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.     

Asbestos content of lung tissue and carcinoma of the lung: a clinicopathologic correlation and mineral fiber analysis of 234 cases

The aim of this study was to investigate the asbestos content of lung tissue in a series of patients with lung cancer and some history of asbestos exposure. This information was then correlated with demographic information, occupational and smoking history, presence or absence of pathologic asbestosis or pleural plaques, and pathologic features of the cancer. The pulmonary concentration of asbestos fibers in 234 cases of primary carcinoma of the lung was determined by means of a tissue digestion technique. Asbestos body counts were performed in 229 cases and fiber analysis by scanning electron microscopy in 221 cases. Asbestos content was recorded as total asbestos fibers, commercial amphibole fibers, noncommercial amphibole fibers, and chrysotile fibers 5 microm or greater in length per gram of wet lung tissue. The study group included 70 patients with asbestosis (Group I), 44 patients with parietal pleural plaques but without asbestosis (Group II), and 120 patients with neither (Group III). The median asbestos body content of Group I was more than 35 times greater than Group II and more than 300 times greater than Group III. The total asbestos fiber count for Group I was nearly 20 times greater than Group II and more than 50 times greater than Group III. The difference was due almost entirely to commercial amphiboles.In a series of primary lung cancer cases with some history of asbestos exposure, a markedly elevated asbestos content was identified among those with pathologic asbestosis as compared with patients with pleural plaques alone or with neither plaques nor asbestosis.     

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.     

Predictors of lung cancer among asbestos-exposed men in the {beta}-carotene and retinol efficacy trial

Despite numerous published studies, debate continues regarding the risk of developing lung cancer among men exposed occupationally to asbestos, particularly those without radiographic or functional evidence of asbestosis. The beta-Carotene and Retinol Efficacy Trial (CARET), a study of vitamin supplementation for chemoprevention of lung cancer, has followed 4,060 heavily exposed US men for 9-17 years. Lung cancer incidence for 1989-2002 was analyzed using a stratified proportional hazards model. The study confirmed excessive rates of lung cancer among men with radiographic asbestosis. Comparison of study arms revealed a strong, unanticipated synergy between radiographic profusion category and the active intervention. In the large subgroup of men with normal lung parenchyma on chest radiograph at baseline, there was evidence of exposure-related lung cancer risk: Men with more than 40 years' exposure in high-risk trades had a risk approximately fivefold higher than men with 5-10 years, after adjustment for covariates. The effect in these men was independent of study intervention arm, but pleural plaques on the baseline radiograph and abnormal baseline flow rate were strong independent predictors of subsequent lung cancer. Residual confounding by subclinical asbestosis, exposure to unmeasured lung carcinogens, or differences in smoking are unlikely to explain these observations better than a carcinogenic effect of asbestos per se.     

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.     

Lung cinescintigraphy in the dynamic assessment of ventilation and mucociliary clearance of asbestos cement workers.

OBJECTIVES: To verify in vivo whether lung cinescintigraphy confirms the effect of asbestos on the patency of the smallest airways and on the efficiency of mucociliary clearance in asbestos cement workers. METHODS: 39 male subjects were examined: 30 asbestos cement workers and nine workers never exposed to occupational respiratory irritants. All subjects had a chest radiograph (International Labour Organisation (ILO) 1980); standard questionnaire on chronic bronchitis; spirometry; arterial blood gas analysis; carbon monoxide transfer factor (TLcosb); pulmonary O2 and CO2 ductances (DuO2, DuCO2); electrocardiogram; and lung cinescintigraphy after radioaerosol inhalation for the measurement of mucociliary clearance time in vivo in the smallest ciliated airways and for the assessment of radioaerosol deposition in alveoli (alveolar deposition index). RESULTS: Apart from nine non-exposed subjects, the 30 asbestos cement workers were so classified on the basis of chest radiography: nine of them as healthy exposed, 10 with pleural plaques, and 11 with asbestosis. The four groups had similar ages, work seniority, and smoking habits. Exercise dyspnoea was significantly more frequent in asbestos cement workers. Lung function variables of workers with effects related to asbestos were significantly lower than the other two groups. The PaO2, TLcOsb and DuO2 mean values were significantly lower in exposed workers than non-exposed. The mean PacO2 value was significantly higher in the asbestosis group than in the other three groups. Workers with effects related to asbestos showed a significantly lower alveolar deposition index and a significantly higher mucociliary clearance time than the other two groups. Subjects with asbestosis showed similar differences from those with pleural plaques. CONCLUSIONS: Lung cinescintigraphy confirms in vivo the effects of asbestos on bronchiolar and alveolar patency and on efficiency of mucociliary clearance in the smallest ciliated airways. Finally, lung cinescintigraphic variables are able to discriminate workers with asbestosis from those with pleural plaques.     

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.     

A patient with asbestos-induced lung cancer complicated by silicosis

A 76-year-old male died of lung cancer. At first, he was diagnosed as a silicosis, because he had worked for 30 years as a caster in shipyard and large opacities detected by chest x-ray and CT scanning. After the operation of lung cancer, numerous asbestos bodies were observed in the operated lung tissues. The detailed occupational inquiry revealed his asbestos use as a caster in shipyard. Early stage of asbestosis was suspected by chest CT scanning, but not definitely diagnosed in premortal examinations. Asbestosis, pleural plaques, silicosis and large cell carcinoma of the lung were histopathologically confirmed at the autopsy. A patient with asbestos-induced lung cancer complicated by silicosis was rarely published in the literature.     

The prevalence of pleural plaques and/or pulmonary changes among construction workers in Okayama, Japan

BACKGROUND: Since asbestos has been widely used in Japanese building materials since 1960s, a large number of Japanese construction workers may be exposed to asbestos occupationally. METHODS: Among 2951 construction workers in Okayama, Japan, the prevalence of asbestos-induced pleural or pulmonary changes was examined by screening chest x-rays; these findings were confirmed by computed tomography (CT) scanning of the chest. RESULTS: Among 2951 construction workers, 168 (5.7%) were found to have significant findings for pleural plaque or pulmonary changes on chest x-ray. Seventy-four had both pleural plaque and asbestosis, 85 pleural plaques alone, and 9 asbestosis alone. In 11 subjects, pleural plaques were suggested by chest x-ray, but neither pleural plaque nor asbestosis was demonstrated by chest CT. Honeycombing as one of the characteristic findings of asbestosis was found in 29 subjects. Others showed subpleural spots or curvilinear shadow, which suggested the early stage of asbestosis. The occupations of these workers were carpenters (64), plasterers (27), and concrete board cutters (14). About 30% of the workers with these findings were aware that they were handling asbestos in activities such as installation of asbestos boards, and/or asbestos spraying. CONCLUSIONS: As the incidence of malignant mesothelioma and primary lung cancer associated with asbestos exposure are high, screening by chest CT is necessary for detecting asbestos-induced pulmonary and/or pleural lesions. Education for protection such as telling about the presence of asbestos in building materials is also necessary.     

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.     

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.     

Asbestos lung burden and asbestosis after occupational and environmental exposure in an asbestos cement manufacturing area: a necropsy study

OBJECTIVE: The largest Italian asbestos cement factory had been active in Casale Monferrato until 1986: in previous studies a substantial increase in the incidence of pleural mesothelioma was found among residents without occupational exposure to asbestos. To estimate exposure to asbestos in the population, this study evaluated the presence of histological asbestosis and the lung burden of asbestos fibres (AFs) and asbestos bodies (ABs). METHODS: The study comprises the consecutive series of necropsies performed at the Hospital of Casale Monferrato between 1985 and 1988. A sample of lung parenchima was collected and stored for 48 out of 55 necropsies. The AF concentration was measured with a TEM electron microscope with x ray mineralogical analysis. The ABs were counted and fibrosis evaluated by optical microscopy. The nearest relative of each subject was interviewed on occupational and residential history. Mineralogical and histological analyses and interviews were conducted in 1993-4. RESULTS: Statistical analyses included 41 subjects with AF, AB count, and interview. Subjects without occupational exposure who ever lived in Casale Monferrato had an average concentration of 1500 AB/g dried weight (gdw); Seven of 18 presented with asbestosis or small airway lung disease (SAL). G2 asbestosis was diagnosed in two women with no occupational asbestos exposure. One of them had been teaching at a school close to the factory for 12 years. Ten subjects had experienced occupational asbestos exposure, seven in asbestos cement production: mean concentrations were 1.032 x 10(6) AF/gdw and 96,280 AB/gdw. Eight of the 10 had asbestosis or SAL. CONCLUSION: The high concentration of ABs and the new finding of environmental asbestosis confirm that high asbestos concentration was common in the proximity of the factory. Subjects not occupationally exposed and ever living in Casale Monferrato tended to have higher AB concentration than subjects never living in the town (difference not significant). The concentrations of ABs and AFs were higher than those found in other studies on nonoccupationally exposed subjects.

 

     

A retired shipyard worker with rapidly progressive pulmonary interstitial fibrosis

We present a case of progressive interstitial fibrosis in a retired shipyard worker who was exposed to asbestos during the postwar era of the late 1940s and 1950s, when asbestos exposures in the workplace were not regulated. Forty years later, at 63 years of age, the patient presented with restrictive lung disease. The patient was diagnosed with asbestos-related pleural disease and parenchymal asbestosis. He remained stable for the next 7 years, but then he began to manifest rapid clinical progression, which raised the possibility of an unusual variant of asbestosis, a concomitant interstitial process, or an unrelated disease. Lung biopsy was not undertaken because of the patient's low pulmonary reserve and limited treatment options. An empiric trial of oral steroids was initiated, but his pulmonary status continued to deteriorate and he died of pulmonary failure at 72 years of age. Many diseases result in pulmonary interstitial fibrosis. Ideally, open lung biopsy should be performed, but this procedure inevitably causes complications in many patients with end-stage restrictive lung disease. Furthermore, while the presence of asbestos bodies in tissue sections is a sensitive and specific marker of asbestos exposure, neither this finding nor any other charge is a marker indicative of asbestosis or the severity of asbestosis. With the enactment of the Asbestos Standard in the United States, asbestos exposures have been decreasing in this country. However, industries that produce asbestos products and wastes continue to expand in developing countries. Prevention of asbestos-related lung disease should be a global endeavor, and asbestos exposures should be regulated in both developed and developing countries.     

Exposure-response analysis of risk of respiratory disease associated with occupational exposure to chrysotile asbestos.

OBJECTIVES: To evaluate alternative models and estimate risk of mortality from lung cancer and asbestosis after occupational exposure to chrysotile asbestos. METHODS: Data were used from a recent update of a cohort mortality study of workers in a South Carolina textile factory. Alternative exposure-response models were evaluated with Poisson regression. A model designed to evaluate evidence of a threshold response was also fitted. Lifetime risks of lung cancer and asbestosis were estimated with an actuarial approach that accounts for competing causes of death. RESULTS: A highly significant exposure-response relation was found for both lung cancer and asbestosis. The exposure-response relation for lung cancer seemed to be linear on a multiplicative scale, which is consistent with previous analyses of lung cancer and exposure to asbestos. In contrast, the exposure-response relation for asbestosis seemed to be nonlinear on a multiplicative scale in this analysis. There was no significant evidence for a threshold in models of either the lung cancer or asbestosis. The excess lifetime risk for white men exposed for 45 years at the recently revised OSHA standard of 0.1 fibre/ml was predicted to be about 5/1000 for lung cancer, and 2/1000 for asbestosis. CONCLUSIONS: This study confirms the findings from previous investigations of a strong exposure-response relation between exposure to chrysotile asbestos and mortality from lung cancer, and asbestosis. The risk estimates for lung cancer derived from this analysis are higher than those derived from other populations exposed to chrysotile asbestos. Possible reasons for this discrepancy are discussed.     

Evidence for excess colorectal cancer incidence among asbestos-exposed men in the Beta-Carotene and Retinol Efficacy Trial

The relation between asbestos exposure and colorectal cancer remains controversial. The authors of this 1984-2004 US study examined the association among 3,897 occupationally exposed participants in the Beta-Carotene and Retinol Efficacy Trial (CARET) for chemoprevention of lung cancer, followed prospectively for 10-18 years. When a Cox stratified proportional hazards model was used, risks of colorectal cancer were elevated among male heavy smokers exposed to asbestos. Their relative risk was 1.36 (95% confidence interval: 0.96, 1.93) when compared with that for CARET heavy smokers not exposed to asbestos, after adjusting for age, smoking history, and intervention arm. The presence of asbestos-induced pleural plaques at baseline was associated with a relative risk of 1.54 (95% confidence interval: 0.99, 2.40); colorectal cancer risk also increased with worsening pulmonary asbestosis (p = 0.03 for trend). A dose-response trend based on years of asbestos exposure was less evident. Nonetheless, these data suggest that colorectal cancer risk is elevated among men occupationally exposed to asbestos, especially those with evidence of nonmalignant asbestos-associated radiographic changes.     

Asbestos exposure in lung carcinoma: a necropsy-based study of 414 cases.

BACKGROUND: The prerequisites necessary for attributing lung carcinoma to asbestos, represent a controversial issue. METHODS: Three parameters (occupational history, pleural plaques, and lung asbestos bodies) were investigated in 414 consecutive cases of lung carcinoma, examined at necropsy at the Hospital of Monfalcone, Italy. Occupational data were obtained from the patients' relatives by personal or telephone interviews. Pleural plaques were classified into three classes (small, moderate, large). Routine lung sections were examined for asbestos bodies in all cases; isolation and counting were performed in 408 cases. RESULTS: The series included 353 men, and 61 women, aged between 38 and 97 years. The male patients had worked in industries in 74% of cases (60% in shipbuilding). Men showed pleural plaques in 82% of cases (moderate or large plaques in 58.7%). Asbestos bodies were observed in routine lung sections in 34.8%, and in 31% exceeded the value of 5,000 bodies per gram of dried tissue. Among women the principal features were: history or domestic exposure to asbestos in 36% of the cases, prevalence of pleural plaques 34% (moderate or large plaques 15%), asbestos bodies in routine lung sections in 3.3% and there was no case with an asbestos body burden over 5,000/g. The fraction of asbestos-related carcinomas among male patients varied between 24.7 and 61%, depending on the criteria used for attribution. CONCLUSIONS: Different criteria indicated about 60% of the present lung carcinomas among men as plausibly attributable to asbestos.     

Haemorrhagic pericardial effusion in an asbestos worker

BACKGROUND: Occupational exposure to asbestos may cause pleural and lung disorders and, less frequently, diseases of the peritoneum and pericardium. An exceedingly small number of cases of benign pericardial effusion have been described so far in the medical literature. OBJECTIVES: To report a rare case of haemorrhagic pericardial effusion caused by occupational asbestos exposure in a patient with pre-existent aortic regurgitation, bilateral pleural plaques and no signs of interstitial lung involvement due to asbestosis. METHODS: A thorough clinical and instrumental evaluation (laboratory tests, tuberculin skin test, chest X-rays, transthoracic and transesophageal echocardiography, contrast coronary and aortic angiography, a histological examination of pericardial and pleural surgical specimens) was performed to examine all the known causes of pericardial effusion. RESULTS: The tests performed did not demonstrate any specific cause of pericardial effusion. Surgical assessment three months later, during an aortic valve replacement, showed no signs of aortic dissection or intraparietal hematoma. A nine-year follow up did not reveal any reoccurrence of pericardial effusion. CONCLUSIONS: Asbestos related pericardial effusion is rarely described in the medical literature but must be considered in patients with previous occupational asbestos exposure. There are no specific clinical or pathological aspects indicative of this etiology and the diagnosis remains one of exclusion. A thorough occupational history should be obtained in patients with pericardial effusion of unknown etiology.     

Occupational respiratory cancer and exposure to asbestos: A case-control study in a cohort of workers in the electricity and gas industry

Cancers of the pleura, lung, and larynx between 1978 and 1989 among active male workers of Electricité de France-Gaz de France were studied in association with asbestos exposure using a case-control design nested within the cohort of workers of the company. The cohort included about 1,400,000 person-years, corresponding to a mean of 117,000 men per year. Exposure to asbestos and to some potential occupational confounders selected among agents from groups I, IIa, and IIb of the International Agency for Research on Cancer was assessed by a job-exposure matrix specific to the company. During the observation period, 12 cases of pleural cancer, 310 cases of lung cancer, and 116 cases of larynx cancer were registered in the cancer register of the company social security department. Four controls per case, matched for year of birth, were randomly selected among the cohort. Conditional logistic regression was used to estimate the odds ratios. A first analysis was conducted in order to assess the validity of the job-exposure matrix by investigating already known relationships between asbestos exposure and asbestosis. For asbestosis, a strong exposure-response relation was found with an odds ratio (OR) of 57.4 [95% confidence interval (CI): 17.0–194.0] in the highest exposure group. There was an elevated risk of pleural cancer (OR, 4.8, CI, 1.2–19.8). For lung cancer, significant ORs of 2.0 (CI, 1.3–3.2) and 1.9 (CI, 1.2–3.0) were found among the two highest cumulative exposure groups; adjustement for confounders slightly decreased the ORs. Squamous cell neoplasm of the lung was associated with asbestos exposure. The association between larynx cancer and asbestos exposure showed a tendency towards a nonsignificant increase in ORs in the highest cumulative exposure categories; this tendency disappeared when adjusting for occupational confounders. This study showed that occupational exposure to asbestos could increase the risk of pleural and lung cancer in a sector in which exposure levels are not considered to be high compared with other industrial settings.     

Asbestos exposure in a shipyard area, northeastern Italy

The Monfalcone area, northeastern Italy, is a small industrial district (population 60,000), with a large shipyard. In order to monitor asbestos exposure in this area, a series of 3,640 necropsies, carried out at the Monfalcone Hospital between October 1979 and September 1998, were investigated. The thoracic cavities were examined for pleural plaques; these were classified into three classes (small, moderate, large). Routine histological sections of lung tissue were examined for asbestos bodies. Isolation and counting of asbestos bodies were performed in 1,075 cases. Lifetime occupational data were collected in 1,277 cases. Pleural plaques were observed in 70.5% among men and in 23.8% among women. The prevalences of pleural plaques did not show significant variations during the study period. Asbestos bodies were found on routine lung sections in 23.7% of men and 3.0% of women. The shipyard workers, the most numerous category in the series, were characterized by high prevalence of pleural plaques (total 86.7%, large 32.4%), high prevalence of asbestos bodies on routine lung sections (35.3%), and high amounts of lung asbestos bodies after isolation. The present data indicate that asbestos exposure may reach alarming levels in the shipyard areas.