Brainstem auditory evoked potentials in children with lead exposure

Abstract

IntroductionEarlier studies have demonstrated an auditory effect of lead exposure in children, but information on the effects of low chronic exposures needs to be further elucidated. ObjectiveTo investigate the effect of low chronic exposures of the auditory system in children with a history of low blood lead levels, using an auditory electrophysiological test. MethodsContemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6 years, 8 months±3 years, 2 months). ResultsThe mean time-integrated cumulative blood lead index was 12μg/dL (SD±5.7, range: 2.433). All participants had hearing thresholds equal to or below 20dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I–III, III–V, and I–V, and the cumulative lead values. ConclusionNo evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area.