title: Gestational exposure to polychlorinated biphenyls and dibenzofurans induced asymmetric hearing loss: Yucheng children study.
abstract: BACKGROUND
  In 1979, approximately 2000 people in central Taiwan were exposed to polychlorinated biphenyls and dibenzofurans (PCBs/PCDFs) due to ingestion of contaminated rice oil. The children born to mothers exposed to PCBs/PCDFs were called Yucheng children. We conducted a follow-up study to examine the association between gestational PCBs/PCDFS exposure and auditory function in Yucheng children's early adulthood.
  
  
  METHODS
  In 1985 and early 1992, Yucheng children and their age, gender, socio-economic matched unexposed referent children were recruited for physical examination and long-term follow-ups. In 2007, Yucheng children and referent children were invited to participate in a health examination, including assessment of pure-tone air-conduction thresholds and distortion product otoacoustic emissions (DPOAEs) test. Gestational exposure to PCBs/PCDFs in Yucheng children were estimated by back-extrapolation of their mother's serum concentration to the time of childbirth.
  
  
  RESULTS
  A total of 86 Yucheng children (51.2% males) and 97 referent children (50.5% males) were included for analysis. No difference was found in demographic characteristics between two groups. Among the Yucheng children, 53 had estimated PCBs/PCDFs concentrations. We found that Yucheng children were at higher risk of having elevated hearing threshold at low frequencies in the right ear. Estimated maternal concentrations of 2,3,4,7,8-pnCDF at the time of birth were associated with increased hearing thresholds and decreased DPOAEs amplitudes at low frequencies in the right ear.
  
  
  CONCLUSIONS
  Gestational exposure to PCBs/PCDFs caused adverse asymmetrical hearing effects detectable even in early adulthood.
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan; Graduate Institute of Law and Interdisciplinary Studies, National Chengchi University College of Law, Taipei, Taiwan.
authors.forename: Ming-Chieh
authors.initials: MC
authors.lastname: Li
authors.affiliation: Department of Otolaryngology, Buddhist Tzuchi General Hospital, Taichung Branch, Taichung, Taiwan; School of Medicine, Tzuchi University, Hualien, Taiwan; Department of Otolaryngology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hung-Pin
authors.initials: HP
authors.lastname: Wu
authors.affiliation: Department of Health Business Administration, Hung-Kuang University, Taichung, Taiwan.
authors.forename: Chiu-Yueh
authors.initials: CY
authors.lastname: Yang
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan; Department of Environmental and Occupational Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Pau-Chung
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Retired Director NIH/NIEH Children Center, Rutgers, The State University of New Jersey, USA.
authors.forename: George H
authors.initials: GH
authors.lastname: Lambert
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan; Department of Environmental and Occupational Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei, Taiwan. Electronic address: leonguo@ntu.edu.tw.
authors.forename: Yue
authors.initials: Y
authors.lastname: Leon Guo
mesh_terms: D000293:Adolescent; D000328:Adult; D001572:Benzofurans / Q000097:blood*; D016022:Case-Control Studies; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D034381:Hearing Loss / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D008297:Male; D018811:Maternal Exposure; D011078:Polychlorinated Biphenyls / Q000097:blood*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000453:epidemiology; D013624:Taiwan; D055815:Young Adult
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls
keywords: Gestational; Hearing loss; PCBs; PCDFs; Polychlorinated biphenyls; Polychlorinated dibenzofurans; Prenatal; Yucheng