The association between occupational asbestos exposure and the subsequent development of malignant mesothelioma of pleura is well recognized. We analyzed an asbestos body by energy dispersive X-ray analyser in a case of malignant mesothelioma of pleura who had a history of asbestos exposure 30 years ago. In transmission electron microscope, the asbestos body was composed of a core of refractile thin asbestos fiber bundle and beaded masses of electron-dense iron and protein complex. The core fibers were analyzed as an amphibole type crocidolite fiber [(Na2Fe3Fe2(Si8O22)(OH)2] which composed of high content of silicon, iron and sodium.
Asbestos* ; Asbestos, Crocidolite ; Iron ; Mesothelioma* ; Pleura ; Silicon ; Sodium

OBJECTIVES: The objective of this study was to examine the prevalence of respiratory symptoms, asbestos-related chest radiograph abnormalities and abnormal pulmonary function tests among former asbestos textile factory workers and to reveal the related factors of these abnormal findings. METHODS: There were 119 persons former asbestos textile industry workers registered in the health management pocketbook. Of 97 retired asbestos workers living in Busan, Yangsan and Gimhae, 63(64.9%) retired asbestos workers were enrolled into this study. The researchers administered questionnaires, and performed chest radiographys, and pulmonary function tests (PFT) on participants. The survey was conducted during July, 2009. RESULTS: Among former workers the number of lung fibrosis, pleural plaque, pleural calcification, and pleural thickening was 13(20.6%), 6(9.5%), 3(4.8%), and 1(1.6%) in chest radiography, respectively. Asbestos-related disorders and abnormal pulmonary function test groups had higher prevalence of respiratory symptoms. Participants with crocidolite exposure or long latency period had higher asbestos-related x-ray findings or abnormal PFT findings. CONCLUSIONS: Former asbestos textile workers had a high rate of asbestos-related disorders. Workers with crocidolite exposure or having had a longer latency period had more asbestos-related disorders. Because gradual increase of asbestos related disorders among high asbestos exposure group is expected, sustained, and intensive management is needed for these former workers.
Asbestos ; Asbestos, Crocidolite ; Fibrosis ; Humans ; Latency Period (Psychology) ; Lung ; Prevalence ; Questionnaires ; Respiratory Function Tests ; Retirement ; Textile Industry ; Textiles ; Thorax

Asbestos, Crocidolite ; adverse effects ; Female ; Humans ; Mesothelioma ; etiology ; Middle Aged ; Pleural Neoplasms ; etiology

OBJECTIVETo analyze asbestos exposure level between 1984 and 2010 in a district of malignant mesothelioma with clustering incidence in Zhejiang Province, in order to improve the recognizing and early diagnosis of malignant mesothelioma, protect the health of workers.

METHODSMonitoring data of total asbestos dust concentration in the air of workplace from 1984 to 2010 in asbestos textile enterprises, family hand spinning operation, brake production, and asbestos board production in Zhejiang Province were collected in the local CDC. A total of 766 TWA copies of mass concentration were collected, and 1233 copies of MAC data. Asbestos mass concentration and fibre counting concentration of 29 points of family hand spinning operation were parallel determinated in the same time and the same sampling point. Raw asesbtos materials and dust composition of local asbestos processing corporations were collected and analyzed using X-ray diffraction method.

RESULTSRaw materials of asbestos used between 1984 and 2010 in this area were chrysotile from Sichuan, Qinghai, Xinjiang, Russia, Zimbabwe, and some were mixed with SiO2, CaCO3 and other impurities. Raw materials used in asbestos board production were blue asbestos. Dust concentration between 1960s and 1980s in asbestos processing plants far exceeded the national standard. After then the dust concentration decreased significantly, but still higher than the national standard. 95.2% of air dust concentrations in the workplaces of asbestos factories exceeded the standard, and dust concentrations of workplaces of raw material, spinning, weaving, carding and labor insurance were above 90% in which carding work had the highest median concentration. 37.9% of dust mass concentrations in hand spinning work exceeded the standard where textile machinery side had the highest value. Beating job in asbestos board manufacturing and grinding job in brake production had higher concentrations.

CONCLUSIONSMost of production technologies in asbestos processing industry exceed the standard level, indicating that the workers were at risk for malignant mesothelioma and other asbestos related diseases, which should draw high attention.

Asbestos ; analysis ; Asbestos, Crocidolite ; analysis ; Asbestos, Serpentine ; analysis ; China ; epidemiology ; Dust ; analysis ; Humans ; Lung Neoplasms ; epidemiology ; Mesothelioma ; epidemiology ; Occupational Diseases ; epidemiology ; Silicon Dioxide ; analysis ; Workplace

Asbestos is a fibrous silicate that was widely used because of its heat resistance properties. Asbestos exposure affects workers involved in mining or processing asbestos or those involved in the use of asbestos in the shipbuilding, construction, and textile- and insulation-manufacturing industries. There are three commonly available types of asbestos; chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). All three have been associated with cancerous and non-cancerous lung disease. Asbestos-related diseases includes benign pleural effusion, pleural plaques, diffuse pleural thickening (a non-malignant disease affecting the lung lining), rounded atelectasis, asbestosis (a scarring of the lung tissue caused by asbestos), mesothelioma and lung cancer. Mesothelioma is a malignant pleural or peritoneal tumor that rarely occurs in patients who have not been exposed to asbestos. The latency period of most asbestos-related disease is 10 years or longer, asbestos-related disease remains an important public health issue. The clinical diagnosis of asbestos related diseases should be based on a detailed interview of the patient and occupational data on asbestos exposure, signs and symptoms, radiological and lung physiological findings and selected cytological, histological and other laboratory studies. Radiological imaging plays a pivotal role in the diagnosis and management of asbestos-related disease.
Asbestos ; Asbestos, Amosite ; Asbestos, Crocidolite ; Asbestos, Serpentine ; Asbestosis ; Cicatrix ; Compensation and Redress ; Hot Temperature ; Humans ; Latency Period (Psychology) ; Lung ; Lung Diseases ; Lung Neoplasms ; Mesothelioma ; Mining ; Pleural Effusion ; Public Health ; Pulmonary Atelectasis ; Silicates ; Workers' Compensation

Asbestosis is a chronic inflammatory disorder of lower respiratory tract in which alveolar wall are progressively thickened by a fibrotic process. Fibrotic process characterized by an expansion of fibroblast and collagenous extracellular matrix secreted from this fibroblast. Alveolar macrophage is believed to be a primary target cell and major participant in the evolution of lung fibrosis after asbestos inhalation. Alveolar macrophage are known to release a variety of substance that induce tissue damage and stimulate inflammatory cells and fibroblast. Macrophage also release a variety of metabolite of arachidonic acid. Of these, PGE(2) is known to suppress fibroblast proliferation. Asbestos may be a very effective stimulus for fibroblasts without triggering the relase of PGE(2). To assess the fibrogenic properties of asbestos according to kind and dosage of asbestos and the ability of PGE(2) to suppress the proliferation of fibroblast, alveolar macrophages cultured with crocidolite, amosite and chrysotile in presence or absence of PGE(2)10(-5)M. At 24 hours after alveolar macrophage cultured with various stimuli, the released fibronectin and TNF-alpha was measured. Viability of alveolar macrophages was observed and growth promoting activity of macrphage supernatant to fibroblasts was quantified. The results were as follows; 1. The viability of alveoair macrophages stimulated with asbestos fiber was markedly decreased compared with control group except chrysotile 10 microgram group. Crocidolite and amosite were more cytotoxic than chrysotile. 2. All of asbestos augmented fibronectin production in concentration dependent fashion. 3. There was a significant positive correlation between TNF-alpha production in supernatant and fiber concentration. 4. Supernatant from alveolar macrophages cultured with asbestos were inducible a significant increase in fibroblast proliferation. 5. Incubation of avieolar macrophages with asbestos in the presence of PGE(2) resulted in significant decrease of TNF-alpha production in supernant. 6. Supernatant from alveolar macrophages cultured with asbestos were inducible a: sig nificnat decrease in fibroblast proliferation when PGE(2) was added. The result of this study strongly suggested that crocidolite and amosite were more cytotoxic and fibrogenic and exogenous PGE(2) suppressed fibroblast proliferation following exposed to asbestos.
Animals ; Arachidonic Acid ; Asbestos* ; Asbestos, Amosite ; Asbestos, Crocidolite ; Asbestos, Serpentine ; Asbestosis ; Collagen ; Extracellular Matrix ; Fibroblasts* ; Fibronectins ; Fibrosis ; Inhalation ; Lung ; Macrophages ; Macrophages, Alveolar ; Rats* ; Respiratory System ; Tumor Necrosis Factor-alpha

The inhalation of crystalline silica results in the production of reactive oxygen species(ROS). Among these ROS, hydroxyl radical( OH) is believed to be the most reactive one. OH is generated in reaction between superoxide and hydrogen peroxide catalyzed by transition metal, especially iron. Therefore iron should be important in the bioactivity of crystalline silica. Desferrioxamine, a iron chelator, may be protective in silica-induced pulmonary reaction. To test this assumption we investigated the protective effect of desferrioxamine on lipid peroxidation of cell membrane, cytotoxicity, production of proinflammatory and chemotactic cytokine and fibroblast proliferation by crystalline silica in vitro model. The results were as follows: 1. Fenton activity of silica and asbestos was significantly higher than that of control. Fenton activity in crocidolite was higher than silica at the same dose. This result correlated with iron content of dust. Fenton activity of silica and crocidolite was decreased by preincubation of silica with desferrioxamine. 2. Silica induced a dose-dependent increase of MIDA concentration in lung epithelial cell lysate dose dependently. Marked decrease of MDA was observed in desferrioxaminetreated silica group compared with untreated group. 3. As concentration of stimulated silica, silica?induced cytotoxicity was increased. There was significant decrease of cytotoxicity in desferrioxamine?treated silica group compared with untreated group. 4. a-quartz augmented the production of TNF-a and IL-8 from A549 cell. While desferrioxa-mine suppressed the release of cytokines. 5. Supernatant of silica-cocultured A549 cell induced a significant proliferation of fibroblast, which desferrioxaime blocked this proliferation. From these result, we concluded that desferrioxamine has a protective effect on silica induced pulmonary reaction.
Asbestos ; Asbestos, Crocidolite ; Cell Membrane ; Crystallins ; Cytokines ; Deferoxamine* ; Dust ; Epithelial Cells ; Fibroblasts* ; Hydrogen Peroxide ; Inhalation ; Interleukin-8 ; Iron ; Lipid Peroxidation ; Lung ; Oxygen ; Silicon Dioxide ; Superoxides

Asbestos exposure may cause asbestosis, pleural plaques and benign pleural disease, and may give a predisposition to malignant mesothelioma in occupationally exposed workers. This case report describes a 50-year-old man, dying from histologically confirmed, diffuse, malignant mesothelioma after asbestos exposure. As a young man, he had been exposed at the workplace to crocidolite for 2 years, but he had no other known history of occupational or environmental asbestos exposure. The patient presented with chest pain and general weakness. Computed tomography showed bilateral irregular pleural thickening along both lower lateral chest walls and a low attenuating mass in the anterior portion of the left lobe. Pathological examinations revealed that it was an epithelial type with tubulopapillary structures and it tested immunohistochemically positive for antibodies against cytokeratin, calretinin and vimentin. The patient was started on chemotherapy but he died to the disease at ten months after the first onset of the symptoms. Mesothelioma is a rare neoplasm in the general population. Nevertheless, the importance of close medical surveillance of the high-risk population is emphasized, because of increased asbestos exposure.
Antibodies ; Asbestos ; Asbestos, Crocidolite* ; Asbestosis ; Calbindin 2 ; Chest Pain ; Drug Therapy ; Humans ; Keratins ; Mesothelioma* ; Middle Aged ; Occupations ; Pleural Diseases ; Thorax ; Vimentin

OBJECTIVETo explore the risk factors for mesothelioma so as to provide epidemiological evidences for prevention of this disease and for further study of its pathogenesis.

METHODSA 1:1 paired case-control study was carried out in which asbestos exposure, life style and histories of cancer in first-degree relatives of 23 patients who had mesothelioma were compared with those of controls.

RESULTSThe mean age of patients was 57.96 years with a latency period of 52 years. There were no significant differences in mean exposure age, mean exposure periods, and smoking, drinking habits between patients and controls. The mean cumulative exposure of patients was 37.2 x 10(5) f, which was significantly higher than that of controls (32.3 x 10(5) f, P = 0.005). The odds ratio increased with the cumulative exposure. The percentage of cancer in first-degree relative of patients (26.1%) was significantly higher than that of controls [(4.4%, P < 0.05), OR = 7.75 (95% CI: 0.85-71.43)].

CONCLUSIONThere may be a dose-response relationship between mesothelioma and asbestos exposure. A family history of cancer may be a risk factor for mesothelioma, or may indicate an increased susceptibility to mesothelioma under the same level of asbestos exposure.

Asbestos, Crocidolite ; adverse effects ; Case-Control Studies ; Environmental Exposure ; Family ; Humans ; Life Style ; Mesothelioma ; etiology ; genetics ; Middle Aged ; Pleural Neoplasms ; etiology ; genetics ; Risk Factors

Exposure to various particles and fibers can result in lung inflammation that may progress to fibrosis, even lung cancer for which there is no effective clinical treatment now. The mechanism involved in pulmonary injury has not been well defined ; however, most current evidence implicates a central role for alveolar macrophages (AM) in this process. Also apoptosis or programmed cell death is regarded as a mechanism which is related with the pulmonary fibrosis. We propose that the cytotoxic potential of various particles may be evaluated by measuring lactic dehydrogenase (LDH) from particle co-cultured supernatant and theses particles may induce the characteristics of apoptosis, DNA ladder. We analyzed rat AM culture media which was incubated for 3 days with the same concentration (10 ug/ml) of silica(Si), chrysotile(Ch), crocidolite(Cr), ceramic fiber(CF), rock wool(RW) and glass wool (GW). And each particles (50ug/cm(2)) was incubated with A549 (pneumocyte in tracheal epithelium) cell lines for 24 hours to confirm the DNA ladder. Additionally, silica induced apoptosis in vivo was confirmed by electromicroscopic observation. The results were as follows; 1. Silica, asbestos and man-made mineral fibers (MMMF) co-cultured with AM showed the increase of LDH significantly with the time interval of 24, 48, 72 hours except for ceramic fiber in 48 and 72 hours and crocidolite in 72 hours. 2. Silica, asbestos and man-made mineral fibers (CF, GF) showed the characteristics of apoptosis, DNA ladder, which was induced by incubating A549 cell with each particles for 24 hours in vitro 3. Apoptotic alveolar macrophage was observed the findings of zeiosis (membrane blebbing), condensation of nuclear chromosome and many vacuoles in cytoplasm, electomicroscopically.
Animals ; Apoptosis* ; Asbestos* ; Asbestos, Crocidolite ; Cell Death ; Cell Line ; Ceramics ; Culture Media ; Cytoplasm ; DNA ; Fibrosis ; Glass ; Lung Injury ; Lung Neoplasms ; Macrophages, Alveolar ; Mineral Fibers* ; Oxidoreductases ; Pneumonia ; Pulmonary Fibrosis ; Rats ; Silicon Dioxide* ; Vacuoles ; Wool