kaolinite and Pneumoconiosis

Refractory ceramic fiber (RCF) is an energy-efficient, high-temperature insulation, used principally in industrial furnaces, heaters, and reactors. Prior to the 1980s, there were few publications dealing with the potential health effects of this material. However, with the advent of higher energy costs and the need for thermally efficient high-temperature insulating materials, production of RCF grew rapidly, as did interest in its potential health effects. This article provides a comprehensive and integrated review of the toxicology (in vitro and in vivo), epidemiology, and risk analysis literature of RCF. Based on the available literature, we conclude that an occupational exposure of 0.5 fibers per cubic centimeter (cm(3)) [8-h time-weighted average (8-h TWA)] results in an occupational health risk no greater than 9.1 x 10(-5).

Topics: Administration, Inhalation; Air Pollutants; Air Pollutants, Occupational; Animals; Ceramics; Humans; In Vitro Techniques; Inhalation Exposure; Kaolin; Lung; Mineral Fibers; Pneumoconiosis; Risk Assessment; Toxicity Tests; United States

Topics: Aluminum Compounds; Aluminum Silicates; Animals; Calcium Compounds; Glass; Humans; Iron; Kaolin; Lung Diseases; Magnesium; Magnesium Compounds; Mesothelioma; Minerals; Mining; Occupational Diseases; Pleural Neoplasms; Pneumoconiosis; Silicates; Silicic Acid; Talc; Zeolites

Topics: Aluminum Compounds; Aluminum Silicates; Coal; Humans; Kaolin; Magnesium Compounds; Minerals; Pneumoconiosis; Silicates; Silicic Acid; Silicon Dioxide; Silicosis

Topics: Aged; Humans; Kaolin; Mining; Pneumoconiosis

Kaolin pneumoconiosis may produce radiologic findings similar to those of malignancy. Current management includes serial radiologic examination and lung sampling of suspicious parenchymal opacities and nodules to exclude associated malignancy. This may result in unnecessary pulmonary resections in patients with already compromised lung function. In a patient with known kaolin pneumoconiosis and multiple nodules, we used positron emission tomography to identify suspicious areas for malignancy that were confirmed by open lung biopsy, leading to successful lung cancer treatment.

Topics: Diagnosis, Differential; Fluorodeoxyglucose F18; Humans; Kaolin; Male; Middle Aged; Pneumoconiosis; Pneumonectomy; Positron-Emission Tomography; Radiopharmaceuticals

Chronic exposure to talc in the course of carpet installation can result in pneumoconiosis.. We present a case of a young carpet installer who was diagnosed with silicatosis of the lung. Review of occupational history revealed that the patient had been working as a carpet installer for approximately 15 years, since he was 15 years of age. The patient was exposed to talc in the course of his work.. Exposure to talc in the course of carpet installation has not been reported as a possible cause of pneumoconiosis. In this article we review different causes of silicatosis and discuss chronic exposure in the course of carpet installation and development of pneumoconiosis. In addition, we also review the relevance of mycobacterial infection in cases of silicosis and silicatosis.. Exposure to talc in the course of carpet installation should be added to conditions that can cause pneumoconioses, specifically silicatosis of the lung.

Topics: Adult; Bronchoalveolar Lavage Fluid; Floors and Floorcoverings; Humans; Kaolin; Male; Occupational Exposure; Pneumoconiosis; Radiography, Thoracic; Respiratory Function Tests; Talc; Tomography, X-Ray Computed

Topics: Chemical Industry; Dust; Free Radical Scavengers; Humans; Hydroxyproline; In Vitro Techniques; Kaolin; Models, Chemical; Occupational Diseases; Occupational Exposure; Pneumoconiosis

Topics: Air Pollutants, Occupational; Aluminum Silicates; Bronchitis; Chronic Disease; Crystallization; Dust; Free Radicals; Humans; Kaolin; Models, Theoretical; Occupational Diseases; Pneumoconiosis; Risk Factors; Silicon Dioxide; Silicosis; Thermodynamics

Kaolin is found along the "fall line" in Georgia, and parenchymal changes, both simple and complicated pneumoconiosis, have been previously described. This study was done to determine whether pleural thickening occurs in workers with mild kaolin pneumoconiosis.. We evaluated 350 workers at a kaolin plant in Georgia. Thirty-two workers with abnormal chest radiographs were clinically evaluated. Twelve workers with mild kaolinosis but without any evidence of pleural changes on chest roentgenograms had computed tomography (CT) of the chest to assess the presence of pleural thickening.. Nineteen workers had radiographic changes consistent with kaolin pneumoconiosis (prevalence 5.4%), and four workers had evidence of pleural plaques (prevalence 1.1%). Five of the 12 workers had evidence of pleural thickening on CT.. This study shows that pleural thickening may be common on chest tomography in workers with kaolinosis and that the exposure to kaolin dust should be considered in the differential diagnosis of pleural thickening.

Topics: Adult; Diagnosis, Differential; Dust; Georgia; Humans; Kaolin; Lung Diseases, Obstructive; Middle Aged; Mining; Occupational Exposure; Pleural Diseases; Pneumoconiosis; Prevalence; Pulmonary Fibrosis; Radiography, Thoracic; Tomography, X-Ray Computed

A 62-year-old white male employed for 43 years in the polishing room of a cotton textile mill was admitted to a tertiary care center with progressive dyspnea and productive cough that had not responded to therapy for tuberculosis. In spite of aggressive antibiotic therapy and respiratory support, the patient died as a consequence of respiratory failure. Small rounded and irregular opacities had been noted on the chest radiograph. Review of job-site spirometry demonstrated a worsening restrictive pattern over a 4-year period prior to his death. Additional occupational history revealed long-term exposure to kaolin in the polishing room, and pathologic examination of lung tissue confirmed extensive fibrosis and substantial quantities of kaolin. Kaolinosis is a disease typically found among individuals involved in mining or processing this material rather than in user industries. This case illustrates the importance of obtaining a complete occupational history in reaching a diagnosis. The clinicopathologic aspects of kaolinosis are also reviewed.

Topics: Fatal Outcome; Gossypium; Humans; Kaolin; Lung; Male; Middle Aged; Occupational Diseases; Pneumoconiosis; Pulmonary Fibrosis; Respiratory Insufficiency

Seventeen cases of "talc pneumoconiosis" were examined pathologically and mineralogically to ascertain whether a true talc pneumoconiosis existed and also to compare these results in primary, secondary, and tertiary exposures. Mineralogic analyses were performed on wet tissue or tissue blocks by a variety of techniques, including analytical transmission electron microscopy and x-ray diffraction. Overall, the pathologic appearance of the tissues was similar in primary, secondary, and tertiary exposures, although ferruginous bodies and foreign body giant cells were not always present in cases caused by secondary exposures. Mixed dust fibrotic lesions were found in two cases in which there were substantial quantities of quartz present. There was great variation in the minerals found within the lung tissues. Several cases showed significant quantities of mica and kaolin in addition to talc. One case consisted predominantly of mica and in fact could be regarded as "mica pneumoconiosis"; this diagnosis was correctly attributed because of the mineralogic findings. Tremolite fibers were found in only two cases. Substantial quantities of crocidolite and amosite fibers were found in one case. This study shows that "talcosis" frequently represents disease associated with a variety of minerals and that talc is a common denominator. It shows also the usefulness of lung dust mineral analysis, particularly in secondary industries, for evaluating the cause of a pathologic reaction when exposures are especially complex.

Topics: Aged; Aluminum Silicates; Female; Humans; Kaolin; Lung; Male; Microscopy, Electron; Middle Aged; Pneumoconiosis; Talc; X-Ray Diffraction

The catalytic activity of kaolin, an aluminum silicate, for generating hydroxyl radicals (.OH) from hydrogen peroxide (H2O2) was studied in a chemical system that measured .OH as evolution of methane (CH4) from dimethyl sulfoxide. In the presence of a reducing agent and 10 mM H2O2, hydrous and calcined kaolin generated mean +/- SE CH4 concentrations of 1634 +/- 328 and 1395 +/- 29 ppm, respectively. Surface modification with dipalmitoyl lecithin, the lipid of pulmonary surfactant, blocked generation of .OH in hydrous kaolin (38 +/- 38 ppm CH4) but not in calcined kaolin (875 +/- 262 ppm CH4). The catalytic activity of kaolin for producing .OH from H2O2 may be important in the pathogenesis of kaolin toxicity, and calcined kaolin may be more toxic than hydrous kaolin because the calcined form is resistant to surface modification by lipids of pulmonary surfactant.

Topics: Humans; Hydrogen Peroxide; Hydroxylation; Kaolin; Microscopy, Electron, Scanning; Pneumoconiosis

To investigate the origin of differences in previously published pulmonary function studies of workers in kaolin plants in Georgia, spirometric and radiographic data collected in a cross sectional survey of two large plants were analysed. As compared with workers in plant 2, workers in plant 1 had a 2.7-fold greater prevalence of pneumoconiosis and a mean 0.361 decrement in adjusted forced vital capacity. Our previous finding that exposure to kaolin was not associated with a decrement in lung function may have resulted from failure to consider differences between the plants.

Topics: Adolescent; Adult; Aged; Forced Expiratory Volume; Georgia; Humans; Kaolin; Lung; Middle Aged; Pneumoconiosis; Prevalence; Regression Analysis; Vital Capacity

Topics: Environmental Exposure; Forecasting; Humans; Kaolin; Lung; Occupational Diseases; Pneumoconiosis; Pulmonary Fibrosis; Radiography, Thoracic

We studied the prevalence of ventilatory impairment, chest symptoms, and radiographic abnormality in a selected sample of more than 2,000 kaolin workers from east central Georgia. The presence of ventilatory impairment was related to the presence of complicated pneumoconiosis, employment in clay calcining, and cigarette smoking. In those working with calcined clay, there was an increased prevalence of abnormality of the FEV1, but not the FVC, when compared to both wet and dry processors and which could not be explained by either cigarette smoking or the presence of pneumoconiosis. The magnitude of abnormality in the calcined clay workers was, however, unlikely to lead to disabling impairment. In workers with more than 3-yr tenure, there were 90 subjects with simple pneumoconiosis and 18 with complicated pneumoconiosis, yielding an adjusted prevalence of 3.2% and 0.63%, respectively, in the sample examined. Dry processing was associated with a greater risk of developing pneumoconiosis than wet processing.

Topics: Adult; Dust; Forced Expiratory Volume; Humans; Kaolin; Lung; Male; Pneumoconiosis; Radiography, Thoracic; Respiratory Tract Diseases; Vital Capacity

A combined clinical, radiological, pathological, and mineralogical study was undertaken on 62 cases referred to the Medical Research Council Pneumoconiosis Unit by the Cardiff Pneumoconiosis Panel as Cornish china clay workers. Considerable pathological lesions were found in the lungs, both nodular and interstitial fibroses being present. Some men had worked with china stone but others had worked entirely with china clay. Nodular fibrosis appeared to be related to a high quartz content of the dust recovered from the lung, whereas among those with a high content of kaolinite dust in the lungs interstitial fibrosis was observed.

Topics: Adult; Aged; England; Humans; Kaolin; Lung; Male; Middle Aged; Minerals; Pneumoconiosis; Quartz; Radiography

A short account of the industrial process used to produce kaolin is given. The chest radiographs of 68 selected cases of kaolinosis were reviewed and the radiological appearances are presented. We also describe two cases of Caplan's syndrome occurring in kaolinosis.

Topics: Caplan Syndrome; England; Humans; Kaolin; Pneumoconiosis; Pulmonary Fibrosis; Radiography; Silicosis

Kaolin is removed from underground seams in the mining area to a processing area, where it is sliced, dried, and pulverised to make the finished product. A study was undertaken to determine the dust concentrations in various work areas and to assess the prevalence of radiographic and pulmonary function abnormalities in 65 workers at a Georgia kaolin mine. Respirable dust concentrations were higher in the processing area than in the mine or maintenance areas for all determinations from 1977 to 1981. The mean respirable dust level in the processing area in 1981 was 1.74 mg/m3 and 0.14 mg/m3 in the mine area. Five workers, all of whom had worked at the processing area, had radiographic evidence of kaolin pneumoconiosis. The mean values of forced vital capacity (FVC) and FEV1 of the entire group were within the normal range. When the spirometric values were expressed as a percentage of the predicted values, the FVC and FEV1 were significantly lower in the workers with kaolinosis than in other workers in the processing area. The FVC and FEV1 also declined significantly with increasing years of work in the processing area. The FEV1/FVC%, however, was not significantly altered either by the presence of kaolinosis or by an increasing number of years of work, indicating that the impairment was restrictive and hence likely to be a consequence of dust inhalation rather than smoking. In this study the highest dust concentrations occurred in the processing area, and kaolin pneumoconiosis was limited to those who had worked there. Kaolin exposure appeared to have a small but significant effect on ventilatory capacity in those with kaolin pneumoconiosis and in workers with a longer exposure. There was no association between the radiographic appearances of kaolinosis and cigarette smoking or between the presence of radiographic abnormalities and reduced arterial blood gas tensions.

Topics: Adult; Dust; Georgia; Humans; Kaolin; Lung; Male; Middle Aged; Mining; Pneumoconiosis; Radiography; Respiratory Function Tests; Smoking

Pulmonary tissue obtained at thoracotomy or autopsy from 5 kaolin workers with complicated pneumoconiosis was studied by optical light and scanning electron microscopy. Premortem or preoperative chest roentgenograms demonstrated small irregular shadows and large opacities typical of kaolin pneumoconiosis. On gross examination, there were firm, grey-brown nodules and masses in the parenchyma and in the hilar lymph nodes. Histologically, there was extensive pulmonary kaolinite deposition associated with formation of peribronchiolar macules and nodules. The latter were comprised of kaolinite aggregates traversed by bands of fibrous tissue rather than dense whorled collagen, as seen in silicosis. Crystallographic studies confirmed the presence of kaolinite in the lungs, but silica was not demonstrable by either analytical scanning electron microscopy or X-ray diffractometry. These findings illustrate the pathology of human kaolin pneumoconiosis, confirm the fibrogenic potential of kaolinite, and emphasize differences in pulmonary responses to kaolinite and to silica.

Topics: Adult; Aged; Humans; Kaolin; Lung; Male; Microscopy, Electron, Scanning; Middle Aged; Pneumoconiosis; Radiography; X-Ray Diffraction

Topics: Bronchitis; Cross-Sectional Studies; Environmental Exposure; Forced Expiratory Volume; Humans; Kaolin; Lung; Lung Diseases; Pneumoconiosis; Silicic Acid

The problems encountered in diagnosing the rare types of pneumoconiosis ( silicatosis other than asbestosis, aluminosis and hard metals fibrosis), result from the difficulties in realising a good occupational anamnese and from the disease pattern by itself. The classical examinations, (X-rays of the thorax and lung function measurements), are not able to detect the cause of these diseases, which are fundamentally characterised by an absence of specificity. These last years, new methods of diagnoses (angiotensin converting enzyme, gallium scan, transbronchial biopsies, mineralogical, cytological and histological examinations of the lung tissues and of the bronchial alveolar lavage) were developed and progressively introduced in the daily practice in pneumology. Only the examination of lung biopsies and of the products of bronchial alveolar lavage, in particular the mineralogical examinations, may usefully orientate the diagnosis. The bronchial alveolar lavage has the advantage of an easy repetition and of a small invasive character. Moreover this technique is of a rather low financial cost. However the results of these examinations must be interpreted with the greatest caution, in function of the complete medical and occupational data. The experience following more than 500 BAL shows that the discovery of talc and kaolin is very significant for an exposition since these minerals were never observed among not exposed subjects. The evidence of these minerals argues also for the diagnosis of talcosis or kaolinosis if there are radiological lesions that are compatible with these diseases. On the other hand a recent study suggests that the identification of multinuclear macrophages and of tungsten and/of tantalum in the bronchial alveolar lavage is pathognomonic of the pathology of the hard metals.

Topics: Adult; Aged; Biopsy; Bronchi; Diagnosis, Differential; Female; Humans; Kaolin; Male; Metals; Middle Aged; Pneumoconiosis; Pulmonary Fibrosis; Silicosis; Talc; Therapeutic Irrigation

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.

Topics: Adult; Air Pollutants, Occupational; Environmental Exposure; Humans; Industry; Kaolin; Male; Pneumoconiosis; Pulmonary Fibrosis

Middle Georgia kaolin workers (n = 459) were surveyed for the presence of pneumoconiosis by chest radiograph and for respiratory symptoms by questionnaire. Pulmonary function was measured in all workers by spirometry. The overall prevalence of pneumoconiosis in this population was 9.2%. Multivariate analysis demonstrated that the only significant correlates with the radiographic presence of pneumoconiosis were ages greater than 55 yr and greater than 15 yr work exposure in the job category associated with greatest dust exposure. There was no correlation between the radiographic presence of pneumoconiosis and respiratory symptoms, cigarette smoking, or history of tuberculosis. Except in cases of complicated pneumoconiosis (large opacities), spirograms of workers with radiographic evidence of pneumoconiosis were not significantly different from spirograms of workers with normal radiographs. Clinical impairment of pulmonary function does not occur except in advanced cases, and appears to be mild even in these.

Topics: Adolescent; Adult; Aged; Black People; Dyspnea; Forced Expiratory Volume; Georgia; Humans; Kaolin; Middle Aged; Mining; Pneumoconiosis; Radiography; Smoking; Vital Capacity; White People

In June 1981, 65 current and former workers at a kaolin mine and mill were examined by chest radiography, spirometry, and a questionnaire. Five (13%) of 39 current workers and 3 (19%) of 16 former workers with 5 yr or more of exposure had radiographic evidence of pneumoconiosis. Among the 8 workers with pneumoconiosis, conglomerate upper lobe lesions were present in one half. No pneumoconiosis was observed among 8 current workers with less than 5 yr of exposure. Lung function testing showed significant reductions (p less than 0.05) in FVC, FEV1, and peak flow rate in kaolin workers compared with that in a control group. Environmental sampling during the testing period showed airborne dust to be composed of kaolinite (96%) and titanium dioxide (4%). Additional controlled epidemiologic studies among kaolin workers are needed to generate reliable prevalence data for pneumoconiosis and to assess the impact of dust exposure on pulmonary function.

Topics: Adult; Aged; Forced Expiratory Volume; Georgia; Humans; Kaolin; Lung; Male; Middle Aged; Mining; Pneumoconiosis; Time Factors; Vital Capacity

A radiological survey of men employed in the china clay industry in Cornwall was carried out in 1977. Each man completed a short questionnaire on respiratory symptoms and smoking habits, his occupational history was determined, and his forced expiratory volume and vital capacity were measured. The radiographs were read independently by three observers, using the 1980 ILO classification. Of the 1728 men in the study, 23 had had dust exposure elsewhere, mostly in tin mining, and were excluded. Readings of the radiographs were available for 1676 men: 77.4% were within category 0, 17.9% in category 1, and 4.7% in categories 2 and 3. In 19 men (1.1%) one or more readers recorded the presence of a large shadow and read it as complicated pneumoconiosis, but in only four men were the readers unanimous. Every job recognised as dusty contributed significantly to the amount of simple pneumoconiosis, and in two jobs the conditions were such that the average worker would reach category 2 in a working lifetime. Smoking appeared unrelated to the radiographic appearance. Vital capacity showed a significant reduction with increasing amount of pneumoconiosis, but not, when this was allowed for, on the duration of exposure in any of the job categories. In addition it depended, as would be expected, on smoking. The effect of one category increase in pneumoconiosis was equivalent to 4.1 years of age in smokers, 3.9 years of age in ex-smokers, and 5.4 years of age in non-smoker. Forced expiratory volume did not decline significantly with amount of pneumoconiosis, so that FEV% VC showed an increase, though not to a significant extent. No extent. No relationship between symptoms and past exposure was detected.

Topics: Adolescent; Adult; Aged; England; Forced Expiratory Volume; Humans; Kaolin; Male; Middle Aged; Mining; Pneumoconiosis; Radiography; Smoking; Vital Capacity

We report a patient with multiple pulmonary kaolin granulomas. The granulomas developed secondary to the use of a liquid kaolin suspension for pleural poudrage to treat recurrent spontaneous pneumothoraces. Presumably the kaolin entered the lung through pleuro-alveolar or pleuro-bronchial openings. Kaolin pneumoconiosis is generally regarded as an inhalational pneumoconiosis. However, on rare occasions kaolin may incite lung damage by the mechanism described above.

Topics: Adult; Granuloma; Humans; Kaolin; Male; Pneumoconiosis; Pneumothorax; Recurrence

Topics: Aluminum Silicates; Asbestos; Beryllium; Humans; Kaolin; Lung; Lung Neoplasms; Pathology; Pneumoconiosis; Talc

Topics: Adult; Air Pollutants; Air Pollutants, Occupational; Bronchitis; Chronic Disease; Dust; Humans; Kaolin; Middle Aged; Pneumoconiosis; Risk

Topics: Humans; Kaolin; Lung; Male; Middle Aged; Pneumoconiosis

Topics: Coal Mining; Humans; Kaolin; Pneumoconiosis; Quartz; Silicon Dioxide; United Kingdom

The toxicity of various minerals (kaolin, muscovite, illite) was compared by tracheal tests on rats to that of reference dusts (quartz, titanium dioxide, coal). These minerals have various degrees of toxicity. Owing to their sometimes very high concentration in the respirable dust, their toxicity should be taken into consideration. In order to define the aggravating role of quartz more accurately, dust inhalation tests were also conducted on rats with coal and a coal-quartz mixture containing about 10% quartz. The difference in the toxicity of these two types of dust which is practically not detectable up to 12 months, then increases progressively after that period. In addition, in rats having inhaled either coal or a quartz-coal mixture for 24 months, there appear tumoral lesions, principally of epidermoid type.

Topics: Adenocarcinoma; Aluminum Silicates; Animals; Carcinoma, Squamous Cell; Coal Mining; Female; Kaolin; Lung; Lung Neoplasms; Neoplasms, Experimental; Papilloma; Pneumoconiosis; Quartz; Rats; Time Factors

Risks of developing abnormalities on chest X-rays differ widely between collieries in the Ruhr, despite comparable dust exposures. Simple pneumoconiosis hazard indices have been determined for thirteen collieries, taking into consideration variations in miners' individual cumulative dust exposures, their ages at start of dust exposure, the residence time of dust in their lungs, and the mineral content of the dust. Fine dust samples were taken in five collieries at places selected as representative of seams worked during the past 20 years. They were used for mineralogical and physical analyses and for cell and animal studies. Cytotoxicity of dusts with comparable composition increased with geological age and rank of coal seams. This finding is consistent with results from epidemiological studies.

Topics: Coal Mining; Dust; Germany, West; Humans; In Vitro Techniques; Kaolin; Macrophages; Particle Size; Pneumoconiosis; Quartz; Risk

An extraction replication technique has been used for the study, by electron microscopy, of lung tissue from a number of different cases of pneumoconiosis. The technique provides a relatively simple means of studying the surface area of replicated tissues, and any foreign particles present which are either replicated or extracted from the tissue can be identified. A set of standard micrographs of different types of mineral particles likely to be encountered should be kept for reference. Most of the particles identified by this technique were beyond the limits of resolution of optical microscopy. Furthermore, the procedure involves the minimum of chemical and physical treatment. The histochemical diagnosis and industrial history was confirmed in the first two cases described, by the electron microscopy investigations. The third case presented an uncertain histological and industrial history, but an electron microscopy study confirmed the presence of the mineral particle considered responsible for the clinical condition. The fourth and fifth cases described illustrate the use of this technique in identifying a particular type of pleomorphic mineral, and illustrating its position in situ in relation to surrounding tissue.

Topics: Adult; Aged; Asbestos; Histological Techniques; Humans; Kaolin; Lung; Male; Microscopy, Electron; Middle Aged; Minerals; Pneumoconiosis; Talc

Topics: Adult; Animals; Culture Media; Guinea Pigs; Humans; Injections; Kaolin; Lung; Middle Aged; Mycobacterium tuberculosis; Pneumoconiosis; Silicon Dioxide; Statistics as Topic; Talc; Time Factors; Tuberculosis, Pulmonary

Topics: Humans; Kaolin; Occupational Diseases; Pneumoconiosis

Topics: Aluminum; Asbestosis; Beryllium; Caplan Syndrome; Diagnosis, Differential; Disability Evaluation; Environmental Exposure; Humans; Kaolin; Metals; Pneumoconiosis; Radiography; Silicosis; Silicotuberculosis; Talc; Tomography; Workers' Compensation

Topics: Apatites; Ceramics; Dust; Humans; Kaolin; Pneumoconiosis; Silicon Dioxide; Silicosis; Spectrum Analysis; Talc

Topics: Bronchial Neoplasms; Dust; Humans; Kaolin; Lung; Pneumoconiosis; Prevalence; Radiography, Thoracic; Silicosis; Tuberculosis; Tuberculosis, Pulmonary

Topics: Aluminum Silicates; Bronchitis; Humans; Kaolin; Pneumoconiosis

Topics: Animals; Bacillus; Coal; Dust; Guinea Pigs; Kaolin; Lung; Mining; Mycobacterium bovis; Pneumoconiosis; Rats; Tuberculosis; Tuberculosis, Pulmonary

Topics: Humans; Kaolin; Pleura; Pneumoconiosis; Pneumothorax; Pneumothorax, Artificial; Thinking; Thorax

Topics: Humans; Kaolin; Pneumoconiosis