title: Prenatal and postnatal serum PCB concentrations and cochlear function in children at 45 months of age.
abstract: BACKGROUND
  Some experimental and human data suggest that exposure to polychlorinated biphenyls (PCBs) may induce ototoxicity, though results of previous epidemiologic studies are mixed and generally focus on either prenatal or postnatal PCB concentrations exclusively.
  
  
  OBJECTIVE
  Our aim was to evaluate the association between pre- and postnatal PCB concentrations in relation to cochlear status, assessed by distortion product otoacoustic emissions (DPOAEs), and to further clarify the critical periods in development where cochlear status may be most susceptible to PCBs.
  
  
  METHODS
  A total of 351 children from a birth cohort in eastern Slovakia underwent otoacoustic testing at 45 months of age. Maternal pregnancy, cord, and child 6-, 16-, and 45-month blood samples were collected and analyzed for PCB concentrations. At 45 months of age, DPOAEs were assessed at 11 frequencies in both ears. Multivariate, generalized linear models were used to estimate the associations between PCB concentrations at different ages and DPOAEs, adjusting for potential confounders.
  
  
  RESULTS
  Maternal and cord PCB-153 concentrations were not associated with DPOAEs at 45 months. Higher postnatal PCB concentrations at 6-, 16-, and 45-months of age were associated with lower (poorer) DPOAE amplitudes. When all postnatal PCB exposures were considered as an area-under-the-curve metric, an increase in PCB-153 concentration from the 25th to the 75th percentile was associated with a 1.6-dB SPL (sound pressure level) decrease in DPOAE amplitude (95% CI: -2.6, -0.5; p = 0.003).
  
  
  CONCLUSIONS
  In this study, postnatal rather than maternal or cord PCB concentrations were associated with poorer performance on otoacoustic tests at age 45 months.
authors: Division of Epidemiology, Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
authors: Todd A
authors: TA
authors: Jusko
authors: Renata
authors: R
authors: Sisto
authors: Ana-Maria
authors: AM
authors: Iosif
authors: Arturo
authors: A
authors: Moleti
authors: Sonˇa
authors: S
authors: Wimmerová
authors: Kinga
authors: K
authors: Lancz
authors: Juraj
authors: J
authors: Tihányi
authors: Eva
authors: E
authors: Sovčiková
authors: Beata
authors: B
authors: Drobná
authors: L'ubica
authors: L
authors: Palkovičová
authors: Dana
authors: D
authors: Jurečková
authors: Kelly
authors: K
authors: Thevenet-Morrison
authors: Marc-André
authors: MA
authors: Verner
authors: Dean
authors: D
authors: Sonneborn
authors: Irva
authors: I
authors: Hertz-Picciotto
authors: Tomáš
authors: T
authors: Trnovec
mesh_terms: D000328:Adult; D001301:Audiometry, Pure-Tone; D002675:Child, Preschool; D004785:Environmental Pollutants / Q000097:blood* / Q000633:toxicity; D005260:Female; D005312:Fetal Blood; D034381:Hearing Loss / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D015999:Multivariate Analysis; D017084:Otoacoustic Emissions, Spontaneous; D011078:Polychlorinated Biphenyls / Q000097:blood* / Q000633:toxicity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D018154:Slovakia
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl