Gestational exposure to polychlorinated biphenyls and dibenzofurans induced asymmetric hearing loss: Yucheng children study

Environ Res. 2015 Feb:137:65-71. doi: 10.1016/j.envres.2014.12.002. Epub 2014 Dec 6.


Introduction: 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.

Conclusion: Gestational exposure to PCBs/PCDFs caused adverse asymmetrical hearing effects detectable even in early adulthood.

Keywords: Gestational; Hearing loss; PCBs; PCDFs; Polychlorinated biphenyls; Polychlorinated dibenzofurans; Prenatal; Yucheng.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Benzofurans / blood*
  • Case-Control Studies
  • Dibenzofurans, Polychlorinated
  • Environmental Monitoring
  • Environmental Pollutants / blood*
  • Female
  • Follow-Up Studies
  • Hearing Loss* / chemically induced
  • Hearing Loss* / epidemiology
  • Humans
  • Male
  • Maternal Exposure*
  • Polychlorinated Biphenyls / blood*
  • Pregnancy
  • Prenatal Exposure Delayed Effects* / chemically induced
  • Prenatal Exposure Delayed Effects* / epidemiology
  • Taiwan
  • Young Adult


  • Benzofurans
  • Dibenzofurans, Polychlorinated
  • Environmental Pollutants
  • Polychlorinated Biphenyls