 0.48 µg/L), diethlphosphate (GM: 2.46), and diethylthiophosphate (GM: 0.67 µg/L). There was no significant difference in mean concentrations for these OC or OP pesticide constituents or metabolites between tea drinkers - of any type - and non-tea drinkers. Further, no association was found between tea intake and adverse birth outcomes.
  
  
  CONCLUSIONS
  Pesticide concentrations did not differ by tea intake. Further, tea intake in the first trimester was not associated with adverse birth outcomes. In this study population, there was no evidence for concern about tea intake being a source of the OP or OC pesticide metabolites measured or adversely affecting birth outcomes; however, tea intake was lower than national Canadian data for women of reproductive age.
authors.affiliation: Université de Sherbrooke Departement of Obstetrics and Gynecology, 3001, 12e Avenue Nord, Sherbrooke, QC, Canada J1H 5N4. Electronic address: cynthia.colapinto@gmail.com.
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Colapinto
authors.affiliation: Population Studies Division, Environmental Health Science and Research Bureau, Environmental and Radiation Health Sciences Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Room 153, Environmental Health Center, 50 Colombine Dr. Tunney's Pasture, AL 0801A, Ottawa, ON, Canada K1A 0K9. Electronic address: tye.arbuckle@hc-sc.gc.ca.
authors.forename: Tye E
authors.initials: TE
authors.lastname: Arbuckle
authors.affiliation: University of Ottawa, Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, 600 Peter Morand Crescent (312C), Ottawa, ON, Canada K1G 5Z3. Electronic address: ldubois@uottawa.ca.
authors.forename: Lise
authors.initials: L
authors.lastname: Dubois
authors.affiliation: Université de Sherbrooke Departement of Obstetrics and Gynecology, 3001, 12e Avenue Nord, Sherbrooke, QC, Canada J1H 5N4. Electronic address: William.Fraser@USherbrooke.ca.
authors.forename: William
authors.initials: W
authors.lastname: Fraser
mesh_terms: D002170:Canada; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D018811:Maternal Exposure / Q000009:adverse effects; D010573:Pesticide Residues / Q000009:adverse effects* / Q000097:blood; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D047928:Premature Birth / Q000139:chemically induced; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced; D011795:Surveys and Questionnaires; D013662:Tea / Q000009:adverse effects* / Q000737:chemistry*
chemical_list: D010573:Pesticide Residues; D013662:Tea
keywords: Adverse birth outcomes; MIREC.; Organochlorine pesticides; Organophosphate pesticides; Tea