title: Disinfection By-Product Exposures and the Risk of Specific Cardiac Birth Defects.
abstract: Epidemiological studies suggest that women exposed to disinfection by-products (DBPs) have an increased risk of delivering babies with cardiovascular defects (CVDs).
  
  
  
  We examined nine CVDs in relation to categorical DBP exposures including bromoform, chloroform, dibromochloromethane (DBCM), bromodichloromethane (BDCM), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and summary DBP measures (HAA5, THMBr, THM4, and DBP9).
  
  
  
  We calculated adjusted odds ratios (aORs) in a case-control study of birth defects in Massachusetts with complete quarterly 1999-2004 trihalomethane (THM) and haloacetic acid (HAA) data. We randomly matched 10 controls each to 904 CVD cases based on week of conception. Weight-averaged aggregate first-trimester DBP exposures were assigned to individuals based on residence at birth.
  
  
  
  We detected associations for tetralogy of Fallot and the upper exposure categories for TCAA, DCAA, and HAA5 (aOR range, 3.34-6.51) including positive exposure-response relationships for DCAA and HAA5. aORs consistent in magnitude were detected between atrial septal defects and bromoform (aOR = 1.56; 95% CI: 1.01, 2.43), as well as DBCM, chloroform, and THM4 (aOR range, 1.26-1.67). Ventricular septal defects (VSDs) were associated with the highest bromoform (aOR = 1.85; 95% CI: 1.20, 2.83), MBAA (aOR = 1.81; 95% CI: 0.85, 3.84), and DBCM (aOR = 1.54; 95% CI: 1.00, 2.37) exposure categories.
  
  
  
  To our knowledge, this is the first birth defect study to develop multi-DBP adjusted regression models as well as the first CVD study to evaluate HAA exposures and the second to evaluate bromoform exposures. Our findings, therefore, inform exposure specificity for the consistent associations previously reported between THM4 and CVDs including VSDs. Citation: Wright JM, Evans A, Kaufman JA, Rivera-Núñez Z, Narotsky MG. 2017. Disinfection by-product exposures and the risk of specific cardiac birth defects. Environ Health Perspect 125:269-277; http://dx.doi.org/10.1289/EHP103.
authors: National Center for Environmental Assessment (NCEA), Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Cincinnati, Ohio, USA.
authors: J Michael
authors: JM
authors: Wright
authors: Amanda
authors: A
authors: Evans
authors: John A
authors: JA
authors: Kaufman
authors: Zorimar
authors: Z
authors: Rivera-Núñez
authors: Michael G
authors: MG
authors: Narotsky
mesh_terms: D016022:Case-Control Studies; D004202:Disinfectants / Q000633:toxicity*; D004203:Disinfection; D016021:Epidemiologic Studies; D005260:Female; D006330:Heart Defects, Congenital / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008404:Massachusetts / Q000453:epidemiology; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D014238:Trichloroacetic Acid; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D004202:Disinfectants; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; D014238:Trichloroacetic Acid; C025191:bromodichloromethane; C015044:bromoform