title: Early-life exposure to organophosphate pesticides and pediatric respiratory symptoms in the CHAMACOS cohort.
abstract: BACKGROUND
  Although pesticide use is widespread, the possible effect of early-life exposure to organophosphate (OP) on pediatric respiratory health is not well described.
  
  
  OBJECTIVE
  We investigated the relationship between early-life exposure to OPs and respiratory outcomes.
  
  
  METHODS
  Participants included 359 mothers and children from the CHAMACOS birth cohort. Dialkyl phosphate (DAP) metabolites of OP pesticides, specifically diethyl (DE) and dimethyl (DM) phosphate metabolites, were measured in urine from mothers twice during pregnancy (mean = 13 and 26 weeks gestation) and from children five times during childhood (0.5-5 years). Childhood DAP concentrations were estimated by the area under curve (AUC). Mothers reported their child's respiratory symptoms at 5 and 7 years of age. We used generalized estimating equations (GEE) to examine associations of prenatal and childhood DAP concentrations with repeated measures of respiratory symptoms and exercise-induced coughing at 5 and 7 years of age, adjusting for child's sex and age, maternal smoking during pregnancy, secondhand tobacco smoke, season of birth, PM2.5, breastfeeding, mold and cockroaches in home, and distance from highway.
  
  
  RESULTS
  Higher prenatal DAP concentrations, particularly DE, were nonsignificantly associated with respiratory symptoms in the previous 12 months at 5 or 7 years of age [adjusted odds ratio (aOR) per 10-fold increase = 1.44; 95% CI: 0.98, 2.12]. This association was strongest with total DAP and DE from the second half of pregnancy (aOR per 10-fold increase = 1.77; 95% CI: 1.06, 2.95; and 1.61; 95% CI: 1.08, 2.39, respectively). Childhood DAP, DE, and DM concentrations were associated with respiratory symptoms and exercise-induced coughing in the previous 12 months at 5 or 7 years of age (total DAPs: aOR per 10-fold increase = 2.53; 95% CI: 1.32, 4.86; and aOR = 5.40; 95% CI: 2.10, 13.91, respectively).
  
  
  CONCLUSIONS
  Early-life exposure to OP pesticides was associated with respiratory symptoms consistent with possible asthma in childhood.
authors.affiliation: Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, California, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Raanan
authors.forename: Kim G
authors.initials: KG
authors.lastname: Harley
authors.forename: John R
authors.initials: JR
authors.lastname: Balmes
authors.forename: Asa
authors.initials: A
authors.lastname: Bradman
authors.forename: Michael
authors.initials: M
authors.lastname: Lipsett
authors.forename: Brenda
authors.initials: B
authors.lastname: Eskenazi
mesh_terms: D000328:Adult; D001249:Asthma / Q000139:chemically induced*; D002140:California; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000633:toxicity* / Q000652:urine; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D010755:Organophosphates / Q000633:toxicity* / Q000652:urine; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D012137:Respiratory System / Q000187:drug effects
chemical_list: D004785:Environmental Pollutants; D010755:Organophosphates