Comparative Study of Evoked Otoacoustic Emissions in Offshore and Onshore Seafaring Workers

Endereço para correspondência: Moara Karoline Silveira Malheiros Serviço de Fonoaudiologia, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro – UFRJ Rua Rodolpho Paulo Rocco, 255, Terceiro andar, Cidade Universitária, Ilha do Fundão, Rio de Janeiro (RJ), Brasil. CEP: 21941-913. E-mail: moarakaroline@gmail.com

MKSM: Conception and project; analysis and interpretation of data; writing of the article; finally, responsible for all aspects of the work in ensuring the accuracy and integrity of any part of the work. VMC: Relevant critical review of the intellectual content and final approval of the version to be published. TRG: Conception and design, analysis and interpretation of data. DCC: Conception and project; data collection and relevant critical review of intellectual content. LWM: Conception and project; data collection, analysis, and interpretation of data. MIKPA: Participation as an advisor, conception and project; analysis, relevant critical review of the intellectual content and final approval of the version to be published.

Criterion		Offshore Group	Onshore Group
	Both genders	✓	✓
Inclusion	Age between 20 and 49 years;	✓	✓
	Report good audibility in both ears;	✓	✓
	Normal otoscopy;	✓	✓
	Being an offshore worker exposed to noise and/or chemicals in the workplace;	✓	✗
	Being an onshore worker with no current or previous occupational exposure to noise and/or chemicals;	✗	✓
	Minimum time in current position equivalent to one year.	✓	✓
Exclusion	Alteration of the external and/or middle ear; history of ear surgery.	✓	✓
	Report of use of ototoxic medication;	✓	✓
	Report of acoustic trauma;	✓	✓
	History of neurological, metabolic, or genetic diseases;	✓	✓
	History of measles, mumps, or meningitis;	✓	✓
	Hearing loss history;	✓	✓
	History of exposure to loud noise and/or ototoxic chemicals in an extra-occupational environment or previous function^* * For seafarers in the Offshore group, workers with a history of exposure to loud noise and/or chemical substances in previous jobs that were also offshore were not considered for exclusion .	✓	✓

Variable	Category	Offshore Group
Variable	Category	N	%
Exposure to noise	Yes	48	100
Exposure to noise	No	0	0
Exposure time to noise	≤10 years	28	58.3
Exposure time to noise	>10 years	20	41.7
Exposure to chemical subst.	Yes	39	81.3
Exposure to chemical subst.	No	9	18.8
Chemical exposure type	Not exposed	9	18.8
	Cleaning prod.	7	14.6
	Solvents, cleaning agents prod., oils and greases	16	33.3
	Solvents, cleaning agents prod., oils, greases, and vapors	16	33.3
Exposure time to chemical subst.	≤10 years	30	76.9
Exposure time to chemical subst.	>10 years	9	23.1

Variable	Group	Mean	Median	Minimum	Maximum	Standard Deviation	p-value
Duration	Offshore	50.4	60.5	9	124	29.5	0.000*
TEOE RE	Onshore	25.5	14	9	70	19.5	0.000*
Duration	Offshore	53.3	64.5	6	184	31.5	0.002*
TEOE LE	Onshore	35.5	24	9	161	33.2	0.002*
Duration	Offshore	48.6	35.5	19	183	35.3	0.001*
DPOAE RE	Onshore	31.7	19	19	132	25.7	0.001*
Duration	Offshore	52.8	44.5	19	144	34.7	0.003*
DPOAE LE	Onshore	33.7	19	19	132	26.7	0.003*
Number of frequencies that approved	Offshore	2.6	3	0	4	1.3	0.001*
TEOE RE	Onshore	3.7	4	2	4	0.7	0.001*
Number of frequencies that approved	Offshore	2.8	3	0	4	1.4	0.009*
TEOE LE	Onshore	3.6	4	0	4	1.2	0.009*
Number of frequencies that approved	Offshore	2.8	3	0	5	1.4	0.000*
DPOAE RE	Onshore	4.6	5	2	5	1	0.000*
Number of frequencies that approved	Offshore	2.7	3	0	5	1.6	0.000*
DPOAE LE	Onshore	4.1	4	0	5	1.4	0.000*

Brasil