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Query: UMLS:C0037116 (silicosis)
 1,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The trade of pottery was practised already in antiquity. This very old art had culmination points of its artistic performance in several epochs. The ornamentation of the body of the ware by glazing came in use in Germany (Rhine Territory) in the 12th century. The raw material applied were plastic argils baking with colour, at that time just as now. After dressing with water the plastic material was shaped to the most different objects. It was done, either off-hand or by the aid of the potter's wheel. Dust is developing when the argils are crushed representing a danger to health if technical control of the dust is not made effective. Wearing respiratory protection apparatuses is sufficient in shorttime work but must be regularly checked according to our experience. In the production of earthenware relatively high concentrations of dust occur only temporarily, but in very few cases they may cause silicosis. Among the 35 cases of silicosis in potters observed by the different special services for prophylaxis and control of dust 25 developed by exposition in plants of the GDR. 8 of the 10 diseased persons with exposition in plants outside the GDR had worked as potters in Bunzau (Silesia). The danger of silicosis is by for less than in the porcelain industry; it can be prevented by keeping clean the places of employment. This low danger is proven also by the very long exposition time of 30--40 years in average.
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PMID:[Danger of silicosis in pottery (author's transl)]. 71 91

Six cases of silicosis in workers involved in the processing of semiprecious gem stones have been seen in our clinic since 1976. They had been employed as stone sculptors in lapidaries where they processed tiger's-eye, rose quartz, amethyst, quartz crystal, and a variety of other locally occurring semiprecious stones. In five of the cases, exposure was in small and poorly regulated lapidaries without specific dust control measures. The sixth was detected during the course of a health and hygiene survey (including dust sampling) that was conducted in one of two lapidaries still operating in our area. Progressive massive fibrosis (PMF) or accelerated silicosis was noted in four of the six cases, three of whom had progression of their disease after cessation of exposure. With the development of PMF, the initial restrictive pulmonary function abnormalities were followed by steadily worsening airflow obstruction. Lung biopsies confirmed silicosis in three cases. Tuberculosis was confirmed in two cases and suspected and treated in a third. Workmen's Compensation was awarded in five cases. The survey confirmed that in semiprecious gem stone processing, the risk of silicosis appears to be confined to stone sculptors. Tried and proven techniques of general and local exhaust ventilation combined with water or oil to control dust at source were capable of effectively reducing dust emission to acceptable levels.
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PMID:Silicosis among gemstone workers in South Africa: tiger's-eye pneumoconiosis. 129 May 52

Pathohistological findings are playing an important role in the advice of toxic organ damages. After presentation of some details about the frequency of toxic organ damages, the pathways of toxic agents in the organism are discussed. In cells toxic damage may induce cell necrosis, functional disturbance, inhibition of cell proliferation or malignant transformation; in extracellular structures it may lead to degradation phenomena in the connective tissue matrix. As demonstrated in example of calciphylaxis, a combination of different noxes may not only add but even potentiate the effects of the single noxes. In intracellular reparation processes the lysosomal system is involved. In case of necrosis regeneration is possible in most kinds of tissues, if connective tissue rails are preserved. Otherwise an irreversible reparative fibrotic alteration of organ structure is induced which develops according to particular general and schematic rules. As mostly character and course of the tissue reaction is unspecific, pathohistological findings do not enable conclusions on the type of inducing toxic agent. The following presentation of some examples of toxic damages with pathognomonic histological appearance deals with asbestosis, silicosis, chloroquine-induced cardiomyopathy, aluminum-induced osteopathy and a recently described liver cirrhosis in early childhood induced by copper-containing drinking water. Some limits of traditional pathohistological evaluation of toxic organ damages have been overcome by application of new morphological techniques. Own investigations revealed that the immunocytochemical demonstration of the C5b-9-complement complex enables a better and earlier detection of irreversibly damaged cells. Discrimination of toxic and virus-induced tissue damage is facilitated by the technique of in-situ-hybridization. Sometimes a specific recognition and localization of toxic agents is achieved by X-ray microanalysis, electron-spectroscopic imaging (= ESI) resp. laser microprobe mass spectrometry (= LAMMA); comparing these techniques X-Ray microanalysis and ESI, both, enable specific identification of chemical elements, while LAMMA, in addition, offers some information about the involved molecules and isotopes.
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PMID:[Toxic organic damage]. 265 Apr 56

Electron spin resonance (ESR) spectrum of the hydroxyl (.OH) radical spin adduct with the spin trap 5,5-dimethyl-1-pyrroline-N-oxide has been obtained in suspensions of freshly ground quartz particles. The concentration of the spin adduct (and hence of the .OH radicals) increases with the amount of grinding. The dust's potential for the generation of the .OH radicals is maximum when fresh (i.e., immediately after grinding) and decreases to 50% in about a day on storage in air. Studies involving metal chelates indicate that the .OH radical formation involves mainly the silica surface and H2O rather than the Fenton reaction. The results suggest that hydroxyl radical reaction(s) could be important in the lipid peroxidation and fibrogenicity by quartz dust, particularly in acute silicosis.
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PMID:ESR evidence for the hydroxyl radical formation in aqueous suspension of quartz particles and its possible significance to lipid peroxidation in silicosis. 284 12

The anti-oxidant phenotype was determined in red blood cell haemolysates of 62 healthy elderly persons (Mean age: 56) and a number of male silicosis patients (Mean age: 65, n = 19). Moreover, analysis of water-soluble fluorescent substances in plasma, recently introduced as a new test for in vivo lipid-peroxidation, was included. Within the control group results were analyzed on the effect of smoking (no effect), use of medication (lowered GSH-content) or gender (no differences apart from haemoglobin content). No simple relationship between any pair of the measured parameters in erythrocytes was present. When comparing the male control persons with the silicosis group a significantly higher red blood cell GSH-level was observed in the latter. Moreover, some factors of the anti-oxidant system are strongly correlated in the diseased, but not in the healthy subjects.
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PMID:Red blood cell anti-oxidant parameters in healthy elderly subjects versus silicosis patients. 350 25

The anti-oxidant phenotype was determined in red blood cells and plasma of a group of male control subjects (n = 48) and a number of silicosis patients (n = 19). Haemoglobin, reduced and oxidized glutathione, glutathione peroxidase and superoxide dismutase were determined in red blood cells after haemolysis. In plasma, water soluble fluorescent substances were determined as a measure of in vivo lipid peroxidation. A significant increase in red blood cell glutathione was observed in silicosis patients. Moreover, some factors of the anti-oxidant system are strongly correlated in the diseased, but not in the healthy subjects. We hypothesize that individual susceptibility differences towards the development of silicosis after prolonged inhalation of silica is associated with a genetically controlled anti-oxidant phenotype.
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PMID:Red blood cell anti-oxidant parameters in silicosis. 377 Sep 63

Inhalation of crystalline silica causes fibrotic pulmonary disease. The lung pathology of silicosis is well characterized and predictable, but the initial patterns of particle deposition and translocation are unknown. Scanning electron microscopy and backscattered electron imaging were utilized to quantify silica particle distribution in the distal air spaces of rats following a three-hour exposure to silica dust at a concentration of 100mg/m3. Lungs were perfused through the vasculature with 2% Karnovsky's fixative at a pressure of 15cm of water for 30 minutes. Blocks of tissue were dissected from five predetermined regions of the left lung and critical point dried. Mounted blocks were further dissected to reveal terminal bronchioles and their attached alveolar ducts. The tissue was sputter-coated with gold. Silica particles were visualized on the alveolar duct surfaces, then counted using negative backscattered electron imaging. The precise area of alveolar duct surfaces was calculated by using a standard magnification of 10,000X and a grid of 64cm2 over the viewing cathode ray tube. Thus, quantitation of silica particles could be expressed as number of particles per square micron. Our data show that there were fewer particles on the alveolar duct surfaces and in alveolar spaces of animals 8 hours after exposure when compared with animals 3 hours post-exposure.
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PMID:Use of backscattered electron imaging to quantify the distribution of inhaled crystalline silica. 625 39

This article reports the author's field investigation into the effects of economic development on environmental health in Rwanda. It was hypothesized that the placement of environmentally hazardous industry would not be given meaningful consideration in the course of the introduction of advanced technolgies. Rwanda is a poor, overpopulated country with a subsistence economy whose development has been largely stimulated by international aid projects. Site visits to industrial and agricultural processing facilities revealed significant perticide exposure, lack of respiratory protection from mineral dusts, respiratory symptoms from organic dusts, and sources of heavy metal contamination. The Rwanda experience suggests that 2 major economic activities are most likely to have a major environmental impact in developing countries: exploitation of natural resources and agricultural commercialization. Mining activity, for example, has produced both chronic diseases such as silicosis and general environmental degradation such as runoff to surface water sources. The use of agricultural petrochemicals is likely to produce acute and chronic poisoning among peasant farmers with little access to adequate health care. Even the smallest industrial installation can have widespread impact if the proper infrastructure for waste treatment is not established. In addition, the technology required to test for environmental contamination is beyond the scope of Third World economies. Hazardous environmental exposures may have amplified or additive effects in the presence of compromised baseline health and sanitary conditions and inadequate health care facilities. It is concluded that Rwanda represents an example of the failure of economic developers to consider the far-reaching effects of changes in the work environment, introduction of new agricultural techniques, alteration of the rural-urban equilibrium, and degradation of the air, water, and soil quality. There is a need to adapt models of environmental protection in industrialized developed countries to developing economies.
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PMID:Environmental health and development in a developing country: Rwanda, a case study. 647 Jan 35

Although most were unknown a few years ago, present evidence indicates that at least 25 trace elements have some pertinence to health. Unlike vitamins, they cannot be synthesized. Some trace elements are now considered important only because of their harmful effects but traces of them may be essential. Zinc is especially important during puberty, pregnancy and menopause and is related to protein metabolism. Both fluoride and cadmium accumulate in the body year after year. Cadmium is positively correlated with several chronic diseases, especially hypertension. It is obtained from smoking and drinking soft water. Silicon, generally associated with silicosis, may be necessary for healthy bone and connective tissue. Chromium, believed to be the glucose tolerance factor, is obtained from brewer's yeast, spices, and whole wheat products. Copper deficiency may be implicated in a wide range of cardiovascular and blood related disorders. Either marginal deficiencies or slight excesses of most trace elements are harmful. Nurses should instruct patients to avoid highly refined foods, fad diets, or synthetic and fabricated foods. A well balanced and varied diet is the best safeguard against trace element excesses or deficiencies.
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PMID:Trace elements: implications for nursing. 689 39

Exposure to crystalline silica can result in damage to the lung parenchyma and scarring that can lead to fibrosis. Pulmonary damage may be the direct consequence of toxic interaction between quartz particles and cell membranes, or it may be due to silica-induced production of oxidant species by pulmonary phagocytes, that in turn overwhelms pulmonary antioxidant systems and causes lung injury. Data indicate that grinding or fracturing quartz particles breaks Si-O bonds and generates .Si and Si-O. radicals on the surface of the cleavage planes. Upon contact with water, these silica-based radicals can generate hydroxyl radicals (.OH). These surface radicals decay as fractured silica dust is aged. Freshly fractured quartz is significantly more potent than aged silica in directly causing lipid peroxidation, membrane damage, and cell death. Furthermore, freshly ground silica is a more potent stimulant of alveolar macrophages than aged silica. This silica-induced activation results in the production of superoxide (O2-), hydrogen peroxide (H2O2), nitric oxide (NO.), and other oxidant species that can damage lung cells. Tetrandrine, an herbal medicine that exhibits antifibrotic activity in rat models of silicosis, effectively blocks the ability of quartz to stimulate oxidant release from pulmonary phagocytes.
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PMID:Generation of oxygen radicals and mechanisms of injury prevention. 770 9


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