RESUMO
This study included 114 workers who have been exposed to noise levels of 78 to 91.4 dBA and followed over a six year period. Workers exposed to nose levels up to 85 dBA eight hours daily for six days per week and for twelve years showed a slightly higher (1%) hearing impairment than the corresponding control subjects. Impairment of hearing among workers exposed to higher noise levels was 9.6%.
Assuntos
Perda Auditiva Provocada por Ruído/epidemiologia , Ruído Ocupacional , Ruído , Adulto , Audiometria , Egito , Feminino , Perda Auditiva Provocada por Ruído/etiologia , Humanos , Masculino , Concentração Máxima Permitida , Indústria TêxtilRESUMO
Manual flax processing originated in Egypt in 2 000 BC. In the present study a representative sample of the workers involved in this trade, where flax is processed in small workshops or homes, was examined, and their dust exposure was evaluated. The study showed that workers handling and processing flax are exposed to high concentrations of dust; the levels of dust at hackling and combing are considerably higher than at batting and spinning. Byssinosis prevailed in 22-9% of the examined workers, and 18-4% of them had their forced expiratory volume in one second reduced by more than 10% at the end of the first morning work period (4 hours) of the week. Both the rates and the grades of these syndromes increased with duration of exposure. Smoking appeared to be one of the important contributory factors in the production of byssinosis. The relationship between dust concentration and prevalence of byssinosis seems to be curvilinear.
