An outbreak of cancer and asbestosis among former amosite-exposed subjects in Ledro Valley, Italy. From discovery to environmental cleanup.

Here are reviewed the studies conducted on asbestos-amosite pollution and its effects on the health of workers exposed from 1928 to 1973 at the Collotta-Cis factory of Ledro, Italy. The methods adopted to conduct the initial research, involving the population itself and the local administrations are described. The data summarized include: epidemiological studies of mortality carried out in 1977-85 and updated in 2009; results of the investigations carried out throughout the 1980s on the health consequences on workers, their families and residents near the factory; process of environmental cleanup from asbestos of the industrial area, completed in 1989, and the pollution risk assessment in the whole Ledro Valley. Although this was a small community of about 400 workers, these studies show that exposure to asbestos is responsible for the death of 81 people (22 mesotheliomas, 21 asbestosis, 38 malignant tumors of the lung, digestive system, ovary), for 1400 years of life lost, and for about 100 invalidity pensions, as recognized to former workers by INAIL.

"Candido's List": the workers of Collotta Cis & Figli at Molina di Ledro in Trento Province, Italy. A tale of magnesia, asbestos and work.

The study entitled "Candido's List" (La Lista di Candido) is not the work of the three authors alone. A good part of the community is entitled to feel itself coauthor, each for his/her own part, of a research project that has succeeded in blending a variety of different ingredients: history, entrepreneurship, the industrialization of the Trento Province with all its high and low points, personal life stories, medicine, genius, work, women's emancipation, the past but also the present and future. The research comprises an eloquent collection of memories and a variety of iconographic materials; it has now become a book and a travelling exhibition containing the accounts of the people who worked at the Collotta-Cis factory in Molina di Ledro. It starts with the brilliance of Pier Antonio Cassoni, who in 1816 deposited the first patent in the world for the extraction of magnesium carbonate, and closes with the decontamination of the factory site in the late 1980s. A needful section has been set aside for the painful facts relating to the processing of asbestos fibre; a final space, midway between an artistic reading and an interpretation for the future, has seen the involvement of the Circolo Fotoamatori di Ledro, with a photographic itinerary enabling the reader to "virtually' enter the remaining worksites and listen to these spaces "tell" their stories after years of silence. A story in black and white, where the two tones are also messages for reading a complex story, one that it is important to remember.

Amianto. Cáncer de laringe / Asbestos. Laryngeal cancer

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[Asbestos exposure assessment in the first case of intrasplenic mesothelioma]. / Accertamento dell'esposizione ad amianto nel primo caso di mesothelioma splenico.

BACKGROUND: In 2013 the International Journal of Surgical Pathology published a case report of intrasplenic malignant mesothelioma (MM) in a 48-year-old man: it was the first report in literature describing a case of primitive intra-splenic MM, described without  a history of asbestos exposure. OBJECTIVE: To verify the possible past exposure to asbestos, ignored by the patient himself, by studying in depth his environmental and occupational history. METHODS: Information about the occupational and non-occupational history of the subject was collected by Experts of the Operational Unit of Occupational Health and Safety Control (UOC PSAL) of the Local Health Unit Umbria 1 - Perugia, using the Italian National Mesothelioma Register (ReNaM) questionnaire and guide lines; an inspection was  carried out at the past canning industry where the patient worked in the period 1982-1990 and material was taken to be analysed by MOCF and SEM. RESULTS: Samples showed the presence of asbestos  fibres belonging to the amphibole class (amosite and crocidolite) and to the serpentine class (chrysotile). CONCLUSIONS: The survey described the past occupational exposure to asbestos in a canning industry, where  the subject worked in the period 1982-1990,  unknown to the patient himself. The authors strongly confirm the  usefulness of standardized methods, such as the ReNaM Questionnaire, and the importance of technical expertise of the investigator to find and analyse the suspect materials and to demonstrate  possible past occupational exposure to asbestos.

Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden.

BACKGROUND: We have conducted a population-based study of pleural mesothelioma patients with occupational histories and measured asbestos lung burdens in occupationally exposed workers and in the general population. The relationship between lung burden and risk, particularly at environmental exposure levels, will enable future mesothelioma rates in people born after 1965 who never installed asbestos to be predicted from their asbestos lung burdens. METHODS: Following personal interview asbestos fibres longer than 5 µm were counted by transmission electron microscopy in lung samples obtained from 133 patients with mesothelioma and 262 patients with lung cancer. ORs for mesothelioma were converted to lifetime risks. RESULTS: Lifetime mesothelioma risk is approximately 0.02% per 1000 amphibole fibres per gram of dry lung tissue over a more than 100-fold range, from 1 to 4 in the most heavily exposed building workers to less than 1 in 500 in most of the population. The asbestos fibres counted were amosite (75%), crocidolite (18%), other amphiboles (5%) and chrysotile (2%). CONCLUSIONS: The approximate linearity of the dose-response together with lung burden measurements in younger people will provide reasonably reliable predictions of future mesothelioma rates in those born since 1965 whose risks cannot yet be seen in national rates. Burdens in those born more recently will indicate the continuing occupational and environmental hazards under current asbestos control regulations. Our results confirm the major contribution of amosite to UK mesothelioma incidence and the substantial contribution of non-occupational exposure, particularly in women.

[Estimation of the indoor diffusion of asbestos fibers with the diffusion model for the external environment of Pasquill and Gifford]. / Stima della diffusione indoor di fibre di amianto con il modello diffusionale di Pasquill e Gifford per l'ambiente esterno.

In absence of results of environmental monitoring to proceed with the assessment of occupational exposure, it was developed a model that retraces the one of Pasquill and Gifford, currently used for the estimation of concentrations of pollutants at certain distances from the source in outdoor environment. Purpose of the study is the quantitative estimate of the diffusion of airborne asbestos fibers in function of the distance from the source in an factory where railway carriages were produced during the period when asbestos was sprayed as insulator of the body. The treatment was carried out in a large shed without separation from other operations. The application of the model, given the characteristics of the emitting source, has allowed us to estimate the diffusion of particles inside the shed with an expected decrease in concentration inversely proportional to the distance from the source. By appropriate calculations the concentration by weight has been converted into number offibers by volume, the unit of measure currently used for the definition of asbestos pollution.

[Asbestosis still exists ]. / L'asbestose existe encore

A diagnosis of asbestosis, lung fibrosis due to asbestos exposure, was proposed in 2003 in a 64-year-old woman on the basis of the history, computed tomography appearances, lung function studies, and biometric data. This diagnosis was confirmed by the pathological examination of a lung lobe resected surgically for bronchial carcinoma in 2010. The diagnosis of asbestosis is now rarely made as a result of a substantial decrease in dust exposure over the past decades and mainly because of the interdiction of asbestos use in western countries. Currently, the most frequent thoracic manifestations of asbestos exposure are benign pleural lesions and mesothelioma. It has also become exceptional to have pathological confirmation of the diagnosis, obtained in this woman thanks to the surgical treatment of another complication of her occupational exposure.

[Asbestos fibre lung burden and exposure indices in asbestos-cement workers]. / Carico polmonare di fibre di asbesto e indici di esposizione cumulativa in lavoratori del cementoamianto.

BACKGROUND: In many previous studies, the asbestos fibres retained in the lung were regarded as a good index of cumulative occupational asbestos exposure. Twelve workers suffering from asbestos-related diseases and had been employed in an asbestos-cement factory operating from 1961 to 1994 underwent post mortem investigations in the course of a criminal law suit. OBJECTIVES: Samples of lung tissues were collected for electron microscopy analysis to measure the asbestos fibre burden of the lungs in workers with high exposure, and assess the possible correlation between asbestos fibre lung burden and the estimated levels of cumulative exposure. METHODS: Samples of lung parenchyma obtained from a consecutive series of 12 post-mortem examinations that were performed between 1994 and 2007and included 5 cases of malignant pleural mesothelioma, 4 lung cancers, 1 case of asbestosis and2 ofpleuralplagues, were collected, stored and analysed by SEM electron microscopy, according to the methods suggested by the current scientific literature. For each worker, all males, a detailed occupational history was reconstructed by means ofpersonal interviews; both the measurements of airborne asbestos fibresperformed by the factory in the 1970's and the duration of each single job in the plant were taken into account to estimate an individual cumulative exposure index. RESULTS: A wide variation of total asbestos fibre concentrations in the lung (1,320-118 million) was observed; in all 12 workers, the lung amphibole fibre burden exceeded 1,000,000 fibres per g/dry tissue, The highest values were detected in the mesothelioma cases, in which the mean fibre concentrations differed statistically (t=2.29, p=0.045) from the mean calculated for the other asbestos-related diseases; in 9 subjects only amphibole fibres were detected. There was a good correlation between total asbestos fibre concentration and cumulative exposure index (r=0.91, p<0.0001). CONCLUSION: This study, which was numerically the biggest ever performed in Italy for this category of workers, confirms a wide range of total asbestos fibre burden in heavily occupationally exposed workers and showed that of the asbestos-related diseases, the highest lung concentrations of asbestos fibres were reached in cases of mesothelioma. It was also observed that almost the entire lung burden consists of only amphibole fibres, all exceeding 1 million per gramme of dry tissue. This study tested a synthetic cumulative occupational exposure index, which appears to be well correlated to the level of exposure established by biological analysis.

Occupational, domestic and environmental mesothelioma risks in the British population: a case-control study.

We obtained lifetime occupational and residential histories by telephone interview with 622 mesothelioma patients (512 men, 110 women) and 1420 population controls. Odds ratios (ORs) were converted to lifetime risk (LR) estimates for Britons born in the 1940s. Male ORs (95% confidence interval (CI)) relative to low-risk occupations for >10 years of exposure before the age of 30 years were 50.0 (25.8-96.8) for carpenters (LR 1 in 17), 17.1 (10.3-28.3) for plumbers, electricians and painters, 7.0 (3.2-15.2) for other construction workers, 15.3 (9.0-26.2) for other recognised high-risk occupations and 5.2 (3.1-8.5) in other industries where asbestos may be encountered. The LR was similar in apparently unexposed men and women (approximately 1 in 1000), and this was approximately doubled in exposed workers' relatives (OR 2.0, 95% CI 1.3-3.2). No other environmental hazards were identified. In all, 14% of male and 62% of female cases were not attributable to occupational or domestic asbestos exposure. Approximately half of the male cases were construction workers, and only four had worked for more than 5 years in asbestos product manufacture.

Crocidolite and mesothelioma.

This study reports changes in the frequency of detection of various asbestos fiber types between 1982 and 2005. Crocidolite is increasingly detected in U.S. mesothelioma patients. The percentage of crocidolite fibers detected in lung tissue has risen from 4 to 10%, and the percentage of cases in which crocidolite was detected increased from 19 to 37%. Meanwhile, the frequency of detection of amosite and chrysotile has decreased. The authors performed a detailed analysis of cases in which crocidolite was identified in the absence of amosite. Most of such cases were identified in recent years, a finding of concern since crocidolite is considered the most potent fiber type with respect to the pathogenesis of mesothelioma.

Human health effects associated with the commercial use of grunerite asbestos (amosite): Paterson, NJ; Tyler, TX; Uxbridge, UK.

Grunerite asbestos (amosite) has been shown in epidemiological and experimental animal studies to cause lung cancer, mesothelioma and pulmonary fibrosis commonly referred to as asbestosis. An overview of the human and experimental animal studies describing the health hazards of grunerite asbestos (amosite) is presented. Of the many human studies describing the health hazards of asbestos, only three factories using mainly, if not exclusively, grunerite asbestos (amosite) have been studied. The first is a series of reports on a cohort of 820 workers from a plant located in Paterson, NJ. Among this cohort, 18.7% died of lung cancer and 17 mesotheliomas occurred. The Paterson factory closed in 1954 and moved to Tyler, Texas where it operated until 1972. Among the 1130 former workers in the Tyler plant 6 mesotheliomas were reported with 15.8% lung cancer mortality. The third grunerite asbestos (amosite) exposed cohort was an insulation board manufacturing facility in Uxbridge, United Kingdom. Here 17.1% of the workers died of lung cancer and 5 mesotheliomas occurred. The lung content from 48 Uxbridge workers was analyzed by analytical transmission electron microscopy for mineral fibers. The relationship between grunerite asbestos (amosite) concentrations in the lung correlated with grades of fibrosis and asbestos bodies and was lower than the concentration found in the cases with malignant tumors. The lung cancer cases contained more grunerite asbestos (amosite) than mesothelioma cases, and in the cases of non-malignant disease the concentrations were still lower. In both types of malignancies the concentration of grunerite asbestos (amosite) was very high-over a billion fibers per gram of dried lung tissue. Occupational exposure to airborne concentrations of between 14 and 100 fibers of grunerite asbestos (amosite) per milliliter after 20 year latency causes marked increases in lung cancer, mesothelioma and pulmonary fibrosis (asbestosis).

Health effects of amosite mining and milling in South Africa.

This study focuses on the amosite mining region in South Africa and associated health effects, compared to other mined asbestos fiber types. Historically, dust and fiber levels were high in the amosite mills and mines, and many miners and members of the surrounding communities were exposed to the fibers. Research has shown that amosite produces both benign and malignant disease. Nevertheless, the mesotheliomagenic potential of amosite is several fold lower than crocidolite. The risk of disease associated with amosite exposure is difficult to quantify. Reasons for this include the scarcity of available information, including fiber measurements, and case ascertainment, as well as the juxtaposition of the amosite and crocidolite asbestos seams in South Africa.

South African experience with asbestos related environmental mesothelioma: is asbestos fiber type important?

South Africa (SA), a country in which all three commercially important asbestos minerals have been mined and milled, has retained proven cases of mesothelioma linked with environmental exposure to asbestos. This study illustrates the importance of fiber type in the occurrence of environmental mesothelioma. Four studies have reviewed the source of occupational or environmental asbestos exposure in 504 histologically proven cases of mesothelioma in South Africa. One hundred and eighteen cases (23%) were thought to be related to environmental exposure to asbestos. In the vast majority of these cases, exposure was linked to crocidolite mining activities in the Northern Cape Province. Two cases were thought to have occurred in relation to amosite and Transvaal crocidolite exposure in the Limpopo Province. In the balance of cases there was some uncertainty. No cases were reported with exposure to South African chrysotile. Consequently, in the vast majority of cases of mesothelioma, environmental exposure to asbestos occurred in the Northern Cape Province, in proximity to mines, mills and dumps where crocidolite was processed. Crocidolite appears to be far more mesotheliomagenic than amosite, and chrysotile has not been implicated in the disease. This is true for both occupationally and environmentally exposed individuals.

The role of analytical SEM in the determination of causation in malignant mesothelioma.

The causative relationship between asbestos exposure and mesothelioma is firmly established. Some information in this regard comes from analysis of the fiber content of lung tissue by means of analytical electron microscopy. The author has had the opportunity to study the lung asbestos content of 396 cases of mesothelioma, including 28 peritoneal cases, by means of analytical scanning electron microscopy. The highest fiber levels occurred in patients who also had asbestosis, which was found in 12% of pleural and 43% of peritoneal cases. Elevated tissue asbestos content was identified in 87% of pleural and 75% of peritoneal cases. Peritoneal cases that are asbestos related have on average a higher lung fiber burden than pleural cases. Mesotheliomas in women have elevated tissue asbestos content in about 60% of cases, and many of these had a history of exposure as a household contact of an asbestos worker. The main fiber type identified in our series was amphibole, predominantly amosite. These fibers have been demonstrated to reach the target tissue, the pleura.

Asbestos burden in cases of mesothelioma from individuals from various regions of the United States.

Mesothelioma is a rare tumor that is considered an asbestos marker disease. It occurs in individuals following a longer latency period from first exposure than other asbestos-related diseases. The tumor also occurs in individuals with a wide range of exposures, including individuals with lower level or secondary exposures. In the present study lung tissue from 54 individuals with a pathological diagnosis of mesothelioma was evaluated for ferruginous body and uncoated asbestos fiber content. The data were compared with an earlier study of mesothelioma cases from the northwestern United States. Tissue was prepared via a digestion procedure, with the collected digestate reviewed by light microscopy for quantification of asbestos bodies and analytical transmission electron microscopy for determination of uncoated fiber burden. Twenty-seven cases in the present study had over 1000 ferruginous bodies per gram of dry tissue. The data suggest that amosite provides a more likely stimulus for ferruginous coating than the other forms of asbestos. All individuals were found to have asbestos fibers in their lung tissue. Amosite was the most commonly found fiber, with anthophyllite being the second most commonly found type of asbestos. The finding of tremolite in the tissue most often was associated with the finding of anthophyllite. A limited number of asbestos fibers of each type would have been seen in the light microscope, with the least detected being chrysotile. The majority of all fiber types were found as short fibers (< 8 mum), although some longer fibers were represented in each type of asbestos. The majority of the individuals were found to have mixed types of asbestos in their lungs.

Quantitative analysis of asbestos burden in women with mesothelioma.

BACKGROUND: Lung tissue from 15 women who died from mesothelioma was evaluated for tissue burden of ferruginous bodies and uncoated asbestos fibers. The group contained individuals who had occupational exposure to asbestos and others had family members whose work history included vocations where contact with asbestos containing materials occurred. METHODS: Tissue samples from tumor free lung were digested and filtered and then investigated for ferruginous bodies by light microscopy and asbestos and non-asbestos fibers by analytical transmission electron microscopy (ATEM). Size and type of fibers were also analyzed. RESULTS: Asbestos bodies were found in 13 of the 15 samples and asbestos fibers were found in all cases. The most commonly found uncoated asbestos fiber in these individuals was amosite whereas tremolite was the second most commonly found form. The asbestos fiber burden in these females was often of mixed types. CONCLUSIONS: The asbestos body and fiber burden in these cases show variation in tissue burden. Some cases in this study had appreciable burden, which was attributed to secondhand exposure from occupationally exposed family members. Mesothelioma can occur also in individuals with comparatively low tissue burdens of asbestos.

Airway wall remodeling induced by occupational mineral dusts and air pollutant particles.

OBJECTIVES: COPD has been reported in workers exposed to particulates, and there is increasing evidence that high levels of ambient particulate pollutants may also be associated with COPD. The studies here investigate the hypothesis that particulates, including air pollution particles, can induce airway wall fibrosis, a process that can lead to COPD. DESIGN: Rat tracheal explants were exposed to various occupationally encountered dusts, air pollution particles, and model air pollution particles. In some experiments, iron was loaded onto the particle surface. Gene expression and nuclear factor (NF)-kappaB activation were measured after 7 days of air culture. Adhesion to and uptake of dusts by the tracheal epithelium were also evaluated. RESULTS: Known fibrogenic dusts such as amosite asbestos produced increased gene expression of procollagen, transforming growth factor-beta, and platelet-derived growth factor, and increased hydroxyproline in the explants, and the addition of iron increased these effects. The addition of iron also converted nonfibrogenic TiO2 into a fibrogenic dust. Dusts with surface complexed iron activated NF-kappaB via an oxidant mechanism. However, an ultrafine TiO2 with very low iron was also fibrogenic. In separate experiments, exogenous tumor necrosis factor-alpha increased dust adhesion to, and exogenous ozone increased dust uptake by, tracheal epithelial cells. CONCLUSIONS: Mineral dusts can directly induce fibrosis in the airway wall. Exogenous inflammatory cells and exogenous agents are not required, but they probably exaggerate the fibrogenic effects. An iron-mediated oxidant mechanism underlies the fibrogenic effects of some, but not all, of these dusts. Particle-induced airway wall fibrosis may lead to COPD.

Community health risk assessment after a fire with asbestos containing fallout.

BACKGROUND: A factory fire in Tranmere, Merseyside, England, deposited asbestos containing fallout in an urban area. There was considerable community anxiety for months after the incident. Therefore an assessment of the long term health risks of this acute environmental incident were requested by the local health authority. METHODS: The facts of the incident were gathered and appraised from unpublished and press reports, involved personnel, and further analysis of material collected at the time of the incident. The literature on the long term health risks of asbestos was reviewed, and combined with evidence on asbestos exposure to estimate community health risk. RESULTS: Risk was almost entirely from exposure to fire fallout of chrysotile in asbestos bitumen paper covering the factory roof. Amosite was only detected in a few samples and in trace amounts. The number of people who lived in the area of fallout was 16 000 to 48 000. From a non-threshold model with assumptions likely to overestimate risk, the lung cancer risk is estimated to be undetectably small. Risk of mesothelioma from chrysotile exposure, and risks of lung cancer and mesothelioma from amosite exposure were based on observational studies and were estimated to be even lower than that of lung cancer risk from chrysotile exposure. Academically, there are assumptions that while reasonable cannot be proven, for example, the validity of extrapolating observed risk from much higher exposures to lower exposures, estimates of individual exposure, and that there is no threshold for asbestos to cause cancer. CONCLUSIONS: The author is unaware of a similar study on long term health risks in a community exposed to asbestos in a fire. It is concluded that, using methods that do not underestimate risk, risk is undetectably small. Practical lessons from this methodology and approach to health risk assessment are discussed.