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, 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

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 determine the effects of buthionine sulfoximine (BSO) and free radical scavenger, dimethyl sulfoxide (DMSO), on mutation frequency and the formation of 8-hydroxydeoxyganosine (8-OHdG) induced by crocidolite fibers in human-hamster hybrid (A(L)) cells.

METHODSThe cytotoxicity and mutagenicity were determined by the formation of colonies. 8-OHdG was examined by immunoperoxidase staining. Non-protein sulfhydryl (NPSH) compound was assayed by modified Tietze's method.

RESULTSThe level of NPSH in A(L) cell pretreated with 25 micro mol/L of BSO was decreased to 2 nmol/10(7) cells, only 5% of the control after 24 h. The mutation frequency of CD59 gene of A(L) cell in crocidolite alone treated group was 208 +/- 18 while that in BSO pretreated group (397 +/- 55) was about twice the former (P < 0.05). The mutation frequency of CD59 gene in the group treated with crocidolite and in the presence of DMSO (57 +/- 8) was 72.6% less than that in crocidolite alone treated group. Crocidolite fibers induced a dose-effect relationship in the formation of 8-OHdG in A(L) cells (y = 150 + 20x, r = 0.9621). The level of 8-OHdG in cells was 289 +/- 6 at the dose of 6 micro g/cm(2) crocidolite, which was about twice the control group (137 +/- 9). In the presence of DMSO, 8-OHdG level decreased to 170 +/- 3 at the same dose of crocidolite.

CONCLUSIONFree radicals are the important inducer of mutagenesis and DNA damage in A(L) cells caused by crocidolite, which has dose-effect relationship.

Animals ; Asbestos, Crocidolite ; pharmacology ; Buthionine Sulfoximine ; pharmacology ; CD59 Antigens ; genetics ; Cricetinae ; DNA ; drug effects ; genetics ; DNA Damage ; Deoxyguanosine ; analogs & derivatives ; metabolism ; Dimethyl Sulfoxide ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Free Radical Scavengers ; pharmacology ; Humans ; Hybrid Cells ; Immunoenzyme Techniques ; Mutation

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