[Hearing health of workers exposed to noise and insecticides].
OBJECTIVE
To examine the peripheral auditory disorders in a group of workers exposed to organophosphate and pyrethroid insecticides, used in vector control campaigns.


METHODS
The prevalence study examined a population of 98 individuals who sprayed insecticides in campaigns for the prevention of Dengue, Chagas disease and Yellow fever. The sampling approach was finalistic, and included the workers in a health district of Pernambuco, during the year 2000. A questionnaire was used to collect data on occupational and non-occupational risks, safety measures utilized, family history of auditory problems and health symptoms. Previous noise exposure history was also investigated, since noise can be a confounding factor for hearing loss. Hearing sensitivity and middle ear function were assessed by pure tone audiometry.


RESULTS
Among those exposed to insecticides, 63.8% demonstrated a hearing loss. For the group of workers exposed to both noise and insecticides, hearing loss was observed in 66.7% of the cases. The median exposure time necessary to detect high-frequency losses was 3.4 years for workers exposed to both agents and 7.3 years for workers exposed to insecticides only. Hearing thresholds were poorest among workers exposed to both agents. Auditory damage for those with combined exposures to the two factors was more severe than the hearing losses observed among those exposed only to insecticides.


CONCLUSIONS
There is evidence that exposure to insecticides was associated with peripheral sensorioneural hearing loss and that noise exposure can potentiate the ototoxic effects of insecticides. It is necessary to evaluate this possible association through epidemiological studies.
Teixeira
Cleide Fernandes
CF
Faculdade Integrada do Recife, Recife, PE, Brasil. lcteix@elogica.com.br
Augusto
Lia Giraldo da Silva
LG
Morata
Thais C
TC
D000328:Adult; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D034381:Hearing Loss / Q000453:epidemiology* / Q000209:etiology; D006317:Hearing Loss, Noise-Induced / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D007300:Insect Control; D007306:Insecticides / Q000009:adverse effects*; D008297:Male; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D009943:Organophosphorus Compounds; D015995:Prevalence; D012306:Risk
D007306:Insecticides; D009943:Organophosphorus Compounds