SÔBRE A OCORRÊNCIA DE SILICOSE EM FUNÇÃO DA EXPOSIÇÃO À POEIRA DE SÍLICA LIVRE: MÉTODO DE INVESTIGAÇÃO E EXEMPLO DE APLICAÇÃO PRÁTICA

Abstract

After emphasizing the importance of the joint role of physician, chemist and engineer in field studies related to occupational hygiene, a method of investigating the occurrence of silicosis due to exposure to dust containing free sílica is described. Severa! record forms are presented for the systematic registration of the necessary data related to the conditions of the environment (preliminary survey of the establishment, occupational analysis, duration of exposures, selection of points for air sampling, counting of dust particles and determination of free sílica) and of the worker(occupational and clinicai history, physical examination, radiological examination and lung function tests). From the environmental data and by first relating partial exposure values to threshold limit values one calculates, for each worker or group of workers similary exposed, partial degrees of exposure and, from these, a final time-weighted average degree of exposure in the eight-hour working day. The applicability of the method is exemplified by the results obtained in a study of the composing and mixing section of a glass factory in the city of São Paulo, where the time-weighted average degrees of exposure to dust were lower than the maximum allowable and not a single case of silicosis was found.