1/7. pneumoconiosis in a vermiculite end-product user.BACKGROUND: Vermiculite is a silicate used as an insulating agent, soil additive, and carrier for chemicals and fertilizers. It is currently perceived to have no adverse effects to "end-product" users. An 82-year-old man presented with complaints of progressive dyspnea on exertion. methods: A clinical evaluation included a chest radiograph, complete pulmonary function testing, CT scan of the thorax, and comprehensive occupational and environmental history. RESULTS: The patient had clinical and radiographic features of advanced pulmonary interstitial fibrosis. The presence of calcified pleural plaques, together with the other clinical and radiographic features, strongly supported a diagnosis of asbestosis. His only significant exposure was to vermiculite used in the workplace for several hours per day from 1970 to 1987. CONCLUSIONS: This case represents the first report of an end-product vermiculite-user with probable asbestosis, and together with recent similar findings in a vermiculite expansion plant worker, requires further epidemiologic investigations.- - - - - - - - - - ranking = 1keywords = plant (Clic here for more details about this article) |
2/7. 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.- - - - - - - - - - ranking = 1keywords = plant (Clic here for more details about this article) |
3/7. Hard metal interstitial pulmonary disease associated with a form of welding in a metal parts coating plant.We describe two cases of hard metal pulmonary disease (one fatal) in workers employed in the same area of a metal coating plant using the detonation gun process for applying a durable metal surface to metal parts. In this form of welding, a mixture of powdered metals, including tungsten carbide and cobalt, is heated by ignition of a flammable gas and propelled from the end of the "gun" at high temperature and velocity to form a welded metal coating. This process is done in an enclosed chamber and with each application, large volumes of fine aerosols are created. inhalation exposure to hard metal may occur during the mounting and removal of the metal parts between applications, in spite of engineering controls and industrial hygiene surveillance. One of the cases presented with minimal chest x-ray abnormalities and an obstructive pattern on pulmonary function testing, although subsequent open lung biopsy showed diffuse interstitial pulmonary fibrosis. The fact that two cases of hard metal pulmonary interstitial disease occurred where thorough exposure control procedures and a surveillance program for cobalt were in place may indicate the need for revisions of the current technology used when hard metal is applied in the detonation gun process.- - - - - - - - - - ranking = 5keywords = plant (Clic here for more details about this article) |
4/7. Respiratory disease in tungsten carbide production workers.We carried out a medical and environmental survey to evaluate respiratory disease at two tungsten carbide (TC) production plants. The study population of 290 subjects (19.2 percent of the total work force) was chosen to focus on those with the greatest potential exposures to cobalt, a binding agent which is probably the cause of interstitial fibrosis and airways disease in TC workers. We found peak air concentrations of cobalt exceeding 500 micrograms/m3 during many major steps in TC production. Nine subjects at plant A and two at plant B had interstitial infiltrates. Two of these nine from plant A had restriction (total lung capacity less than 80 percent of predicted). A lung biopsy specimen in one showed interstitial fibrosis. Two nonsmokers at plant A and one nonsmoker at plant B had obstructive defects. These results suggest that interstitial and obstructive lung disease occur in TC workers in association with elevated peak air concentrations of cobalt.- - - - - - - - - - ranking = 6keywords = plant (Clic here for more details about this article) |
5/7. polyvinyl chloride pneumoconiosis.A 53-year-old man, who had been exposed for 23 years to polyvinyl chloride (PVC) in the bagging area of a vinyl chloride polymerisation plant, presented with a diffuse micronodular infiltrate on his chest radiograph. light microscopy of lung obtained by drill biopsy showed a diffuse infiltration with histiocytes and multinucleated giant cells, with some collagen formation. Ultrastructural studies showed foreign particles in the macrophages, which were identical with PVC powder viewed under the electron microscope. Incubation of PVC powder with human lung macrophages in vitro showed that the macrophages englufed the powder to give a similar ultrastructural appearance.- - - - - - - - - - ranking = 1keywords = plant (Clic here for more details about this article) |
6/7. kaolin pneumoconiosis. A case report.A 35-year-old man who had been occupationally exposed to aerosolized kaolin for 17 years in a georgia processing plant had diffuse reticulonodular pulmonary infiltrates and an upper lobe mass. Exploratory thoracotomy, performed to evaluate the nature of the mass, revealed an 8 X 12 X 10-cm conglomerate pneumoconiotic lesion containing large amounts of kaolinite. Coincident deposition of silica in the tissue was not demonstrable by either analytic scanning electron microscopy or x-ray diffraction. The case illustrates the effect of chronic kaolin exposure on the human lung and emphasizes the need for periodic evaluation of exposed workers.- - - - - - - - - - ranking = 1keywords = plant (Clic here for more details about this article) |
7/7. Pulmonary dust retention in a silicon carbide worker.This paper reports on pulmonary dust retention in a man who worked 42 years in the vicinity of an Acheson furnace of a silicon carbide plant and had a carborundum pneumoconiosis. Special attention is paid to the retained silicon carbide fibers in the lung parenchyma. The concentration of silicon carbide fibers longer than 5 microns is 39,300 fibers/mg dry lung. These fibers have a similar morphology to fibers observed in the working environment. The result is compared to pulmonary retention of workers exposed to asbestos.- - - - - - - - - - ranking = 1keywords = plant (Clic here for more details about this article) |