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

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

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

The aim of this paper is to clarify the mineral origin of traditional Chinese medicine (TCM) Yangqishi and Yinqishi and guide identification of the both, by X-ray diffraction (XRD) Fourier patterns. Morphological identification and conventional physical and chemical analysis wee used to identify 22 batches of Yangqishi and Yinqishi. It used XRD Fourier patterns which has been collected from sample powders to analyze phase composition. It has been found experimentally that the mineral origin of Yinqishi is Talc schist and the mineral origin of Yangqishi is tremolite and actinolite. The results also showed that the method using XRD can get not only an accurate but also rapid identification of Yangqishi and Yinqishi. There are many differences in medicinal properties, efficacy, indications and composition of Yangqishi and Yinqishi, so be careful not to mix them up.
Asbestos, Amphibole ; chemistry ; Drugs, Chinese Herbal ; chemistry ; X-Ray Diffraction

The present review summarizes the results of several follow-up studies assessing an asbestos product manufacturing plant in Chongqing, China, and discusses three controversial issues related to the carcinogenicity of asbestos. The first issue is the amphibole hypothesis, which asserts that the carcinogenicity of asbestos is limited to amphiboles, such as crocidolite, but not serpentines, such as chrysotile. However, considering the possible multiple component of asbestos carcinogenicity in the presence of tobacco smoke or other carcinogens, chrysotile cannot be regarded as non-carcinogenic. Additionally, in a practical sense, it is not possible to assume "pure" chrysotile due to its ubiquitous contamination with tremolite, which is a type of amphibole. Thus, as the International Agency for Research on Cancer (IARC) assessed, all forms of asbestos including chrysotile should be regarded carcinogenic to humans (Group 1). The second issue is the chrysotile/tremolite paradox, which is a phenomenon involving predominant levels of tremolite in the lung tissues of individuals who worked in locations with negligible levels of tremolite due to the exclusive use of chrysotile. Four possible mechanisms to explain this paradox have been proposed but this phenomenon does not support the claim that amphibole is inert. The final issue discussed is the textile mystery, i.e., the higher incidence of cancer in asbestos textile plants compared to asbestos mines where the same asbestos was produced and the exposure levels were comparable. This phenomenon was first reported in North America followed by UK and then in the present observations from China. Previously, levels of fiber exposure were calculated using a universal converting coefficient to estimate the mass concentration versus fiber concentration. However, parallel measurements of fiber and mass concentrations in the workplace and exposed air indicated that there are wide variations in the fiber/mass ratio, which unjustifies the universal conversion. It is possible that contamination by airborne non-fibrous particles in mines with mass fiber conversion led to the overestimation of fiber concentrations and resulted in the textile mystery. Although the use and manufacturing of asbestos has been banned in Japan, more than 10 million tons of asbestos had been imported and the majority remains in existing buildings. Thus, efforts to control asbestos exposure should be continued.
Asbestos ; classification ; toxicity ; Asbestos, Amphibole ; toxicity ; Asbestos, Serpentine ; toxicity ; Carcinogens ; China ; Follow-Up Studies ; Humans ; Lung Neoplasms ; chemically induced ; epidemiology ; Manufacturing and Industrial Facilities ; statistics & numerical data ; Mining ; statistics & numerical data ; Occupational Diseases ; epidemiology ; Occupational Exposure ; adverse effects ; Textiles ; Tobacco Smoking ; epidemiology

The pulmonary recruitment and activation of inflammatory cells, in particular, neutrophils is thought to contribute to lung injury resulting from dust exposure. MIP-2 (macrophage inflammatory protein-2) which is a member of C-X-C chemokine plays a key role in neutrophil recruitment to sites of tissue injury. Especially, mineral fiber induced pulmonary response is as a model for the neutrophil recruitment. Therefore, we evaluated the distribution of MIP-2 expression in lung tissue of mineral fiber exposed rat using immunohistochemical study and the relationship between degree of inflammation of lower respiratory tract and MIP-2 expression. Total cell counts in bronchoalveolar lavage (BAL) fluid in mineral fiber-exposed group were markedly increased compared with each control group even not in ceramic fiber group. Number of neutrophil in BAL fluid in mineral fiber-exposed group were markedly increased compared with each control group until 4th week but except ceramic fiber group. In chrysotile group, number of neutrophil in BAL fluid were markedly increased compared with control group at 8th week. Lung tissue instilled with all kinds of mineral fibers showed remarkable developments of bronchus associated lymphoid tissue (BALT) and small multiple granulomas but not for ceramic fiber group. In chrysotile group, multiple granuloma and inflammatory change were more profuse response compared with other groups. MIP-2 was predominently expresses in epithelial cells of bronchioles and bronchus and was express also found in macrophages with lung section at 1 week after fiber instillation. Small amount of epithelial cell associated MIP-2 was present in chrysotile at 8 week group. But MIP-2 was not seen in epithelial cells and macrophages in the lung tissue instilled with crocidolite, ceramic fiber and glass fiber at 8 weeks. Our finding suggest that MIP-2 is predominantly expressed in bronchial epithelial cells of lung from mineral fiber-exposed rat and correlated with inflammatory cell, especially neutrophil, recruitment and tissue reaction. And we documented that MIP-2 expression and neutrophil recruitment in man-made vitreous fiber-exposed rat, especially glass fiber, less than chrysotile.
Animals ; Asbestos, Crocidolite ; Asbestos, Serpentine ; Bronchi ; Bronchioles ; Bronchoalveolar Lavage ; Cell Count ; Ceramics ; Dust ; Epithelial Cells ; Glass ; Granuloma ; Inflammation ; Lung ; Lung Injury ; Lymphoid Tissue ; Macrophages ; Mineral Fibers ; Neutrophil Infiltration ; Neutrophils ; Rats ; Respiratory System

No abstract available.
Asbestos*

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

OBJECTIVES: To report a case of lung cancer caused by long-term asbestos exposure in a shipyard. METHODS: We evaluated chest X-ray, pulmonary function test, and chest CT and analyzed asbestos concentration in the lung tissue and bulk sample from the workplace. We also performed a workplace survey. RESULTS: The patient had worked at the shipyard for 31 years. The biopsy samples were processed to determine the asbestos content in the lung tissue and bulk sample using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer (EDX). The TEM-EDX analysis revealed many asbestos fibers, the majority of which were amosite. In addition, the concentration asbestos fibers in the workplace exceeded the occupational exposure limits of asbestos. CONCLUSIONS: Our findings strongly suggest that this patient's lung cancer was related to the long-term asbestos exposure.
Asbestos* ; Asbestos, Amosite ; Biopsy ; Humans ; Lung Neoplasms* ; Lung* ; Occupational Exposure ; Respiratory Function Tests ; Thorax ; Tomography, X-Ray Computed