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Query: UMLS:C0032273 (pneumoconiosis)
 1,578 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A medical examination has been carried out of 500 workers (290 men and 210 women) of a ceramic plates plant. Also, the measurements of dust concentrations were made at some standard work places . In the materials used for manufacturing the plates crystalline phases and the content of free crystalline silica were determined using the X-ray diffraction method. In the animal experiments the fibrogenic activity of all materials used in the plant was examined and compared to the fibrogenic activity of standard quartz. As a result of the medical examination 64 cases of pneumoconiosis were diagnosed (13% of the subjects). The incidence rate of pneumoconiosis was similar for men and women. The radiological changes characteristic of pneumoconiosis took approximately 24 years of the workers tenure to develop. Type q changes were most frequent (69%), types p and r were observed in 14% of workers (mostly women). In 31% of workers tuberous changes of size B were observed. In 43.8% of the subjects restrictive disorders of ventilation were found. In 30% of workers chronic bronchitis was diagnosed. Dust concentrations at 11 work places were measured using the individual dosimetry method. Total dust concentrations ranged from 0.6 mg/m3 at the electricians posts to 60.1 mg/m3 at the workposts where the furnace truck restorers worked. Dust concentrations exceeded the MACs at 7 workposts. The respirable fraction concentrations ranged from 0.1 mg/m3 to 8.4 mg/m3. During the replacement of asbestos ropes and asbestos board used for insulating the furnace trucks mineral fibres (0.1-0.5 fibre/cm3) were found in the air. The following crystalline phases were determined in the materials: kaolinite, illite, quartz, orthoclase and microline.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Evaluation of long-term occupational exposure to dust and its effect on health during production of ceramic tiles]. 132 40

Dust exposure and pneumoconiosis were investigated in a South African pottery that manufactured wall tiles and bathroom fittings. This paper describes the objectives of the investigation and presents dust measurement data. x Ray diffraction showed that the clays used by the pottery had a high quartz content (range 58%-23%, mean 38%). Exposure to respirable dust was measured for 43 workers and was highest (6.6 mg/m3) in a bathroom fitting fettler. Quartz concentrations in excess of 0.1 mg/m3 were found in all sections of the manufacturing process from slip production to biscuit firing and sorting. The proportion of quartz in the respirable dust of these sections was 24% to 33%. This is higher than is usually reported in English potteries. Four hundred and six (80%) of the 509 workers employed at the pottery were potentially at risk of occupational lung disease. The finding of large numbers of pottery workers exposed to unacceptable dust concentrations is not surprising as poor dust control was found in all six wall tile and sanitary ware factories surveyed by the National Centre for Occupational Health between 1973 and 1989. Dust related occupational disease can be expected in potters for many years to come.
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PMID:Dust exposure and pneumoconiosis in a South African pottery. 1. Study objectives and dust exposure. 163 5

The relationship between biochemical changes in bronchoalveolar lavage fluid (BALF), serum and the lung of different dustexposed rats was studied. Wistar rats were divided into 5 groups: 1. Xingkong chrysotile asbestos (CH-As); 2. Dust in a sieve selection workshop of Xingkong asbestos mine (Dust-Wo); 3. Silica group (SiO2); 4. Titanium dioxide (TiO2) and 5. Normal control group (Control). All the rats were killed in three months after experiment. The results showed that the level of alveolar macrophages (AM), lactic dehydrogenase (LDH) and acid phosphatase (AcP) in each group was marked by related to collagen, lung fat, ceruloplasmin (Cp) and hydroxyproline (HoP) by r and t-test. Among the LDH from BALF, culture fluid and serum, there was also a marked relationship. So the authors pointed out that the BALF especially AM and LDH test could serve as a good and valuable index for detection the condition of pneumoconiosis.
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PMID:[The relationship of biochemical changes among bronchoalveolar lavage fluid serum and lung on dust-exposed rats]. 166 Aug 48

A multivariate logistic model for measuring and comparing pneumoconiosis risk is described. In the first stage variables are screened on the basis of contributed variability via Pearson Chi Square statistic. Age, dust years and pack years so chosen as explanatory variables are fitted in the above model. The coefficients are estimated as linear discriminant function co-efficient. The model gives quite a good fit between observed and expected frequencies. Dust years discriminate maximum between the normal and pneumoconiosis group. Nearly sixty per cent of the variation is explained by these variables.
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PMID:Pneumoconiosis risk assessment in agate workers--multiple logistic model. 260 50

For the period from 1973 to the end of 1986, 70,656 data sets on occupational preventive medical examinations in employees exposed occupationally to asbestos dust (G 1.2) were made available to us by the Central Registry for Employees Exposed to Asbestos Dust (ZAS). On the basis of this data, an analysis of asbestosis risk was to be made in relation to specific areas of work, taking into consideration the beginning and duration of exposure. Proceedings for declaratory appraisal in accordance with occupational disease no. 4103 were instituted in 1760 cases in the report period. In accordance with the character of the available data, the X-ray findings in the lungs were available from the persons investigated as parameters of possible asbestosis risk on the basis of coding consistent with the International Pneumoconiosis Classification (ILO U/C 1971 and/or ILO 1980 West Germany). The major result of the statistical analyses on the mainframe macrocomputer of the University of Erlangen-Nuremberg was that the relatively highest risk of asbestosis was present in persons whose exposure began before 1955. On the other hand, with increasing duration of exposure, an unequivocal rise of the asbestosis risk could not be detected on the basis of the overall population. In relation to the individual fields of work, the relatively highest risk of asbestosis was shown to be in the asbestos textile and paper industry, as well as in the asbestos cement industry. No detectable risk of asbestosis was present in the fields of mining, traffic and health service and for women in the industrial sectors of building material, gas and water, catering trade, building, commerce as well as banking and insurance. Accordingly, it can be assumed that certain fields of work are or were exposed to such a small extent or not at all that a risk of asbestosis which is relevant in terms of occupational medicine is no longer to be assumed or was not to be assumed. This applies above all to certain work in the frictional coating (brake lining) and asbestos paper industry. Furthermore, the analysis of the data material did not provide any unequivocal indications that inhalative smoking habits have a negative effect on the risk of asbestosis. In principle, it can be stated that the occupational preventive medical investigations according to G 1.2 are effective.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Health hazards from fine asbestos dusts. An analysis of 70,656 occupational preventive medical investigations from 1973 to the end of 1986. 280 71

It is generally accepted that fibrotic lung diseases are mediated by macrophage-derived cytokines. We investigated the release of the monokine tumor necrosis factor-alpha (TNF) from blood monocytes in a group of 66 coal miners and 12 non-dust-exposed individuals. Twenty-seven miners had simple Coal Workers' Pneumoconiosis (CWP). Control miners (n = 39) were matched with respect to age, years underground, and smoking. Monocytes were assayed for TNF release, spontaneously or in response to soluble (endotoxin) or particulate (coal mine dust, silica) stimulation. TNF was measured with a TNF-specific ELISA. Monocytes of all subjects responded to stimulants by the release of TNF. Dust-exposed controls' monocytes revealed higher TNF release as compared to normal controls. The greatest discriminator between control miners and cases (CWP) was coal mine dust-induced TNF release. Interestingly, the largest difference was observed between controls and those cases with a small number of opacities (0/1, 1/0, 1/1, and 1/2), giving an odds ratio of 6.3 to find an individual with a "high" dust-induced TNF release in the patient group.
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PMID:Spontaneous and stimulated release of tumor necrosis factor-alpha (TNF) from blood monocytes of miners with coal workers' pneumoconiosis. 284 51

Dust dose and composition do not appear to account wholly for changes in the prevalence of coal workers' pneumoconiosis in Europe. In certain coal pits high progression evidently occurred with relatively low dust exposure or vice versa, whereas progression in relation to dust levels might be variable. Exceptionally high quartz concentrations occur in coal mine dust when pneumoconiosis may progress with unusual rapidity. Under such circumstances lesions resembling silicotic nodules may be found, but with the customarily lower levels of quartz the pathological features assume the form characteristic of coal workers. Morphological changes in relation to dust content of human and animal lungs, as well as cellular behavior, have not accounted completely for the epidemiological findings. Considering all the pathological evidence helps explain the pathogenesis of pneumoconiosis and vagaries of progression. The origin of progressive massive fibrosis cannot be explained simply in terms of dust burden or immunological features, and the role of an infective factor cannot be dismissed. Moreover, lipid secretion by alveolar epithelium introduces a new element that could affect the development of simple and complicated pneumoconiosis. In vitro, cytotoxicity appeared to be too variable for predictive purposes, though direct assay of fibrogenicity using the macrophage fibrogenic factor suggested that dust dose was more important than dust composition. Assessing individual susceptibility presents serious obstacles.
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PMID:Prevalence and pathogenesis of pneumoconiosis in coal workers. 306 Mar 52

A sample of men working in the British coal industry in the 1950s has been followed up and examined 22 years later. The relations between lung function and individual cumulative exposure to respirable dust have been studied in 1867 men who were still working in the industry at the time of follow up and 2192 men who had left. Levels of forced expired volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio at follow up were found to be inversely related to exposure to respirable dust after allowing for other factors, even in men without pneumoconiosis. The magnitude of this estimated effect was equivalent to a loss of 228 ml FEV1 in response to an exposure of 300 gh/m3, a moderately high exposure for this group. Ex-miners aged under 65 had worse lung function than miners on average, suggesting that ill health had encouraged some of these men to leave the industry. Whereas a more severe response to dust exposure among ex-miners under 65 was suggested, this difference could easily have arisen by chance. The presence of symptoms of chronic bronchitis was associated with reduced levels of lung function, however, and, additionally, ex-miners under 65 with chronic bronchitis showed a more severe response of the FVC to dust exposure than miners without these symptoms. Among these ex-miners with chronic bronchitis a small group of men who had taken other jobs showed a much more severe effect of dust exposure on their lung function than the average, likely in heavily exposed men to contribute importantly to disability. Men in this group who had given up smoking showed and even more severe effect of dust exposure, equivalent to a loss of 940 ml FEV1 in response to an exposure of 300 gh/m3. These results indicate that exposure to respirable dust can occasionally cause severe respiratory impairment in the absence of progressive massive fibrosis. Dust exposure was related to a parallel reduction of FEV1 and FVC, implying that the pathology of dust induced lung damage differs form that induced by smoking. This pattern of abnormality was shown by some non-smokers, whereas smokers and ex-smokers apparently severely affected by dust showed a classic obstructive pattern of abnormality with pronounced reduction of the FEV1/FVC ratio.
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PMID:Relation between dust exposure and lung function in miners and ex-miners. 370 68

The different sequelae of lung and pleura resulting from the inhalation of asbestos dust are discussed in detail, taking into consideration the improvements in dust-control measures. The use of Lung Dust Separation and Investigation and Radiological Classification of Pneumoconioses (ILO 1980) with regard to diagnostics is critically reviewed. Certain problems of compensation for asbestos-induced neoplasms are pointed out with special reference to the regulations of the Federal Republic of Germany.
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PMID:[Morphology and roentgenology of asbestosis]. 397 84

Pneumoconioses produced by intratracheal applications of various dusts (quartz, coal, cadmium and lead sulfide) in rats were investigated by electron microscopy in order to follow the pathway of the dust particles from the alveoli into the pulmonary interstitium. As postulated by Spencer in 1977 on the basis of light microscopic investigations, the dust particles produce necroses of the alveolar septae ('alveolar ulcers'). TWo forms of necroses appear to occur: with a less severe dust exposure, individual pneumocytes and their basement membrane are destroyed by dust particles. Dust-laden, macrophages are deposited here which are displaced into the stroma after re-epithelization of the alveolar defect. On the other hand, with massive dust exposure, almost all pneumocytes of the affected alveoli become necrotic. The affected alveoli collapse and are replaced by connective tissue, so that the dust is situated in the connective tissue stroma. A transcellular penetration of the dust particles into the pulmonary interstitium or an immigration of dust-laden macrophages into the pulmonary stroma through the intercellular junctions of intact pneumocytes was not observed in any of the pneumoconiosis models.
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PMID:Electron microscopic investigations on dust penetration into the pulmonary interstitium in experimental pneumoconioses. 710 Jun 60


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