Respiratory impairment in Brazilian foundry workers exposed to sand.

OBJECTIVE: Foundries date back to the 16th century in Brazil and still constitute a strong economic activity today. Workers are at risk of respiratory diseases due to various exposures such as polycyclic aromatic hydrocarbons, pyrolysis degradation products, mineral dust, organic dust, resin, and isocyanates. We evaluate respiratory morbidity among workers in foundries using sand. METHODS: Six foundries with sand molding operations were selected. Length of exposure in years was utilized as a surrogate for exposure. The medical evaluation consisted of a respiratory symptoms questionnaire, occupational history, spirometry, and chest X-rays. Additionally, workers exposed to resins and a control group underwent bronchial provocation tests. RESULTS: A sample of 598 male workers with a mean age of 36.5 years (SD = 10.0) was analyzed. The mean length of exposure was 10.1 years (SD = 7.4). The overall prevalence of pneumoconiosis was 4.5%. Chronic bronchitis (CB) and X-ray profusion were significantly related to the quartiles of length of exposure (trend tests: P = 0.0055 and P < 0.001, respectively). There was a significant risk of having an abnormal FVC and FEV(1) with the presence of pneumoconiosis (OR = 4.63 CI 1.40-13-23, OR 3.34 CI 1.03-9.26, respectively). Workers exposed to resins compared with controls showed no differences in relation to spirometry, respiratory symptoms and bronchial reactivity. CONCLUSIONS: There were significant associations between length of exposure CB and prevalence of profusion 1/0 or above. There was also a significant association for pneumoconiosis versus and abnormal FVC and FEV(1). Foundry workers currently exposed to resins did not show an excess of respiratory symptoms, abnormal spirometry or increased bronchial reactivity.

Pneumoconiosis after sericite inhalation.

BACKGROUND: Between 1997 and 1999 three sericite plant workers in Parana, Brazil, were diagnosed with pneumoconiosis. AIMS: To investigate and describe the radiological, clinical, and pathological changes in miners and millers exposed to sericite dust with mineralogical characteristics of inhaled dust. METHODS: The working premises were visited to examine the sericite processing and to classify the jobs according to make qualitative evaluation. Respirable dust was collected and the amount of crystalline silica and particle size distribution were measured. Forty four workers were examined by a standard questionnaire for respiratory symptoms, spirometry, and chest x ray. Material from an open lung biopsy was reviewed for histopathological and mineralogical analysis, together with sericite samples from the work site to compare the mineral characteristics in lung lesions and work area. RESULTS: Respirable dust contained 4.5-10.0% crystalline silica. Particle size distribution showed a heavy burden of very fine particles (23-55%) with a mean diameter of <0.5 microm. Mean age of sericite miners was 41.0 (11.9) and mean number of years of exposure was 13.5 (10.1). In 52.3% of workers (23/44), chest radiographs presented a median category of 1/0 or above, and 18.2% (8/44) had a reduced FEV1. There was a significant association between exposure indices and x ray category. Histological studies of the lung biopsy showed lesions compatible with mixed dust fibrosis with no silicotic nodules. x Ray diffraction analysis of the lung dust residue and the bulk samples collected from work area showed similar mineralogical characteristics. Muscovite and kaolinite were the major mineral particle inclusions in the lung. CONCLUSION: Exposure to fine sericite particles is associated with the development of functional and radiological changes in workers inducing mixed dust lesions, which are distinct histologically from silicosis.