title: Brainstem auditory evoked potentials in children with lead exposure.
abstract: BACKGROUND
  Earlier 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.
  
  
  OBJECTIVE
  To 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.
  
  
  METHODS
  Contemporary 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).
  
  
  RESULTS
  The mean time-integrated cumulative blood lead index was 12 μg/dL (SD ± 5.7, range: 2.433). All participants had hearing thresholds equal to or below 20 dBHL 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.
  
  
  CONCLUSIONS
  No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area.
authors.affiliation: Department of Speech Therapy and Audiology, Faculdade de Odontologia de Bauru, Universidade de São Paulo (FOB-USP), Bauru, SP, Brazil.
authors.forename: Katia de Freitas
authors.initials: Kde F
authors.lastname: Alvarenga
authors.affiliation: National Institute for Occupational Safety and Health (NIOSH), Division of Applied Research and Technology, Cincinnati, OH, United States.
authors.forename: Thais Catalani
authors.initials: TC
authors.lastname: Morata
authors.affiliation: Department of Speech Therapy and Audiology, Faculdade de Odontologia de Bauru, Universidade de São Paulo (FOB-USP), Bauru, SP, Brazil.
authors.forename: Andrea Cintra
authors.initials: AC
authors.lastname: Lopes
authors.affiliation: Department of Speech Therapy and Audiology, Faculdade de Odontologia de Bauru, Universidade de São Paulo (FOB-USP), Bauru, SP, Brazil.
authors.forename: Mariza Ribeiro
authors.initials: MR
authors.lastname: Feniman
authors.affiliation: Department of Speech Therapy and Audiology, Faculdade de Odontologia de Bauru, Universidade de São Paulo (FOB-USP), Bauru, SP, Brazil. Electronic address: lilianjacob@fob.usp.br.
authors.forename: Lilian Cassia Bornia Jacob
authors.initials: LC
authors.lastname: Corteletti
mesh_terms: D000158:Acoustic Impedance Tests; D000293:Adolescent; D001301:Audiometry, Pure-Tone; D001302:Audiometry, Speech; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D005260:Female; D006320:Hearing Tests; D006801:Humans; D007223:Infant; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*; D013997:Time Factors
chemical_list: D007854:Lead
keywords: Audiometria de tons puros; Brainstem auditory evoked potentials; Intoxicação por chumbo; Lead poisoning; Potenciais evocados auditivos do tronco encefálico; Pure-tone audiometry; Toxicidade; Toxicity