Asbestos in commercial indian talc.

BACKGROUND: Easily available commercial Indian talc products widely used in Southeast Asia were examined for the presence of asbestos. Asbestos in talc products carry all risks of asbestos-related disease. METHODS: Using polarizing light microscopy, transmission electron microscopy (TEM), electron diffraction, and X-ray analysis, multiple over-the-counter Indian talc products were examined for the presence of asbestos. RESULTS: Results In an initial group of five Indian talc products, one was found to contain tremolite asbestos. The second group of eight products was tested and six of eight contained tremolite asbestos as well. No other regulated amphibole was found. CONCLUSION: Large quantities of body talc products containing asbestos are used throughout Southeast Asia and are likely to pose a public health risk for asbestos-related diseases, especially for the cancers related to asbestos exposure. The country of origin in which the talc examined was sourced for production is unknown to the authors, and further investigation to measure associated public health risk is needed.

Asbestos fiber identification in liver from cholangiocarcinoma patients living in an asbestos polluted area: a preliminary study.

PURPOSE: To assess whether asbestos fibers may be observed in liver tissue of patients with cholangiocarcinoma (CC) with environmental or working asbestos exposure. METHODS: Detection of fibers was performed directly on histologic sections of liver from 7 patients with CC using optical microscope and variable pressure scanning electron microscopy equipped with energy-dispersive spectroscopy (VP-SEM/EDS). All patients were from Casale Monferrato, Italy, a highly asbestos-polluted town. Due to ethical constraints, observers were blinded to patients' clinical features. RESULTS: Fibers/bundles of fibers of chrysotile were detected in 5 out of 7 patients (71%). The boundary between healthy and neoplastic tissue or the fibrocollagen tissue produced by the neoplasia were identified as areas of fiber incorporation. CONCLUSIONS: This study is the first report about the detection of chrysotile asbestos fibers in the liver of patients with CC. Further studies on larger cohorts are needed to corroborate our preliminary findings.

Utilidad del lavado broncoalveolar en el diagnóstico de enfermedades relacionadas con el amianto / Utility of Bronchoalveolar Lavage for the Diagnosis of Asbestos-Related Diseases

Introducción: El análisis del lavado broncoalveolar (LBA) se ha propuesto como técnica objetiva para certificar la exposición a amianto. Sin embargo, la fiabilidad y rendimiento diagnóstico de este procedimiento diagnóstico no se han analizado en España. El propósito de este estudio fue evaluar la utilidad del análisis de cuerpos de amianto (CA) en el LBA para el diagnóstico de enfermedades relacionadas con el amianto (ERA). Métodos: Se analizaron muestras de LBA de 72 pacientes (66 varones, edad media de 66 años) sometidos a broncoscopia. También se analizó el tejido pulmonar de 23 de estos pacientes. La exposición al amianto se evaluó a partir de la anamnesis y la revisión de las historias clínicas de los pacientes. Las muestras de LBA y de tejido pulmonar se procesaron, y la cantidad de CA se determinó mediante microscopia óptica. El valor umbral aceptado para diagnosticar una enfermedad relacionada con el amianto fue de 1 CA/ml de LBA o 1.000 CA/g de tejido seco. Resultados: Treinta y nueve pacientes refirieron exposición a amianto. En 13 (33%) de estos pacientes, los niveles de CA fueron superiores a 1 CA/ml de LBA. De los 33 pacientes no expuestos, los valores de CA fueron superiores a 1 CA/ml de LBA en 5 casos (15%). La diferencia entre los niveles de CA de los pacientes expuestos y los no expuestos fue significativa (p = 0,006). La curva ROC indicó que el nivel de 0,5 CA/ml de LBA era el que alcanzaba mayor sensibilidad (46%), con un 83% de especificidad. El grado de correlación entre los niveles de CA en el LBA y el tejido pulmonar fue de 0,633 (p = 0,002). Conclusiones: El estudio del LBA ofrece una prueba objetiva de la exposición a amianto. La buena correlación observada entre los recuentos de CA en el LBA y en el tejido pulmonar indica la validez de ambas técnicas para analizar el contenido de amianto (AU)

Introduction: Bronchoalveolar lavage (BAL) analysis has been proposed as an objective technique for confirming asbestos exposure. However, the reliability and diagnostic yield of this procedure has not been studied in Spain. The aim of this study was to assess the usefulness of the analysis of asbestos bodies (AB) in bronchoalveolar lavage (BAL) for the diagnosis of asbestos-related diseases (ARD). Methods: BAL samples from 72 patients (66 male, mean age 66 years) undergoing bronchoscopy were analyzed. Lung tissue from 23 of these patients was also analyzed. Asbestos exposure was assessed by anamnesis and a review of the patient's medical records. BAL and lung samples were processed and AB count was determined by light microscopy. The accepted threshold value to diagnose asbestos-related diseases was 1 AB/ml BAL or 1000 AB/gr dry tissue. Results: Thirty-nine patients reported exposure to asbestos. Of these, 13 (33%) presented AB values above 1 AB/ml BAL. In the 33 non-exposed patients, 5 (15%) presented AB values above 1 AB/ml BAL. There was a significant difference between the AB levels of exposed and non-exposed patients (P = .006). The ROC curve showed that a value of 0.5 AB/ml BAL achieved the most satisfactory sensitivity, 46%, and a specificity of 83%. The correlation between AB levels in BAL and lung was 0.633 (P = .002). Conclusions: BAL study provides objective evidence of exposure to asbestos. The good correlation between the AB counts in BAL and lung tissue indicates that both techniques are valid for the analysis of asbestos content (AU)

Residual fibre lung burden among patients with pleural mesothelioma who have been occupationally exposed to asbestos.

OBJECTIVES: To evaluate the lungs asbestos fibres concentration in participants with malignant pleural mesothelioma (MPM) who have been occupationally exposed. METHODS: The lung samples were obtained from pleuropneumonectomies or autopsies of 271 male MPMs. The lung samples were examined through scanning electron microscopy. Retrospective assessment was used to assess for asbestos exposure. This study includes 248 MPMs with an occupational exposure defined as either 'definite' or 'probable' or 'possible'. RESULTS: The participants had finished working in asbestos exposure conditions more than 20 years ago (on average 26.1±11.0 years). The fibre burden resulted with a geometric mean equal to 2.0 (95% CI 1.6 to 2.4) million fibres per gram of dry lung tissue. The burden was higher among participants employed in asbestos textiles industry and in shipyards with insulation material, if compared with construction workers or non-asbestos textile workers or participants working in chemicals or as auto mechanics. 91.3% of MPMs had a detectable amount of amphibole fibres. A strong lung clearance capability was evident among workers exposed to chrysotile fibres. Owing to that, the 1997 Helsinki Criteria for occupational exposure were reached in <35% of cases among participant working in construction, in metallurgical industry, in chemical or textile industry and among those performing brake repair activities. CONCLUSIONS: The MPM cases are now occurring in Italy in participants who ceased occupational asbestos exposure decades before the analysis. A large majority still shows a residual content of amphibole fibres, but given the lung clearance capability, attribution to occupational exposure cannot rely only on fibres detection.

Development of a testing method for asbestos fibers in treated materials of asbestos containing wastes by transmission electron microscopy.

Appropriate treatment of asbestos-containing wastes is a significant problem. In Japan, the inertization of asbestos-containing wastes based on new treatment processes approved by the Minister of the Environment is promoted. A highly sensitive method for testing asbestos fibers in inertized materials is required so that these processes can be approved. We developed a method in which fibers from milled treated materials are extracted in water by shaking, and are counted and identified by transmission electron microscopy. Evaluation of this method by using asbestos standards and simulated slag samples confirmed that the quantitation limits are a few million fibers per gram and a few µg/g in a sample of 50mg per filter. We used this method to assay asbestos fibers in slag samples produced by high-temperature melting of asbestos-containing wastes. Fiber concentrations were below the quantitation limit in all samples, and total fiber concentrations were determined as 47-170×10(-6) f/g. Because the evaluation of treated materials by TEM is difficult owing to the limited amount of sample observable, this testing method should be used in conjunction with bulk analytical methods for sure evaluation of treated materials.

Contenido pulmonar de amianto en trabajadores de los astilleros de Ferrol / Asbestos pulmonary content in workers of Ferrol shipyards, Spain

Fundamento y objetivo: Desde hace unos años se está llevando a cabo el estudio de los trabajadores expuestos a amianto en los astilleros de Ferrol con la finalidad de llegar al diagnóstico de las enfermedades derivadas de la exposición. El objetivo del presente estudio fue conocer el contenido pulmonar de amianto en esta población. Material y método Se obtuvieron muestras pulmonares necrópsicas correspondientes a individuos que habían trabajado en los astilleros de Ferrol. En la mayoría de los casos se analizaron muestras de los 2 pulmones. Tras eliminar la materia orgánica pulmonar con hipoclorito sódico, el residuo inorgánico fue analizado mediante microscopia óptica. Los resultados se expresaron como cuerpos de amianto (CA) por gramo de tejido seco. Se consideraron niveles causantes de enfermedad aquellos que superaron los 1.000 CA/g. Resultados Se estudiaron 30 pacientes varones, con una edad media de 67 años (extremos 56-89 años). Veintiséis sujetos eran fumadores o ex fumadores, mientras que 4 no habían fumado. Todos tenían una enfermedad pulmonar, pleural o peritoneal relacionada con la exposición a amianto (16 cáncer de pulmón, 6 mesotelioma, 25 enfermedad pleural benigna). Solo en 6 de los 16 casos de cáncer de pulmón existía asbestosis concomitante. La mediana (intervalo) de CA observados fue de 6.171 (249-4.660.059) CA/g. El 97% de individuos presentaron valores superiores a los 1.000 CA/g. Se encontró correlación entre los CA y la edad del sujeto (r=0,5676; p=0,0011).Conclusiones Los trabajadores de los astilleros de Ferrol analizados tienen valores pulmonares de amianto elevados. Se debe aumentar la sospecha clínica del amianto como factor potencialmente causante de enfermedad pulmonar en este colectivo (AU)

Background and objective: In the last years, a study is being conducted about exposure to asbestos among shipyards workers in order to know the diagnosis of the diseases associated with the exposure. Our goal was to know the asbestos pulmonary contents in this population. Material and methods: We obtained autopsy pulmonary samples from individuals who had worked in Ferrol shipyards. We analyzed samples from both lungs in most cases. After removing the lung organic matter with sodium hypochlorite, the inorganic residue was analyzed with optic microscopy. Results were expressed as asbestos bodies (AB) per gram of dry tissue. We considered as disease causative levels those above 1,000 AB/g. Results: We studied 30 males, with a mean age of 67 years (r: 56-89 years). Twenty-six were smokers or former smokers, and 4 had never smoked. All had a lung, pleural or peritoneal disease related to asbestos exposure (16 lung cancer, 6 mesothelioma, 25 benign pleural disease). Only in 6 out of the 16 lung cancercases there was coexisting asbestosis. The median (interval) of AB was 6,171 (249-4,660,059) AB/g. Ninety-seven per cent of individuals had levels above 1,000 AB/g. There was a correlation between A Band age (r = .5676; P = .0011).Conclusions: Workers from Ferrol shipyards who were analyzed had increased pulmonary levels of asbestos. It is essential to raise clinical suspicion of asbestos as a factor that can potentially cause lungdisease in this group (AU)

Peroxidase-like activity of ferruginous bodies isolated by exploiting their magnetic property.

Ferruginous bodies (FB) are polymorphic structures whose formation is macrophage dependent, and are composed of a core, which may consist of an asbestos fiber coated with proteins, among which ferritin is the main component. Within ferritin, the ferric and ferrous ions are coordinated as ferrihydrite, which is the main iron (Fe) storage compound. However, when ferritin accumulates in some tissues following Fe overload it also contains magnetite along with ferrihydrite, which endows it with magnetic properties. Recently studies showed that magnetite exerts peroxidase-like activity, and since ferruginous bodies display magnetic properties, it was postulated that these particular structures may also contain magnetite within the ferritin coating, and thus may also exert peroxidase-like activity. Histochemical analysis for peroxidase of isolated FB smears demonstrated positive staining. Samples isolated from 4 different autopsy lung fragments were also able to oxidize 3,3',5,5'-tetramethyl-benzidine to a blue colored compound that absorbs at 655 nm. This activity was (1) azide and heat insensitive with optimal pH from 5 to 6, and (2) highly variable, changing more than 25-fold from one sample to another. These findings, together with evidence that the peroxidase-like activity of ferruginous bodies has a hydrogen peroxide and substrate requirement different from that of human myeloperoxidase, can exclude that this enzyme gives a significant contribution to the formation of FB. Standard Fe-rich asbestos fibers also express a peroxidase-like activity, but this appears negligible compared to that of ferruginous bodies. Strong acidification of standard Fe-containing asbestos fibers or magnetically isolated ferruginous bodies liberates a high amount of peroxidase-like activity, which is probably accounted for by the release of Fe ions. Further, FB also damage mesothelial cells in vitro. Data suggest that FB exert peroxidase-like activity and cytotoxic activity against mesothelial cells, and hence may be an important factor in pathogenesis of asbestos-related diseases.

[Exposition markers: mineralogical analysis in the sputum and the bronchoalveolar lavage--asbestos bodies--uncoated fibres]. / Les marqueurs de l'exposition: analyses biométrologiques dans l'expectoration et le LBA - corps asbestosiques - fibres non gainées.

The aim of mineralogical analysis of lung tissue, bronchoalveolar lavage (BAL) and sputum is to characterize individuals' exposure to asbestos fibres by identifying markers of this; asbestos bodies (AB) and uncoated fibres. The techniques of mineralogical analysis, habitually used to identify AB and uncoated fibres, are respectively optical microscopy (OM) and analytical electronic microscopy (EM). Correlations between levels of retention of AB in lung tissue, BAL and sputum have been established and validated threshold values indicating a high probability of significant exposure exist. These results must be interpreted in the context of clinical and occupational information. Mineralogical analysis is not suitable for use in routine medical screening but it can be considered when a source of exposure is not evident from the questionnaire since a positive analysis of BAL or of sputum is highly specific and thus useful to confirm an important retention of asbestos in the lung, which justifies medical follow-up. A negative result does not exclude previous significant asbestos exposure (frequent false negatives occur especially in sputum and biopersistence of chrysotile is lower than for amphiboles). Thus it can be a complementary tool for the assessment of asbestos exposure but its use imposes conditions for the collection and handling of samples.

Comparison of lung asbestos fiber content in cancer subjects with healthy individuals with no known history of occupational asbestos exposure in Korea.

To evaluate the effects of environmental asbestos exposure on the inducement of lung cancer, pulmonary asbestos and non-asbestos fiber content was determined in 36 normal Korean subjects and 38 lung cancer subjects with no known occupational history of asbestos exposure. Pulmonary asbestos fiber content was measured by transmission electron microscopy (TEM) with energy-dispersive x-ray analysis after applying a low-temperature ashing procedure. Chrysotile fibers were the major fiber type found in the lungs of the Korean subjects. The asbestos fiber concentrations found in the lungs of normal males (25) and females (11) were 0.26 x 10(6) fibers/g of dry lung tissue and 0.16 x 10(6) fibers/g of dry lung tissue, respectively. The asbestos concentrations found in the lungs of cancer subjects were 0.16 x 10(6) fibers/g of dry lung tissue for 32 males and 0.44 x 10(6) fibers/g of dry lung tissue for 6 females. No statistical difference was found in pulmonary asbestos content between the normal and lung cancer subjects, whereas a statistical difference was noted between normal and lung cancer subjects with respect to lung non-asbestos content, indicating a potential role for non-asbestos fibers being associated with lung cancer.

Occupational exposure to asbestos and mortality among asbestos removal workers: a Poisson regression analysis.

The asbestos industry has shifted from manufacture to stripping/removal work. The aim of this study was to investigate early indications of mortality among removal workers. The study population consisted of 31 302 stripping/removal workers in the Great Britain Asbestos Survey, followed up to December 2005. Relative risks (RR) for causes of death with elevated standardised mortality ratios (SMR) and sufficient deaths were obtained from Poisson regression. Risk factors considered included dust suppression technique, type of respirator used, hours spent stripping, smoking status and exposure length. Deaths were elevated for all causes (SMR 123, 95% CI 119-127, n=985), all cancers including lung cancer, mesothelioma, and circulatory disease. There were no significant differences between suppression techniques and respirator types. Spending more than 40 h per week stripping rather than less than 10, increased mortality risk from all causes (RR 1.4, 95% CI 1.2-1.7), circulatory disease and ischaemic heart disease. Elevated mesothelioma risks were observed for those first exposed at young ages or exposed for more than 30 years. This study is a first step in assessing long-term mortality of asbestos removal workers in relation to working practices and asbestos exposure. Further follow-up will allow the impact of recent regulations to be assessed.

Identification and enumeration of asbestos fibers in the mining environment: mission and modification to the Federal Asbestos Standard.

Since the promulgation of the first Federal Asbestos Standard by the Occupational Safety and Health Administration in 1972, other federal agencies have modified the standard to better carry on their own unique missions. The instruments used to identify and measure asbestos, the sampling protocol, and the criteria used to define asbestos, have been modified to some degree. The Mine Safety and Health Administration regulates and controls asbestos dust in the mining and mineral commodity industries. However, crushed stone and processed ores contain mineral fragments that are frequently difficult to distinguish from asbestos. Mineral nomenclature, instruments for particle analysis, and sampling strategy must be accommodated to some degree to make asbestos control workable and meaningful. Precedent in other agencies has made consideration of these changes possible. Newly identified amphibole asbestos minerals have further complicated the agency's regulatory charge. Changes in its Asbestos Standard are now being considered. Crushed taconite ore in the Eastern Mesabi highlights many of these issues.

Asbestos reclamation at a disused industrial plant, Bagnoli (Naples, Italy).

Asbestos reclamation works were carried out at a disused industrial plant (157,000 m(2)) in Bagnoli, a high population density area of Naples. The case-study here presented recommends a new reclamation procedure that is not usually provided for by current international standards. To this purpose, a specific innovative cleaning machine (Safecar) was built in order to control the reclamation procedures also in non-confined areas. An accurate identification was planned and worked out of the various types of materials (10,111 t) present within the area, and this allowed a thorough mapping of the site to be decontaminated. Besides these reclamation activities, which were carried out in both confined and open sites, each material was cleaned, collected and encapsulated following diversified procedures, according to their characteristics. Moreover, the evaluation of airborne asbestos fibre concentrations, both within and outside the decontaminated area, assured a strict respect of environmental safety level.

Synchronous diffuse malignant mesothelioma and carcinomas in asbestos-exposed individuals.

AIMS: The development of synchronous diffuse malignant mesothelioma and carcinoma in individuals exposed to asbestos is rare. We report nine cases and discuss the medico-legal implications. METHODS AND RESULTS: Five hundred patients seeking compensation for asbestos-related diffuse malignant mesothelioma were reviewed with access to post-mortem data. The study group comprised cases in which a second (non-mesothelial) neoplasm was identified. The study group comprised eight males, one female, mean age 68 years (range 60-75). All individuals gave a history of asbestos exposure. Synchronous malignant mesothelioma with carcinoma was identified in 9/500 (1.8%). Eight malignant mesotheliomas were pleural, one was primary peritoneal in origin. By morphological subtyping there were four epithelioid, three biphasic and two sarcomatoid mesotheliomas. In 6/9 (67%) the second tumour was a primary bronchogenic carcinoma (three adenocarcinomas, two squamous cell carcinomas and one small-cell carcinoma). In 3/9 (33%) the second tumour was a non-bronchogenic carcinoma (colonic, pancreatic and breast ductal adenocarcinoma). No other neoplasms were identified in the cohort of malignant mesotheliomas studied. Five persons had pathological evidence of asbestosis (four had bronchogenic carcinomas, one colorectal adenocarcinoma). Two persons with non-bronchogenic carcinomas had identifiable asbestos bodies but no interstitial fibrosis. In two cases the second neoplasms (primary bronchogenic squamous cell and small-cell carcinomas) were associated with diffuse interstitial fibrosis but no asbestos bodies were seen on light microscopy. In each case transmission electron microscopic mineral analysis revealed an asbestos fibre burden within the background population range for control subjects and well below that seen in cases of established asbestosis. These cases were considered to represent cryptogenic fibrosing alveolitis in subjects with a history of asbestos exposure. CONCLUSIONS: Synchronous malignant mesothelioma with carcinomas in asbestos-exposed workers is rare and identified in 1.8% of 500 malignant mesotheliomas in this series. In most cases the carcinoma represents a primary bronchogenic neoplasm. Primary lung carcinomas are recognized to be asbestos related only when occurring in association with asbestosis. In this series this combination (bronchogenic carcinoma and asbestosis) was seen in four (0.8%) cases. In post-mortem cases for possible malignant mesothelioma it is important to identify any other neoplasia and determine whether it is related to asbestos. Their presence impact upon anticipated life expectancy and in the presence of malignant mesothelioma will affect the compensation settlement.

Anthophyllite exposure and endemic pleural plaques in Kumamoto, Japan.

OBJECTIVES: This study explored the high prevalence of pleural plaques in the town of Matsubase in Kumamoto, Japan. METHODS: Small-size chest X-ray film was used for screening, and all persons with pleural plaques were confirmed by computed tomography (CT). The prevalence rate of pleural plaques in the 4 districts of Matsubase and its surrounding towns and cities were also examined. The age-adjusted mortality rate for lung cancer in this town was compared with that of its surrounding towns and cities. RESULTS: Pleural plaques were found in 1357 persons (724 men and 633 women) among the inhabitants who were more than 20 years of age in Matsubase between 1988 and 1993. CT scans ascertained 938 cases with pleural plaques among the 11 14 persons who participated. Thus at least 9.5% of the inhabitants over 20 years of age in this town had pleural plaques. The neighboring towns had a higher rate than the more distant towns. A large-scale open-cast asbestos mine and mill had been in operation in Matsubase between 1883 and 1970. Mineral analysis revealed anthophyllite fibers. Most of the plaques were found in persons who had never worked in the mine or mill. CONCLUSIONS: The high prevalence of pleural plaques in Matsubase was due to anthophyllite exposure, mainly environmental. No mesotheliomas were found, however. These findings agree with those from an earlier study from Finland.

Analysis of asbestos fiber burden in lung tissue from mesothelioma patients.

Mesothelioma is a rare neoplasm that occurs most frequently in individuals with previous asbestos exposure. Differences for risk of development of asbestos-related mesothelioma and lung cancer have been attributed to the various types of asbestos, as well as to the dimension of the inhaled fibers. In the present study, 55 individuals with the pathological diagnosis of mesothelioma were evaluated as to ferruginous body and fiber content in lung tissue. The procedures used in the analysis included tissue digestion and analysis of the collected material for ferruginous bodies by light microscopy and for uncoated fibers by analytical transmission electron microscopy. Forty-six of the samples had ferruginous body concentrations of over 1000/per gram dry weight of lung tissue. The majority of the cores of these ferruginous bodies were amosite. Likewise, the most common uncoated asbestos fiber in the tissue was amosite. Only a small percentage of each type of asbestos would have been visible by light microscopy or even potentially by electron microscopy if the magnification was not sufficient to detect those with thin (< 0.2 micron) diameters. The consistent finding in most of the cases was a considerable presence of asbestos, often of mixed types.

[Asbestos fiber count in extra-pulmonary tissues]. / Riscontro di fibre di asbesto in tessuti extrapolmonari.

Most autoptic tissues of three men (two with pulmonary asbestosis and one without any exposure to asbestos) were analyzed by transmission electron microscopy and energy dispersion spectrometry for the quantitative and qualitative evaluation of asbestos fibers. Preliminary results indicate that only in cases with occupational exposure were found asbestos fibers (in lung, pleura , bladder, kidney and liver). These results allow interesting speculations on some environmental pathogenetic questions and deserve further investigations.

[Lung cancers attributable to asbestos on a pathological basis]. / Carcinomi polmonari attribuibili ad asbesto su base patologica.

More than 1,000 asbestos bodies/gram dry weight (AB/gdw) were found by light microscopy in lung tissues, out of 429 non selected cases of pulmonary carcinoma (264 from surgery and 165 from autopsy). Asbestosis was detected by histology in 28% of the cases with AB > 1,000/gdw (in 19% of the surgical cases, and in 38% of the autopsy cases). A proportion of 4% of the total cases may be related to asbestos exposure.