kaolinite and Silicosis

Several inhaled substances, from occupational or other environmental exposure, produce significant pulmonary disease and abnormalities demonstrated by pulmonary imaging. Areas of controversy and misconception relate principally to the extent and nature of both the clinical disease and the imaging abnormalities specific to each substance. The size and shape of the inhaled particles is an important determinant of the nature and severity of the disease produced, with fibrous shapes usually being the most pathogenetic. Fibrogenicity is another important pathogenetic characteristic of talc and kaolin, as well as asbestos. Talc produces four distinct forms of pulmonary disease, depending not only on the other substances with which it is inhaled, but also whether it is inhaled or injected intravenously. When inhaled alone, talc does not appear to produce significant pulmonary fibrosis or malignancy. Kaolin, mica, fuller's earth, zeolite, and fiberglass all vary in disease production according to their shape and fibrogenicity. Silica, diatomaceous earth, and other forms of silica are all highly fibrogenic and thus produce clinically obvious disease with sufficient inhalation. The largest particles usually produce nodular patterns in the upper pulmonary fields, as is typical of silicosis. The fibrous particles are more likely to manifest themselves as interstitial patterns in the lower pulmonary fields.

Topics: Aluminum Silicates; Humans; Kaolin; Radiography; Silicon Dioxide; Silicosis; Talc; Zeolites

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

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

Topics: Adult; Detergents; Dust; Female; Humans; Kaolin; Quartz; Radiography; Silicosis

Topics: Cuba; Dust; Humans; Kaolin; Silicosis

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

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

Topics: Animals; Candida albicans; Candidiasis; Guinea Pigs; Kaolin; Lung Diseases, Fungal; Silicosis; Talc

Nine patients with disabling pneumoconiosis were selected over a three-year period for study because of a work history of kaolin exposure. All had worked in the Missouri firebrick industry. Chest roentgenograms from all nine and lung tissue from two were consistent with silicosis. Worksite analysis of airborne dust at several Missouri firebrick factories revealed that some current workers are exposed to both free silica (up to 4.5%) and cristobalite (up to 8.9%) at levels exceeding the threshold limit value (TLV). Analysis of airborne dust from several kaolin processing plants in South Carolina and Georgia revealed that a few workers are exposed to about 1% free silica at levels occasionally exceeding the TVL. We conclude that silicosis is a serious risk for Missouri kaolin workers and a potential risk for workers in South Carolina and Georgia. A prevalence survey is needed in Missouri to assess the problem.

Topics: Aged; Air Pollutants, Occupational; Georgia; Humans; Kaolin; Lung; Maximum Allowable Concentration; Middle Aged; Missouri; Occupational Diseases; Radiography; Silicon Dioxide; Silicosis; South Carolina

The pleuro-pulmonary pathology of asbestos, top most of silicates, is today well known. Other silicates, talcum powder, clays, micas essentially, are exploited and commercialized. Their pathology is less well known and often contradictory because of the heterogeneity of the inhaled minerals. All can contain large quantities of quartz and some varieties of talcum and a considerable proportion of asbestos fibres. These minerals can provoke severe pneumoconioses, silicoses and asbestoses respectively. Some relatively pure products do not contain these contaminants. In case of intense and prolonged dust inhaling, they can produced an impressive pneumoconiosis with relatively mild clinical signs as shown by the series of 27 cases of pneumoconiosis from the french talcum powder as reported by the authors. The chemical nature and electronic structure of different silicates are very similar. It raises the question of the noxious effect of asbestos and the relative innocuousness of other minerals of the same family, and wether the fibrous structure alone is implicated.

Topics: Adult; Aged; Humans; Kaolin; Male; Middle Aged; Radiography; Silicic Acid; Silicosis; Talc

Following intratracheal inoculation the pulmonary fibrogenic response of kaolin, mica and talc was investigated in mice over a period of 210 days. All the three dusts incited acute inflammatory reaction at early periods but with mica dust the acute reaction persisted longer. Subsequently there was gradual increase in the fibroblastic activity in the focal areas and mica produced, in addition, many cholesterol cleft-like structures together with marked fibroblastic activity and lymphocytic infiltration. Towards the termination of experiment at 210 days the fibrosis, in general, remained restricted to grade II with kaolin and mica while talc produced thickened interalveolar septa. The transport of dust from lungs to lymph nodes occurred earlier with mica than with kaolin or talc dust accompanied with little fibrotic reaction. The significance of the findings has been discussed.

Topics: Animals; Dust; Female; Kaolin; Male; Mice; Silicosis; Talc

Topics: Adult; Age Factors; Aged; Dust; Female; France; Humans; Kaolin; Lung; Male; Middle Aged; Occupational Diseases; Occupational Medicine; Protective Clothing; Protective Devices; Radiography; Silicon Dioxide; Silicosis; Time Factors

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; Kaolin; Liver; Lung; Lymph Nodes; Pathology; Peritoneum; Rats; Research; Silicon Dioxide; Silicosis; Spleen; Toxicology

Topics: Aluminum Silicates; Humans; Kaolin; Silicosis; Talc