Health effects of asbestos exposure in humans: a quantitative assessment

Asbestos causes four diseases in humans: Lung fibrosis (asbestosis) follows heavy exposure and, in industrialized countries, is mainly a relic of past working conditions. The risk of pleural fibrosis and plaques is likely to be linearly dependent from time since first exposure and is present for all types of asbestos fibres. The diagnostic uncertainties regarding pleural plaques and the substantial degree of misclassification make it difficult to precisely estimate the shape of the dose-response relationship. The risk of lung cancer seems to be linearly related to cumulative asbestos exposure, with an estimated increase in risk of 1% for each fibre/ml-year of exposure. All fibre types seem to exert a similar effect on lung cancer risk; a multiplicative interaction with tobacco smoking has been suggested. Pleural mesothelioma is a malignant neoplasm which is specifically associated with asbestos exposure: the risk is linked with the cubic power of time since first exposure, after allowing for a latency period of 10 years, and depends on the fibre type, as the risk is about three times higher for amphiboles as compared to chrysotile. Environmental exposure to asbestos is also associated with mesothelioma risk.     

Environmental exposure to asbestos and risk of pleural mesothelioma: review and meta-analysis

A number of epidemiological studies have addressed the risk of pleural mesothelioma from environmental (household and neighborhood) exposure to asbestos, but no overall risk estimate is available. We reviewed the epidemiological studies on risk of pleural mesothelioma and household or neighborhood exposure to asbestos. We identified eight relevant studies; most were conducted in populations with relatively high exposure levels. We combined the risk estimates in a meta-analysis based on the random-effects model. The relative risks (RRs) of pleural mesothelioma for household exposure ranged between 4.0 and 23.7, and the summary risk estimate was 8.1 (95% confidence interval [CI]: 5.3–12). For neighborhood exposure, RRs ranged between 5.1 and 9.3 (with a single RR of 0.2) and the summary estimate was 7.0 (95% CI: 4.7–11). This review suggests a substantial increase in risk of pleural mesothelioma following high environmental exposure to asbestos; however, the available data are insufficient to estimate the magnitude of the excess risk at the levels of environmental exposure commonly encountered by the general population in industrial countries.     

Lung cancer in a female non-smoker with occupational exposure to asbestos: a case report

BACKGROUND: Until recently, asbestos was widely used in a variety of industrial processes. Workers exposed to asbestos may develop lung and pleural diseases such as asbestosis, lung cancer, benign pleural effusion, pleural plaques and mesothelioma. OBJECTIVE: To describe a clinical case of lung cancer in a female non-smoker with occupational exposure to asbestos. METHODS: The clinical and occupational history was based on the information kindly provided by the Occupational Unit of the National Health Service and on the case history of a hospital admittance in 2001, when the patient underwent surgery for lung cancer. RESULTS: The patient worked for 6 years in an asbestos manufacturing industry where she was exposed to high concentrations of asbestos, and then worked for 14 years in a sugar refinery only during the summer. She had benign pleural effusion, pleural plaques, asbestosis and lung cancer. CONCLUSIONS: We concluded that a six-year exposure to high doses of asbestos may induce lung cancer and asbestosis in a female non-smoker.     

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.     

Non-malignant asbestos diseases in workers in an electrochemical plant.

The prevalence of non-malignant asbestos related disorders was studied in a group of men who had been subjected to different levels of asbestos exposure when working at an electrochemical plant producing nitric acid sometime between 1928 and 1970. There were 153 men eligible for an initial clinical examination in 1979-80 and that group has been followed up to 1985. Among the cohort members the "accumulated prevalence" of lung fibrosis alone or in combination with pleural plaques and of "pleural plaques only" was 24.2% and 24.8% respectively. The subgroup with the heaviest exposure had a total prevalence of asbestos related disorders of 82.5%. Only study subjects with lung fibrosis had statistically significant increased prevalences of respiratory symptoms. All subgroups from the study population, however, had mean spirometric values under the age, height, and smoking specific predicted means. Subjects with heavy asbestos exposure and current smoking had a prevalence of three or more respiratory symptoms of 28.8% compared with 5.6% among lightly exposed never smokers. Pleural crepitations at chest auscultation were more prevalent among subjects with radiologically visible asbestos related disorders than among study subjects with normal chest x ray films. During the follow up from 1980 to 1985, three cases of lung cancer, two of pleural malignant mesothelioma, and one of stomach cancer were found among the cohort members.     

Non-malignant asbestos diseases in workers in an electrochemical plant

The prevalence of non-malignant asbestos related disorders was studied in a group of men who had been subjected to different levels of asbestos exposure when working at an electrochemical plant producing nitric acid sometime between 1928 and 1970. There were 153 men eligible for an initial clinical examination in 1979-80 and that group has been followed up to 1985. Among the cohort members the "accumulated prevalence" of lung fibrosis alone or in combination with pleural plaques and of "pleural plaques only" was 24.2% and 24.8% respectively. The subgroup with the heaviest exposure had a total prevalence of asbestos related disorders of 82.5%. Only study subjects with lung fibrosis had statistically significant increased prevalences of respiratory symptoms. All subgroups from the study population, however, had mean spirometric values under the age, height, and smoking specific predicted means. Subjects with heavy asbestos exposure and current smoking had a prevalence of three or more respiratory symptoms of 28.8% compared with 5.6% among lightly exposed never smokers. Pleural crepitations at chest auscultation were more prevalent among subjects with radiologically visible asbestos related disorders than among study subjects with normal chest x ray films. During the follow up from 1980 to 1985, three cases of lung cancer, two of pleural malignant mesothelioma, and one of stomach cancer were found among the cohort members.     

Five cases of pleural mesothelioma with endemic pleural calcifications in a rural area in Greece.

The authors describe 5 cases of pleural mesothelioma in a rural population of Macedonia, Greece. This population had been covered by an X-ray study over a 3-year period to detect pleural calcifications compatible with asbestos exposure. The study revealed a 24.2% prevalence of pleural plaques among the inhabitants aged over 40 years of 7 rural villages. High contents of asbestos (chrysotile and tremolite)--up to 90% by volume--were found in the material that was used for whitewashing the houses up to 1935. Even now, environmental concentrations of 0.01 fibres/ml were recorded in the houses. The prevalence of pleural mesothelioma in this rural population is high compared to the general population. A possible explanation of the phenomenon may be a cumulative environmental exposure to asbestos which, even though presumably within the acceptable limits for occupational exposure, lasted over a much longer time period, in terms of both daily exposure and total duration.     

Investigation of micronucleus frequencies in lymphocytes of inhabitants environmentally exposed to chrysotile asbestos

Exposure to asbestos minerals has been associated with a wide variety of adverse health effects including lung cancer, pleural mesothelioma, and cancer of other organs. Many of the regions of Turkey have asbestos deposits. People in Do?anl? village – one of these regions – have been environmentally exposed to chrysotile asbestos since they were born. In this study the effects of asbestos on micronucleus (MN) frequencies of inhabitants exposed to chrysotile asbestos have been examined. Thirty subjects who had been environmentally exposed to chrysotile asbestos and living in Do?anl? village, and 25 controls were studied to assess the MN frequency. The control group was selected from healthy individuals with no exposure to asbestos and living in similar geographic conditions to Do?anl? village. Peripheral blood samples were collected from each subject and cultured for MN assay. Cytochalasin-B was added to lymphocyte cultures for evaluation of MN in binucleated (BN) cells. The differences between those exposed to chrysotile asbestos and controls were not statistically significant in terms of BN cells with MN (p > 0.05). There was not a significant relationship between MN frequencies and age, sex, smoking, both in chrysotile asbestos-exposed subjects and in controls (p > 0.05). Although the detection of calcified pleural plaques found in the inhabitants has indicated environmental exposure to chrysotile asbestos, our results show that chrysotile asbestos was not an inducer of MN in subjects exposed to chrysotile asbestos.     

Environmental exposure to asbestos in the area around Goor has been established as the cause of pleural mesothelioma in women

OBJECTIVE: To determine whether a disease cluster of 22 additional cases of pleural mesothelioma among women could be attributed to environmental asbestos exposure due to asbestos fibers from waste material on roads and property yards. The women studied were observed in an area with substantial environmental exposure to asbestos during the period 1989-2002. DESIGN: Ecological study. METHOD: In the study period of 1989-2002, all cases of mesothelioma among women, based on a strict histopathologic definition, occurring in the region of Twente, The Netherlands (n = 59) were provided by the regional cancer register. Additional information was collected on the occupational histories of the cases and their partners and addresses of residence through medical records, general practitioners, and next-of-kin. Environmental asbestos exposure was assigned to all cases that had had a long-term stay in a house in the area around Goor with demonstrated local environmental asbestos pollution and where any contact with asbestos through occupation or in the household had been excluded. RESULTS: In the risk area around Goor, out ofa total of 28 cases ofwomen with pleural mesothelioma, asbestos in the environment was found to be the only source of asbestos exposure for to women. In a further 4 women, environmental asbestos exposure was found to be the most likely cause of pleural mesothelioma. The average cumulative exposure was around 0.11 fiber/ml x exposure years. The observed extra incidence of 22 cases was attributed to the environmental exposure to asbestos in 64% (14/22) of cases. CONCLUSION: The environmental pollution to asbestos waste materials in the area around Goor was the main cause of the strongly increased incidence of pleural mesothelioma among women in this area. Taking into account an equal risk among men, the consequences of asbestos exposure in the area around Goor in the next 25 years are likely to result in 2 cases of pleural mesothelioma each year.     

Clinical consequences of asbestos-related diffuse pleural thickening: A review

Asbestos-related diffuse pleural thickening (DPT), or extensive fibrosis of the visceral pleura secondary to asbestos exposure, is increasingly common due to the large number of workers previously exposed to asbestos. It may coexist with asbestos related pleural plaques but has a distinctly different pathology. The pathogenesis of this condition as distinct from pleural plaques is gradually becoming understood. Generation of reactive oxygen and nitrogen species, profibrotic cytokines and growth factors in response to asbestos is likely to play a role in the formation of a fibrinous intrapleural matrix. Benign asbestos related pleural effusions commonly antedate the development of diffuse pleural thickening. Environmental as well as occupational exposure to asbestos may also result in pleural fibrosis, particularly in geographic areas with naturally occurring asbestiform soil minerals. Pleural disorders may also occur after household exposure. High resolution computed tomography (CT) is more sensitive and specific than chest radiography for the diagnosis of diffuse pleural thickening, and several classification systems for asbestos-related disorders have been devised. Magnetic resonance imaging and fluorodeoxyglucose positron emission tomography (PET) scanning may be useful in distinguishing between DPT and malignant mesothelioma. DPT may be associated with symptoms such as dyspnoea and chest pain. It causes a restrictive defect on lung function and may rarely result in respiratory failure and death. Treatment is primarily supportive.     

Asbestos-related lung cancer and mesothelioma in Japan

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

Diachronic study of pleural plaques in rural population with environmental exposure to asbestos

BACKGROUND: The progress of pleural plaques in persons exposed to environmental asbestos in Almopia, Greece were studied prospectively. METHODS: During a 15-year period, 198 individuals, in whom pleural plaques had been observed during the period 1988-1990 were followed. Respiratory function was initially evaluated in 23. All were inhabitants of seven villages of Northern Greece, where rocks with high concentration in asbestos fibers were used for whitewashing until 1935. RESULTS: Out of this population, 126 survived and underwent chest X-ray in 2003 while respiratory function was retested in 18. New radiological findings were compared to previous ones using digital technology. Furthermore, the cause of death of the remaining 72 was recorded. Deterioration of X-ray findings was observed in all survivors. Not only did the surface area of previous plaques increase (8.66 +/- 12.6 cm2, mean value +/- SD) but new ones also appeared. Total lung capacity decreased from 95.6 +/- 14.8 in 1998 to 76.5 +/- 9.3% predicted in 2003. It was found that out of 72 deaths, 11 people died of malignant lung neoplasm, and 4 of mesothelioma. CONCLUSIONS: Radiological appearance of pleural plaques and respiratory function of people previously exposed to asbestos environmental pollution worsens over the years. Prevalence of mesothelioma was found to be higher than expected.     

Asbestos content of lung tissue in asbestos associated diseases: a study of 110 cases

Diseases associated with asbestos exposure include asbestosis, malignant mesothelioma, carcinoma of the lung, and parietal pleural plaques. In this study the asbestos content of lung tissue was examined in groups of cases representing each of these diseases and in several cases with non-occupational idiopathic pulmonary fibrosis. Asbestos bodies (AB), which are the hallmark of asbestos exposure, were present in the lungs of virtually everyone in the general population and present at increased levels in individuals with asbestos associated diseases. The highest numbers of AB occurred in individuals with asbestosis, all of whom had levels greater than or equal to 2000 ABs/g wet lung tissue. Every case with a content of 100,000 ABs/g or higher had asbestosis. Intermediate levels occurred in individuals with malignant mesothelioma and the lowest levels in patients with parietal pleural plaques. There was no overlap between the asbestos content of lung tissue from patients with asbestosis and those with idiopathic pulmonary fibrosis. Lung cancer was present in half the patients with asbestosis, and the distribution of histological patterns did not differ from that in patients with lung cancer without asbestosis. The asbestos body content in patients with lung cancer was highly variable. Control cases had values within our previously established normal range (0-20 ABs/g). There was a significant correlation (p less than 0.001) between AB counted by light microscope and AB and uncoated fibres counted by scanning electron microscopy. The previous observation that the vast majority of asbestos bodies isolated from human tissues have an amphibole core was confirmed.     

Asbestos content of lung tissue in asbestos associated diseases: a study of 110 cases.

Diseases associated with asbestos exposure include asbestosis, malignant mesothelioma, carcinoma of the lung, and parietal pleural plaques. In this study the asbestos content of lung tissue was examined in groups of cases representing each of these diseases and in several cases with non-occupational idiopathic pulmonary fibrosis. Asbestos bodies (AB), which are the hallmark of asbestos exposure, were present in the lungs of virtually everyone in the general population and present at increased levels in individuals with asbestos associated diseases. The highest numbers of AB occurred in individuals with asbestosis, all of whom had levels greater than or equal to 2000 ABs/g wet lung tissue. Every case with a content of 100,000 ABs/g or higher had asbestosis. Intermediate levels occurred in individuals with malignant mesothelioma and the lowest levels in patients with parietal pleural plaques. There was no overlap between the asbestos content of lung tissue from patients with asbestosis and those with idiopathic pulmonary fibrosis. Lung cancer was present in half the patients with asbestosis, and the distribution of histological patterns did not differ from that in patients with lung cancer without asbestosis. The asbestos body content in patients with lung cancer was highly variable. Control cases had values within our previously established normal range (0-20 ABs/g). There was a significant correlation (p less than 0.001) between AB counted by light microscope and AB and uncoated fibres counted by scanning electron microscopy. The previous observation that the vast majority of asbestos bodies isolated from human tissues have an amphibole core was confirmed.     

Railways and asbestos in Japan (1928-1987)--epidemiology of pleural plaques, malignancies and pneumoconioses-

Asbestos has been an indispensable insulating material for railway industries, especially steam locomotives (SLs). This review (1928-1987) consists of three parts. 1) Pleural plaques: Since the 1970s, pleural plaques have been regarded as evidence of past asbestos inhalation, and more recently recognized as a risk factor of asbestos-related malignancies. For diagnostic criteria on plain radiographs, the modified ILO 1980 International Classification of Radiographs of Pneumoconioses was used. Most cases had pleural plaques with normal lungs. Large plant workers showed a significantly higher rate of plaques than workers in smaller plants. Bilateral plaques were dominant followed by the left, then the right lung, and chest wall plaques were dominant over the diaphragm. The manifestation of pleural plaques was more correlated to years since the onset of the asbestos exposure than the sum of asbestos work years, although the result was not significant. The boilermen of railway ferry steamers had a significantly higher plaque rate than other seamen. CT studies on plaques started in 1978. 2) Asbestos-related malignancies: Five retrospective cohort studies 1960-1970 were made on primary lung cancer incidence and mortality among 350,000 active railway men with smoking information. The follow-up period was 20 yr at the longest. Almost all plant workers showed a tendency of higher incidence or mortality than the controls. Two cases of mesothelioma were reported in 1980. 3) Pneumoconioses: Most studies (1928-1975) had relatively low prevalence rates among SL-related workers.     

Environmental exposure to tremolite and respiratory cancer in New Caledonia: a case-control study

A case-control study on respiratory cancers was conducted in New Caledonia (South Pacific), where a high incidence of malignant pleural mesothelioma had been observed. The disease pattern suggested an environmental exposure to asbestos. The first results showed that, in some areas, tremolite asbestos derived from local outcroppings was used as whitewash (locally named "p?"). All cases diagnosed between 1993 and 1995 (including 15 pleural mesotheliomas, 228 lung cancers, and 23 laryngeal cancers) and 305 controls were included in the study. Detailed information on past or present use of the whitewash, residential history, smoking, diet, and occupation was collected. The risk of mesothelioma was strongly associated with the use of the whitewash (odds ratio (OR) = 40.9; 95% confidence interval (CI): 5.15, 325). All Melanesian cases had been exposed. Among Melanesian women, exposure to the whitewash was associated with an increased risk of lung cancer (OR = 4.89; 95% CI: 1.13, 21.2), and smokers exposed to po had an approximately ninefold risk (OR = 9.26; 95% CI: 1.72, 49.7) compared with women who never smoked and had never used the whitewash. In contrast, no association was noted between exposure to p? and lung cancer risk among Melanesian men, probably because of lower exposure levels. Among non-Melanesians, the numbers of exposed subjects were too small to assess the effect of exposure to po. There was no indication of elevated risks for the other cancer sites.     

Malignant mesothelioma in Lynch syndrome: A report of two cases and a review of the literature

Malignant mesothelioma is a rare and aggressive cancer most typically associated with prior asbestos exposure. The nature of the relationship between asbestos exposure and hereditary familial syndromes predisposing to malignancy has not been determined. We report two Lynch syndrome patients with paraoccupational asbestos exposure who developed diffuse malignant mesothelioma of the pleura or peritoneum. Interestingly, one showed a separate focus of pleural well-differentiated papillary mesothelioma. It is likely that Lynch syndrome patients are at increased risk for the development of mesothelioma in the setting of exposure to asbestos, even at what is generally considered to be low levels. In the presence of a documented history of low-level asbestos exposure, patients with genetic predisposition disorders (including Lynch syndrome) should be considered to have an independent risk factor modifying the effects of asbestos exposure.     

Asbestos-related mesothelioma in monfalcone,Italy

The Monfalcone area, in northeastern Italy, is a small industrial territory (population about 60,000), with a large shipyard. Between October 1979 and April 1992, ninety-two malignant mesotheliomas were diagnosed at the Monfalcone Hospital. The series included 84 men and 8 women, aged 42 to 89 years (median age 68 years). There were 89 pleural and 3 peritoneal tumors. Seventy patients (69 men and 1 woman) had worked in the shipyards; six were seamen, and four insulators. Five men had been exposed to asbestos in various industries; six women had histories of domestic exposure, and one woman had a history of possible environmental exposure. The latency periods (intervals between first exposure to asbestos and diagnosis of the tumor) ranged from 20 to 65 years (median 52 years). Latency periods among insulators were significantly lower than among shipyard workers, as well as lower than among the other categories (p<0.01). Lung asbestos bodies were isolated after chemical digestion in 73 cases at necropsy, and in two cases at surgery. In necropsy cases, asbestos body burdens ranged between 100 and 10,000,000 bodies per gram of dried tissue (median 11,000). Pleural plaques were observed at necropsy in 62 out of 73 cases, and in two cases at surgery. In the time period we considered, the annual incidence rates for pleural mesothelioma were very high among male Monfalcone residents, being 189 per 100,000 among people aged 75 years or more. On the basis of occupational data and of objective signs (lung asbestos bodies, pleural plaques), all the cases of the present series but one (that with possible environmental exposure) were considered as asbestos-related. The role of co-factors in the development of asbestos-related mesothelioma is suggested. © 1993 Wiley-Liss, Inc.     

Unusually high incidence of malignant pleural mesothelioma in a town of eastern Sicily: an epidemiological and environmental study

In a recent epidemiological study, researchers investigated mortality from malignant pleural neoplasms in Italy, and they detected some geographic clusters of cases of this disease. We found a town located in a volcanic area of eastern Sicily to be of special interest. The residents, some of whom were diagnosed with pleural mesothelioma, had never had any relevant exposure to asbestos during their professional lives. The results of an environmental survey suggested that a possible cause of asbestos exposure was the stone quarries near the town. The products of the quarries contain fibrous amphiboles, which are used widely in the local building industry. These fibrous amphiboles were identified as intermediate phases between tremolite and actinolite. Samples were collected from buildings in the town, and concentrations of amphibole fibers were evaluated. Fibrous phases were detected in 71% of the samples, and fiber concentrations ranged from a few thousand to more than 4 x 10(4) fibers/mg of material. In addition, we conducted a study on the mineral fiber lung burden in a pleural mesothelioma case. Many mineral fibers that were classified as the same tremolite-actinolite fibrous amphibole found in the quarries and in the building materials were detected in the lung tissue. The results suggest that the inhabitants of the town we studied had been exposed for several decades to asbestos fibers that were present in the material extracted from the local stone quarries. The material was subsequently used in the building industry, and this has caused an increased risk of pleural mesothelioma in the area.     

Unusually High Incidence of Malignant Pleural Mesothelioma in a Town of Eastern Sicily: An Epidemiological and Environmental Study

In a recent epidemiological study, researchers investigated mortality from malignant pleural neoplasms in Italy, and they detected some geographic clusters of cases of this disease. We found a town located in a volcanic area of eastern Sicily to be of special interest. The residents, some of whom were diagnosed with pleural mesothelioma, had never had any relevant exposure to asbestos during their professional lives. The results of an environmental survey suggested that a possible cause of asbestos exposure was the stone quarries near the town. The products of the quarries contain fibrous amphiboles, which are used widely in the local building industry. These fibrous amphiboles were identified as intermediate phases between tremolite and actinolite. Samples were collected from buildings in the town, and concentrations of amphibole fibers were evaluated. Fibrous phases were detected in 71 % of the samples, and fiber concentrations ranged from a few thousand to more than 4 × 10⁴ fibers/mg of material. In addition, we conducted a study on the mineral fiber lung burden in a pleural mesothelioma case. Many mineral fibers that were classified as the same tremolite-actinolite fibrous amphibole found in the quarries and in the building materials were detected in the lung tissue. The results suggest that the inhabitants of the town we studied had been exposed for several decades to asbestos fibers that were present in the material extracted from the local stone quarries. The material was subsequently used in the building industry, and this has caused an increased risk of pleural mesothelioma in the area.