Malignant mesothelioma in non-asbestos textile workers in Florence

By means of a review of histological diagnosis in the Pathology Department of the University of Florence, suspected cases of malignant mesothelioma, diagnosed in the period 1979-1984, were identified. Study of histological specimens permitted the selection of 13 cases of malignant mesothelioma resident in the Province of Florence. To these cases, referents were matched for age, sex, and year of hospital admission, with residence weighted for the general population of the Province. Both cases and referents (or their next of kin) completed an occupational questionnaire detailing possible occupational exposures. Out of the 13 cases of mesothelioma, 6 were textile workers and 5 of these were "rag-sorters". There were only 5 textile workers among the 52 controls. No asbestos cloth production plants have been in operation in the area from which the cases and referents are derived. Possible sources of exposure to asbestos in the textile industry of this area are discussed.     

Malignant mesothelioma from neighborhood exposure to anthophyllite asbestos

BACKGROUND: Anthophyllite asbestos has been reported to cause asbestosis, lung cancer, mesothelioma, and pleural plaques in occupationally exposed workers. Anthophyllite has also been associated with pleural plaques in Finland and Japan among those who live near mines and mills and have neighborhood or environmental exposure. METHODS: We evaluated a 38-year-old patient with pleural mesothelioma who lived, attended school, and delivered newspapers near a manufacturing facility that used exclusively anthophyllite asbestos fiber from ages 8-17 years. He had no work exposure to asbestos. RESULTS: The pleural mesothelioma was an epithelial type with tubulopapillary structures and was treated with an extrapleural pneumonectomy followed by radiation therapy. The malignant cells were positive by immunohistochemistry for cytokeratin but negative for carcinoembryonic antigen, S100, B72.3, and leu M1 antigen. Anthophyllite fibers were > 5 microm in length in lung tissue compared to 3 microm from a general population study. CONCLUSIONS: Anthophyllite asbestos has been associated with neighborhood environmental exposure and pleural plaques; we now report a neighborhood exposure and pleural mesothelioma.     

Malignant mesothelioma of the pleura in Trieste, Italy.

One hundred and seventy malignant pleural mesotheliomas seen at necropsy at the Institute of Pathological Anatomy of the Trieste University during the period 1968-1987 were reviewed. The series included 153 men and 17 women, aged between 33 and 92 years (median 70 years). Lifetime work histories were obtained from the patients' relatives by personal or telephone interviews in 162 cases. A majority of the male subjects had been employed in "naval" work, 99 people having worked in the ship-building industry, 19 in the navy and merchant marine, and 7 in docks. A variety of trades appeared in the remaining histories. Work histories were indicative of occupational exposure to asbestos in 150 cases. A further 5 patients with negative or insufficient data showed asbestos bodies in routine lung sections and 5 women had a history of domestic exposure. A majority of the patients had had their first exposure before 1950. The intervals between first exposure and death ranged from 14 to 71 years (median 48 years).     

Malignant mesothelioma caused by childhood exposure to long-fiber low aspect ratio tremolite

A 41-year-old man was found to have a malignant mesothelioma of the pleura. During childhood in Corsica, he had been exposed at home to chrysotile ore from the Canari mine. Analysis of lung mineral content revealed background levels of chrysotile but an elevated level of tremolite and actinolite asbestos. The latter had a geometric mean length of 3.7 μm, a value considerably longer than we have found for tremolite and actinolite from Quebec chrysotile miners but roughly the same as the mean length of amosite and crocidolite in workers with occupational amphibole exposure. No tremolite or actinolite fibers of length greater than 8 μm microns and width less than 0.25 μm were observed. The mean aspect ratio of the tremolite and actinolite fibers was 7, a value similar to that found in chrysotile miners with mesothelioma but considerably less than the mean aspect ratio of amosite and crocidolite from those with occupational expsoure. These data suggest that long-fiber tremolite is a potential mesothelial carcinogen in humans, and that fiber length is more important than fiber aspect ratio in this regard.     

Malignant mesothelioma in Australia, 1945-2000

BACKGROUND: Australia has maintained a total national malignant mesothelioma case register since 1980. There has been a marked increase in the incidence of mesothelioma in the last 20 years. Currently 450-600 cases are notified annually in a population of 20 million. While the history of the Wittenoom (Western Australia) crocidolite mine and its aftermath is well known, these cases comprise only 5% of the total. This study describes the incidence of mesothelioma in Australia from 1945 to 2000. METHODS: Using register data, time trends in mesothelioma incidence were calculated. Analyses of incidence are reported by age, sex, anatomical site, and state of notification. Associations with occupational and environmental asbestos exposure histories are described. Lung fiber content measurements were made on a subset of cases. RESULTS: Australia has had 6,329 cases of mesothelioma from 1 January 1945 to 31 December 2000. (A further 620 cases were notified in the period from 1 January 2001 to 31 October 2001.) Annual incidence rates for Australia per million population > or = 20 years (1997) were: male, 59.8; female, 10.9; total, 35.4. Incidence rates have been continually increasing and are the highest reported national rates in the world. While Western Australia has the highest rate (1997 total rate, 52.8), most cases arise from the two most populous eastern states, New South Wales and Victoria. In 88% (male 90%, female 61%) of cases, a history of asbestos exposure was obtained. Exposures occurred in a wide variety of occupational and environmental circumstances. In 80% of cases with no history of exposure, TEM lung asbestos fiber counts > 200,000 fibers > 2 microm length per gm dry lung were obtained, suggesting unrecognized exposure. CONCLUSIONS: Australia's high incidence of mesothelioma is related to high past asbestos use, of all fiber types, in a wide variety of occupational and environmental settings. The number of cases in total is expected to be about 18,000 by 2020, with about 11,000 yet to appear.     

Malignant pleural mesothelioma in bakers and pastry cooks

BACKGROUND: The occurrence of malignant pleural mesothelioma (MPM) among bakers and pastry cooks has never been documented. CASE REPORTS: We detected eight cases of MPM in bakers, pastry cooks, and biscuit cooks engaged in making, baking/cooking, and selling pastry/bread in two hospital-based series (Rome and Orbassano/Turin, Italy; period 1990-1997; 222 cases). Field-investigations revealed asbestos-containing material (ACM) in ovens for baking bread, that were manufactured prior to the 1980s. CONCLUSIONS: It is suggested that there is a possible new association of the risk of having worked as a baker or pastry cook and MPM. Presumptive source of exposure to asbestos was the use of asbestos-insulated ovens.     

Malignant mesothelioma in thermoelectric power plant workers in Italy

Asbestos has been widely used in Italian thermoelectric power plants and instances of exposure to workers have been documented in a variety of jobs. Preventive measures were put into effect only in the late 1970s. We report here on four mesothelioma cases among workers of three Italian power plants where cohort studies were carried out, and on three additional cases recorded by a systematic survey carried out on this neoplasm in Tuscany. When the data of the cohorts sources are merged, a significant excess of lung cancer is also evident. Even without a quantitative assessment of exposure, this report shows the importance of asbestos risk in thermal power plants. The risk appears not to be restricted to any particular category of workers. © 1995 Wiley-Liss, Inc.     

Asbestos burden predicts survival in pleural mesothelioma

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rapidly fatal asbestos-associated malignancy with a median survival time of <1 year following diagnosis. Treatment strategy is determined in part using known prognostic factors. OBJECTIVE: The aim of this study was to examine the relationship between asbestos exposure and survival outcome in MPM in an effort to advance the understanding of the contribution of asbestos exposure to MPM prognosis. METHODS: We studied incident cases of MPM patients enrolled through the International Mesothelioma Program at Brigham and Women's Hospital in Boston, Massachusetts, using survival follow-up, self-reported asbestos exposure (n=128), and a subset of cases (n=80) with quantitative asbestos fiber burden measures. RESULTS: Consistent with the established literature, we found independent, significant associations between male sex and reduced survival (p<0.04), as well as between nonepithelioid tumor histology and reduced survival (p<0.02). Although self-reported exposure to asbestos was not predictive of survival among our cases, stratifying quantitative asbestos fiber burden [number of asbestos bodies per gram of lung (wet weight)] into groups of low (0-99 asbestos bodies), moderate (100-1,099), and high fiber burden (>1,099), suggested a survival duration association among these groups (p=0.06). After adjusting for covariates in a Cox model, we found that patients with a low asbestos burden had a 3-fold elevated risk of death compared to patients with a moderate fiber burden [95% confidence interval (CI), 0.95-9.5; p=0.06], and patients with a high asbestos burden had a 4.8-fold elevated risk of death (95% CI, 1.5-15.0; p<0.01) versus those with moderate exposure. CONCLUSION: Our data suggest that patient survival is associated with asbestos fiber burden in MPM and is perhaps modified by susceptibility.     

Influence of age at death on accuracy of death certificate disease diagnosis: findings in 475 consecutive deaths of mesothelioma among asbestos insulation workers and asbestos factory workers.

Age at death had no appreciable influence on accuracy of death certificate diagnoses of 475 consecutive deaths of mesothelioma among asbestos insulation and asbestos factory workers, until age 75 or older.     

Asbestos fiber analysis in 27 malignant mesothelioma cases.

The asbestos body counts per 5 gm wet lung tissue in 27 (23 pleural and 4 peritoneal) malignant mesothelioma cases derived from 19 autopsy and 8 surgical cases were, according to our own criteria, low level exposure in 13 cases (48.2%), moderate level exposure in 2 cases (7.4%), and high level exposure in 12 cases (44.4%). In our previous study on 235 consecutive autopsy cases, the low level exposure was considered to be environmental, the moderate level was secondary or blue collar, and the high level was occupational. In the present study, about half of the cases examined (44.4%, high level exposure) are closely related to some occupational asbestos exposure and the other half (48.2%) to environmental exposure. The type and size of asbestos fibers from the 12 cases of high level exposure were analyzed and the characteristics were compared with those of cases of low level exposure without lung cancer or mesothelioma. Most fibers analyzed (98%) were longer than 5 microns and thicker than 0.10 micron by our counting rules. In the control group, predominant fibers were tremolite or actinolite. In all the 11 pleural mesothelioma cases, the content of amosite fibers was significantly higher than in the controls. In one case of peritoneal mesothelioma, incipient asbestosis was found and the predominant fibers were crocidolite. It is suggested that the presence of amosite and crocidolite is linked to mesothelioma. The mean lengths of amosite and crocidolite, as detected by our resolution capabilities, were 36.0 and 20.9 microns, and the mean diameters were 0.51 and 0.27 micron, respectively. Both amosite and crocidolite fibers had high aspect ratios (94.2 and 115.4).     

Asbestos-induced lung injury among danish jewelry workers

Asbestos has been used extensively in a variety of occupations. In the jewelry industry, inadequate hygiene practices may often go unrecognized with resultant exposure to hazardous amounts of asbestos. We report on four retired jewelers. Two of these had both pleural and parenchymal changes. One had isolated pleural plaques and the final patient showed only parenchymal infiltrates. Their work involved hand cutting asbestos plates used for protection during soldering. In the soldering process asbestos fibers were then blown into the workroom air as the plates broke down. In addition, at the end of each work day the workroom floor was swept, with subsequent airborne asbestos dust distribution. Any patient with pleural plaques or interstitial lung disease should be questioned about potential sources of asbestos exposure in the past, regardless of present employment status.     

The incidence of malignant mesothelioma in Australia 1982-1988.

From 1980 to 1985, the Australian Mesothelioma Surveillance Program, and since 1986, the Australian Mesothelioma Register, have been collecting data on all cases of malignant mesothelioma that could be ascertained in Australia. Incidence rates were calculated on 854 Program and 696 Register cases (total 1271) diagnosed in Australia between January 1, 1982 and December 31, 1988. Australia has one of the highest national rates of mesothelioma in the world (15.8 cases per million of population aged 20 years and older), and the rate is rising. The rate is far higher in males (28.3) than females (3.3). The Western Australian rate (28.9) is the highest among the states, as may be expected because of the crocidolite mine at Wittenoom; however, the largest numbers of cases occur in the more populous and industrial New South Wales. The high incidence rate, its expected continuing increase, and absence of a history of exposure to asbestos in approximately 28% of cases, demand consideration of potential environmental factors other than asbestos in the causation of this tumor, as well as continued surveillance.     

Pleural mesothelioma after a short interval from first exposure in the wine filter industry

Pleural mesotheliomas are usually reported after a long interval has passed since first exposure to asbestos. We, however, describe a case observed after a latent period of only 7.5 years in a worker exposed in a factory manufacturing auxiliary products for wine treatment, including chrysotile asbestos filters. The exposure to asbestos lasted 3-4 months per year, during which airborne fiber concentrations ranged from 1 to 4 ff/cc in the patient's workplace. Due to the characteristics of the manufacturing process, the asbestos fibers were very thin in diameter. The patient also suffered from nasal breathing impairment. An examination of the literature showed that asbestos-related mesotheliomas have been reported, albeit rarely, after less than 10 years from onset of exposure. Therefore, it is believed that this case should be related to past exposure to asbestos.     

Incidence of malignant mesothelioma in Aboriginal people in Western Australia

Objectives : To describe the incidence of malignant mesothelioma (MM) in Aboriginal people in Western Australia (WA) and determine the main routes of exposure to asbestos in this population. Methods : All MM cases in Western Australia, as well as the primary source of asbestos exposure, are recorded in the WA Mesothelioma Register. Aboriginal cases up to the end of 2013 were extracted from the register and compared with non‐Aboriginal cases with respect to the primary means/source of exposure. Age‐standardised incidence rates for each decade from 1980 were calculated for both Aboriginals and non‐Aboriginals. Age‐standardised mortality rates were calculated for the period 1994–2008 and compared with international rates. Results : There were 39 cases (77% male) of MM among WA Aboriginal people. Twenty‐six (67%) were a direct result of the mining of crocidolite at Wittenoom and the subsequent contamination of the surrounding lands. Of the non‐Aboriginal MM cases (n = 2070, 86.3% male), fewer than 25% can be attributed to Wittenoom. Aboriginals had consistently higher 10‐year incidence rates than non‐Aboriginals and, when compared to world populations, the highest mortality rate internationally. Conclusion : When incidence rates in Aboriginal people are compared with non‐Aboriginal people, the Wittenoom mining operation has had a disproportionate effect on MM incidence in the local Aboriginal population.