Download PDF
Arquivos Internacionais de Otorrinolaringologia 2012; 16(01): 050-056
DOI: 10.7162/S1809-48722012000100007
Original Article
Thieme Publicações Ltda Rio de Janeiro, Brazil

Cochlear condition and olivocochlear system of gas station attendants exposed to organic solvents

Condição coclear e do sistema olivococlear medial de frentistas de postos de gasolina expostos a solventes orgânicos
Lenita da Silva Quevedo
1   College Degree . Speech Therapist, Master Student in Human Communication Disturb by Federal University of Santa Maria.
,
Tania Maria Tochetto
2   PhD. Associated Professor of Federal University of Santa Maria.
,
Márcia do Amaral Siqueira
3   Master in Human Communication Disturb by Federal University of Santa Maria. Speech therapist of Worker Health Reference Center of Santa Maria.
› Author Affiliations
Further Information

Publication History

28 May 2011

10 July 2011

Publication Date:
12 February 2014 (online)

   Permissions and Reprints

Summary

Introduction: Organic solvents have been increasingly studied due to its ototoxic action.

Objective: Evaluate the conditions of outer hair cells and olivocochlear system in individuals exposed to organic solvents.

Method: This is a prospective study. 78 gas station attendants exposed to organic solvents had been evaluated from three gas stations from Santa Maria city, Rio Grande do Sul (RS). After applying the inclusion criteria, the sample was constituted by 24 individuals. The procedures used on the evaluation were audiological anamnesis, Transient otoacoustic emissions (TEOAES) and research for the suppressive effect of TEOAES. A group control (GC) compounded by 23 individuals was compared to individuals exposed and non-exposed individuals. The data collection has been done in the room of Speech Therapy of Workers Health Reference Center of Santa Maria.

Results: The TEOAES presence was major in the left ear in both groups; the average relation of TEOAES signal/noise in both ears was greater in GE; the TEOAES suppressive effect in the right ear was higher in the individual of GE (62,5%) and in the left ear was superior in GC (86,96%), with statistically significant difference. The median sign/noise ratio of TEOAES, according to the frequency range, it was higher in GC in three frequencies ranges in the right ear and one in the left ear.

Conclusion: It was not found signs of alteration on the outer hair cells neither on the olivocochlear medial system in the individuals exposed to organic solvents.

Resumo

Introdução: Solventes orgânicos são cada vez mais estudados em função de sua ação ototóxica.

Objetivo: Avaliar a condição das células ciliadas externas e o sistema olivococlear medial de sujeitos expostos a solventes orgânicos.

Método: Trata-se de um estudo prospectivo. Foram avaliados 78 frentistas de três postos de gasolina da cidade de Santa Maria, Rio Grande do Sul (RS) expostos a solventes orgânicos. Após a aplicação dos critérios de inclusão, a amostra ficou constituída por 24 sujeitos. Os procedimentos utilizados na avaliação foram anamnese audiológica, Emissões Otoacústicas Transientes (EOAT) e pesquisa do efeito supressor das EOAT. Um grupo controle (GC) composto por 23 sujeitos, foi utilizado para comparar sujeitos expostos e não-expostos. A coleta de dados foi realizada na sala de Fonoaudiologia do Centro de Referência em Saúde do Trabalhador de Santa Maria.

Resultados: A presença de EOAT foi maior na orelha esquerda em ambos os grupos; a média da relação sinal/ruído das EOAT de ambas as orelhas foi maior no GE; o efeito supressor das EOAT na orelha direita foi maior nos sujeitos do GE (62,5%) e na orelha esquerda foi superior no GC (86,96%), com diferença estatisticamente significante. A mediana da relação sinal/ruído das EOAT, segundo a faixa de frequência, foi maior no GC em três faixas de frequência na orelha direita e em uma na orelha esquerda.

Conclusão: Não foram encontrados sinais de alteração nas células ciliadas externas nem no sistema olivococlear medial nos sujeitos expostos a solventes orgânicos.

Keywords

toluene - solvents - hearing

Palavras-chave

tolueno - solventes - audição
 

  • Bibliographic References

  • 1 Johnson AC, Morata TC. Occupational exposure to chemicals and hearing impairment. The Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals, 2010; 44: 1-177
    Search in Google Scholar
  • 2 ACGIH. TLVs and BEIs. Based on the documentation of the threshold limit values for chemical substances and physical agents and biological exposure indices. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists; 2009
    Search in Google Scholar
  • 3 Morata T, Lemasters GK. Epidemiologic considerations in the evaluation of occupational hearing loss. Occupational Medicine: State of the Art Reviews 1995; 10: 641-56
    Search in Google Scholar
  • 4 Pouyatos B, Campo P, Lataye R. Use of DPOAEs for assessing hearing loss caused by styrene in the rat. Hear Res 2002; 165: 156-164
    CrossrefSearch in Google Scholar
  • 5 SuBkowski WJ, Kowalska S, Matyja W, Guzek W, WesoBowski W, Szymczak W , et al . Effects of occupational exposure to a mixture of solvents on the inner ear: A field study. Int J Occup Med Environ Health 2002; 15: 247-56
    Search in Google Scholar
  • 6 Aquino AMCM, Massaro CAM, Tiradentes JB, Garzón JCV, Oliveira JAA. Emissões otoacústicas no diagnóstico precoce de lesão coclear na doença de Meniére. Rev Bras Otorrinolaringol 2002; 68: 761-6
    CrossrefSearch in Google Scholar
  • 7 Collet L, Kemp DT, Veuillet E, Duclaux R, Moulin A, Morgon A. Effect of contralateral audititory stimuli on active cochlear micro-mechanical properties in human subjects. Hear Res 1990; 43: 251-62
    CrossrefSearch in Google Scholar
  • 8 Hood LJ, Berlin CI, Hurley A, Cecola P, Bell B. Contralateral suppression of transient-evoked otoacustic emissions in humans: intensity effects. Hear Res 1996; 101: 113-8
    CrossrefSearch in Google Scholar
  • 9 Gopal KV. Audiological findings in individuals exposed to organic solvents: Case studies. Noise Health 2008; 10: 74-82
    CrossrefPubMedSearch in Google Scholar
  • 10 Cardoso PCM, Viana KS, Oliveira JS, Castro IM. Audição em trabalhadores de manutenção de aeronaves. Revista do Centro de Ensino Superior Unificado de Brasília 2004; 1: 215:232
    Search in Google Scholar
  • 11 Fuente A. Auditory Damage Associated with Solvent Exposure: Evidence from a Cross-Sectional Study. Hong Kong, 2008, p.376 (Tese de Doutorado - University of Hong Kong).
  • 12 Bernardi APA. Trabalhadores expostos simultaneamente a ruído e tolueno: estudo das emissões otoacústicas evocadas transitórias e efeito de supressão. Dissertação de Mestrado, São Paulo, 2000, p.141 (Tese de Mestrado - Faculdade de Saúde Pública, Universidade de São Paulo).
  • 13 Lataye R, Campo P, Pouyatos B, Cossec B, Blache're V, Morel G. Solvents ototoxicity in the rat and guinea pig. Neurotoxicology and Teratology 2003; 25: 39-50
    CrossrefSearch in Google Scholar
  • 14 Johnson AC, Canlon B. Toluene exposure affects the functional activity of the outer hair cells. Hear Res 1994; 72: 189-96
    CrossrefSearch in Google Scholar
  • 15 Campo P, Lataye R, Cossec B, Placid V. Toluene-induced hearing loss: a mid-frequency location of the cochlear lesions. Neurotoxicology and Teratol 1997; 9: 129-140
    Search in Google Scholar
  • 16 Campo P, Loquet G, Blachère V, Roure M. Toluene and styrene intoxication route in the rat cochlea. Neurotoxicology and Teratol 1999; 21: 427-434
    Search in Google Scholar
  • 17 Gagnaire F, Langlais C. Relative ototoxicity of 21 aromatic solvents. Arch Toxicol 2005; 79: 346-354
    CrossrefSearch in Google Scholar