Asbestos related diseases in Italy: an integrated approach to identify unexpected professional or environmental exposure risks at municipal level

PURPOSE: Past intensive use of asbestos has implied severe public health consequences. Spatial distribution of deaths from malignant mesothelioma and of compensated cases for asbestos related diseases in Italy were compared to identify unexpected sources of asbestos exposure. METHODS: Mortality for malignant mesothelioma at municipal level and geographical clusters of compensated cases for asbestos related diseases, as proxy of industrial asbestos exposure, were identified in the period 1988-2001. RESULTS: Municipalities with at least four mesothelioma deaths and a statistically significant mortality excess were 148; and 53 out of them had no compensated case for asbestos-related diseases. Finally 22 of these lay outside of any aforementioned cluster, thus suggestive of a possible unrecognized exposure. CONCLUSIONS: Availability long-term national figures and the different etiology of asbestos related diseases are the key features of this exercise that was applied to Italy, but can be replicated wherever registration systems of diseases related to long term exposure to asbestos are available.     

Malignant mesothelioma of the pleura among women

BACKGROUND: The epidemiological features of mesothelioma among women differ from those observed among men. OBJECTIVES: To trace the outline of pleural mesothelioma among women in the Monfalcone area, Italy. METHODS: Thirty-three malignant mesotheliomas of the pleura observed in female patients at the Hospital of Monfalcone, Italy, in the period 1979-2002 were reviewed. The diagnosis was based on/or confirmed by necropsy findings in 30 cases. Occupational and social histories were obtained from the patients themselves or from their relatives by personal or telephone interviews. In 29 necropsy cases thoracic cavities were examined for the presence of pleural plaques. Routine lung section were examined for asbestos bodies in 30 cases. In 21 cases asbestos bodies were isolated and counted after chemical digestion of lung tissue. RESULTS: The age of the patients ranged between 48 and 89 years (mean 72.85, median 73.00). All the patients had histories of exposure to asbestos, single in 25 cases and mixed in 8. Exposure at home due to cleaning of work clothes was the most frequent type of exposure. Various patients had been exposed in non-asbestos text industries (cotton mills). Unusual types of exposure occurred in some cases (distillery, small sodium carbonate factory, starch factory). The latency periods (time intervals elapsed between first exposure to asbestos and diagnosis of the tumour), calculated in 23 cases, ranged from 34 to 62 years. Pleural plaques were found in 21 cases. Twelve patients showed asbestos bodies on routine lung sections. The asbestos body burden ranged between only a few bodies and 92,000/g dried tissue. CONCLUSIONS: In contrast with other series of mesothelioma among women, all the present cases were attributable to asbestos. The detection of objective signs of exposure (pleural plaques, lung asbestos bodies) played a key role in attribution.     

Role of occupational asbestos exposure in Hungarian lung cancer patients

Objective: What is the frequency of occupational asbestos exposure among patients suffering from malignant respiratory tumours and how many of these tumours are associated with asbestos in Hungary? Methods: An internationally established questionnaire with 29 questions, covering the most characteristic activities of asbestos exposure at the workplace was completed for 300 patients with respiratory malignancies, i.e. 297 patients with lung cancer and three with mesothelioma of the pleura. From the questionnaire, the smoking habits were estimated and cumulative asbestos exposure was assessed in fibre-years. Additionally, lung X-rays were classified and the national data on the incidence of malignant pleura mesothelioma were analysed. Results: A cumulative asbestos exposure of 25?fibre-years or more was detected in 11 patients with lung cancer (4%) and in each of the three patients with pleural mesothelioma (100%). In a further 72 patients (24%), cumulative occupational asbestos exposure was assessed as below 25?fibre-years (between 0.01 and 23.9?fibre-years). In this group, car and truck mechanics, and installation and construction workers using asbestos-cement were registered. Among patients with an asbestos exposure of 25?fibre-years or more, six asbestos-cement production workers were observed, among them the three mesothelioma cases. A weak but significant association between positive X-ray findings and exposure estimates could be demonstrated. Additionally, results of the lung tissue fibre counts by scanning transmission electron microscopy were available for 25 of the lung cancer patients. A good correlation was observed between the asbestos fibre counts and the assessment of cumulative asbestos exposure. In Hungary, 84 cases of pleural mesothelioma were registered in 1997 and 73 in 1998. These numbers correspond to an annual incidence of about one new case per 100,000 inhabitants older than 15?years. Conclusions: The annual incidence of lung cancer in Hungary is about 6,000. Since in our series of lung cancer patients about 4% were observed, which could be accepted as representing occupational disease because of a cumulative exposure to 25?fibre-years or more, the annual asbestos related lung tumour incidences may be estimated to be approximately 150 or more. The proportion of nearly two estimated cases of lung cancer per case of pleural mesothelioma corresponds to international experience. Up to now, lung cancer cases only exceptionally have been registered as occupational diseases, i.e. they were seriously under-diagnosed in Hungary. For improving this situation, diagnostic assistance by a self-interview with a questionnaire covering the working history for all newly diagnosed lung cancer patients would be helpful.     

Cancer incidence among workers in the asbestos-cement producing industry in Norway

OBJECTIVES: The incidence of cancer among employees of a Norwegian asbestos-cement factory was studied in relation to duration of exposure and time since first exposure. The factory was active in 1942-1968. Most of the asbestos in use was chrysotile, but for technical reasons 8% amphiboles was added. METHODS: For the identification of cancer cases, a cohort of 541 male workers was linked to the Cancer Registry of Norway. The analysis was based on the comparison between the observed and expected number of cancer cases. Standardized incidence ratios (SIR) and 95% confidence intervals (95% CI) were estimated. Period of first employment, duration of employment, and time since first employment were used as indicators of exposure. Poisson regression analysis was used for the internal comparisons. RESULTS: The standardized incidence ratio was 52.5 (95% CI 31.1-83.0) for pleural mesothelioma, on the basis of 18 cases. The highest standardized incidence ratio was found for workers first employed in the earliest production period (SIR 99.0, 95% CI 51.3-173). No peritoneal mesothelioma was found. The standardized incidence ratio for lung cancer was 3.1 (95% CI 2.14.3), but no dose-response effect was observed. The ratio of mesothelioma to lung cancer cases was 1:2. CONCLUSIONS: This study showed a high incidence of mesothelioma and a high ratio of mesothelioma to lung cancer among asbestos-cement workers. The high incidence of mesothelioma was probably due to the fact that a relatively high proportion of amphiboles was used in the production process.     

Familial mesothelioma of the pleura--a report of 40 cases

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.     

Pleural mesothelioma in women in the Veneto Region who used to work as rag sorters for textile recycling and paper production

The paper reports 9 cases of mesothelioma diagnosed by means of histology or cytology that were observed among women resident in the Veneto Region, Northern Italy, whose only activity that could involve exposure to asbestos was as rag sorter. These cases are part of a group of about 260 subjects with mesothelioma whose entire working and residential history has been collected. The women worked as rag sorters between the 1940's and 1960's in textile recycling (8 cases) or (one case) at a paper mill where cotton was used for paper production. The work as rag sorter helps to explain the high proportion of mesotheliomas among women with an occupational exposure to asbestos.     

Tuscany mesothelioma registry (1988-2000): evaluation of asbestos exposure

BACKGROUND: The Tuscany Mesothelioma Register (ARTMM) records pleural malignant mesothelioma cases of Tuscany residents, diagnosed by histological, cytological, or clinical (radiography or computerized tomography) examinations. The ARTMM began in 1988 and estimates mesothelioma incidence in Tuscany and collects information on past asbestos exposure of mesothelioma cases. OBJECTIVES: The aim of this paper was to describe the incidence of pleural mesothelioma cases in Tuscany and to analyse their possible past asbestos exposures. METHODS: We considered pleural mesothelioma cases recorded in ARTMM in the period 1988-2000 and interviews collected for these cases. In order to identify past asbestos exposure in the occupational and non-occupational history of patients, interviews were carried out using a standardised questionnaire. RESULTS: In the period 1988-2000, 494 pleural malignant mesothelioma cases were recorded in the ARTMM; 82% were males. In the periods 1988-1993, 1994-1997, 1998-2000 the incidence rates, standardised on the Italian population (per 100,000), were respectively 1.15, 1.57, 2.58 among males; 0.29; 0.27; 0.29 among females. Information on occupational history was collected for 418 mesothelioma patients (85% of recorded cases): 173 mesothelioma cases were directly interviewed; for 245 cases relatives or work colleagues were interviewed. Occupational asbestos exposure was ranked as certain, probable or possible in 72% of the interviewed cases (80% of males; 20% of females). Environmental and non-occupational asbestos exposure was identified in 1% of males, and 3% of females. In 24% of the interviewed cases (15% of males; 74% of females) no known asbestos exposure was identified. Occupational asbestos exposure occurred in maritime activities (shipyards, dock work, merchant and regular Navy), the building industry, railway carriage construction and maintenance, rail transport, textile industries (mainly rag sorting), electricity production, asbestos cement manufacture, chemical, iron and steel industries and in glass manufacturing. In Tuscany two areas are distinguished for their well-documented and massive use of asbestos: the coastal areas (Livorno and Massa Carrara) for maritime activities, and the areas of Pistoia and Arezzo for railway carriage construction and repair. Mesothelioma incidence rates in these areas are the highest in the whole region. CONCLUSIONS: Further investigation is needed in order to identify unknown asbestos uses and consequent exposure, in particular for females. Uncertainty as regards occurrence of asbestos exposure persists in the textile industries where the mesothelioma epidemics have not yet declined. Research hypotheses are addressed on the re-use of jute bags previously containing asbestos, therefore collection of further information on periods and methods of this recycling activity is essential.     

A one-generation cluster of malignant mesothelioma within a family reveals exposure to asbestos-contaminated jute bags in Naples,Italy

Substantial evidence supports the role of asbestos in malignant mesothelioma. Clustering for this malignancy among relatives not only suggests genetic susceptibility as a relevant component but also provides a clue to investigate non-occupational sources of exposure. We identified five cases of malignant mesothelioma within one family with exposure to asbestos experienced during childhood, as next door residents of a workshop recycling asbestos-contaminated jute sacks in Naples, Italy. This cluster discloses the health risk in the reuse of bags that previously had contained asbestos. Furthermore, it emphasizes the role of asbestos in the genetic–environmental interaction issue of malignant mesothelioma.     

Asbestos and Peritoneal Mesothelioma among College-educated Men

Abstract

The proportion of peritoneal mesotheliomas among all mesotheliomas has been decreasing, leading some to suggest that peritoneal mesothelioma occurs only after high levels of exposure to asbestos. To investigate the relationship between asbestos exposure and the development of peritoneal mesothelioma, a case–control study examined 40 cases of primary peritoneal mesothelioma from a single institution. This series differed from previous reports in that 75% of the cases and controls had attended college. Results show an odds ratio of 6.6 for asbestos exposure among this group of primary peritoneal mesothelioma cases with relatively slight asbestos exposures.     

Malignant mesothelioma in Basse-Normandie, a French population study. Descriptive analysis, prognostic factors and survival

BACKGROUND: Malignant mesothelioma is a pleural and/or peritoneal tumor closely related to asbestos exposure, and its incidence should continue to increase during the first two decades of the 21(rst)century. The main prognostic factors described for this tumor are older age, sex, tumor stage and histological type. The aim of this study was to assess the incidence of pleural and peritoneal malignant mesothelioma in the County of Basse-Normandie (France), as well as their epidemiological characteristics, and the prognostic factors related to survival duration. METHODS: Cases were identified through repeated inquiries among all chest physicians and pathologists of the County of Basse-Normandie. A special care was taken in the validation of the diagnosis of each case. Incidence of mesothelioma was determined according to sex and age (5 years categories). Qualitative and quantitative variables were compared with the use of chi-square or Student's t tests respectively. Survival rate was calculated by Kaplan-Meier method, and prognostic factors were studied by means of Cox model. RESULTS: Study population consisted in all 80 malignant mesothelioma cases diagnosed in Basse-Normandie between the 1(rst) of September 1995 and the 31(rst) of August 1999. Annual incidence rates of pleural mesothelioma were 1.1/100 000 in men and 0.23/100 000 in women; annual incidence rates for peritoneal mesothelioma were 0.21/100 000 in men and 0.13/100 000 in women. Asbestos exposure was present in 63 cases (78.8%). The study of geographic distribution of mesothelioma cases revealed the influence of the main asbestos industrial settings, as well as the numerous scattered cases related to other occupational exposure. Mean survival duration was 9 months for pleural mesothelioma and 5 months for peritoneal mesothelioma. After adjustment on age, death risk was higher in asbestos-exposed than in non asbestos-exposed cases. CONCLUSION: This study confirms that malignant mesothelioma is closely related to asbestos exposure, but not only in main asbestos industrial settings. It suggests that asbestos exposure may take place among prognostic factors of this tumor.     

National epidemiologic surveillance systems of asbestos-related disease and the exposed workers register

INTRODUCTION: Italy was the main European producer of asbestos for most of the 20th century and raw asbestos imports wee also significant until the 1990's; there was a mean delay of about ten years in the pattern of asbestos consumption in Italy compared with the USA, Australia, UK and Scandinavian countries. METHODS: A national surveillance system (ReNaM) was implemented to identify cases of mesothelioma and investigate the modalities of asbestos exposure. A register of exposed workers and a database of companies presumably involved in the asbestos exposure problem was also developed. ReNaM has a regional structure and an operative centres (COR) have been established in 16 Italian regions. RESULTS: The ReNaM database currently contains more than 5,000 mesothelioma cases and for 3,500 of these exposure modalities have been defined. Cases of pleural mesothelioma represent 93% of the total but there were also 334 cases of peritoneal mesothelioma, 15 of the pericardium and 14 of the tunica vaginalis of the testicle. Cases with ascertained exposure are thus distributed: 67.4% occupational exposure (ascertained, probable, possible), 4.3% domestic, 4.2% environmental and 1.3% hobby-related exposure, totalling 77.2%; 22.8% had unlikely or unknown exposure. The latency period is very long: on average 43.6 years. The register of asbestos-exposed workers contains figures on exposed workers notified to ISPESL up to 2004 and refers to the exposure period 1993-2003. The data registered cover 160 firms and about 700 workers. CONCLUSIONS: A national, coordinated and uniform epidemiological surveillance system of cases of mesothelioma and the definition of asbestos exposure through active research is extremely important in identifying unexpected contaminating sources. The register of asbestos-exposed workers allows risk to be monitored and protection measures to be implemented.     

Occupational asbestos exposure among respiratory cancer patients in Lithuania

BACKGROUND: Despite intensive use of asbestos, no cancer case has ever been diagnosed as asbestos related in Lithuania. This paper attempts to estimate the proportion of those occupationally exposed to asbestos among respiratory cancer patients. MATERIAL AND METHODS: Occupational exposure to asbestos was assessed retrospectively for 298 lung cancer and four mesothelioma patients, admitted to the Institute of Oncology, Vilnius. The evaluation was based on personal interview data using an internationally established questionnaire covering most likely activities of asbestos exposure at the workplace. Cumulative exposure to asbestos at work was estimated in fiber years. Lung tissue asbestos fiber burden analysis was conducted by scanning transmission electron microscopy on 23 samples. RESULTS: A cumulative asbestos exposure of > or =25 fiber years was found for 10 lung cancer patients (3.4%). They worked in foundries, construction, installation, shipyard, power plant, railway, asbestos cement, glass and chemical industry. In a further 56 lung cancer patients (18.8%) and for one (25%) mesothelioma patient, a cumulative exposure from 5 to 24.9 fiber years was assessed. Asbestos fibers were detected in 18 cases, the burden ranged from 0.1 to 4.1 million fibers/g dry lung tissue; concentrations exceeding 1 million f/g dry lung tissue were found in four cases. All fibers were chrysotile. CONCLUSIONS: Findings indicate that a fraction (3.4%) of the lung cancer cases could be attributed to heavy occupational exposure to asbestos using the Helsinki criterion of > or =25 fiber years. Therefore, approximately 50 lung cancer cases per year in Lithuania could be asbestos-related compensable occupational diseases.     

Histological types of malignant mesothelioma and asbestos exposure.

The Los Angeles County Cancer Surveillance Program abstracts hospital pathology records on almost all cases of cancer occurring in the county. Those cases of pleural and peritoneal mesothelioma that occurred between 1972 and 1978 were identified. Occupational histories were obtained from interviews, and the histopathology of the tumours was reviewed by a member of a mesothelioma reference panel who was unaware of the exposure histories. The relation of asbestos exposure to the three histological types of mesothelioma (epithelial, mesenchymal, and mixed) was studied among the 29 cases for whom occupational histories were available and who were also considered to have histopathology consistent with mesothelioma. The proportion of cases exposed to asbestos was high for both the epithelial (11/17, 65%) and mixed histological types (6/11, 55%). The single case of mesothelioma classified as a mesenchymal type was also exposed to asbestos. Cases who had worked in shipyards were represented in each of the three groups. In cases who had worked in asbestos production and manufacture an exclusively epithelial type of tumour was observed. In cases who had worked as insulators or in heating trades the histological type was predominantly (3/4) mixed. These data do not support the hypothesis that any specific histological type of mesothelioma is especially related to asbestos exposure.     

Routes of asbestos exposure and the development of mesothelioma in an English region.

OBJECTIVES: To investigate the contribution of exposure to asbestos through different routes in the development of mesothelioma. METHODS: Case-control study. 185 confirmed cases of mesothelioma and 160 controls were identified, when death had occurred between 1979 and 1991 in four health districts in Yorkshire. The surviving relatives were interviewed to ascertain lifetime exposure to asbestos. Adjusted odds ratios (ORs) of exposure to asbestos (through occupational, paraoccupational, and residential routes) were calculated for cases and were compared with controls. RESULTS: Likely or possible occupational exposure to asbestos was more common in cases than in controls (OR 5.6, 95% confidence interval (95% CI) 3.1 to 10.1). After excluding those with likely or possible occupational exposure, likely or possible paraoccupational exposure was more common in cases than controls (OR 5.8, 95% CI 1.8 to 19.2). Only six cases of mesothelioma were identified as being solely exposed to asbestos through their residence, compared with nine controls. The OR for residential exposure to asbestos varied between 1.5 and 6.6, depending on which potential industrial sources were included, but the 95% CIs were so wide that slightly reduced or greatly increased odds comparing cases with controls could not be excluded. CONCLUSION: Study results support previous evidence that occupational and paraoccupational exposure to asbestos is associated with developing mesothelioma. Despite a rigorous search, purely residential exposure seemed to account for only 3% of identified cases. No firm conclusion can be drawn about the risks from residential exposure alone, as many of the study subjects could also have been occupationally or paraoccupationally exposed to asbestos.     

Histological types of malignant mesothelioma and asbestos exposure

The Los Angeles County Cancer Surveillance Program abstracts hospital pathology records on almost all cases of cancer occurring in the county. Those cases of pleural and peritoneal mesothelioma that occurred between 1972 and 1978 were identified. Occupational histories were obtained from interviews, and the histopathology of the tumours was reviewed by a member of a mesothelioma reference panel who was unaware of the exposure histories. The relation of asbestos exposure to the three histological types of mesothelioma (epithelial, mesenchymal, and mixed) was studied among the 29 cases for whom occupational histories were available and who were also considered to have histopathology consistent with mesothelioma. The proportion of cases exposed to asbestos was high for both the epithelial (11/17, 65%) and mixed histological types (6/11, 55%). The single case of mesothelioma classified as a mesenchymal type was also exposed to asbestos. Cases who had worked in shipyards were represented in each of the three groups. In cases who had worked in asbestos production and manufacture an exclusively epithelial type of tumour was observed. In cases who had worked as insulators or in heating trades the histological type was predominantly (3/4) mixed. These data do not support the hypothesis that any specific histological type of mesothelioma is especially related to asbestos exposure.     

Malignant mesothelioma: global incidence and relationship with asbestos

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.     

Asbestos and peritoneal mesothelioma among college-educated men

The proportion of peritoneal mesotheliomas among all mesotheliomas has been decreasing, leading some to suggest that peritoneal mesothelioma occurs only after high levels of exposure to asbestos. To investigate the relationship between asbestos exposure and the development of peritoneal mesothelioma, a case-control study examined 40 cases of primary peritoneal mesothelioma from a single institution. This series differed from previous reports in that 75% of the cases and controls had attended college. Results show an odds ratio of 6.6 for asbestos exposure among this group of primary peritoneal mesothelioma cases with relatively slight asbestos exposures.     

Cohort mortality study of women compensated for asbestosis in Italy.

BACKGROUND: The carcinogenic effect of asbestos is accepted for lung cancer and mesothelioma, while conflicting opinions exist for other cancer sites. The aim of the present investigation is to study cause-specific mortality of women compensated for asbestosis who had certainly been exposed to high levels of asbestos fibers. METHODS: The cause-specific mortality of all Italian women compensated for asbestosis and alive December 31, 1979, was investigated through October 30, 1997. In the total cohort, which included 631 subjects, 277 deaths occurred. Cause-specific SMRs (Standardized Mortality Ratio) were computed using the national rates for comparison. RESULTS: A significantly increased mortality for all diseases related to asbestos exposure was observed. Mortality for all causes, all neoplasms, lung cancer, uterine cancer, ovarian cancer, and non-neoplastic respiratory diseases was significantly increased. Separate analyses for textile (n = 276) and asbestos-cement (n = 278) workers were performed. Women employed in the textile industry, mainly exposed to chrysotile, who are compensated at a younger age, showed higher SMRs for lung cancer and asbestosis. Women in the asbestos-cement industry, mainly exposed to crocidolite containing asbestos mixtures, experienced higher mortality for pleural malignancies. CONCLUSIONS: The role of asbestos exposure in the development of gastrointestinal and genital neoplasms is discussed.     

The incidence of malignant mesothelioma (1977-1996) and asbestos exposure in the population of an area neighboring Lake Iseo, northern Italy

The study was stimulated by the occurrence of malignant mesotheliomas among the workers of two adjacent factories located in Sarnico, near Lake Iseo (province of Brescia, northern Italy), one of which manufactured crocidolite and chrysotile ropes and gaskets until 1993. The aim of the study was: identification of malignant mesotheliomas occurring between 1977 and 1996 among the residents of 11 villages, which constituted the recruitment area of the work-force; estimation of the incidence of malignant pleural mesothelioma; collection of working histories of all cases to evaluate previous exposure to asbestos and radiation therapy. 21 cases of mesothelioma were detected (20 pleural, 1 peritoneal; 9 among males), and 20 were supported by histopathologic diagnosis. The incidence (x 100,000 person-years, standard: European population) was 2.5 (0.7-4.2) and 2.8 (1.2-4.3) among males and females, respectively, corresponding to a three-fold increase among males and a more than ten fold increase among women in comparison with the incidence reported by the Lombardy Cancer Registry. No cases had been exposed to radiation therapy, whereas all cases had been occupationally exposed to asbestos. Occupational exposure to asbestos had occurred in work on the production of crocidolite and chrysotile ropes and gaskets (6 males); in work in a textile factory producing cotton garments that was adjacent to and polluted by the former, where, in addition, chrysotile blankets were used for fireproofing in the weaving area and pipes were insulated using amosite-containing materials (10 cases, 6 among females); 5 cases occurred among women working in silk factories, where asbestos exposure was possible because of the presence of pipes insulated with asbestos and because women were handling temperature-controlled trays insulted with asbestos. In conclusion, the study demonstrated that the occurrence of mesothelioma was higher among females than males in the study area and that all cases of mesotheliomas had been occupationally exposed to asbestos.