Pleural mesothelioma resulting from exposure to amosite asbestos in a building

Malignant Mesothelioma in Rome and Latium Region, 1993-2001

Aims and background

Epidemiological studies on malignant mesothelioma have provided evidence on the etiologic role of occupational asbestos exposure and, to some extent, domestic and residential exposures. Less attention has been given to the occurrence of mesothelioma in urban areas where large quantities of asbestos have been employed in the past. The purpose of the study was to investigate the occurrence of mesothelioma in patients living in the urban area of Rome and in other parts of the Latium Region and the patterns of asbestos exposure.

Methods and study design

A pathology-based, malignant mesothelioma archive operating in Rome, Italy, was the source of cases. Included in the survey were cases resident in Latium and diagnosed in the period January 1, 1993, through December 31, 2001. Information on asbestos exposure was derived from interviews to the patient or his/her next of kin and from available medical records.

Results

The case series included: 114 males and 53 females; total, 167. Information on asbestos exposure was available for 138 cases (83%). Occupational exposure was ascertained or suspected for 33% of cases resident in Rome and 63% of those resident in other municipalities of Latium. Sex ratio was 1.6 in Rome and 3.3 in Latium.

Conclusions

The high prevalence of women among mesothelioma cases and lower proportion of occupational exposure in Rome versus the other municipalities of Latium suggest a possible role of environmental asbestos exposure in the urban area.

Malignant Mesothelioma in Rome, Italy 1980-1995. A Retrospective Study of 79 Patients

Aim and background

To evaluate the characteristics of a case-series of 79 malignant mesothelioma patients collected from the main teaching hospital of Rome, Italy, and other local clinics of Latium Region and to assess the role of asbestos exposure, since previous studies on the occurrence of the disease in this area were lacking.

Methods

The study included cytohistologically diagnosed malignant mesothelioma (71 pleural, 7 peritoneal, and 1 testicular tunica vaginalis) detected or referred for consultation during the period 1980-1995. Information regarding occupational and/or nonoccupational exposures was derived from clinical records and interviews, when available.

Results

Patients were resident in Rome and other towns of Latium; a few were from other parts of central and southern Italy. Exposure to asbestos was assessed for 45.5% of patients, another 45.5% had unknown exposure, and for the remaining 9% such information was lacking. Occupational exposure occurred in 53% of men for whom information was available and nonoccupational exposure occurred in 20% of women. The study identified two clusters of cases from an asbestos-cement plant and a facility where asbestos was ubiquitous. Furthermore, most exposed subjects reported occupations in the construction industry, which is particularly active in the Latium Region; others were railroad workers, naval mechanics and navy personnel, bakers, explosive workers and car mechanics. A few patients reported indoor exposure to asbestos at home and/or in the workplace.

Conclusions

The study confirmed that mesothelioma risk is present in several job titles of the construction industry, and it is no longer confined to workers employed in the manufacture or application of asbestos products. The occurrence of malignant mesothelioma in patients with unexpected occupational and nonoccupational exposures indicates the need for further investigation on previously underestimated exposures.

Lung cancer from asbestos textured ceilings: a case study

BACKGROUND

Asbestos was used in spray applied textured ceilings from 1945 to at least 1980. Exposure to asbestos and the probability of developing lung disease is high in individuals who lived with these types of ceilings in their home. Asbestos exposure and frequency of disease is even higher in an apartment suffering from flooding, maintenance, and/or multiple structural impacts.

PURPOSE

Our goal is to examine a case of lung cancer in a non-smoking individual exposed to asbestos from the damaged acoustic ceilings in her apartment.

METHODS

The subject's medical and occupational records were obtained and reviewed and a physical examination was performed. Exposure ratings were obtained from previous literature for discussion purposes.

CONCLUSION

Asbestos-textured ceilings are a possible source of asbestos exposure and there may be a risk of developing cancer in individuals exposed to ceiling deterioration.

Mesothelioma in patients with nonoccupational asbestos exposure

The specific parameters of nonoccupational asbestos exposures (NOAE) that can distinguish an idiopathic from an asbestos-caused malignant mesothelioma (MM) are controversial. A systematic literature review yielded 1028 cases with this putative association. Only 287 of those reports had a defined single exposure to a household, building occupant, or neighborhood/community asbestos source. The available "evidence" was used to develop semiarbitrary evidence-based causation guideline rules for the assessment of putative associations between MM and NOAE. The rules are classified into class A (tissue burden analysis shows asbestos body counts or fiber counts in lung tissues comparable to MM caused by occupational exposure to asbestos) and classes B to D based on whether certain combinations of NOAE features and MM (evidence) have been described in over 15% (class B), 5% to 15% (class C), and less than 5% (class D) of the patients reviewed. The proposed 4 classes of evidence-based causation guidelines provide a semiarbitrary framework to evaluate the causation of individual MM patients by NOAE based on decreasing levels of currently available evidence. The neoplasms in classes A to C patients are probably caused by NOAE, with decreasing weight of evidence in the 3 groups. There is minimal evidence to support the causation of MM by NOAE in class D patients. There is no evidence or only anecdotal evidence to support a causal association between MM and NOAE in individuals who cannot be classified into any of the 4 classes. Future studies are needed to provide more comprehensive data regarding the association between MM and NOAE.

Quantitative analysis of asbestos burden in women with mesothelioma

BACKGROUND

Lung tissue from 15 women who died from mesothelioma was evaluated for tissue burden of ferruginous bodies and uncoated asbestos fibers. The group contained individuals who had occupational exposure to asbestos and others had family members whose work history included vocations where contact with asbestos containing materials occurred.

METHODS

Tissue samples from tumor free lung were digested and filtered and then investigated for ferruginous bodies by light microscopy and asbestos and non-asbestos fibers by analytical transmission electron microscopy (ATEM). Size and type of fibers were also analyzed.

RESULTS

Asbestos bodies were found in 13 of the 15 samples and asbestos fibers were found in all cases. The most commonly found uncoated asbestos fiber in these individuals was amosite whereas tremolite was the second most commonly found form. The asbestos fiber burden in these females was often of mixed types.

CONCLUSIONS

The asbestos body and fiber burden in these cases show variation in tissue burden. Some cases in this study had appreciable burden, which was attributed to secondhand exposure from occupationally exposed family members. Mesothelioma can occur also in individuals with comparatively low tissue burdens of asbestos.

Mesothelioma: cases associated with non-occupational and low dose exposures

OBJECTIVES

To estimate the importance of low dose exposure to asbestos on the risk of mesothelioma.

METHODS

A review of the literature.

RESULTS AND CONCLUSIONS

There is no evidence of a threshold level below which there is no risk of mesothelioma. Low level exposure more often than not contains peak concentrations which can be very high for short periods. There might exist a background level of mesothelioma occurring in the absence of exposure ot asbestos, but there is no proof of this and this "natural level" is probably much lower than the 1-2/million/year which has been often cited.

Asbestos and cancer: epidemiological and public health controversies

This paper discusses many of the currently controversial issues surrounding asbestos health effects and their relationship to cancer risk assessment and risk management. The major conclusions reached from this analysis are: (1) All asbestos fiber types are carcinogenic and pose a threat to human health. Therefore, all fiber types should be regulated similarly. (2) The health risks associated with indoor asbestos exposure are uncertain. Available data show that some groups, such as building maintenance personnel (among others), may contract asbestos-related diseases secondary to indoor exposure. Clearly, additional research is needed to accurately determine the extent and nature of disease risk under these conditions. (3) Controlled use has proved an elusive goal. Limited information from underdeveloped countries parallels the experience of Western industrialized nations. Efforts by the Canadian government to establish markets for asbestos in these areas should be opposed. (4) Finally, asbestos-related cancer risk is no longer confined to asbestos industry workers. Asbestos-related mesothelioma has been documented in a wide variety of occupational and nonoccupational settings, highlighting the need for continued surveillance to minimize potential health risks.

Changing risk groups for malignant mesothelioma

Although malignant mesothelioma is a relatively rare tumor, its incidence is rising. Much of the increase is attributable to widespread exposure to asbestos in past decades in asbestos-related industries. In recent years, it has become increasingly clear that mesothelioma risk is no longer confined to workers in the asbestos industry. This article reports a variety of recently identified "risk groups" and highlights the need for increased surveillance of these groups to document the occurrence of asbestos-related malignancy and the institution of measures for disease prevention.

Malignant mesothelioma of the pleura in Trieste, Italy

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

Mineral fiber content of lung tissue in patients with environmental exposures: household contacts vs. building occupants

Analysis of tissue mineral fiber content in patients with environmental exposures has seldom been reported in the past. Our studies of six household contacts of asbestos workers indicate that these individuals often have pulmonary asbestos concentrations similar to some occupationally exposed individuals. In contrast, our studies of four occupants of buildings with asbestos-containing materials indicate that these individuals often have pulmonary asbestos burdens indistinguishable from the general nonoccupationally exposed population. However, one such building occupant exposed for many years and who later developed pleural mesothelioma was studied in detail, and it was concluded that her exposure as a teacher's aide in a school building containing acoustical plaster was the likely cause of her mesothelioma.

Asbestos-related disease in public school custodians

A cross-sectional prevalence study of 120 public school custodians was carried out. The purposes were 1) to investigate the prevalence of asbestos-related disease in a group of custodians at risk for asbestos exposure in public schools and 2) to determine the proportion with disease attributable to exposures in school buildings. Medical and occupational histories, flow-volume loops, and posterior-anterior, lateral, and anterior oblique (AO) chest radiographs were obtained. Single breath DLCO was measured and chest auscultation performed. Mean age of subjects was 57 years and mean duration of work as a custodian, 27 years. Fifty-seven (47.5%) had no known or likely exposure to asbestos outside of their work as a school custodian (NOE). Pleural plaques (PP) occurred in 40 (33%) of the total group and 12 (21%) of the group with NOE. Pulmonary restriction (FVC less than 80% predicted, FEV1/FVC% greater than or equal to 70) occurred in 22 (18%) of the total group and 10 (17%) of those with NOE. DLCO was lower in the group with restriction. Multivariate analysis revealed significant associations (p less than 0.05) between both PP and restriction and duration of asbestos exposure. AO radiographs increased PP detection by a factor of 1.9. Our results reveal PP prevalence in excess of background and pulmonary restriction in the study population, and indicate that PP are attributable to asbestos in schools. Findings with regard to pulmonary restriction need further investigation. Prudent management of asbestos in buildings is indicated for the prevention of related disease.