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

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

This review analytically examines the published data for erionite-related malignant pleural mesothelioma (E-MPM) and any data to support a genetically predisposed mechanism to erionite fiber carcinogenesis. Adult patients of age > or =18 years with erionite-related pleural diseases and genetically predisposed mechanisms to erionite carcinogenesis were included, while exclusion criteria included asbestos- or tremolite-related pleural diseases. The search was limited to human studies though not limited to a specific timeframe. A total of 33 studies (31042 patients) including 22 retrospective studies, 6 prospective studies, and 5 case reports were reviewed. E-MPM developed in some subjects with high exposures to erionite, though not all. Chest CT was more reliable in detecting various pleural changes in E-MPM than chest X-ray, and pleural effusion was the most common finding in E-MPM cases, by both tests. Bronchoalveolar lavage remains a reliable and relatively less invasive technique. Chemotherapy with cisplatin and mitomycin can be administered either alone or following surgery. Erionite has been the culprit of numerous malignant mesothelioma cases in Europe and even in North America. Erionite has a higher degree of carcinogenicity with possible genetic transmission of erionite susceptibility in an autosomal dominant fashion. Therapeutic management for E-MPM remains very limited, and cure of the disease is extremely rare.
Adult ; Asbestos/*adverse effects ; Asbestos, Amphibole ; Environmental Exposure/*adverse effects ; Female ; Humans ; Lung Neoplasms/*chemically induced/radiography ; Male ; Mesothelioma/*chemically induced/radiography ; Middle Aged ; Pleura/radiography ; Pleural Effusion/radiography ; Pleural Neoplasms/*chemically induced/radiography ; Prognosis ; Prospective Studies ; Retrospective Studies ; Tomography, X-Ray Computed ; Zeolites/*adverse effects

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

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

BACKGROUND: The host response to natural fibers results in granuloma formation in an effort to limit tissue destruction. Matrix metalloproteinases (MMPs) are important molecules in the inflammatory granulomatous or reparative reaction. Here, we studied the foreign body reaction that occurs following natural fibers implantation by investigating MMPs and tissue Inhibitor of MMPs (TIMPs) in an in vivo model. METHODS: Female Sprague-Dawley rats were treated with crocidolite fiber or fibrous talc via subcutaneous and intraperitoneal injections and immunohistochemistry was conducted to confirm the expression of MMPs and TIMP-2 in tissue sections. RESULTS: We identified that mineral fibers elicited granulomas. Fibrous talc or intraperitoneal injection resulted in larger granulomas and severe tissue destruction compared with the lesions induced by crocidolite or subcutaneous injection. The expression of MMPs was elevated while granulomatous lesions were formed. The relative levels of MMPs were lower in the talc injected or intraperitoneal route models than those of crocidolite injected or subcutaneous injection models during the entire experiment. CONCLUSIONS: These findings demonstrate that specific expression of MMPs/TIMP is inversely related to the grade of tissue destruction and suggest that expression of MMPs is required for promoting granuloma formation and limiting tissue destruction.
Animals ; Asbestos ; Asbestos, Crocidolite ; Female ; Foreign Bodies ; Foreign-Body Reaction ; Granuloma ; Humans ; Immunohistochemistry ; Injections, Intraperitoneal ; Injections, Subcutaneous ; Matrix Metalloproteinases ; Mineral Fibers ; Rats ; Rats, Sprague-Dawley ; Talc ; Tissue Inhibitor of Metalloproteinase-2

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 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

OBJECTIVETo evaluate the effects of environmental low-dose exposure to crocidolite on people's health and the society. METHODS The mortality data of cancer between 1994 and 2003 in an environmental crocidolite-contaminated area was obtained from hospital medical records of Dayao Center for Disease Prevention and Control, and Dayao Public Health Bureau. The years of life lost with premature death (YLLs), was used to measure and assess the death, health losses and social burden of cancer in this area.

RESULTSIn the environmental crocidolite-contaminated area, lung cancer was the prime cause of death in all kinds of cancers between 1994 and 2003, followed by liver cancer, mesothelioma stomach cancer and colorectal cancer, with mortality 10.15/10(5), 9.04/10(5), 8.48/10(5), 3.96/10(5) and 3.55/10(5) respectively. The mortality of main cancer in male and female increased with age growing except that of breast cancer in female. Results showed that the types of leading cancers of YLLs were liver cancer, lung cancer, mesothelioma, leukemia and stomach cancer with YLLs 1981.39 person-year, 1886.63 person-year, 1799.23 person-year, 948.01 person-year and 754.18 person-year respectively. The distribution of YLLs was similar in both sexes, higher in the middle age group (aged from 15 to 44 years and 45 to 59 years) and lower in other age groups. The indirect economic loss resulting from lung cancer (15.02% of the total loss), liver cancer (13.98% of the total loss) and mesothelioma (13.01% of the total loss) was relatively great. The YLLs and the indirect economic loss attributable to environmental low-dose exposure to crocidolite were 3092.23 person-year and 5,175,800 Yuan respectively.

CONCLUSIONLung cancer, liver cancer, mesothelioma, leukemia and breast cancer are the major cancers with an important impact on people's health and premature mortality in the environmental crocidolite-contaminated area. The impact of cancer mortality is more severer in those aged over 45 years. Social burden of cancer is the greatest in persons aged from 15 to 59 years. Policies and plans should be worked out for the protection of environment and the prevention of cancer.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asbestos, Crocidolite ; adverse effects ; Child ; Child, Preschool ; China ; epidemiology ; Cost of Illness ; Environmental Exposure ; Environmental Pollution ; adverse effects ; Female ; Humans ; Infant ; Life Expectancy ; Male ; Middle Aged ; Neoplasms ; mortality ; Young Adult

OBJECTIVETo explore the characteristic of the signal transduction in BEAS cells induced by the crocidolite fibers.

METHODSThe human respiratory airway epithelial cells BEAS-2B were cultured in vitro. The final 100 microg/ml crocidolite concentration and lOnM of epidermal growth factor were cocultured with BEAS-2B cells for 30 minutes and 120 minutes. Phosphorylated ERKl/2 and MEKl/2 were detected by Western Blotting using specific antibodies.

RESULTSA rapid phosphorylation expression of ERK1/2 (molecular weight at 44 kD and 42 kD, also called as p44 and p42) was observed by treatment of the BEAS-2B cells with 100 microg/ml crocidolite or 100 ng/ml EGF (the proven activator of the ERK signaling pathway) at 30 minutes. This phosphorylation could be still detected by incubation the cells at 2 hours. However no expression was changed for the total ERKl/2 expression at 30 minutes or 120 minutes. Treatment of BEAS cells with 100 microg/ml crocidolite fiber or 100 ng/ml EGF led to the rapid increased phosphorylation of MEK1/2 at 30 minutes; similarly, the overexpression of MEK1/2 could last 2 hours.

CONCLUSIONThe crocidolite induces the MAPK (ERK1/2 and MEK1/2) phosphorylation within a shorter time. It indicates that the MAPKs signals are involved in the process of crocidolite induced damage.

Asbestos, Crocidolite ; toxicity ; Bronchi ; cytology ; Cells, Cultured ; Epidermal Growth Factor ; pharmacology ; Epithelial Cells ; drug effects ; metabolism ; Humans ; MAP Kinase Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Phosphorylation