title: Tobacco smoke exposure during childhood: effect on cochlear physiology.
abstract: The rate of smoking in Brazil is about 18.8%. Exposure to environmental tobacco smoke is one of the major factors predisposing children to several hazardous health problems. The objective of the present research was to analyze the effect of tobacco smoke exposure during childhood on cochlear physiology by measuring the transient evoked otoacoustic emissions (TEOAE) response levels. Cotinine, the main metabolite of nicotine, was measured in 145 students' (8-10 years old) urine. Sixty students indicated tobacco smoke exposure (TSE) (cotinine urine levels ≥ 5.0 ng/mL) and 85 did not. The evaluation of TEOAE of TSE students showed lower response levels, mainly on frequencies of 2.8 kHz on the right and left ears and 2.0 kHz on left ear and lower signal noise response levels, mainly on the 1.0 kHz and 1.4 kHz frequencies, when compared to controls that were not exposed to tobacco. The mean reduction observed in TEOAE of tobacco smoke exposure children was 2.1 dB SPL. These results have important implications on the damage to the cochlear structures and indicate a possible loss in hearing and hearing ability development.
authors.affiliation: Faculdade de Ciências Médicas da Santa Casa de São Paulo (FCMSCSP, School of Medical Sciences of Santa Casa of São Paulo), Arnaldo Vieira de Carvalho Foundation, Street Dr. Cesário Mota Júnior, 61 São Paulo 01221-020, Brazil. alessandra.durante@fcmsantacasasp.edu.br.
authors.forename: Alessandra S
authors.initials: AS
authors.lastname: Durante
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pucci
authors.forename: Nicolly
authors.initials: N
authors.lastname: Gudayol
authors.forename: Beatriz
authors.initials: B
authors.lastname: Massa
authors.forename: Marcella
authors.initials: M
authors.lastname: Gameiro
authors.forename: Cristiane
authors.initials: C
authors.lastname: Lopes
mesh_terms: D001938:Brazil; D002648:Child; D003051:Cochlea / Q000187:drug effects* / Q000502:physiology; D003367:Cotinine / Q000652:urine; D004797:Enzyme-Linked Immunosorbent Assay; D034381:Hearing Loss / Q000209:etiology*; D006801:Humans; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine