ABSTRACT
OBJECTIVES: The aim of this longitudinal study was to assess the rate of decline in FEV1 (deltaFEV1) in gold miners with silicosis and to relate these findings with the radiographic picture, age, smoking habits and cumulative exposure to dusts. METHODS: The study included 73 gold miners with silicosis and 73 miners exposed to dusts but without silicosis. The clinical, radiological and functional assessment was made at least twice in each miner at the beginning and at the end of an adequate interval of the investigation which was extended for a mean period of 38.9 months for the group with silicosis and 33.6 months for the group without silicosis. RESULTS: In the group of miners with silicosis deltaFEV1 was much higher (187 ml/year) as compared with the mean value found in the miners without silicosis (43.2 ml/year). No significant differences were found for deltaFEV1 according to the age criterion (in both groups) and to their smoking habits (in the group with silicosis). In silicosis, a very good correlation exists between the index of cumulative exposure to dusts and the magnitude of the decline rate of FEV1. In the miners, group without silicosis, deltaFEV1 had not any significant correlation with cumulative exposure to dusts. CONCLUSIONS: Our observations revealed that the cumulative exposure to dusts affected the decline rate of FEV1 only to the extent to which it determined silicosis and intervened less in the functional decline in miners without silicosis. Smoking habits increased AFEV1 only in miners without silicosis.
