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PubMed2001

Global asbestos justice: South African asbestos victims win right to sue Cape PLC in U.K. courts.

A ruling by Britain's House of Lords in July 2000 opened the doors of the English courts to foreign plaintiffs injured by the overseas operation of British companies and their subsidiaries. The ruling authorized 3,000 South African asbestos victims to continue their case in the U.K. courts against the multinational British company Cape PLC, which produced both raw asbestos and asbestos products in South Africa. The Lords sided with the asbestos victims in refusing to transfer the case to South Africa, as requested by Cape. This decision was a reversal of fortune for Cape and has implications for other British multinationals that may be called upon to defend their overseas actions domestically.

Asbestosis↗
PubMed1999

An expert system for the evaluation of historical asbestos exposure as diagnostic criterion in asbestos-related diseases.

Compensation schemes for asbestos-related diseases have developed different strategies for attributing a specific disease to occupational exposure to asbestos in the past. In the absence of quantitative exposure information that allows a valid estimate of an individual's historical exposure, general guidelines are required to retrospectively evaluate asbestos exposure. A risk matrix has been developed that contains qualitative information on the proportion of workers exposed and the level of exposure in particular industries over time. Based on this risk matrix, stepwise decision trees were formulated for decisions regarding the decisive role of historical asbestos exposure in case ascertainment of asbestosis and mesothelioma. Application of decision schemes will serve to speed up the process of verifying compensation claims and also contribute to a uniform decision-making process in legal procedures.

Asbestosis↗
PubMed1991

Chrysotile asbestos and health in Zimbabwe: I. Analysis of miners and millers compensated for asbestos-related diseases since independence (1980).

Data on the health effects caused by locally mined chrysotile asbestos in Zimbabwe have been very limited. The prevailing local view has been that risk is minimal. In this report we critically reassess the cases of 51 individuals with asbestos exposure who have been compensated by the Central Pneumoconiosis Bureau since independence in 1980. Results demonstrate that the major health risks of exposure reported elsewhere--morbid asbestosis, nonmalignant pleural disease, malignant mesothelioma, and lung cancer--all occur in Zimbabwe, at least among workers in the asbestos mines and mills. It is concluded that further investigation and control measures in the industry are warranted.

Asbestos↗
PubMed1989

[Fiber emissions from weathered asbestos cement products. 2. Physical-chemical properties of liberated asbestos fibers].

It could be already shown that fibrous particulates can be emitted from weathered and corroded surfaces of asbestos-cement-(AC)-products and that these fibers increase the total ambient air concentration after having been dispersed in the atmosphere. In this investigation we studied the influence of the polluted atmosphere on physical and chemical properties of asbestos fibers in the corroded surface layer. It was found, that in a part of these asbestos fibers the magnesium was partly leached and that the fibers were strongly contaminated by deposited air pollutants.

Air Pollutants↗
PubMed1988

Alveolar fiber load in asbestos workers and in subjects with no occupational asbestos exposure: an electron microscopy study.

The alveolar fiber load was evaluated by bronchoalveolar lavage and by scanning and transmission electron microscopy (SEM and TEM) in 50 subjects with or without occupational exposure to asbestos. The concentration of asbestos fibers in bronchoalveolar lavage was significantly higher in the groups of people currently and formerly occupationally exposed, compared to the concentration found in people only exposed environmentally, despite wide interindividual variation within the groups. Nonasbestos inorganic fibers were present in all groups, but the concentrations did not differ significantly. Both in people occupationally exposed and in those only environmentally exposed, the alveolar load consisted mainly of ultrashort and ultrathin fibers, which can be studied only with TEM. In fact, the percentage of fibers greater than 5 micron long was only around 15% in the occupationally exposed and was minimal in those only environmentally exposed. The geometric mean diameters of asbestos fibers retained in the alveoli ranged from 0.05 micron for chrysotile to 0.15 micron for amphiboles.

Asbestos↗
PubMed1981

Occupational exposure to asbestos fibers resulting from use of asbestos gloves.

To assess the magnitude of fiber emission from asbestos gloves, 10 pairs were compared in an isolation chamber during simulation of a sterilization procedure; 176 air samples were collected. Means of time weighted average (TWA) concentrations ranged from 0.95 to 11.74 fibers (greater than 5 micrometers)/cm3 of air. Well-worn/clean gloves emitted significantly more fibers than did brand-new gloves, but fiber emission decreased with increased surface soiling. Eighty air samples were collected during simulation of the sterilization procedure in a well-ventilated room. The range of mean TWA concentrations was 0.07-0.99 fiber/cm3 for breathing zone samples and 0.06 to 0.60 fiber/cm3 for area samples. Thirteen samples were collected at actual workplaces; the range of TWA concentrations was 0.07-2.93 fibers/cm3 for breathing zone samples and 0.04-0.74 fiber/cm3 for area samples. Five of seven breathing zone samples from workplaces exceeded the proposed TWA concentration limit of 0.1 asbestos fiber/cm3. Hand contamination also was assessed. Four samples collected after touching the worktable ranged from 9953 to 13 108 fibers (greater than 5 micrometers)/cm2 of hand surface area; seven samples collected immediately after taking off gloves ranged from 741 to 3860 fibers/cm2. Available substitutes for asbestos gloves are discussed, and adoption of these substitutes is recommended strongly.

Air Pollutants↗
PubMed2002

Asbestos: when the dust settles an imaging review of asbestos-related disease.

Asbestos-related neoplastic and nonneoplastic diseases of the lungs and pleura range from pleural effusion and pleural plaques to lung cancer and malignant mesothelioma. Pleural effusions are typically hemorrhagic exudates of mixed cellularity but do not typically contain asbestos bodies. The classic distribution of pleural plaques seen on chest radiographs is the posterolateral chest wall between the seventh and tenth ribs, lateral chest wall between the sixth and ninth ribs, the dome of the diaphragm, and the mediastinal pleura. Computed tomographic (CT) findings support this distribution but also show anterior and paravertebral plaques not well shown at chest radiography. Imaging features of diffuse pleural thickening include a continuous sheet, often involving the costophrenic angles and apices, that rarely calcifies. The typical CT features of round atelectasis are of a round or oval mass that abuts the pleura, a "comet tail" of bronchovascular structures going into the mass, and thickening of the adjacent pleura. Features of asbestosis on chest radiographs include ground-glass opacification, small nodular opacities, "shaggy" cardiac silhouette, and ill-defined diaphragmatic contours. CT, however, is more sensitive in their detection. Chest radiography in patients with malignant mesothelioma may show an effusion, pleural thickening, and as the tumor progresses, a more lobulated outline. CT can help identify the disease in its early stages. Asbestos-related cancers can occur anywhere in the lungs. Recognition of the clinical, radiologic, and pathologic features of these diseases will be important for some years to come.

Asbestos↗
PubMed1992

[Evaluation of the distribution of ferruginous bodies and the kind of asbestos fibers in the lungs in lung cancer cases with definite occupational history of asbestos exposure].

The distribution of ferruginous bodies in the lungs of ten lung cancer patients with definite occupational history of asbestos exposure and the kind of core fibers in the center of the ferruginous bodies were evaluated. Six cases had a history of asbestos exposure in shipyards or Japanese naval dockyard, and the other four also had a definite history of occupational asbestos exposure. The largest number of ferruginous bodies was detected in the upper or middle lobes, but in only one case the lung cancer was present in the lobe in which the largest number of ferruginous bodies was detected. Therefore, the primary site of lung cancer is not dependent on the number of ferruginous bodies. The core of the ferruginous bodies was chrysotile in 7 cases, and amosite fibers were frequently detected in the three cases from the Japanese naval dockyard.

Adenocarcinoma↗
PubMed1983

Ambient air concentration of asbestos fibres, dust content and mortality: the case of Asbestos, Quebec.

Ambient air concentrations of asbestos fibres were measured during the period 20 June to 12 August, 1980 at three locations; Danville, Asbestos and Wottenville in the eastern townships of Quebec. Measurements were made with low-volume samplers and measurement periods ranged from 3 to 13 days. Fibre counts were made by means of electron microscopy. Our results indicate that overall fibre concentrations are related to atmospheric stability and to the direction of the prevailing wind with respect to the source of emission. Fibre concentrations are then related to total dust content of the ambient air for the town of Asbestos. Spatial variations of mortality are in turn related to the variations in the concentration of ambient air dust particles.

Air Movements↗
PubMedDate not supplied

[The problem of determining asbestos in bulk materials: a study of the effect of grinding on the diffractometric response of the chrysotile content in an asbestos cement sample].

To determine the asbestos content in a bulk sample by X-ray diffractometry, the sample must be previously comminuted until an adequate granulometry is reached. However, this treatment can produce a decrease in fibre crystallinity which, in turn, causes an attenuation of the diffractometric response of asbestos. The authors studied a "wet" comminution method that was tested on an asbestos-cement sample containing chrysotile. This procedure made it possible to limit the attenuation of the diffractometric response of chrysotile to reasonable values (about 20%). Moreover, the study of the comminution kinetics revealed a time interval during which both fibre granulometry and diffractometric response tend to reach a plateau value. In this interval, the comminution time is not a critical factor with respect to the diffractometric behaviour of chrysotile. Therefore, this interval offers favourable conditions for preparing bulk samples to be submitted to X-ray diffraction.

Asbestos, Serpentine↗
PubMedDate not supplied

Studies on genotoxicity of orally administered crocidolite asbestos in rats: implications for ingested asbestos induced carcinogenesis.

The early genotoxic action of oral exposure to UICC crocidolite asbestos fibres was studied in different short-term tests. Fischer-344 rats were gavaged with 50 mg/b.w.kg untreated asbestos fibres and fibres which had been allowed to adsorb benzo(a)pyrene molecules from extremely low concentration (0.25-2.5 microg/ml) aqueous solutions. This system can be considered a model for the drinking of potable water contaminated by asbestos fibres together with biologically active organic micro-pollutants. The Ames Salmonella mutagenicity assay was performed on concentrated urine and serum samples of treated animals. The formation of micronuclei and sister chromatid exchanges was also studied in the bone marrow of the exposed rats. The micronucleus analysis indicated marginal genotoxic activity only upon treatment with crocidolite prepared from the solution of 1 microg/ml. A dose-dependent increase was, however, demonstrated in the sister chromatid exchange frequency upon treatment with benzo(a)pyrene coated fibres. These experiments suggest the acute cogenotoxic activity of such fibres in orally exposed animals.

Administration, Oral↗
PubMedDate not supplied

Asbestos bodies in sputum of asbestos exposed workers.

The prevalence of asbestos bodies (AB) in sputum was studied in a group of 220 former or current asbestos workers, who came under observation because of a claim for compensation and who had, in most cases, high levels of exposure. Only one sputum specimen was obtained from each subject. The overall AB prevalence was 34%; it was 24.5% among workers exposed to chrysotile only, and 42% among workers also exposed to amphiboles, thus showing a statistically significant difference. No significant differences were found in AB prevalence either between current asbestos workers and former workers or between asbestosis cases and those without asbestosis. AB prevalence among current smokers was significantly lower than that observed among non-smokers and ex-smokers pooled together. The highest AB prevalence was found among currently exposed textile workers (65.7%), especially in male subjects (66.7%). As the exposure of these groups was heavy and included amphiboles, it may be concluded that although AB counts are highly specific they have low sensitivity.

Asbestos↗
PubMed1992

[Exposure to asbestos and asbestos-related pulmonary changes among employees at a magnesium plant].

Prevalence of disease related to previous exposure to asbestos was investigated in a cohort of 394 men who had worked for more than a year at a magnesium plant before 1970. Radiography showed lung fibrosis in nine men (2.3%) and pleural plaques in 40 men (9.5%). Prevalence rates varied considerably between sub-groups subjected to different modes of exposure. For the whole cohort there was a positive correlation between prevalence rate of radiographic changes and duration of work entailing exposure to asbestos. Subjects with pleural changes had more dyspnoea than found in an external reference material. Vital capacity and forced expiratory volume in one second was significantly reduced for the whole cohort. A significant reduction in lung function was found among a larger proportion of subjects with pleural changes than among subjects with no radiographic indications of such changes. The results unveil a need for similar surveys among workers in other energy-intensive industries where a similar mode of exposure to asbestos may be assumed.

Adult↗
PubMed1989

[Asbestos in the work environment. The occurrence of pulmonary changes among workers exposed to asbestos at an electrotechnical factory].

A number of workers exposed to asbestos dust for more than three months were medically examined for lung diseases caused by asbestos. A follow-up examination four years later revealed that the lung capacity of these workers was significantly lower than in the normal population. 9% of them showed changes in the lungs caused by asbestos dust, but no case of cancer was discovered. There was no development of significance in these changes during the four years.

Adult↗
PubMed1985

Evaluation for compensation of asbestos-exposed individuals. I. Detection and quantification of asbestos-related nonmalignant impairment.

An objective method for measuring nonmalignant respiratory impairment caused by inhaled asbestos has been devised. Three standard physiologic tests (the forced vital capacity [FVC], the forced expiratory volume in 1 s [FEV1], the single-breath diffusing capacity for carbon monoxide [DCO]) and the posteroanterior chest roentgenogram are utilized. The age-, height-, and sex-specific normal ranges of the FVC%, the DCO%, and the FEV1/FVC% have been used in the method. The theory and rationale are described. The resulting algorithm can be presented using a nomogram. Data on 586 asbestos-exposed subjects were analyzed by the proposed method. Empirical evaluation showed the sensitivity to be greater than 90% in definitive diagnosis of asbestosis without airflow obstruction, and the specificity to be greater than 80% for those cases judged eligible for nomographic evaluation. Exceptions were found in 15 cases diagnosed clinically as asbestosis, none of whom had any evidence of pulmonary fibrosis. In addition, 50 cases diagnosed as "no asbestosis" did have evidence of pulmonary fibrosis and would have qualified for some compensation by the proposed method. In summary, this approach has been shown to yield a reliable final asbestos-related lung impairment index that, when taken together with individual societal data, can provide a reliable basis for determining compensation.

Aged↗
PubMed1986

Studies on surface properties of asbestos. IV. Catalytic role of asbestos in fluorene oxidation.

To determine whether asbestos is a basic catalyst, catalytic oxidation of fluorene to fluorenone in a heterogeneous system was tested. It was shown that oxidation was quantitatively possible on the surface of all basic minerals, such as asbestos (chrysotile and crocidolite) and magnesia, but was not possible with acidic mineral materials such as silica. The effects of different factors are discussed.

Adsorption↗