Industrial Health

About the journal

Publisher: National Institute of Industrial Health
Published: 1963 to the present, Japan
Language: English
ISSN: 0019-8366 (print), 1880-8026 (electronic)
Continues: Rōdō Eisei Kenkyūjo Kenkyū Hōkoku
Its record in the NLM Catalog

2020s

Evaluation of respiratory toxicity and peritoneal mesothelioma induced by heat-treated and milled amosite following intratracheal and intraperitoneal injection in rats. H. Yamauchi, A. Takata, K. Yamashita, et al. 2026;64(5):421-438. PubMed · Publisher · Free full text

Abstract

Amoste is highly carcinogenic, and its incomplete removal from the environment continues to pose significant health risks. High temperatures are known to alter the crystal structure of asbestos. In this study, we evaluated the carcinogenicity and respiratory toxicity of heat-treated amosite (AM-1000; heated at 1,000°C) and its milled derivative (AM-1000G; heat-treated at 1,000°C and milled), using untreated amosite as a positive control. Physicochemical analyses confirmed that AM-1000G predominantly consisted of non-asbestiform structures with an aspect ratio of less than 3. In a single intratracheal administration study in rats (2 mg; observation period up to 540 d), AM-1000G induced much less severe acute and chronic pulmonary inflammation than amosite or AM-1000 and did not cause fibrosis. No pulmonary adenoma, lung cancer, or pleural mesothelioma was observed in any group. Following intraperitoneal administration (10 mg; two-year observation period), peritoneal mesotheliomas developed in 56% (14/25) of rats in the amosite group, whereas only one (1/25) rat in the AM-1000 group developed mesotheliomas. In contrast, no peritoneal mesothelioma was observed in the AM-1000G group. This study demonstrated that AM-1000G is non-carcinogenic and exhibits markedly reduced acute and chronic respiratory toxicity. These findings provide the first scientific evidence supporting the feasibility of amosite detoxification through heat treatment, based on its biological evaluation.
Mesothelioma carcinogenesis of chrysotile and forsterite compared and validated by intraperitoneal injection in rat. A. Takata, H. Yamauchi, K. Yamashita, et al. 2025;63(1):14-28. PubMed · Publisher · Free full text

Abstract

Asbestos, especially chrysotile, continues to be exposed to humans globally. Hence, it should be disposed properly to prevent asbestos-related diseases, including mesothelioma and lung cancer. This study aimed to verify whether forsterite, a heating product of chrysotile, can cause carcinogenicity, particularly mesothelioma. Forsterite (FO-1000) and enstatite (EN-1500) produced by heating chrysotile at 1,000°C and 1,500°C, respectively, were subjected. We injected 10 mg of chrysotile, FO-1000, or EN-1500 in rats intraperitoneally and observed the development of peritoneal mesothelioma until 24 months. The incidence of peritoneal mesothelioma in the chrysotile group was 91.2%, whereas in the FO-1000 and EN-1500 groups, peritoneal mesothelioma did not develop. Urinary 8-hydroxy-2'-deoxyguanosine and serum N-ERC/mesothelin concentrations significantly increased in the chrysotile group that developed peritoneal mesothelioma, while they only temporarily changed in the FO-1000 or EN-1500 groups during early treatment. Furthermore, there was a significant homozygous deletion of the CDKN2A/p16 gene in the chrysotile group compared to the control group, in contrast to no significant difference in the FO-1000 and EN-1500 groups. Therefore, this study provides clear evidence that forsterite is a nonmesothelioma carcinogen and suggests that forsterite and enstatite are sufficient substances for chrysotile detoxification.
Asbestos in organochlorine insecticide powder sprinkled between pages of antiquarian books in a library in Japan. Y. Sakakibara, K. Sakai, N. Hisanaga, et al. 2024;62(4):271-280. PubMed · Publisher · Free full text

Abstract

Librarians at a university had planned to check the collection prior to the library renovations that began in 2015. They had previous knowledge of the presence of a light greyish-white powder with an unpleasant odour (hereinafter referred to as 'powder') sprinkled between the pages of antiquarian books in the library archive. The purpose of this study was to identify this powder with the help of experts from both inside and outside the university. The powder was qualitatively analysed using gas chromatography with mass spectrometry after hexane extraction. The powder was examined under a polarised light microscope and a field-emission scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. Benzene hexachloride (BHC) was detected in the powder. Talc was the most abundant particle in the powder. The powder also contained 0.52 wt% asbestos, which belonged to the tremolite-actinolite series. No other types of asbestos were detected. The powder was presumed to be a bulking agent for BHC, and its major constituent was talc. This is the first report on asbestos-containing insecticides.
Asian Intensive Reader of Pneumoconiosis program: examination for certification during 2008-2020. N.A. J-P, A.D. Susanto, E. Samoedro, et al. 2024;62(2):143-152. PubMed · Publisher · Free full text

Abstract

This study examined physicians' participation and performance in the examinations administered by the Asian Intensive Reader of Pneumoconiosis (AIR Pneumo) program from 2008 to 2020 and compared radiograph readings of physicians who passed with those who failed the examinations. Demography of the participants, participation trends, pass/fail rates, and proficiency scores were summarized; differences in reading the radiographs for pneumoconiosis of physicians who passed the examinations and those who failed were evaluated. By December 2020, 555 physicians from 20 countries had taken certification examinations; the number of participants increased in recent years. Reported background specialty training and work experience varied widely. Passing rate and mean proficiency score for participants who passed were 83.4% and 77.6 ± 9.4 in certification, and 76.8% and 88.1 ± 4.5 in recertification examinations. Compared with physicians who passed the examinations, physicians who failed tended to classify test radiographs as positive for pneumoconiosis and read a higher profusion; they likely missed large opacities and pleural plaques and had a lower accuracy in recognizing the shape of small opacities. Findings suggest that physicians who failed the examination tend to over-diagnose radiographs as positive for pneumoconiosis with higher profusion and have difficulty in correctly identifying small opacity shape.
Observation of the same asbestos body by both phase contrast microscope and analytical transmission electron microscope. S. Iijima, S. Takahashi, N. Kohyama. 2023;61(2):134-139. PubMed · Publisher · Free full text

Abstract

The amount of asbestos body (AB) in the human lungs is used as an index to assess asbestos lung cancer (ALC). This study reports a new method to observe the same AB previously observed by analytical transmission electron microscope (ATEM) by phase contrast microscope (PCM) or the contrary order. Four kinds of specimens were prepared from the lung tissue of an asbestos related worker: ordinary PCM specimen (A); PCM specimen (B) of which the cover glass was stripped off and ashed at a low temperature; transmission electron microscope (TEM) specimen (C); and PCM specimen (D) covered a TEM specimen (C) with immersion liquid and cover glass. These specimens were all observed by PCM, and the specimen (C) by analytical TEM (ATEM). The results showed that the TEM specimen (C) is transparent in visible light and we can also see the particles by PCM. The image by PCM of the TEM specimen (C) showed very similar features to that of PCM specimens (A) and (B). Accordingly, we could observe various same particles by both ATEM and PCM. In conclusion, the method observing the same AB by both PCM and ATEM will contribute to standardize the recognition of AB for PCM analysts.
A retrospective study on radiological findings of diffuse pleural thickening with benign asbestos pleural effusion in Japanese cases. T. Kishimoto, K. Kato, K. Ashizawa, et al. 2022;60(5):429-435. PubMed · Publisher · Free full text

Abstract

The requirement for compensation for diffuse pleural thickening in benign asbestos pleural effusion include five computed tomography findings of organized pleural effusion: [1] heterogeneity in the pleural effusion, [2] declined chest capacity, [3] "crow's feet" sign at the pleura, [4] immobilization of effusion volume, and [5] air in the effusion. Pleural effusion is diagnosed as organized, immobilized, and in the state of diffuse pleural thickening if at least three of these items are fulfilled, ([1] and [3] compulsory + one of the remaining items). This retrospective study investigated whether the requirement to confirm no organized pleural effusion changes after a follow-up of >3 months were available for cases fulfilling three of the five items; i.e., the confirmation of only [2] with [1] and [3]. Of 302 cases recognized by the Japanese laws, 105 cases with diffuse pleural thickening with organized effusion were enrolled. The number of subjects who fulfilled the diagnostic requirement for organized pleural effusion was confirmed. Eight subjects had a full score of 5 points, 82 subjects scored 4 points, and only 15 subjects scored 3 points. Furthermore, no changes were observed in the organized pleural effusion volume after a follow-up of >3 months.
Inter-observer agreement and accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking AIR Pneumo certification examination. N.A. J-P, A.D. Susanto, E. Samoedro, et al. 2022;60(5):459-469. PubMed · Publisher · Free full text

Abstract

This study examined inter-observer agreement and diagnostic accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking the AIR Pneumo examination. We compared agreement and diagnostic accuracy for parenchymal and pleural lesions across residing countries, specialty training, and work experience using data on 93 physicians. Physicians demonstrated fair to good agreement with kappa values 0.30 (95% CI: 0.20-0.40), 0.29 (95% CI: 0.23-0.36), 0.59 (95% CI: 0.52-0.67), and 0.65 (95% CI: 0.55-0.74) in classifying pleural plaques, small opacity shapes, small opacity profusion, and large opacities, respectively. Kappa values among Asian countries ranging from 0.25 to 0.55 (pleural plaques), 0.47 to 0.73 (small opacity profusion), and 0.55 to 0.69 (large opacity size). The median Youden's J index (interquartile range) for classifying pleural plaque, small opacity, and large opacity was 61.1 (25.5), 76.8 (29.3), and 88.9 (23.3), respectively. Radiologists and recent graduates showed superior performance than other groups regarding agreement and accuracy in classifying all types of lesions. In conclusion, Asian physicians taking the AIR Pneumo examination were better at classifying parenchymal lesions than pleural plaques using the ILO classification. The degree of agreement and accuracy was different among countries and was associated with background specialty training.
Asbestos containing materials in schools of Rome and surrounding area (Italy). A. Campopiano, A. Cannizzaro, A. Olori, et al. 2021;59(6):436-448. PubMed · Publisher · Free full text

Abstract

Despite Italy banning use and production of asbestos in 1992, it continues to represent a risk to human health due to its permanence in the places where it was located. The aim of this work is to estimate how many schools in Rome (Italy) have asbestos containing materials (ACM), and to assess whether the location, condition and nature of ACM can influence the level of risk for student health. 3,672 schools were contacted and 1,451 participated to asbestos survey. 692 bulk samples were collected and analyzed by optical and electron microscope and Fourier transform infrared spectrometer. About 16% of the surveyed schools had ACM. Most of the ACM were not accessible to students (water tanks, boiler thermal insulations). Asbestos-cement materials and vinyl floor tiles were the most common non-friable materials found in schools and equipment insulation linings and Bunsen burner gauze mats were the friable ACM found in science laboratories. Measures to prevent or reduce asbestos hazards were applied where necessary. This study allowed to develop the awareness of the asbestos health hazard among headteachers and the need to manage these hazards appropriately. It represents the beginning of a larger study leading to ACM national mapping in schools.
Asbestos Diseases Research Institute - A New WHO Collaborating Center. Ken Takahashi. 2021;59(3):143-145. PubMed · Publisher · Free full text
Colorectal cancer and asbestos exposure-an overview. Q. Huang, Y.J. Lan. 2020;58(3):200-211. Meta-analysis PubMed · Publisher · Free full text

Abstract

The relationship between colorectal cancer and asbestos exposure has not been fully clarified. This study aimed to determine the associations between asbestos exposure and colorectal cancer. We performed a meta-analysis to quantitatively evaluate this association. A fixed effects model was used to summarize the relative risks across studies. Sources of heterogeneity were explored through subgroup analyses and meta-regression. We analyzed the dose-effect relationship using lung cancer standardized mortality ratio (SMR) and the risk of mesothelioma as a percent (%) as exposure surrogates. A total of 47 cohort studies were included. We identified 28 incidence cohort studies from 17 separate papers and extracted colorectal cancer standardized incidence ratio (SIR). Cancer mortality data were extracted from 19 separate cohorts among 13 papers. The overall colorectal cancer SMR for synthesis cohort was 1.07 (95% CI 1.02-1.12). Statistically significant excesses were observed in exposure to mixed asbestos (SMR/SIR=1.07), exposure to production (SMR/SIR=1.11), among asbestos cement workers (SMR/SIR=1.18) and asbestos textile workers (SMR/SIR=1.11). Additionally, we determined that the SMR for lung cancer increased with increased exposure to asbestos, as did the risk for colorectal cancer. This study confirms that colorectal cancer has a positive weak associations with asbestos exposure.

2010s

Asbestos exposure biomarkers in the follow-up of asbestos-exposed workers. V. Paolucci, R. Romeo, A.G. Sisinni, et al. 2018;56(3):249-254. PubMed · Publisher · Free full text

Abstract

Health surveillance of asbestos exposed workers should be stratified according to the exposure level. Unfortunately there is a lack of information regarding asbestos exposure in many working places and markers of asbestos exposure are often needed. The aim of the study was to assess the reliability of different dose and effect biomarkers in the follow up of asbestos-exposed workers. Mineralogical analysis of bronchoalveolar lavage fluid (BALF) as a biomarker of asbestos fibre burden was performed in a population of 307 male subjects occupationally exposed to asbestos. Using nonparametric statistical methods 8 variables were analyzed with respect to asbestos-related diseases and working sectors. The existence of a relationship between serum soluble mesothelin-related peptides (SMRP) and asbestos exposure levels was also investigated. Concentrations of amphiboles, chrysotile and asbestos bodies in BALF were higher in patients with asbestosis as well as in railway industry workers. A correlation between the onset of non malignant asbestos-related diseases and the levels of SMRP concentration was not found. This study confirms that fibre concentration in BALF may be considered as a reliable biomarker of previous asbestos exposure, whereas SMRP does not appear to be influenced by asbestos exposure levels.
Assessment of physicians' proficiency in reading chest radiographs for pneumoconiosis, based on a 60-film examination set with two factors constituting eight indices. T. Tamura, Y. Kusaka, N. Suganuma, et al. 2018;56(5):382-393. PubMed · Publisher · Free full text

Abstract

Two hundred and thirty-three individuals read chest x-ray images (CXR) in the Asian Intensive Reader of Pneumoconiosis (AIR Pneumo) workshop. Their proficiency in reading CXR for pneumoconiosis was calculated using eight indices (X1-X8), as follows: sensitivity (X1) and specificity (X2) for pneumoconiosis; sensitivity (X3) and specificity (X4) for large opacities; sensitivity (X5) and specificity (X6) for pleural plaques; profusion increment consistency (X7); and consistency for shape differentiation (X8). For these eight indices, one-way analysis of variance (ANOVA) and Scheffe's multiple comparison were conducted on six groups, based on the participants' specialty: radiology, respiratory medicine, industrial medicine, public health, general internal medicine, and miscellaneous physicians. Our analysis revealed that radiologists had a significant difference in the mean scores of X3, X5, and X8, compared with those of all groups, excluding radiologists. In the factor analysis, X1, X3, X5, X7, and X8 constituted Factor 1, and X2, X4, and X6 constituted Factor 2. With regard to the factor scores of the six participant groups, the mean scores of Factor 1 of the radiologists were significantly higher than those of all groups, excluding radiologists. The two factors and the eight indices may be used to appropriately assess specialists' proficiency in reading CXR.
Medical costs of asbestos-related diseases in Spain between 2004 and 2011. M. García-Gómez, R.U. Garrido, R.C. López, et al. 2017;55(1):3-12. PubMed · Publisher · Free full text

Abstract

The objective of this article was to estimate the medical costs derived from malignant ARD treatment in the Spanish National Health System (NHS) between 2004 and 2011. Estimation of direct healthcare costs was based on national primary data on the cost of specialized care for inpatients and outpatients treated at NHS hospitals and on national and regional secondary data on costs of primary healthcare and pharmaceutical prescriptions. A prevalence approach was used to estimate the overall burden of ARDs. Direct medical costs of 37,557 ARDs attended in Spanish NHS facilities in 2004-2011 were estimated at 464 million euros; specialist care accounted for 50.9% of total costs, primary healthcare 10.15%, and drug prescription 38.9%. The cost was 27.8-fold higher in males than in females. Bronchopulmonary cancers represented the greatest healthcare cost, 281 million euros. The cost of delivering healthcare to ARDs victims in Spain has a negative economic impact on the NHS due to the gross under-recognition of occupational victims under the Spanish National Insurance System.
Comments on the 2014 Helsinki consensus report on asbestos. 2016;54(1):94-7. PubMed · Publisher · Free full text

Abstract

The Collegium Ramazzini is an international scientific society that examines critical issues in occupational and environmental medicine with a view towards action to prevent disease and promote health. The Collegium derives its name from Bernardino Ramazzini, the father of occupational medicine, a professor of medicine of the Universities of Modena and Padua in the late 1600s and the early 1700s. The Collegium is comprised of 180 physicians and scientists from 35 countries, each of whom is elected to membership. The Collegium is independent of commercial interests.
Comments on the causation of malignant mesothelioma: rebutting the false concept that recent exposures to asbestos do not contribute to causation of mesothelioma. 2016;54(1):92-3. PubMed · Publisher · Free full text

Abstract

The Collegium Ramazzini is an international scientific society that examines critical issues in occupational and environmental medicine with a view towards action to prevent disease and promote health. The Collegium derives its name from Bernardino Ramazzini, the father of occupational medicine, a professor of medicine of the Universities of Modena and Padua in the late 1600s and the early 1700s. The Collegium is comprised of 180 physicians and scientists from 35 countries, each of whom is elected to membership. The Collegium is independent of commercial interests.
The association among ferruginous body, uncoated fibers, asbestos and non-asbestos fibers in lung tissue in terms of length. T. Suzuki, Y. Sakakibara, N. Hisanaga, et al. 2016;54(4):370-6. PubMed · Publisher · Free full text

Abstract

To demonstrate the correlations between the concentrations of ferruginous body as well as uncoated fiber both of which can be observed with phase-contrast microscope and the concentration of various inorganic fibers including asbestos which requires the observation with TEM or SEM, we measured those indices among Japanese and Korean cases. Though the concentration of ferruginous body in lung tissue is an important index of asbestos exposure, uncoated fibers observed with phase-contrast microscope might be another index especially in such cases with relatively low exposure due to their history of living in a general environment. However, to establish the reliability of uncoated fibers as an index of asbestos exposure, analysis with more cases and from various backgrounds must be carried out.
The global health dimensions of asbestos and asbestos-related diseases. 2016;54(1):87-91. PubMed · Publisher · Free full text

Abstract

The Collegium Ramazzini is an international scientific society that examines critical issues in occupational and environmental medicine with a view towards action to prevent disease and promote health. The Collegium derives its name from Bernardino Ramazzini, the father of occupational medicine, a professor of medicine of the Universities of Modena and Padua in the late 1600s and the early 1700s. The Collegium is comprised of 180 physicians and scientists from 35 countries, each of whom is elected to membership. The Collegium is independent of commercial interests.
Eliminating occupational cancer. J. Takala. 2015;53(4):307-9. Editorial PubMed · Publisher · Free full text

Summary

In this editorial, the author argued that occupational cancer, described as the biggest killer at work in high-income countries, should be eliminated through a stepwise reduction of exposures to carcinogens. He cited International Labour Organization (ILO) estimates of 666,000 occupational cancer deaths worldwide each year, 212,000 in high-income countries and 102,500 in the 28 European Union countries. He stated that lung cancer accounted for 54–75% of occupational cancer. He also reported that 23% of EU workers, 43% in Canada and 37.6% in Australia were exposed to carcinogens. A section on asbestos cited estimates of 100,000–112,000 asbestos-related deaths per year from the ILO, the EU and WHO. The author used asbestos consumption as a proxy, with one mesothelioma death per 170 tons used and one asbestos-related lung cancer death per 48 tons. On that basis he estimated 47,000 asbestos-caused lung cancer and mesothelioma deaths in the EU, and possibly more than 3,500 mesothelioma and more than 12,000 asbestos-related lung cancer deaths in Japan. He noted that about 2 million tons of asbestos were still consumed each year, mostly in Asia. He called for an international programme on the elimination of occupational cancer, substitution of carcinogens, binding exposure limits and cooperation between WHO, ILO and other institutions. He also warned against exporting risks from developed to developing countries.

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Promoting international collaboration through the International Commission on Occupational Health. K. Kogi. 2015;53(1):1-3. PubMed · Publisher · Free full text
Relationships (I) of International Classification of High-resolution Computed Tomography for Occupational and Environmental Respiratory Diseases with the ILO International Classification of Radiographs of Pneumoconioses for parenchymal abnormalities. T. Tamura, N. Suganuma, K.G. Hering, et al. 2015;53(3):260-70. PubMed · Publisher · Free full text

Abstract

The International Classification of High-resolution Computed Tomography (HRCT) for Occupational and Environmental Respiratory Diseases (ICOERD) has been developed for the screening, diagnosis, and epidemiological reporting of respiratory diseases caused by occupational hazards. This study aimed to establish a correlation between readings of HRCT (according to the ICOERD) and those of chest radiography (CXR) pneumoconiotic parenchymal opacities (according to the International Labor Organization Classification/International Classification of Radiographs of Pneumoconioses [ILO/ICRP]). Forty-six patients with and 28 controls without mineral dust exposure underwent posterior-anterior CXR and HRCT. We recorded all subjects' exposure and smoking history. Experts independently read CXRs (using ILO/ICRP). Experts independently assessed HRCT using the ICOERD parenchymal abnormalities grades for well-defined rounded opacities (RO), linear and/or irregular opacities (IR), and emphysema (EM). The correlation between the ICOERD summed grades and ILO/ICRP profusions was evaluated using Spearman's rank-order correlation. Twenty-three patients had small opacities on CXR. HRCT showed that 21 patients had RO; 20 patients, IR opacities; and 23 patients, EM. The correlation between ILO/ICRP profusions and the ICOERD grades was 0.844 for rounded opacities (p<0.01). ICOERD readings from HRCT scans correlated well with previously validated ILO/ICRP criteria. The ICOERD adequately detects pneumoconiotic micronodules and can be used for the interpretation of pneumoconiosis.
The extent and influence of Asbestos Safety Awareness training among managers who had previously commissioned an asbestos survey in their workplace buildings. J. Hickey, J. Saunders, P. Davern. 2015;53(5):398-409. PubMed · Publisher · Free full text

Abstract

A telephone survey was conducted among a sample of managers (n=30) in Ireland who had previously commissioned an asbestos survey in their workplace buildings. The aims of the telephone survey were to examine the extent to which managers had completed Asbestos Safety Awareness (ASA) training, and to assess how such training might influence (i) their instinctive thoughts on asbestos, and (ii) their approach to aspects of asbestos management within their buildings. Managers' motivations for commissioning the asbestos survey were also identified. The study found that ASA-trained managers (n=11) were not significantly more likely to work in larger organisations or in organisations which operated an accredited management system. Though ASA-trained managers' instinctive thoughts on asbestos were of a slightly poorer technical quality compared with those of non-ASA-trained managers, they were still significantly more cognisant of their responsibilities towards those of their employees at specific risk of asbestos exposure. Most managers (n=28) commissioned the asbestos survey to satisfy a pre-requisite of external contractors for commencing refurbishment/demolition work in their buildings. Given its potential to positively influence the occupational management of asbestos, the authors recommend the general promotion of suitably tailored ASA-training programmes among building managers and external contractors alike.
Asbestos exposure among construction workers during demolition of old houses in Tehran, Iran. H. Kakooei, M. Normohammadi. 2014;52(1):71-7. PubMed · Publisher · Free full text

Abstract

Air quality in demolition practices has seldom been evaluated in Iran. Accordingly, we evaluated asbestos exposure among Tehran construction workers during the demolition of old houses. To identify possible sources of asbestos exposure, including thermal insulations, chimney pipes and cement sheets, were all sampled. This study also were taken the personal air samples to evaluate any asbestos exposure during the demolition. The asbestos fibers found in the samples were analyzed by phase-contrast optical microscopy (PCM), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray analysis, and polarized light microscopy (PLM) methods. Personal monitoring of asbestos fiber levels indicated a range from 0.01 to 0.15 PCM f/ml (0.02-0.42 SEM f/ml). The geometric mean concentrations were 0.07 PCM f/ml (0.20 SEM f/ml), which is considerably higher than the threshold limit value (TLV) proposed by American Conference of Governmental Industrial Hygienist (ACGIH), which is 0.1 f/ml. The analysis showed a presence in the bulk samples only chrysotile asbestos and an absence of the other type asbestos. Therefore, it might be expected that workers who worked in the demolition of old houses will suffer from negative effects of exposing to the asbestos fibers.
Lung cancer probably related to talc exposure: a case report. J. Kim, C. Oak, T. Jang, et al. 2013;51(2):228-31. Case report PubMed · Publisher

Abstract

Industrial talc has been widely circulated in the world for a long time. The pure talc has little effects on humans, but inhalation of talc contaminated with asbestos can causes severe asbestos-related diseases such as lung cancer and malignant mesothelioma. Herein, we represent a case of lung cancer after occupational exposure to industrial talc in the rubber manufacturing industry.
Variations of lung cancer risk from asbestos exposure: impact on estimation of population attributable fraction. E.K. Moon, M. Son, Y.W. Jin, et al. 2013;51(1):128-33. Review PubMed · Publisher

Abstract

The purpose of this study is to investigate the potential impact of differing lung cancer risks in study populations on estimating population attributable fraction (PAF) from asbestos exposure. Studies were identified via a MEDLINE search up to September 2009 and from the reference lists of publications about asbestos exposure and lung cancer risk. Relative risk estimates were extracted from 160 studies and meta-relative risks were calculated according to random-effect models. Hypothetical PAFs were calculated based on the meta results and on the difference exposure scenarios. The risks for lung cancer from asbestos exposure were variable according to the region as well as other study characteristics. The risk estimates proved higher in Asian countries (RR=3.53), in studies with 500 or fewer subjects (RR=2.26), and papers published in the 1990s or earlier (RR=1.91), than did those for European or North American countries, studies with more than 500 subjects, and papers published in the 2000s, respectively. The differences in PAFs between Asian and North American studies were 15.5%, 30.3%, and 36.2% when the exposure prevalence was 10%, 30%, and 50%, respectively. This study suggested that it is important to apply appropriate lung cancer estimates to each study population when calculating PAF from asbestos exposure.
Future trends of mesothelioma mortality in Japan based on a risk function. T. Myojin, K. Azuma, J. Okumura, et al. 2012;50(3):197-204. PubMed · Publisher

Abstract

Mesothelioma is a malignancy with poor prognosis. It is chiefly caused by asbestos exposure and its symptoms can occur about 30-50 yr after the initial exposure. This study aims to predict the future trends in mesothelioma mortality in Japan using a method that is an alternative to the age-cohort model. Our approach is based on a risk function that links mesothelioma mortality combined with data pertaining to the population, size of the labor force, and quantity of asbestos imports. We projected the number of deaths occurring in individuals aged 50-89 for yr 2003-2050 using risk functions. Our results have indicated that mesothelioma mortality among Japanese people aged 50-89 yr will continue to increase until 2027 and reach a maximum of 66,327 deaths in the years 2003-2050. Our estimate has also suggested that the number of mesothelioma deaths could be significantly reduced if there were adequate compliance with the administrative level guidelines for occupational asbestos exposure.
Leukotrienes B4, C4, D4 and E4 in the exhaled breath condensate (EBC), blood and urine in patients with pneumoconiosis. D. Pelclová, Z. Fenclová, S. Vlcková, et al. 2012;50(4):299-306. PubMed · Publisher

Abstract

Leukotrienes (LTs) are involved in the pathogenesis of lung fibrosis and were increased in exhaled breath condensate (EBC) of the patients with pneumoconiosis. However the possible influence of extra-pulmonary disorders on the EBC markers is not known. Therefore in parallel with EBC, LTs' levels in the plasma and urine were measured in patients with pneumoconiosis (45 × asbestos exposure, 37 × silica exposure) and in 27 controls. Individual LTs B4, C4, D4 and E4 were measured by liquid chromatography - electrospray ionization - tandem mass spectrometry (LC-ESI-MS/MS). In EBC, LT D4 and LT E4 were increased in both groups of patients (p<0.001 and p<0.05), comparing with the controls. Both LT B4 and cysteinyl LTs were elevated in asbestos-exposed subjects (p<0.05). Asbestosis with more severe radiological signs (s1/s2-t3/u2) and lung functions impairment has shown higher cysteinyl LTs and LT C4 in the EBC (p<0.05) than mild asbestosis (s1/s0-s1/s1). In addition, in the subjects with asbestosis, cysteinyl LTs in EBC correlated with TLC (-0.313, p<0.05) and TLCO/Hb (-0.307, p<0.05), and LT C4 with TLC (-0.358, p<0.05). In pneumoconioses, EBC appears the most useful from the 3 fluids studied.
Evaluation of asbestos exposure during brake repair and replacement. H. Kakooei, M. Hormozy, H. Marioryad. 2011;49(3):374-80. PubMed · Publisher

Abstract

Occupational exposure to asbestos fiber of brake repair job (auto mechanics) has seldom been evaluated in Iran. Accordingly, we evaluated asbestos fiber concentrations in the breathing zone of auto mechanics between July 2008 and December 2008. The asbestos fiber concentrations of 60 personal air samples collected from 30 cars and trucks brake replacement and they were analyzed by phase-contrast optical microscopy (PCM) and scanning electron microscopy (SEM) by energy-dispersive X-ray analysis. The geometric means of the personal monitoring fiber concentrations were 0.92 PCM f/ml and 0.46 PCM f/ml respectively in car and passenger heavy truck auto shops. There was a significant differences in the asbestos fiber concentrations between the car and truck auto shops (p=0.006). Based on these findings, auto mechanics who worked with asbestos containing brake may have been exposed to asbestos concentrations approximately 7 times higher than the current occupational safety and health agency (OSHA) permissible exposure limit (PEL) of 0.1 f/ml. Fiber morphology and energy dispersive X-ray analysis by SEM revealed that amphibole fibers such as tremolite and actinolite existed in the brakes dust and that the vast majority (>30%) of the airborne chrysotile fibers were greater than 1 μm in diameter. It can be concluded that the imported chrysotile asbestos contains trace amounts of tremolite and actinolite fibers and they are responsible for the high airborne asbestos levels and occupational exposure to amphibole asbestos in auto mechanics job in Iran. Thus, it is to be expected that the auto mechanics will suffer negative health effects due to exposure to the serpentine and amphibole asbestos fibers.
Malignant mesothelioma: a clinical study of 238 cases. S.E. Haber, J.M. Haber. 2011;49(2):166-72. PubMed · Publisher

Abstract

Malignant mesothelioma is a diffuse tumor arising in the pleura, peritoneum, or other serosal surface and is closely associated with asbestos exposure. An estimated 2,500 to 3,000 cases are diagnosed each year in the United States. Although there are individual case reports and small series detailing the clinical aspects of mesothelioma, few studies examine a large series of patients with malignant mesothelioma from the clinical perspective. This study reports on the findings of 238 cases of malignant mesothelioma from a private consultative medical practice. Most cases had a history of occupational asbestos exposure. The mean latency was 48.5 yr, with women having a longer latency than men. The mean age at diagnosis was 70. Survival overall was poor (mean 8.8 months), but treatment was beneficial (mean 11.3 versus 6.4 months). Epithelioid histology conferred a survival advantage over sarcomatoid and responded better to treatment. Our data support an inverse relationship between asbestos dose and latency.
Oxidative stress markers in exhaled breath condensate in lung fibroses are not significantly affected by systemic diseases. D. Pelclová, Z. Fenclová, K. Syslová, et al. 2011;49(6):746-54. PubMed · Publisher

Abstract

Exhaled breath condensate (EBC) is assumed to reflect processes in the lungs, yet it is unknown whether oxidative stress markers in EBC are affected by systemic disorders (atherosclerosis, hypertension, diabetes) or whether lung diseases increase markers in plasma and urine. 8-isoprostane, 4-hydroxy-trans-2-nonenale (HNE) and malondialdehyde (MDA) were measured using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS) in EBC, plasma and urine in 82 patients (45 with asbestosis and hyalinosis, and 37 with silicosis) and in 29 control subjects. 8-isoprostane and HNE in EBC, and HNE in urine were higher in both groups of patients. In addition, 8-isoprostane in plasma and urine, and MDA in urine were higher in asbestos-exposed patients and MDA in plasma in silicotics, with this marker in plasma correlated with the grade of silicosis. In all subjects, 8-isoprostane in EBC correlated with urine (r=0.38, p<0.001) and plasma levels (r=0.28, p=0.003), and HNE and MDA with urine levels (r=0.31, p<0.001; r=0.23, p=0.016, respectively). Most markers positively correlated with lung function impairment, EBC markers negatively with vitamin E supplementation. To conclude: The influence of satisfactorily controlled systemic disorders on markers in EBC in patients with pneumoconioses is not significant. In addition to oxidative stress markers in EBC, lung fibroses may increase oxidative stress markers in plasma and urine.
Pleural plaque profiles on the chest radiographs and CT scans of asbestos-exposed Japanese construction workers. M. Elshazley, E. Shibata, N. Hisanaga, et al. 2011;49(5):626-33. PubMed · Publisher

Abstract

Pleural plaques are asymptomatic focal thickenings of the pleura and considered the hallmark of asbestos exposure. However, it is often difficult to detect pleural plaques on chest x-rays (CXR). In a retrospective study, using chest CT scans of 140 Japanese asbestos-exposed construction workers who have probable or definite findings of pleural plaque on CXR; firstly, we proposed plaque morphology-based classification for CXR findings, and then we examined if those classified findings could be confirmed as pleural plaques on CT scans. Our morphology-based classification of pleural plaque findings included nine types. The percentages of confirmed pleural plaques on CT scans by type (number of confirmed pleural plaque on CT/number of observed on CXR) were 93% (40/43) for straight, 89% (56/63) for diamond, 88% (7/8) for double, 83% (19/23) for tapered medially, 80% (20/25) for parallel, 77% (23/30) for crescent, 79% (11/14) for tenting, 72% (18/25) for tapered-laterally (long type), and 0% (0/9) for tapered-laterally (short type). When added to the ILO classification, morphology-based classification of CXR pleural plaque findings makes its detection easier and hence chest radiograph continues to be a suitable tool for screening asbestos-related pleural plaques based on its simplicity, low radiation exposure, wide availability and cost-effectiveness.
Safety evaluation of rock wool after nasal inhalation in rats. Y. Kudo, Y. Aizawa. 2011;49(1):47-55. PubMed · Publisher

Abstract

Asbestos is reported to cause pulmonary fibrosis, and its use has been banned. We examined the biopersistence and histopathological effect of rock wool (RW) fibers in rat lungs by a nose-only inhalation exposure study. Twenty-four rats were exposed to RW fibers for 6 h daily for 5 consecutive days. Six rats each were sacrificed shortly and 1, 2, and 4 wk after exposure, and the fiber numbers and sizes in lungs were determined. The fiber number in the lungs 4 wk after exposure significantly decreased. The clearance half time was 28 d for fibers with L>20 μm and 50 d for World Health Organization fibers. The reasons for the decrease in number and size of fibers include: 1) discharge outside of the body by mucociliary movement, 2) dissolution by body fluid, and 3) phagocytosis and digestion by alveolar macrophages. Twelve rats were used for histopathological examination, and the pathological changes were classified by Wagner's criteria. As a result, changes up to only Grade 2 were observed. The reason for the increase in macrophage number was considered to be a transient reaction of body defense. These results suggest that RW has low biopersistence and only a limited pathological effect.
Characteristics of multiwall carbon nanotubes for an intratracheal instillation study with rats. M. Takaya, F. Serita, K. Yamazaki, et al. 2010;48(4):452-9. PubMed · Publisher

Abstract

Much concern has been raised over the health consequences of workers exposed to carbon nanotubes. In order to characterize multi-wall carbon nanotubes (MWCNT) suspended in a phosphate-buffered saline containing 0.1% Tween 80 for an intratracheal instillation study. Length and width distributions of the MWCNT fibers, dispersion of MWCNT in the suspension and in the lung tissue and the MWCNT contents of metal impurities were investigated. Arithmetic mean length and width of the MWCNT fibers as measured on scanning electron microscope (SEM) photographs were 5.0 microm and 88 nm, respectively, and fibers longer than 5.0 microm were 38.9% of all fibers measured. Dynamic light scattering size measurement revealed that 5-min ultrasonication, together with addition of Tween 80 into the suspension, decreased the hydrodynamic diameters of the agglomerated MWCNT to those of finer particles below 1.0 microm. SEM observation showed good dispersion of MWCNT in the suspension, and in the alveoli on Day 1 after instillation. Concentration of iron, chromium and nickel in the MWCNT were 4,400, 48 and 17 ppm (wt/wt), respectively, all of which were below levels that would elicit positive pulmonary toxic responses to these metals. The results suggest that well-dispersed, long and thin MWCNT fibers exhibit asbestos-like pathogenicity in the lung.
Risk assessment of lung cancer and asbestosis in workers exposed to asbestos fibers in brake shoe factory in Iran. M.R. Azari, A. Nasermoaddeli, M. Movahadi, et al. 2010;48(1):38-42. PubMed · Publisher

Abstract

Chrysotile asbestos fiber, imported from Russia, is used mainly for manufacturing purposes in Iran and related risks in the form of asbestosis and cancer were studied. Occupational exposure of all male workers (61 persons) to asbestos in a brake shoe factory was monitored. Cumulative exposures were determined through multiplication of typical exposure and work history. Risk assessment of exposed workers was estimated by risk criteria recommended by the American Environmental Protection Agency. Measurement of lung function parameters such as forced expiratory volume in one second (FEV(1)), forced volume capacity (FVC) and FEV(1)/FVC of exposed workers were obtained. Unadjusted correlation and adjusted correlation analysis for support of the association between cumulative exposure (fiber/ml-yr) and lung function parameters were used. Exposure of majority of exposed group was far greater than the occupational exposure limits (0.1 fiber/ml) in the range of 0.06-8.06 fiber/ml. Cumulative exposures in the range of 0.02 to 110.77 fiber/ml-yr were obtained. According to the risk criteria stated by ATSDR, risk assessment of workers in term of fibrotic changes was predicted for at least 24.6 percent of the exposed subjects. Again, according to the lung cancer risk criteria stated by EPA, 59 percent of workers will have excess risk. Negative correlation between lung function parameters (FEV(1), FEV(1)/FVC) and cumulative exposures adjusted for age and BMI were significant (p<0.05).

2000s

Asbestos-related occupational cancers compensated under the Industrial Accident Compensation Insurance in Korea. Y.S. Ahn, S.K. Kang. 2009;47(2):113-22. PubMed · Publisher

Abstract

Compensation for asbestos-related cancers occurring in occupationally-exposed workers is a global issue; this is also an issue in Korea. To provide basic information regarding compensation for workers exposed to asbestos, 60 cases of asbestos-related occupational lung cancer and mesothelioma that were compensated during 15 yr; from 1993 (the year the first case was compensated) to 2007 by the Korea Labor Welfare Corporation (KLWC) are described. The characteristics of the cases were analyzed using the KLWC electronic data and the epidemiologic investigation data conducted by the Occupational Safety and Health Research Institute (OSHRI) of the Korea Occupational Safety and Health Agency (KOSHA). The KLWC approved compensation for 41 cases of lung cancer and 19 cases of mesothelioma. Males accounted for 91.7% (55 cases) of the approved cases. The most common age group was 50-59 yr (45.0%). The mean duration of asbestos exposure for lung cancer and mesothelioma cases was 19.2 and 16.0 yr, respectively. The mean latency period for lung cancer and mesothelioma cases was 22.1 and 22.6 yr, respectively. The major industries associated with mesothelioma cases were shipbuilding and maintenance (4 cases) and manufacture of asbestos textiles (3 cases). The major industries associated with lung cancer cases were shipbuilding and maintenance (7 cases), construction (6 cases), and manufacture of basic metals (4 cases). The statistics pertaining to asbestos-related occupational cancers in Korea differ from other developed countries in that more cases of mesothelioma were compensated than lung cancer cases. Also, the mean latency period for disease onset was shorter than reported by existing epidemiologic studies; this discrepancy may be related to the short history of occupational asbestos use in Korea. Considering the current Korean use of asbestos, the number of compensated cases in Korea is expected to increase in the future but not as much as developed countries.
South African data on malignant mesothelioma. J.I. Phillips, J. Murray. 2009;47(2):198-9. Comment · Letter PubMed · Publisher
Asbestos-related occupational lung diseases in NSW, Australia and potential exposure of the general population. E.K. Park, K.M. Hannaford-Turner, R.A. Hyland, et al. 2008;46(6):535-40. Review PubMed · Publisher

Abstract

Asbestos is a fibrous silicate which is recognized as causing a variety of lung disorders including malignant mesothelioma of the pleura, lung cancer and asbestosis. Asbestos use has been banned in most developed countries but exposure still occurs under strict regulation in occupational settings and also occasionally in domestic settings. Although the hazards of asbestos are well known in developed countries, awareness of its adverse health effects is less in other parts of the world, particularly when exposure occurs in non-occupational settings. Experience of asbestos use and its adverse heath effects in developed countries such as Australia have resulted in development of expertise in the diagnosis and treatment of asbestos-related diseases as well as in screening and this can be used to help developing countries facing the issue of asbestos exposure.
Increased 8-isoprostane, a marker of oxidative stress in exhaled breath condensate in subjects with asbestos exposure. D. Pelclová, Z. Fenclová, P. Kacer, et al. 2008;46(5):484-9. PubMed · Publisher

Abstract

Asbestosis and pleural plaques exhibit unpredictable but progressive development, and there are no markers routinely available to measure their prognosis. Asbestos exposure induces the generation of reactive oxygen species, and 8-isoprostane is involved in experimental asbestos-related lung toxicity. This oxidative stress marker was measured in exhaled breath condensate (EBC) in 92 former asbestos workers with mean age 68.8+/-1.7 yr and mean duration of asbestos exposure 24.1+/-2.0 yr. The control group had 46 subjects with mean age 65.2+/-3.3 yr. The mean level of 8-isoprostane, analyzed by liquid chromatography-electrospray ionization-mass spectrometry, was higher in asbestos-exposed subjects (69.5+/-6.6 pg/ml, p=0.0001) compared with the control group, where the concentration was 47.0+/-7.8 pg/ml. The results presented support the hypothesis that oxidative stress due to asbestos is the main cause of increased 8-isoprostane in EBC. Measurement of 8-isoprostane in EBC is a promising non-invasive means for assessing the activity of asbestos-induced diseases.
Asbestos exposure during routine brake lining manufacture. H. Kakooei, M. Sameti, A.A. Kakooei. 2007;45(6):787-92. PubMed · Publisher

Abstract

Occupational exposure to asbestos fiber and total dust of workers of a major brake lining manufacture plant in a developing country were examined and compared with those in developed countries. Time weighted average of total dust and asbestos fiber concentration in the potential sources of exposure were monitored. All personal air sampling were collected on membrane filters and analyzed by phase contrast optical microscopy (PCM) for comparison with the occupational safety and health administration (OSHA) permissible exposure limit (PEL) of 0.1 f/cc, 8-h time--weighted average. This study demonstrates that routine mixing, polishing and beveling process in the brake lining production can result in elevated levels of airborne asbestos. Greater releases of airborne asbestos were observed during mixing process and mixer machine. The results also showed that the employees working in the process had the exposure to total dust concentrations ranging from 2.08 to 16.32 mg/m(3) that is higher than OSHA, recommendation. According to OSHA definition of fibers, it has been indicated that from 3,000 counted particles, 90% of particles are in the form of non-fiber and reaming have fiber-shaped. The particle analyze gives the geometric mean diameter as 6.02 mum, and also indicated that the arithmetic mean of the number distribution for the particle population was 8.4 mum. Approximately 60.4% of the counted fibers were lower than 10 mum in length, from which only 8% consists of fibers (>5 mum in length). In conclusion, the analysis showed a presence in the air of only chrysotile asbestos and an absence of other types of asbestos. During an 8-h shift, the average asbestos fiber exposure (0.78 f/cc) were 7.8 time in excess of OSHA PEL. Additional studies in occupational exposure to asbestos are needed.
Magnetometric evaluation of the effects of man-made mineral fibers on the function of macrophages using the macrophage cell line RAW 264.7. K. Shibata, Y. Kudo, M. Tsunoda, et al. 2007;45(3):426-36. PubMed · Publisher

Abstract

The toxic effects of man-made mineral fibers (MMMFs) have been evaluated by cell magnetometry using alveolar macrophages (AMs). Recently, on the other hand, the murine macrophage cell line, RAW 264.7, became available and has been used as an in vitro model of AMs. The objective of this study was to determine whether or not cell magnetometry using RAW 264.7 cells can be used to evaluate the toxic effects of MMMFs. RAW 264.7 cells were exposed to one of the MMMFs, potassium octatitanate (PT) or silicon carbide whisker (SiC) at 0, 20, 40 and 60 microg/ml, or chrysotile as a positive control at 0, 15, 20 and 25 microg/ml. The toxic effects of fibers were evaluated by cell magnetometry and LDH assay. For this comparison, AMs were also exposed to chrysotile fibers (CF). In the RAW 264.7 cells exposed to PT 20, 40, 60 or SiC 20, 40, 60, CF 15, 20 and 25 microg/ml, significant delayed relaxation were observed compared with the respective control. In the LDH assay, significant increases in LDH in the supernatant of the cells exposed to PT 20, 40, 60, SiC 20, 40, 60 and CF 15, 20, 25 microg/ml were observed. In AMs exposed to CF 20, 25 microg/ml significant delayed relaxation and significant increases in LDH compared with the control were observed. The levels of MMMFs that induced significant differences were similar for cell magnetometry and LDH. The levels of CF that induced significant differences in cell magnetometry and LDH were identical for RAW 264.7 cells and AMs. Our results suggest that cell magnetometry using RAW 264.7 cells is adequate to evaluate the cytotoxicity of exposure to MMMFs.
Malignant mesothelioma: global incidence and relationship with asbestos. C. Bianchi, T. Bianchi. 2007;45(3):379-87. Review PubMed · Publisher

Abstract

Mesothelioma incidence varies markedly from one country to another. The highest annual crude incidence rates (about 30 cases per million) are observed in Australia, Belgium, and Great Britain. A lot of data indicate a relationship between mesothelioma and asbestos. The hot areas for mesothelioma exactly correspond to the sites of industries with high asbestos use, such as shipbuilding and asbestos-cement industry. However, in many countries with high asbestos consumption, mesothelioma incidence is low. The reasons for this fact are not clear. The latency periods elapsing between first exposure to asbestos and development of mesothelioma are mostly longer than 40 yr. An inverse relationship exists between intensity of asbestos exposure and length of the latency period. Mesothelioma generally develops after long-time exposures to asbestos. Some recent studies show that the risk increases with the duration of exposure. Possible co-factors in the pathogenesis of asbestos-related mesothelioma include genetic predisposition, diets poor in fruit and vegetables, viruses, immune impairment, recurrent serosal inflammation. The study of co-morbidity in mesothelioma could give an insight into the pathogenesis of the tumor. While a levelling-off in mesothelioma incidence has been registered in some countries, a worsening of the epidemic is predictable in large parts of the world.
An autopsy case of primary pericardial mesothelioma in arc cutter exposed to asbestos through talc pencils. H. Fujiwara, T. Kamimori, K. Morinaga, et al. 2005;43(2):346-50. Case report PubMed · Publisher

Abstract

An autopsy case of a primary pericardial mesothelioma in a 53-year-old arc cutter is reported. He had often had the chance to inhale dust generated by sharpening the slate pencils composed of talc. He was admitted for heart failure due to pericardial tumor, but later died. The tumor was mainly located on the pericardium with a thickness of about 2.5 cm. Small nodular disseminations were observed in the left parietal pleura. Microscopically, tumor cells were epithelial-like and rich in histochemical demonstrable hyaluronic acid. Findings of immunohistochemical markers revealed keratin (+), EMA (+), calretinin (+), and CEA (-), which were characteristics of mesothelioma of epithelial type. The number of asbestos bodies (AB) in the lung parenchyma was increased (2026 AB/gram dry lung tissue). Subsequent transmission electron microscopic examination equipped with an energy dispersive X-ray analyzer revealed that the fibers identified in the lungs were fibrous talc and actinolite. These findings suggested that this patient had been occupationally exposed to asbestos contaminated in the talc pencils, which induced the development of primary pericardial mesothelioma.
Relationship between chest X-ray findings and pulmonary function tests in dust workers. Y. Tonori, M. Niitsuya, T. Sato, et al. 2005;43(1):256-66. PubMed · Publisher

Abstract

Occupational injuries are decreasing due to the improvement in occupational management in the workplace in recent years. However, pneumoconiosis and its complications remain important occupational diseases. Based on the report 'survey on classification for supervision of pneumoconiosis in Japan' performed in 1994, this study compared age, number of years at the job and pulmonary function tests among work types, and examined the characteristics of cases in which pulmonary function results were worse than expected from the chest X-ray findings. In the comparison among work types, mean age was higher and %VC was lower among workers exposed to silica or asbestos, and FEV1.0% appeared to be lower among silica-exposed workers. Multiple regression analysis showed that silica or asbestos-exposed work environments strongly affected %VC. Some cases showed dissociation between the X-ray findings and pulmonary function tests, which appeared to be caused by certain types of work environments. In this study, all the subjects had findings of pneumoconiosis in their chest X-ray. It is necessary to perform a longitudinal survey on pneumoconiosis-free subjects to clarify the precise association of lung function tests with chest X-ray.
Airborne asbestos and non-asbestos fiber concentrations in non-occupational environments in Korea. H.S. Lim, J.Y. Kim, K. Sakai, et al. 2004;42(2):171-8. PubMed · Publisher

Abstract

Both airborne asbestos and non-asbestos fiber concentrations were evaluated in Korean non-occupational environments. The airborne fiber concentrations were analyzed in 96 air samples, from 48 different points, by transmission electron microscopy, with energy-dispersive X-ray analysis. The geometric means of the airborne asbestos and non-asbestos fiber concentrations were 0.62 and 67.86, and 0.30 and 17.47 fibers/liter in urban and rural areas, respectively. There were significant differences in both the airborne asbestos and non-asbestos fiber concentrations between the urban and rural areas (p<0.05). The geometric means of airborne asbestos and non-asbestos fiber concentrations were 0.67 and 37.93, and 0.27 and 30.67 fibers/liter at the points less than 10 m and more than 30 m away from highways, respectively. The airborne asbestos concentrations were significantly higher at the points less than 10 m away than at the points more than 30 m away from highways (p<0.01).
Familial mesothelioma of the pleura--a report of 40 cases. C. Bianchi, A. Brollo, L. Ramani, et al. 2004;42(2):235-9. Review PubMed · Publisher

Abstract

A survey of 610 pleural mesotheliomas disclosed 40 familial cases. The diagnosis was histologically based in 39 cases, and confirmed by necropsy in 30. Occupational data were collected from the patients or from their relatives by personal interviews. Routine lung sections were examined for asbestos bodies in 32 cases. In 15 cases asbestos bodies were isolated after chemical digestion of lung tissue. Familial mesotheliomas included 31 men and 9 women (age range 44-93 yr, mean 70.7, median 71.0). In 15 families there were blood relations between (or among) the members involved. All the patients had been exposed to asbestos, mostly in the shipyards. Asbestos bodies were found on routine lung sections in 27 cases. Asbestos bodies after isolation ranged from 70 bodies to about 900,000/g dried lung tissue. Latency periods (time intervals between first exposure to asbestos and diagnosis) ranged between 25 and 70 yr (mean 52.0, median 54.0). The occurrence of mesothelioma among subjects with blood relations suggests that genetic factors might play a role in determining the susceptibility to asbestos-related cancer. Familial cases among persons without blood relations raise the question if environmental factors that members of a family share, may act as co-factors in asbestos-related mesothelioma.
Malignant pleural mesothelioma in parts of Japan in relationship to asbestos exposure. T. Kishimoto, S. Ozaki, K. Kato, et al. 2004;42(4):435-9. PubMed · Publisher

Abstract

Malignant pleural mesothelioma is induced by asbestos exposure. Many reports have described this situation in America and European countries, but a few have been published in Japan. In this study malignant pleural mesothelioma cases in hospitals located in an area facing the Seto Inland Sea were evaluated. A total of 106 patients were examined with 100 patients having had occupational exposure to asbestos and 6 patients without such histories of asbestos exposure. Ninety seven were male and 9 were female. Ages ranged from 41 to 87 yr with mean of 64.8+/-5.3 yr. Thirty seven cases showed epithelial type of tumor, 25 biphasic type and 15 showed sarcomatous. The remaining 23 cases had insufficient evidence for typing the tumor. The mean survival rate for all cases was 9.2+/-11.6 months. Fifty-one patients had occupational histories of shipyard work, 16 patients worked in asbestos cement piping, and the remainder were employed in miscellaneous jobs related asbestos exposure. The duration of asbestos exposure ranged up to 20 yr or longer with the mean of 17.2+/-8.9 yr and the average latent period for the occurrence of malignant pleural mesothelioma was more than 31 yr with the mean of 37.0+/-13.3 yr. Quantification of asbestos bodies in the lungs indicated a high concentration in most patients and the major types of asbestos fibers were crocidolite and amosite. Six cases appeared after exposure to chrysotile. These results indicated that ninety four percent of malignant pleural mesothelioma appeared due to the exposure to asbestos including crocidolite and amosite. The remainder may be blamed on exposure to chrysotile.
Occupational health research in India. H.N. Saiyed, R.R. Tiwari. 2004;42(2):141-8. Review PubMed · Publisher

Abstract

India being a developing nation is faced with traditional public health problems like communicable diseases, malnutrition, poor environmental sanitation and inadequate medical care. However, globalization and rapid industrial growth in the last few years has resulted in emergence of occupational health related issues. Agriculture (cultivators i.e. land owners + agriculture labourers) is the main occupation in India giving employment to about 58% of the people. The major occupational diseases/morbidity of concern in India are silicosis, musculo-skeletal injuries, coal workers' pneumoconiosis, chronic obstructive lung diseases, asbestosis, byssinosis, pesticide poisoning and noise induced hearing loss. There are many agencies like National Institute of Occupational Health, Industrial Toxicology Research Centre, Central Labour Institute, etc. are working on researchable issues like Asbestos and asbestos related diseases, Pesticide poisoning, Silica related diseases other than silicosis and Musculoskeletal disorders. Still much more is to be done for improving the occupational health research. The measures such as creation of advanced research facilities, human resources development, creation of environmental and occupational health cells and development of database and information system should be taken.
Pulmonary asbestos and non-asbestos fiber concentrations in autopsied inhabitants in Pohang, Korea. H.S. Lim, J.Y. Kim, K. Sakai, et al. 2004;42(2):163-70. PubMed · Publisher

Abstract

To establish reference values for pulmonary asbestos and non-asbestos fiber concentrations in rural Korean residents, and their comparison with those of urban Korean residents and the Japanese, autopsied lung samples from 22 subjects (20 males and 2 females), in Pohang, without known occupational asbestos exposure histories, were analyzed for asbestos and non-asbestos fibers, using transmission electron microscope equipped with an energy dispersive X-ray analyzer. Chrysotile was the major fiber type found in the lungs of the subjects. The residents in Pohang had significantly lower asbestos and non-asbestos fiber concentrations than the Korean urban residents. The Koreans had significantly lower asbestos and non-asbestos fiber concentrations than the Japanese.
Silicosis and smoking strongly increase lung cancer risk in silica-exposed workers. N. Kurihara, O. Wada. 2004;42(3):303-14. Meta-analysis · Review PubMed · Publisher

Abstract

It remains controversial whether silica is a human lung carcinogen. In this study, we estimated the relative risks of lung cancer due to silica and silicosis by meta-analysis. We collected papers published from 1966-2001 which epidemiologically reported on the relationship between silica/silicosis and lung cancer. We removed papers which did not exclude the effects of asbestos and radioactive materials including radon. We selected the most recent one if some papers were based on the same cohort. Based on the selected papers, we summarized the lung cancer risks from silica, silicosis and non-silicosis with exposure to silica, by meta-analysis using a random effects model. The pooled relative risks were 1.32 (95% confidence interval (CI), 1.23-1.41) for silica, 2.37 (95% CI, 1.98-2.84) for silicosis and 0.96 (95% CI, 0.81-1.15) for non-silicosis with exposure to silica. Since some papers on silica did not exclude silicosis, the risk due to silica itself may be smaller than 1.32. It was less possible that silica exposure directly increases lung cancer risk. On the other hand, the relative risk, 2.37 for silicosis suggested that silicosis increases lung cancer risk. Meta-analysis also revealed that cigarette smoking strongly increased the lung cancer risk in silicotic patients (relative risk, 4.47; 95% CI, 3.17-6.30). Thus, the present study suggested the great importance of preventing silicosis and smoking cessation in reducing lung cancer incidence in silica-exposed workers.
Clinical study of asbestos-related lung cancer. T. Kishimoto, K. Ohnishi, Y. Saito. 2003;41(2):94-100. PubMed · Publisher

Abstract

We analyzed the characteristics of 120 patients of primary lung cancer supposed to be induced by exposure to asbestos. Most of 120 patients were male and the age ranged from 47 to 87 years with a median of 70 years. No particular tendency was observed in the histological types of the lung cancer in 120 patients. Forty of the 120 patients were heavy smokers. When the occupational history was analyzed, most of the patients had been exposed to asbestos in former Japanese naval shipyard, commercial shipyards, construction industry and ironworks. The term of asbestos exposure was 2 to 60 years with a median 27 years. Lung cancers appeared after 15 to 69 years with a median 43 years from the initial exposure to asbestos. Lung cancer was accompanied by asbestosis in 35 patients and by pleural plaques in 77. Twenty-two patients had both asbestosis and pleural plaques. The number of asbestos bodies per 5 g wet lung tissue for 72 patients whose lung tissues obtained from autopsy or surgery was more than 150 bodies which meant the number of occupational asbestos exposure. As for the kinds of asbestos fibers of 32 patients, 14 patients exposed to crocidolite, 10 patients to amosite and 8 patients to chrysotile.
Occupational respiratory diseases in the Czech Republic. P. Brhel. 2003;41(2):121-3. PubMed · Publisher

Abstract

This paper presents the profile of occupational respiratory diseases in the Czech Republic. In a retrospective study the author analyzes structure, causes, occurrence, and trends of occupational diseases. Between 1996 and 2000, a total of 2,127 new cases were recorded, of which 62.0% were pneumoconioses caused by dust containing free silica, 21.0% were occupational asthma or allergic rhinitis and the rest were divided between lung cancer (10.0%), asbestos-related disorders (4.4%) and variety of other respiratory diseases (2.7%). During the period of the investigations, the decreasing trend of occupational respiratory diseases, which began in 1992, has continued.
Reactive oxygen metabolite production induced by asbestos and glass fibers: effect of fiber milling. T. Iwata, E. Yano. 2003;41(1):32-8. PubMed · Publisher

Abstract

Particle stimulated chemiluminescence (CL) production by human polymorphonuclear leucocytes (PMN) has been utilized to evaluate the pathogenicity of mineral and glass fibers with the understanding that reactive oxygen metabolites (ROM) production as measured by CL is etiopathogenically related to fiber toxicity. In the present study to investigate the specific pathogenic role of fiber number and dimensions, CL production from PMN exposed to anthophyllite asbestos mineral and glass fiber samples milled for different time periods was measured. Almost all the fibrous particles in the glass fiber sample were destroyed after milling for 30 minutes. With anthophyllite, the total number of fibrous particles remained almost constant for up to 240 minutes of milling, although the size of fibrous particles was reduced. CL produced by the same mass of glass fiber was elevated after milling for 15 minutes, but then declined when the milling time was further increased. Similarly, with anthophyllite, the production of CL was elevated at the first period of milling for 30 minutes, but then declined at the longer milling times. The level of CL produced was not correlated to the total number of fibrous particles, for both the glass fiber and the anthophyllite samples. Likewise for the glass fiber and anthophyllite samples, no specific range of fiber dimension was correlated to the peak hight CL production. These findings indicate that neither the total number, nor the specific range of fiber dimension solely determines CL production. As a consequence, it may be concluded that other physiochemical factors, such as the surface reactive characteristics of milled fibers, may be more closely related to CL production by PMN.
The role of smoking and exposure to asbestos and man-made vitreous fibers in a questionable case of mesothelioma. G.M. Marsh, M.J. Gula, V.L. Roggli, et al. 2003;41(4):332-4. Case report PubMed · Publisher

Abstract

A remaining uncertainty in the U.S. cohort study of man-made vitreous fiber (MMVF) workers is whether asbestos exposure contributed to 10 questionable cases of mesothelioma. We report further details on one case from our previous mesothelioma investigation, including results of a recent lung tissue analysis. Case is a 68 year-old white male employed 1951-54 in a rock/slag wool plant where asbestos-containing products were manufactured. Cause of death was recorded as "mesothelioma, malignant, right pleural cavity" (ICD9: 163.9). Analysis for presence of asbestos bodies identified 18,300 asbestos bodies per gram of wet lung tissue (AB/gm), which greatly exceeds the normal range of 0-20 AB/gm. No MMVFs were identified in this sample. We conclude that this patient's tumor was not a mesothelioma, but a carcinoma possibly arising in the lung or mediastinum, and that this case supports the view that the few suspected mesotheliomas found in the U.S. cohort may have been caused by asbestos exposure.
Apportionment in asbestos-related disease for purposes of compensation. T.L. Guidotti. 2002;40(4):295-311. Review PubMed · Publisher

Abstract

Workers' compensation systems attempt to evaluate claims for occupational disease on an individual basis using the best guidelines available to them. This may be difficult when there is more than one risk factor associated with the outcome, such as asbestos and cigarette smoking, and the occupational exposures is not clearly responsible for the disease. Apportionment is an approach that involves an assessment of the relative contribution of work-related exposures to the risk of the disease or to the final impairment that arises for the disease. This article discusses the concept of apportionment and applies it to asbestos-associated disease. Lung cancer is not subject to a simple tradeoff between asbestos exposure and smoking because of the powerful biological interaction between the two exposures. Among nonsmokers, lung cancer is sufficiently rare that an association with asbestos can be assumed if exposure has occurred. Available data suggest that asbestos exposure almost invariably contributes to risk among smokers to the extent that a relationship to work can be presumed. Thus, comparisons of magnitude of risk between smokers and nonsmokers are irrelevant for this purpose. Indicators of sufficient exposure to cause lung cancer are useful for purposes of establishing eligibility and screening claims. These may include a chest film classified by the ILO system as 1/0 or greater (although 0/1 does not rule out an association) or a history of exposure roughly equal to or greater than 40 fibres/cm3 x y. (In Germany, 25 fibres/cm3 x y is used.) The mere presence of pleural plaques is not sufficient. Mesothelioma is almost always associated with asbestos exposure and the association should be considered presumed until proven otherwise in the individual case. These are situations in which only risk of a disease is apportioned because the impairment would be the same given the disease whatever the cause. Asbestosis, if the diagnosis is correct, is by definition an occupational disease unless there is some source of massive environmental exposure; it is always presumed to be work-related unless proven otherwise. Chronic obstructive airways disease (COAD) accompanies asbestosis but may also occur in the context of minimal parenchymal fibrosis and may contribute to accelerated loss of pulmonary function. In some patients, particularly those with smoking-induced emphysema, this may contribute significantly to functional impairment. An exposure history of 10 fibre x years is suggested as the minimum associated with a demonstrable effect on impairment, given available data. Equity issues associated with apportionment include the different criteria that must be applied to different disorders for apportionment to work, the management of future risk (eg. risk of lung cancer for those who have asbestosis), and the narrow range in which apportionment is really useful in asbestos-associated disorders. Apportionment, attractive as it may be as an approach to the adjudication of asbestos-related disease, is difficult to apply in practice. Even so, these models may serve as a general guide to the assessment of asbestos-related disease outcomes for purposes of compensation.
Assessment of the mutations of p53 suppressor gene and Ha- and Ki-ras oncogenes in malignant mesothelioma in relation to asbestos exposure: a study of 12 American patients. F. Kitamura, S. Araki, Y. Suzuki, et al. 2002;40(2):175-81. PubMed · Publisher

Abstract

In our previous study, we found no genetic alteration in exons 1 and 2 of Ha- and Ki-ras oncogenes nor in exons 5 to 9 of the p53 suppressor gene in seven Japanese malignant mesothelioma patients exposed to asbestos. To examine further whether malignant mesothelioma due to asbestos has genetic alterations in the p53 suppressor gene and in Ha- and Ki-ras oncogenes, we analyzed point mutations of these genes in paraffin embedded operative open biopsied samples of the primary tumor of malignant mesothelioma in twelve American patients. The genetic analysis was conducted by the PCR-SSCP (polymerase chain reaction single-strand conformation polymorphism) method in all patients and by sequencing analysis of DNA bases in the two patients with suspected gene mutation. The analysis of the p53 suppressor gene showed an amino acid converting mutation of exon 7 in one patient and a polymorphism of exon 6 in another patient; the former patient was a heavy smoker with a biphasic cell type. No genetic alteration was found in exons 1 and 2 of Ha- and Ki-ras oncogenes in any of the patients. The results suggest that the effects of asbestos on the p53 suppressor gene and Ha- and Ki-ras oncogenes in malignant mesothelioma are negligible. Further studies are needed to examine whether the observed mutation of the p53 suppressor gene is due to the combined effects of asbestos and smoking or to other unknown factors.
Concurrent malignant mesothelioma of the pleura and hepatocellular carcinoma in the same patient: a report of five cases. C. Bianchi, L. Ramani, T. Bianchi. 2002;40(4):383-7. Case report · Review PubMed · Publisher

Abstract

Five cases are reported in which malignant mesothelioma of the pleura and hepatocellular carcinoma co-existed in the same patient. The group included four men and one woman, aged between 58 and 86 years. The diagnosis was established at necropsy. In one case the association was clinically suspected. All mesotheliomas were asbestos-related. Liver cirrhosis co-existed in four cases, two of them positive for HCV markers. A lot of elements suggest that the above association is not a fortuitous coincidence. In particular, asbestos could favour liver cancerogenesis by inducing immune impairment.
A patient with asbestos-induced lung cancer complicated by silicosis. T. Kishimoto, K. Tsuda. 2001;39(2):189-93. Case report PubMed · Publisher

Abstract

A 76-year-old male died of lung cancer. At first, he was diagnosed as a silicosis, because he had worked for 30 years as a caster in shipyard and large opacities detected by chest x-ray and CT scanning. After the operation of lung cancer, numerous asbestos bodies were observed in the operated lung tissues. The detailed occupational inquiry revealed his asbestos use as a caster in shipyard. Early stage of asbestosis was suspected by chest CT scanning, but not definitely diagnosed in premortal examinations. Asbestosis, pleural plaques, silicosis and large cell carcinoma of the lung were histopathologically confirmed at the autopsy. A patient with asbestos-induced lung cancer complicated by silicosis was rarely published in the literature.
A trial on the quantitative risk assessment of man-made mineral fibers by the rat intraperitoneal administration assay using the JFM standard fibrous samples. S. Adachi, K. Kawamura, K. Takemoto. 2001;39(2):168-74. PubMed · Publisher

Abstract

We tried to evaluate the carcinogenic risk of man-made mineral fiber based on the mesothelioma incidence in female F344 rats after intraperitoneal administration. Rats (female F344/ Nslc, 5-week-old, n=330) were observed for 2 years after the intraperitoneal administration of 5 to 20 mg of 9 types of the JFM (Japan Fibrous Material Research Association) standard fiber samples (glass wool, rock wool, micro fiber glass, three types of refractory fiber, potassium titanate whisker, silicon carbide whisker, titanium oxide whisker), wollastonite (natural fiber) and UICC chrysotile B. All rats administered 10 mg of silicon carbide whisker had developed peritoneal mesothelioma within a year. The cumulative incidence of peritoneal mesothelioma at the end of the experiment was 85% for 10 mg UICC chrysotile B, 77% for 10 mg of potassium titanate whisker, 70% for 5 mg of silicon carbide whisker, 20% for 5 mg of potassium titanate whisker, 20% for 20 mg of refractory fiber 2 and 10% for 20 mg of refractory fiber 1. Carcinogenicity was estimated 2.4 times for silicon carbide whisker and 0.23 for potassium titanate whisker in comparison with UICC chrysotile B. It has been well documented from several experimental studies that man-made fibers are safer than asbestos because of the different durability in the lung. Present results consistently suggest that man-made fibers with high durability have similar or higher risk as carcinogen than asbestos.
Airborne fiber concentration and size distribution of mineral fibers in area with serpentinite outcrops in Aichi prefecture, Japan. K. Sakai, N. Hisanaga, N. Kohyama, et al. 2001;39(2):132-40. PubMed · Publisher

Abstract

Airborne fiber concentrations and size distributions of both asbestos and nonasbestos fibers were determined at property boundaries of 4 serpentinite quarries producing crushed stone (quarry property boundary), 10 sites within 10 km of the area with serpentinite outcrops (serpentinite area), and 2 sites in a reference area. The asbestos was identified in 7 rock and 3 soil samples collected in the serpentinite area. The geometric means of airborne concentrations of asbestos and nonasbestos fibers longer than 0.2 microm in length were: 384 and 447 fibers/liter (f/L) in the quarry property boundary (in operation), 12 and 124 f/L in the quarry property boundary (in closed), 5 and 103 fibers/liter in the serpentinite area, and less than 2 and 59 fibers/liter in the reference area, respectively. There was a significant difference in airborne concentrations of both asbestos and nonasbestos fibers among the areas. Ttremolite/actinolite were found with chrysotile in the stones. Airborne concentrations of tremolite/actinolite were higher than those of chrysotile at the quarry property boundary and in the serpentinite area. Tremolite/actinolite were also found in the soils. There was no significant difference among the areas in the arithmetic means of fiber size distribution of both asbestos and nonasbestos fibers.
An operated case of lung cancer with pleural plaques: its asbestos bodies, fiber analysis and asbestos exposure. T. Hiraoka, A. Watanabe, Y. Usuma, et al. 2001;39(2):194-7. Case report PubMed · Publisher

Abstract

This case was a 79-year-old man with pleural plaques, which had been pointed out in the left lung field on chest X-ray six years ago. A new shadow in the right chest appeared in 1999 and was closely examined. Cytological class IV carcinoma was detected in his lung tissue obtained by broncho-fiberscope. Lobectomy of the right upper lobe was performed, and calcified pleural plaques were found on the chest wall. The clinical diagnosis was poorly differentiated squamous cell carcinoma, T1N0M0. In World War II when he was 26 years old, he had worked as a boiler man on a battle cruiser for one year. The amount of asbestos bodies (AB) was 3,348 per gram dry lung tissue. The cores of AB and asbestos fibers were examined and showed that amosite was the most prevalent and crocidolite, tremolite and chrysotile were present in that order. After leaving the navy, he had worked as a farmer throughout his life, suggesting that he had never contacted asbestos occupationally after being a boiler man. It is strongly suggested that he had been exposed to asbestos during his work as a boiler man and that produced pleural plaques and lung cancer 50 years' later.
Asbestos exposure in malignant mesothelioma of the pleura: a survey of 557 cases. C. Bianchi, A. Brollo, L. Ramani, et al. 2001;39(2):161-7. PubMed · Publisher

Abstract

A series of 557 malignant mesotheliomas of the pleura diagnosed in the Trieste-Monfalcone area, Italy, in the period 1968-2000 were reviewed. The series included 492 men and 65 women, aged between 32 and 93 years (median age 69 years). Necropsy findings were available in 456 cases (82%). Occupational histories were obtained from the patients themselves or from their relatives by personal or telephone interviews. Routine lung sections were examined for asbestos bodies in 442 cases. In 109 cases isolation and counting of asbestos bodies were performed. A majority of people had histories of working in the shipyards. Asbestos bodies were observed in lung sections in 67% of the cases. Lung asbestos body burdens after isolation ranged between 20 bodies and about 10 millions of bodies/g dried tissue. Latency periods (time intervals between first exposure to asbestos and death) ranged between 14 and 75 years (mean 48.8 years, median 51.0). Latency periods among insulators and dock workers were shorter than among the other categories. High asbestos consumption occurred in many countries in the 1960s and in the 1970s. The data on latency periods obtained in the present study suggest that a world mesothelioma epidemic has to be expected in the coming decades.
Asbestos tissue burden study on human malignant mesothelioma. Y. Suzuki, S.R. Yuen. 2001;39(2):150-60. PubMed · Publisher

Abstract

Asbestos fibers in the lung and mesothelial tissues (mesotheliomatous tissue and hyaline plaque) taken from 151 human malignant mesothelioma cases were identified and characterized by high resolution analytical electron microscopy. Asbestos fibers were present in almost all of the lung tissue as well as in the mesothelial tissue. The most common asbestos types seen in the lung were an admixture of chrysotile with amphiboles followed by amphiboles alone and chrysotile alone. The majority of asbestos types seen in the mesothelial tissues were chrysotile alone, followed by chrysotile plus amphibole and amphibole alone. A disproportion of asbestos types between the lung and mesothelial tissues was frequently observed. The most common pattern of the disproportion was chrysotile plus amphibole(s) in the lung and chrysotile only in the mesothelial tissues, followed by amphibole(s) in the lung and chrysotile only in the mesothelial tissues. Such a disproportion was considered to have been caused by chrysotile fiber's strong capacity to translocate from the lung to mesothelial tissues. The number of asbestos fibers in the lung was 456.4 x 10(6) fibers/dry gram in maximum, 0.08 x 106 fibers/dry gram in minimum and 105 x 10(6) fibers/dry gram on average; in the mesothelial tissues it was 240.0 x 106 fibers/dry gram in maximum, 0.03 x 106 fibers/dry gram in minimum and 49.84 x 106 fibers/dry gram on average. These numbers were greater than those seen in the general population. The majority of asbestos fibers detected in the lung and mesothelial tissues were shorter than 5 microm in length. Asbestos fibers fit to Stanton's hypothetical dimensions (> or =8.0 microm in length and < or =0.25 microm in diameter) were only 4.0%, since the majority of these fibers were shorter (<8 microm) and thinner (<0.25 microm) fibers. We concluded that such short, thin asbestos fibers should not be excluded from those contributing to the induction of human malignant mesothelioma. The present study supports that chrysotile asbestos can induce human malignant mesothelioma, since, in some of the mesothelioma cases, asbestos fibers detected in both the lung and mesothelial tissues, or lung tissue alone or mesothelial tissues alone were exclusively chrysotile fibers.
Asbestos-related lung cancer and mesothelioma in Japan. K. Morinaga, T. Kishimoto, M. Sakatani, et al. 2001;39(2):65-74. Review PubMed · Publisher

Abstract

In Japan, crocidolite had been used for asbestos cement pipe and spraying, and amosite had been used for building board and spraying. These two types of asbestos had stopped to use in Japan in the late 1970s. An extreme increase in imported asbestos (all 3 commercial types) was observed between 1960 and 1974. In 1960, 77,000 tons of asbestos were imported, and reached the peak as 352,316 tons in 1974. This extreme rise of asbestos imports corresponds with the recent rapid increase in mortality of malignant pleural mesothelioma. Between 1995 and 1999, an estimated mean annual death from pleural mesothelioma was about 500. The annual number of compensated occupational respiratory cancers due to asbestos exposure has also been increasing. Up to the end of March 2000, 162 cases with malignant mesothelioma and 197 cases with lung cancer were compensated. As for lung cancer, epidemiological studies are scanty in Japan. Limited environmental data of the working places in asbestos textile factories suggests that heavy asbestos exposure in the past made deaths from respiratory diseases. Less asbestos exposure will enable exposed workers to survive enough to reach cancer age. Even now smoking rate among males in Japan are over 50%. So lung cancer deaths caused by the interaction between smoking and asbestos exposure will be continuing.
Biological effects of asbestos fibers on human cells in vitro--especially on lymphocytes and neutrophils. A. Ueki. 2001;39(2):84-93. Review PubMed · Publisher

Abstract

Biological effects of asbestos fibers were reviewed in relation to the polyclonal activation of human lymphocytes and to the release of free radicals from human neutrophils in vitro. Chrysotile, crocidolite, and amosite asbestos activate CD4+ T lymphocytes polyclonally, followed by activation-induced cell death (a type of apoptosis). The activation is HLA class II dependent, and certain Vbeta repertoire, e.g. Vbeta 5.3, are detected among the fractionated T cells with a high Ca++ level that had been stimulated by asbestos fibers. These observations support the possibility that asbestos acts as a superantigen, and that asbestos stimulate lymphocytes repeatedly in vivo. It has been reported that asbestos-induced cytotoxicity can be suppressed by the scavengers of superoxide or hydroxyl radical. Some of these scavengers such as dimethylsulfoxide (DMSO) or retinoic acid are known as inducers of cell differentiation. The biological functions of DMSO for cell differentiation of HL-60 cells to neutrophils are suppressed by co-culturing of crocidolite asbestos, because DMSO reacts with the hydroxyl radical released after the stimulation with crocidolite and spent itself. Superoxide dismutase (SOD) inhibited the effects of crocidolite, reacting rapidly with *O2- before the secondary release of *OH. It seems to be probable that asbestos fibers, especially crocidolite, suppress the tissue cell differentiation by releasing free radicals and by wasting inducers of cell differentiation as radical scavengers.
Epidemiology of occupational asbestos-related diseases in China. S.X. Cai, C.H. Zhang, X. Zhang, et al. 2001;39(2):75-83. Review PubMed · Publisher

Abstract

In 1950s and 60s, asbestosis had been a major health hazard for asbestos exposed workers. In the late 1970s, lung cancers with or without asbestosis were found among asbestos workers. All cohort studies on asbestos workers and on chrysotile miners in China showed excess deaths from lung cancer. In a large scale of cohort study on asbestos workers, a synergistic effect was found between cigarette smoking and asbestos exposure in the production of lung cancer. There have been not so many cases of malignant mesotheliomas reported, so far. In the cohort of chrysotile miners, 4 cases of pleural mesothelioma were observed. In the large scale of cohort study on asbestos workers in 9 factories using only chrysotile only one case of pleural mesothelioma was detected for 10 years' observation. In another 2 cohort studies, 2 cases of peritoneal mesotheliomas were found, one in Shanghai asbestos factory where a small amount of crocidolite had been used in 1960s, and one in Anqing asbestos factory that was located near tremolite mine. Further study is needed especially for the relationship between exposure to Chinese chrysotile and malignant mesotheliomas.
Estimation of fibrous aerosol deposition in upper bronchi based on experimental data with model bifurcation. T. Myojo, M. Takaya. 2001;39(2):141-9. PubMed · Publisher

Abstract

Lung deposition of fibrous aerosol was studied by using a model of the lung bifurcation with dimensions based on the symmetric model A of Weibel. The fibrous aerosols were introduced to the model under steady inspiratory flow conditions. Glass fibers depositing in the daughter tubes and these escaping from them were observed under a scanning electron microscope (SEM). The deposited fractions were calculated for each length and diameter using a bivariate lognormal distribution. In this study the authors propose empirical equations to estimate total deposited fractions of fibrous aerosol at upper bronchi. The dimensionless relationship among deposited fractions Fd, Stokes number St for randomly-oriented fibers and interception parameter I were used to estimate the deposited fraction at arbitrary position in the upper bronchi. The calculation procedure for Fd(St,I) consists of two steps: the determination of the four deposited fractions, Fdn for each In (n=1-4) followed by interpolation or extrapolation from Fdn to find the deposited fraction Fd at a given I. With this procedure, it is possible to determine the deposited fraction Fd in the range of 2 x 10(-3)<St<5 x 10(-2) and 5 x 10(-4)<I<5 x 10(-2). Penetration from the trachea to the 10th generation of lung bifurcation was calculated for several cases of fiber diameter, length and flow rate. In the case corresponding to an inspiration of 500 cm3 air at a constant rate for 2 s, more than half of the fibers with a length of 100 microm and diameter of 3 microm are deposited at upper bronchi but more than 90% of fibers of the same length and 1 microm in diameter pass through the region.
In vitro studies on biological effects of fibrous minerals. Y. Ishihara. 2001;39(2):94-105. Review PubMed · Publisher

Abstract

Asbestos substitutes have been used recently in industrial various applications. Since certain asbestos substitutes have similar characteristics of asbestos, they require urgent in vitro and in vivo evaluation of these asbestos substitutes prior to occupational applications. Though in vitro studies do not offer precise assessment of toxicity of the fibers, it is possible to provide useful information as to the biological effects of asbestos and its substitutes. This review articles described the findings of in vitro experiments in investigation of biological effects of asbestos and man made mineral fibers (MMMF) and their correlation with in vivo assays; 1. Cytotoxicity, geometry and dimension of fibers. 2. In vitro biological effects of fibers on a mass basis and a numerical basis. 3. Mechanism of cytotoxicity, carcinogenecity and cell proliferation including in vitro cytokines production. The relationships between the in vitro and the in vivo biological effects of fibers do not always coincide. Therefore, safety of the fibers must be assessed in both in vivo and in vitro using an inert fiber as negative control. Additionally, evaluation of safety of these fibers in vitro must be conducted in comparable concentrations, sizes and numbers of fibers for used in in vivo experiments.
In vivo studies of man-made mineral fibers--fibrosis-related factors. Y. Morimoto, I. Tanaka. 2001;39(2):106-13. Review PubMed · Publisher

Abstract

Pneumoconiosis that pursues a chronic course may result from repeated injury and repair caused by dust particles that remain in the lungs, leading to fibrosis. We will introduce in vivo studies concerning these processes using animals exposed to man-made mineral fibers and asbestos. We will report on whether there are developmental changes with the mineral fiber and animal model in proinflammatory cytokine, chemokine, free radicals, proteinase and other genes that lead to injury, as well as in genes that effect repair such as growth factor, and we will also report on the effects of surfactant protein and clara cell secretory protein on fibrosis.
Man-made respirable-sized organic fibers: what do we know about their toxicological profiles?. D.B. Warheit, K.L. Reed, T.R. Webb. 2001;39(2):119-25. Review PubMed · Publisher

Abstract

Man-made organic fibers (MMOFs) have been manufactured for over 50 years. Until recently, there have been few concerns raised regarding the safety of organic fiber dusts. This is due, in large part, to the perception that the dimensions of most, if not all, of these products were too large to be inhaled into the distal lungs of workers, i.e., were considered to be nonrespirable. A brief review of some of the issues related to organic fiber toxicology is presented herein. Some of the organic fiber-types used in commerce are identified and some fundamental tenets of fiber toxicology are discussed. In addition, the European Union, in their recent consideration for banning chrysotile asbestos fibers, evaluated some organic fiber substitutes and compared them to the hazards of asbestos. A brief review of their conclusions is described below. Finally, the results of some recent studies assessing the mechanisms of biodegradability of para-aramid respirable-sized, fiber-shaped particulates (RFP) are presented. Para-aramid (p-aramid) RFP are the most extensively-studied respirable organic fiber-type and RFP is the new term which describes respirable-sized organic fibers (ECETOC, 1996) (1). The results of these studies provide clues regarding the mechanism(s) of p-aramid RFP shortening in the lungs of exposed animals, and may be relevant for humans.
Measurement of airborne fibers: a review. P.A. Baron. 2001;39(2):39-50. Review PubMed · Publisher

Abstract

Current fiber measurement techniques arose primarily due to health concerns over asbestos exposure. Fiber toxicity appears to be primarily a function of fiber concentration, dimensions and durability in the lungs. There are two basic approaches to fiber measurement. Fibers can be collected on filters and counted or analyzed by light or electron microscopy; alternatively, fibers can be detected directly using a combination of fiber alignment and light scattering techniques. All of these measurement approaches work best when the fibers are simple rod-shaped particles. However, most fibers can exist as curved rods, complex bundles of fibrils, and agglomerates of fibers and compact particles. These non-ideal shapes contribute to measurement bias and variability.
Pathology of human malignant mesothelioma--preliminary analysis of 1,517 mesothelioma cases. Y. Suzuki. 2001;39(2):183-5. PubMed · Publisher

Abstract

The author reviewed 1,517 human malignant mesothelioma cases from 1975 through August 2000. These mesothelioma cases were definite or probable in diagnostic certainty. Sources of these cases varied including asbestos insulation workers, UNARCO workers, Cancer and Leukemia B mesothelioma panel cases and random cases. Pathology materials consisted of autopsy, biopsy and rare cytology specimens. 92.3% of these patients were male, and 85.8% were between 50 and 79 years in age. The major primary site of the tumor was the pleura (73.1%). However, in a group of the asbestos insulation workers, the peritoneum was the more common primary site of malignant mesothelioma, compared to the pleura. Histologically, epithelial cell type was the majority (61.1%), followed by biphasic (22.1%) and fibrosarcomatous (16.4%). A double primary tumor (malignant mesothelioma associated with other cancer) was present in 32 of the 1,517 cases. These 32 cancers included lung cancers, renal cell carcinomas, colorectal cancers, pancreatic cancers and a cancer of the larynx, which are known to be at higher risk among asbestos insulation workers. The latency period of the vast majority (98.1%) of these mesothelioma cases were longer than 20 years. It is well accepted that cigarette smoking does not contribute to the induction of malignant mesothelioma. Indeed, the present study confirmed that 19.9% of these mesothelioma patients had never smoked cigarettes.
Present status of asbestos mining and related health problems in India--a survey. A.L. Ramanathan, V. Subramanian. 2001;39(4):309-15. PubMed · Publisher

Abstract

At present in India more than thirty mines are in operation. It produces 2800 tones of asbestos per month (mainly chrysotile and tremolite) and in recent years substantial quantity (-70%) is imported from Canada. The quality of asbestos produced in India is very poor. The mining and milling and other related processes expose the people to cancer and related diseases. Women are more affected by their exposure in processing unit compared to male who are generally working in mines. Direct and indirect employment in asbestos related industry and mine is around 100,000 workers. Latency period (length of the time between exposure and the onset of diseases) in India is estimated to be 20-37 yr. The causes for lung and breathing problem are mainly due to obsolete technology and direct contact with the asbestos products without proper precaution, because in India asbestos are sold without statutory warning. This paper reviews health effects (such as fibrosis, sequelae, bronchogenic cancer, and malignant mesothelioma) on the Indian mine workers caused due to asbestos mining related activities with respect to their present day condition.
Retrospective view of airborne dust levels in workplace of a chrysotile mine in Ural, Russia. S.V. Kashansky, S.G. Domnin, V.A. Kochelayev, et al. 2001;39(2):51-6. PubMed · Publisher

Abstract

The Bazhenovskoye chrysotile asbestos deposit has been exploited for 115 years. All the technological operations in the quarry are accompanied by the formation of high-dispersion asbestos-containing aerosols. The dust concentrations at the miner's working places for the last 30 years (1970-2000) were at or below the Russian MACs(m.s.) level (4.0 mg/m3). The seasonal precipitation amount in the deposit area causes a rise in dust content in certain periods. The maximum density of asbestos respirable fibres exceeded 2.7 f/cm3. All the identified fibres belonged to chrysotile asbestos, and no amphibole asbestos, such as tremolite asbestos, has been identified. An excessive dust level remains, despite the dust content level decrease, at the work sites of oversized lump drillers and unloaders, and oncopathology heightened risk remains in these occupational groups, as a result.
The carcinogenicity of chrysotile asbestos--a review. W.J. Nicholson. 2001;39(2):57-64. Review PubMed · Publisher

Abstract

The world production of asbestos has been declining dramatically in recent years, particularly in Europe and the United States. However, increases have occurred in Asian nations and chrysotile is the dominant fiber used. Important uses are in cement products, wallboards, friction products and textiles. From studies in the United States and Great Britain, chrysotile has been shown to increase the risk of lung cancer and to produce mesothelioma in exposed workers.
The trend in airborne asbestos concentrations at plants manufacturing asbestos-containing products in Japan. K. Yoshizumi, H. Hori, T. Satoh, et al. 2001;39(2):127-31. PubMed · Publisher

Abstract

In Japan, chrysotile is still permitted to use under the Ordinance on Prevention of Hazards due to Specified Chemical Substances. In recent years many countries have introduced a policy of prohibiting the use of asbestos, based on clinical and epidemiological studies. In light of this, it is important to evaluate the airborne asbestos concentrations in workplaces and also estimate the number of related disease cases in order to discuss the ban of asbestos use. The survey covered 528 workplaces in 145 plants and included 2795 asbestos handling workers from 1985 to 1998. These plants were belonging to the Japan Asbestos Association (JAA) as member companies. In Japan, nearly all of the asbestos using manufacturing companies are members of JAA. In our study, all of the workplaces were divided under each separate manufacturing process and classified into 3 categories of Control Classes. Of the 454/528 (86.0%) workplaces classified as Control Class 1 are improved to 376/378 (99.5%). Though in the cases of small enterprises, other factors such as a shift in product lines, and the economic recession, as well as efforts, contributed to improvements in working conditions. JAA recommended self-administered concentrations of 1.0 f/ml (compatible to <0.3 f/ml in personal exposure level) in 1991 to promote further improvements of the work environment. From this point of view, exposure limits can almost be technically achieved in Japan, and it is expected that asbestos related disease could be expected to decrease in 20 to 30 years later. This survey will become basic material for verifications whether we could control asbestos related diseases enough in such well-controlled work environment.
Urinary 8-oxo-7, 8-dihydro-2'-deoxyguanosine and biopyrrins levels among construction workers with asbestos exposure history. R. Yoshida, Y. Ogawa, I. Shioji, et al. 2001;39(2):186-8. PubMed · Publisher

Abstract

It has been suggested that oxidative stress is associated with the cancers caused by asbestos. Since construction workers are sometimes exposed to low levels of asbestos, we investigated whether oxidative stress was elevated in construction workers who had been exposed to low levels of asbestos. The subjects were 48 Japanese construction workers. The defined asbestos-exposed group consisted of subjects who had the history of suspected exposure to asbestos and were diagnosed to have irregular opacities or pleural plaques. We measured the amount of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) and biopyyrins in the urine of the subjects. The results showed that 8-oxodG and biopyyrins levels in the defined asbestos-exposed group were higher, although they were not statistically significant, than those in the control group. In addition, the urinary 8-oxodG levels tended to correlate positively with the duration of suspected exposure to asbestos. These results suggest that even low-level asbestos exposure may induce oxidative stress and that the resulting's the oxidative stress might be related to lung cancer in construction workers.
Asbestos exposure in a shipyard area, northeastern Italy. C. Bianchi, A. Brollo, L. Ramani. 2000;38(3):301-8. PubMed · Publisher

Abstract

The Monfalcone area, northeastern Italy, is a small industrial district (population 60,000), with a large shipyard. In order to monitor asbestos exposure in this area, a series of 3,640 necropsies, carried out at the Monfalcone Hospital between October 1979 and September 1998, were investigated. The thoracic cavities were examined for pleural plaques; these were classified into three classes (small, moderate, large). Routine histological sections of lung tissue were examined for asbestos bodies. Isolation and counting of asbestos bodies were performed in 1,075 cases. Lifetime occupational data were collected in 1,277 cases. Pleural plaques were observed in 70.5% among men and in 23.8% among women. The prevalences of pleural plaques did not show significant variations during the study period. Asbestos bodies were found on routine lung sections in 23.7% of men and 3.0% of women. The shipyard workers, the most numerous category in the series, were characterized by high prevalence of pleural plaques (total 86.7%, large 32.4%), high prevalence of asbestos bodies on routine lung sections (35.3%), and high amounts of lung asbestos bodies after isolation. The present data indicate that asbestos exposure may reach alarming levels in the shipyard areas.

1990s

A historical cohort mortality study of workers exposed to asbestos in a refitting shipyard. N. Kurumatani, Y. Natori, R. Mizutani, et al. 1999;37(1):9-17. PubMed · Publisher

Abstract

To investigate the risks of developing asbestos-related diseases we conducted a historical cohort mortality study on 249 ship repair workers (90 laggers and 159 boiler repairers) in a single U.S. Navy shipyard in Japan. We successfully identified the vital status of 87 (96.7%) laggers and 150 (94.3%) boiler repairers, and, of these, 49 (56.3%) and 65 (43.3%) died, respectively, during the follow-up period from 1947 till the end of 1996. Our in-person interviews with some of the subjects clarified that asbestos exposure was considered to be substantially high in the 1950-60s, decreased thereafter gradually but remained till 1979 in the shipyard. The laggers, who had handled asbestos materials directly, showed a significantly elevated SMR of 2.75 (95% C.I.: 1.08-6.48) for lung cancer. The risk developing the disease was greater in the laggers after a 20-year latency (SMR = 3.42). Pancreatic cancer yielded a greater SMR than unity (7.78, 90% C.I.: 2.07-25.19) in a longer working years group. Four laggers died from asbestosis. The boiler repairers, who had many chances for secondary exposure to asbestos and a few for direct exposure, showed no elevation of the SMR of lung cancer overall, but there was a borderline statistically significant SMR of 2.41 (90% C.I.: 1.05-5.45) in a longer working years group. One boiler repairer died from mesothelioma and four from asbestosis.
Biological effects of man-made mineral fibers (I)--Reactive oxygen species production and calcium homeostasis in alveolar macrophages. Q.E. Wang, C.H. Han, W.D. Wu, et al. 1999;37(1):62-7. PubMed · Publisher

Abstract

10 types of standard mineral fiber samples (JFM fibers) were tested for their cytotoxicity in alveolar macrophages (AM) in vitro experiments, in which UICC chrysotile B was used as a positive control. The cytotoxicity included the production of superoxide anion radical and hydrogen peroxide, depletion of glutathione (GSH) and increase of intracellular free calcium. The results showed that chrysotile and most of the 10 mineral fibers could increase the production of superoxide anion and hydrogen peroxide, deplete the concentration of GSH and increase the level of free intracellular Ca2+ in AM. But all the effects of JFM fibers were lower than that induced by UICC chrysotile B. Although the cytotoxicity of JFM fibers were lower than that of asbestos, these mineral fibers should be used with highly care for workers in industries.
Biological effects of man-made mineral fibers (II)--their genetic damages examined by in vitro assay. Q.E. Wang, C.H. Han, Y.P. Yang, et al. 1999;37(3):342-7. PubMed · Publisher

Abstract

In order to study and compare genetic damage induced by 10 kinds of man-made mineral fibers (JFM fibers) in cells, human lung epithelial cells (A549) were exposed to JFM fibers and chrysotile for 1 h, then single-cell gel electrophoresis (SCGE) assay was used to detect DNA strand breaks, DNA-DNA interstrand crosslink and the ability of DNA to repair; The results showed that all 10 JFM fibers could induce DNA strand breaks, DNA-DNA interstrand crosslinks and inhibit the ability of DNA repair. When human embryo lung (HEL) cells were exposed to JFM fibers and chrysotile for 24 h respectively, the chromosomal aberration was analyzed and the results showed that chrysotile and most of JFM fibers at 5.0 micrograms/ml induced structural chromosomal aberration, but all of these effects were lower than that of chrysotile and were different among them, suggesting that 10 types of JFM fibers had genotoxicity with different degree in vitro, but all of them were lower than that of chrysotile.
Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers. J.H. Kim, H.S. Chang, K.Y. Kim, et al. 1999;37(3):322-8. PubMed · Publisher

Abstract

Man-made mineral fibers (MMMF), most of which are referred to as man-made vitreous fibers (MMVF), are mostly amorphous silicates manufactured from glass, rock, or other minerals. Analysis for MMMF have been restricted largely to the measurement of total airborne mass concentrations, but more recently to the determination of airborne fiber levels by phase contrast optical microscopy. In Korea, many small factories are related with manufacturing and using MMMF without any special evaluation of environmental measurements. Though MMMF are known as the substitute of asbestos and their toxicity are regarded as very low, MMMF do not totally excluded from the respiratory and/or skin diseases now. Therefore, we evaluated the environments of many workplaces with total dust and fiber concentration. Most dust and fiber concentrations were below threshold limit value (TLV) at various industries and working processes. However, these data showed a slight relationship between total dust and fiber concentration.
Impact of acute and subchronic asbestos exposure on some parameters of antioxidant defense system and lung tissue injury. A. Kaiglová, Z. Kováciková, M. Hurbánková. 1999;37(3):348-51. PubMed · Publisher

Abstract

Asbestos fibers have been used in industry for decades. Deleterious effect of asbestos on the lungs has been documented. However, the mechanism of asbestos related diseases has not been fully explained yet. Numerous papers suggest there is a role of reactive oxygen intermediates (ROI) in asbestos-induced lung disease development. The excess ROI produced can be removed from the lungs by enzymatic and nonenzymatic antioxidants. The aim of our study was to compare the levels of antioxidants (ascorbic acid, retinol, alpha-tocopherol, glutathionperoxidase) as well as some markers of lung injury (lipid peroxides, total amount of protein, alkaline phosphatase) in asbestos treated Wistar-rats both 24 hr and 3 months after exposure to those in the controls, and to find out if the changes in antioxidant levels could affect impairment of the lungs. Decreased levels of antioxidants and increased values of lung tissue injury parameters in exposed groups suggest involvement of ROI in the mechanism of asbestos lung disease development, resulting in lung tissue injury, both 24 hr and 3 months after exposure.
The hazards of chrysotile asbestos: a critical review. P.J. Landrigan, W.J. Nicholson, Y. Suzuki, et al. 1999;37(3):271-80. Review PubMed · Publisher

Abstract

Chrysotile, or "white", asbestos is the dominant form of asbestos in international commerce today. It accounts for 99% of current world asbestos production of 2 million tonnes. Chrysotile is an extremely hazardous material. Clinical and epidemiologic studies have established incontrovertibly that chrysotile causes cancer of the lung, malignant mesothelioma of the pleura and peritoneum, cancer of the larynx and certain gastrointestinal cancers. Chrysotile also causes asbestosis, a progressive fibrous disease of the lungs. Risk of these diseases increases with cumulative lifetime exposure to chrysotile and rises also with increasing time interval (latency) since first exposure. Comparative analyses have established that chrysotile is 2 to 4 times less potent than crocidolite asbestos in its ability to cause malignant mesothelioma, but of equal potency of causation of lung cancer. The International Agency for Research on Cancer of the World Health Organization has declared chrysotile asbestos a proven human carcinogen. Sales of chrysotile asbestos have virtually ended in Western Europe and North America, because of widespread recognition of its health hazards. However, asbestos sales remain strong in Japan, across Asia and in developing nations worldwide. The claim has been made that chrysotile asbestos can be used "safely" under "certain conditions" in those nations. That claim is not accurate. The Collegium Ramazzini, an international learned society in environmental and occupational medicine, has called for an immediate worldwide ban on all sales and uses of all forms of asbestos, including chrysotile. The rationale for this ban is threefold: (1) that safer substitute materials are readily available, (2) that "controlled" use of asbestos is not possible, and (3) that the health risks of asbestos are not acceptable in either the industrialized or the newly industrializing nations.
Assessment of mutations of Ha- and Ki-ras oncogenes and the p53 suppressor gene in seven malignant mesothelioma patients exposed to asbestos--PCR-SSCP and sequencing analyses of paraffin-embedded primary tumors. F. Kitamura, S. Araki, T. Tanigawa, et al. 1998;36(1):52-6. PubMed · Publisher

Abstract

To examine whether malignant mesothelioma due to asbestos has genetic alterations in the Ha- and Ki-ras oncogenes or in the p53 suppressor gene, we analyzed the point mutations of these genes in paraffin-embedded autopsy samples of the primary tumors of malignant mesothelioma in seven asbestos patients who died from malignant mesothelioma. The genetic analysis was conducted by the polymerase chain reaction-single strand comformation polymorphysms (PCR-SSCP) method in all patients, and through the sequencing of deoxyribonucleic acid (DNA) bases in one patient. No genetic alterations were found in exons 1 or 2 of Ha- and Ki-ras oncogenes, or in exons 5 to 9 of the p53 gene, in any of the patients. Further studies on a larger number of patients are required to reach a definite conclusion concerning the genetic effects of asbestos on malignant mesothelioma.
Mineral fibre persistence and carcinogenicity. J.C. McDonald. 1998;36(4):372-5. PubMed · Publisher

Abstract

Epidemiological research during the past 40 years has demonstrated with increasing clarity that amphibole asbestos fibres--crocidolite, amosite and tremolite--are more carcinogenic than chrysotile. A smaller number of well-controlled studies using lung burden analyses, while adding to the specificity of this conclusion, have shown that amphibole fibres also differ from chrysotile in being far more durable and biopersistent in lung tissue. Analyses of mesothelioma and lung cancer in a large cohort of Canadian chrysotile miners and millers have recently shown that the low-level presence of fibrous tremolite in these mines, rather than the chrysotile, may well be responsible. The high risk of lung cancer, but not of mesothelioma, in the chrysotile textile industry remains anomalous and cannot be explained in this way. These various findings are directly relevant to the choice of the experimental methods which should be used for screening man-made fibres for industrial use. Although it is clear that biopersistence is a major determinant of cancer risk in animals, and perhaps also in man, other factors affecting the biological activity of mineral fibres may also be important.
Increases of thrombomodulin activity and antigen level on human umbilical vein endothelial cells treated with asbestos and man-made mineral fibers. H. Urano, S. Gotoh, A. Shirahata, et al. 1997;35(3):359-66. PubMed · Publisher

Abstract

The potential influences of crocidolite asbestos fibers and man made mineral fibers (potassium titanate whisker and magnesium sulfate whisker) on a procoagulant system of human umbilical vein-endothelial cells (HUVECs) were investigated by measuring the activity and antigen level of thrombomodulin (TM) on the cell surface. Statistically significant increases in both the TM activity and TM antigen level were observed on HUVECs treated with crocidolite asbestos fibers for 48 h and 72 h compared to untreated cells at low concentrations of the fibers which showed no sign of a cytotoxic effect on the cells. An extensive increase in both the TM activity and TM antigen level was also observed on HUVECs treated with potassium titanate whisker or magnesium sulfate whisker for 48 h and 72 h. A statistical analysis revealed that these fibers had almost the same effects on the increases in both TM activity and the TM antigen level of HUVECs treated with the fibers for 48 h and 72 h, but a treatment of magnesium sulfate whisker at more than 1.25 micrograms/ml for 24 h was slightly more effective in increasing TM activity on HUVECs compared to other fibers (p < 0.05). The [3H]leucine incorporation in HUVECs increased when the cells were treated with crocidolite asbestos or man-made mineral fibers (MMMFs), indicating that the increases in TM activity and the TM antigen level on HUVECs directly exposed to those fibers may not reflect the sole induction of anticoagulant activities, but the general cell damage induced by the fibers.
A total sample preparation method for the measurement of airborne asbestos and other fibers by optical and electron microscopy. N. Kohyama, S. Kurimori. 1996;34(3):185-203. PubMed · Publisher

Abstract

A total sample preparation method utilizing one membrane filter for all or some of the measurements by phase contrast optical microscopy (PCM), optical microscopy (OM), dispersion staining polarized microscopy (DS/PLM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), was developed in order to evaluate airborne asbestos and other mineral fibers comprehensively, including fiber number, sizes and types, in various environments. This method consists of two alternate procedures: parallel and serial preparation. The former uses different portions of a filter for each measurement of PCM, OM, DS/PLM, SEM and TEM. The latter uses a single filter portion for all OM, SEM and TEM measurements by which the same area and same fibers on the filter can be observed. This allows fiber numbers to be directly compared using these measurements on the same filter area, and the fibers observed by OM can be also examined by SEM and/or TEM equipped with an energy dispersive X-ray spectrometer (EDX) to determine the types and precise sizes. Using this method, it was found that OM measurements developed in this study can visualize thinner fibers than PCM measurements and make it easier to count fibers. We also found that currently used PCM measurement can detect fibers thicker than about 0.4-0.5 microns in diameter. This total sample preparation method can be used not only for air samples, but also for liquid and biological tissue samples.
Pollution and its control in asbestos milling processes in India. A.K. Mukherjee, R.R. Rajmohan, S.K. Dave, et al. 1996;34(1):35-43. PubMed · Publisher

Abstract

An intervention study has been conducted in chrysotile asbestos milling processes with an interval of one year. The 'Membrane Filter Method' adopted in the former study for fiber concentration estimation has been followed in the present study, to estimate the environmental samples under the same experimental conditions. Though very high fiber levels compared to the prescribed permissible limit in India, have also been obtained in this study, a general reduction trend in the values of mills common to the both studies are observed. A further suitable control measure has been recommended in the paper to reduce fiber levels in the milling processes.
Effect of long and short fibre amosite asbestos on in vitro TNF production by rat alveolar macrophages: the modifying effect of lipopolysaccharide. S. Dogra, K. Donaldson. 1995;33(3):131-41. PubMed · Publisher

Abstract

The influence of long and short fibre amosite on the generation of tumor necrosis factor (TNF) by rat alveolar macrophages was investigated in vitro. TNF rich supernatants were prepared from macrophages cultured in F10 medium +2% Bovine Serum Albumin (BSA). Spontaneously released TNF from unstimulated macrophages and TNF rich supernatants from macrophages exposed to Lipopolysaccharide (LPS) and fibres were stored at -70 degrees C and then tested for their cytotoxicity towards L929 cells. Maximum spontaneously released TNF was obtained from 24 hour macrophage cultures. Short amosite fibres had no significant effect in stimulating alveolar macrophages to release TNF while the 50 micrograms dose of long fibres resulted in significantly increased release of TNF. Cotreatment of alveolar macrophages with LPS and fibres further enhanced the TNF production and maximum production was obtained with LPS +50 micrograms dose of long fibre resulted in significantly increased release of TNF. Co-treatment of alveolar macrophages with LPS and fibres further enhanced the TNF production and maximum production was obtained with LPS +50 micrograms of long fibre amosite. The present study indicates that fibre dimension is a major factor in in vitro dust activity and TNF has a possible active role to play in dust induced inflammation in vivo.
Effects of smoking on respiratory function and exercise performance in asbestos workers. X. Wang, S. Araki, E. Yano, et al. 1995;33(4):173-80. PubMed · Publisher

Abstract

To determine the role of smoking in the development of pulmonary impairment in asbestos workers, 66 nonsmoking asbestos workers and 70 smoking asbestos workers were studied. Occupational and medical questionnaires, lung function and exercise test were conducted in all subjects. The frequencies of dyspnea and cough on questions were significantly higher in the smoking workers than those in nonsmoking workers. Similarly, FEV1, FEV1/FVC and DLco were significantly lower in the smoking workers. Exercise performance showed that the smoking workers had higher index of dyspnea and lower breathing reserve, Vo2 and Vo2 max than nonsmoking workers did. We concluded that cigarette smoking has marked effects on both of respiratory function and exercise performance in asbestos workers. Among them, smokers show more serious obstructive impairment in static lung function testing and more significant limitation during exercise. The history of cigarette smoking deserves close attention in the evaluation of pulmonary impairment from asbestos exposure.
Effect of lifetime cigarette consumption on time domain spirogram indices. T. Nakadate, T. Sato, J. Kagawa, et al. 1994;32(1):29-40. PubMed · Publisher

Abstract

A cross-sectional analysis on the dose-related change in time domain spirogram indices induced by lifetime cigarette consumption was conducted to examine the ability of those indices to detect early changes in the lung periphery in comparison with conventional spirometric indices. The subjects were asymptomatic healthy male workers from three occupational cohorts including asbestos workers and welders. They were asked to perform the forced expiration maneuver at least three times to obtain reliable results. A total of 893 subjects were enrolled in the study, and 484 of them who were aged 30 years or more and were free from chronic respiratory symptoms and abnormalities in chest radiography and spirometry, were analyzed. Although conventional indices, such as forced expiratory volume in one second and maximal midexpiratory flow, were not significantly different between smokers and nonsmokers, the standard deviation of transit times and of time constant distribution in smokers were significantly elevated compared with nonsmokers. Furthermore a dose-related change according to lifetime cigarette consumption was observed in those indices. We conclude that time domain spirogram indices, especially the standard deviation of time constant distribution, would be more useful than conventional indices in detecting early changes in the lung periphery.
Cell toxicity, hemolytic action and clastogenic activity of asbestos and its substitutes. K. Koshi, N. Kohyama, T. Myojo, et al. 1991;29(2):37-56. PubMed · Publisher

Abstract

The cell toxicity, hemolytic and clastogenic activity were examined in various kinds of asbestos and some asbestos substitutes with reference to the their mineralogical and physicochemical characteristics. There were thirty-five fibrous and non-fibrous samples including UICC chrysotile, size-selected samples of UICC chrysotile, chrysotile altered by heating and grinding, Yamabe (Japan) chrysotile with long and short fibers, Coalinga (U.S. A.) chrysotile with short fibers, UICC crocidolite, amosite, and 19 non-asbestos samples such as, glass fibers, calcium silicates, sepiolites and some clay minerals. The cell toxicity and the hemolytic and clastogenic activity of asbestos were the strongest for chrysotile among all of the asbestos samples tested, and their strengths varied with fiber length and with the conditions of grinding and heating. These cellular effects of Yamabe chrysotile with long fibers and size-selected UICC chrysotile with long fibers were stronger than those of chrysotile of the same origin but with short fibers. These effects were weaker in chrysotile altered by heating and grinding. Among the asbestos substitutes, the cell toxicity, hemolytic and clastogenic activities of thin glass fibers were more marked than those of thick glass fibers. The four types of sepiolite were strongly hemolytic, but their cell toxicity and clastogenicity varied according to their grade of crystallinity and/or fiber size. These effects of calcium silicates and some clay minerals were generally low but varied with mineral species. In general, the cell toxicity, hemolytic and clastogenic activities of the asbestos substitutes tested here were mild compared with those of asbestos.
Peritoneal mesothelioma--how a good occupational case history can best be used. R. Flechsig. 1991;29(2):73-6. Case report · Letter PubMed · Publisher

1980s

A study of magnetic field in the lung of workers in an asbestos factory. X.T. Weng, J.C. Yao, Y.J. Wang, et al. 1989;27(1):9-15. PubMed · Publisher

Abstract

Magnetic field at the chest in 93 male workers exposed to asbestos dust in an asbestos products factory in China was studied by local magnetization and flux-gate gradiometry. The average field intensity at 12 measurement points over the anterior chest wall was compared among workers with and without asbestosis and among workers of different working age. The field intensity in workers with asbestosis and those suspected to have asbestosis on the basis of X-ray findings was significantly higher than that in workers without asbestosis. It was also found that the field intensity increased with working age. It is suggested that dynamic measurement of magnetic field in the lung of workers exposed to dust containing ferrimagnetic particles would at least serve as a quantitative method for estimating lung dust loads and be valuable for pneumoconiosis prevention.
Study on prevalence of pleural plaques in miniature X-ray films in Japan and Sweden. S. Ohyagi, S. Kagamimori, G. Hillerdal, et al. 1985;23(2):127-34. PubMed · Publisher
Biochemical and histopathological response to chrysotile ingestion in guinea pigs. K.C. Saxena, L. Srivastava, R.K. Dogra. 1982;20(1):19-25. PubMed
Effect of BCG on experimental asbestosis. S.H. Zaidi, J.W. Bhattacherjee, R.K. Dogra, et al. 1982;20(2):129-37. PubMed · Publisher

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