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.Objectives: 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.Citation: Jusko TA, Sisto R, Iosif AM, Moleti A, Wimmerová S, Lancz K, Tihányi J, Šovčíková E, Drobná B, Palkovičová L, Jurečková D, Thevenet-Morrison K, Verner MA, Sonneborn D, Hertz-Picciotto I, Trnovec T. 2014. Prenatal and postnatal serum PCB concentrations and cochlear function in children at 45 months of age. Environ Health Perspect 122:1246–1252; http://dx.doi.org/10.1289/ehp.1307473

Altered fine motor function at school age in Inuit children exposed to PCBs, methylmercury, and lead

“…We have previously reported adverse effects attributed to postnatal PCB exposure on neurophysiological and cognitive measures in the same cohort of children (Boucher et al 2011, 2012b; Saint-Amour et al 2006). Interestingly, in a recent birth-cohort study conducted in Eastern Slovakia, postnatal PCB exposure, but not prenatal exposure, was associated with impaired cochlear function in 45-month old children as revealed by distortion product otoacoustic emissions (Jusko et al, 2014). These findings contrast with a large majority of PCB studies, which have concluded that neurodevelopmental effects in children are uniquely observed with prenatal rather than postnatal exposure (e.g., Jacobson and Jacobson 1996; 2003; Forns et al 2012a).…”

Developmental PCB exposure increases susceptibility to audiogenic seizures in adulthood

“…PCBs readily cross the mammalian placenta and are mobilized from body fat into breast milk during lactation, putting the developing offspring at risk (Jacobson et al 1984). One cause for concern is that developmental exposure to PCBs has been associated with long-lasting hearing deficits in animal models and humans (Crofton et al 2000; Goldey et al 1995; Jusko et al, 2014; Poon et al 2011; Powers et al 2006; Trnovec et al 2010). …”

Prenatal chemical exposures and child language development

“…An interesting factor to consider is that all three of these contaminants have been associated with subtle deficits in hearing and/or auditory processing (e.g. Osman et al, 1999; Rice and Gilbert, 1992; Jusko et al, 2014). This suggests there could be a complex interplay whereby subtle deficits in auditory function impair language development resulting in deficits in overall cognitive function, and verbal abilities in particular.…”