Predictors of health-related quality of life among semi-precious stone mineworkers exposed to silica dust.

OBJECTIVE: The study aimed to comparatively evaluate HRQOL in miners of semi-precious stones with and without silicosis, and determine the associated factors, as well as the performance of two different questionnaires in measuring HRQOL. METHODS: In a cross-sectional study of 348 male miners (129 with silicosis) who underwent an interview and spirometry, HRQOL was assessed using the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire and the Saint George's Respiratory Questionnaire (SGRQ). RESULTS: Miners with silicosis were older, had less schooling, worked more hours daily, and had longer exposure to silica. They also had worse scores of QoL in both questionnaires. Respiratory symptoms and %FEV1 were contributing factors for the models of total health and all the domains of the SGRQ, and 40% of the variability of the general health domain of WHOQOL-BREF was due to dyspnea, wheezing, %FEV1, and pack-years of cigarette smoking. Respiratory symptoms, lung function, pack-years of cigarette smoking, years of education, and average monthly income were contributing factors for the models of the different domains of the WHOQOL-BREF. CONCLUSIONS: Our study revealed impaired HRQOL in semi-precious stone miners evaluated using both questionnaire tools of SGRQ and WHOQOL-BREF, of which SGRQ had superior performance. Respiratory symptoms, functional impairment, and pack-years of cigarette smoking were the most important determinants of the workers' general HRQOL.

Lung function and functional exercise capacity in underground semi-precious stone mineworkers.

BACKGROUND: Semi-precious stone mining may cause occupational lung disease. The impact of inhaling silica on workers' exercise capacity has only been partially studied. OBJECTIVES: To study lung function, exercise capacity, and identify factors associated with functional impairment. METHODS: In a cross-sectional study of 193 current miners from Ametista do Sul, Rio Grande do Sul, Brazil, medical and occupational data were collected. The diagnosis of silicosis was established by the history of dust exposure and chest radiographic findings. All workers performed a spirometry and a 6-minute walk test (6MWT). RESULTS: Of the sample 51 (26.4%) had silicosis. Time working in mine was 14.7±8.7 years. Spirometry showed a normal, restrictive or obstructive ventilatory pattern in 75.1 %, 13 % and 9.3 % of the workers, respectively. The diagnosis of silicosis and length of time working in mining negatively affected lung function, although exercise capacity was preserved. In the multivariate analysis, time working in mining, diagnosis of silicosis and education remained significant for forced expiratory volume in one second (FEV1; r = 0.60; r2 = 0.36; p < 0.001) and age and height for distance in 6MWT (r = 0.66; r2 = 0.43; p < 0.001). CONCLUSIONS: Our results show impaired lung function and preserved exercise capacity in current mineworkers exposed to silica. Length of time working in mining, presence of silicosis and lower education were factors associated with reduced lung function.