Documents chrysotile 58 results

"The incidence of cancer among employees of a Norwegian asbestos-cement factory was studied in relation to duration of exposure and time since first exposure. The factory was active in 1942-1968. Most of the asbestos in use was chrysotile, but for technical reasons 8% amphiboles were added.This study showed a high incidence of mesothelioma and a high ratio of mesothelioma to lung cancer among asbestos-cement workers. The high incidence of mesothelioma was probably due to the fact that a relatively high proportion of amphiboles was used in the production process."

"Objectives: The prevalence of asbestos-related radiographic abnormalities was surveyed among Finnish construction, shipyard, and asbestos industry workers.

Methods: The radiographic screening focused on active and retired workers who were under the age of 70 years and had been employed for at least 10 years in construction or for at least 1 year in shipyards or in the asbestos industry. In 1990-1992, 18,943 people participated in an X-ray examination of the lungs and an interview on work history and exposure. The criteria for a positive radiological finding were (i) small irregular lung opacities clearly consistent with interstitial pulmonary fibrosis (ILO 1/1 or higher), (ii) lung opacities indicating mild pulmonary fibrosis (ILO 1/0) with unilateral or bilateral pleural plaques, (iii) marked adhesions with or without thickening of the visceral pleura, or (iv) findings consistent with bilateral pleural plaques.

Results: Fulfilling the criteria were 4133 workers (22%) (22% from construction, 16% from shipyards, and 24% from the asbestos industry). The radiological findings included signs of pulmonary fibrosis (3%), changes in the visceral pleura (7%), bilateral plaques (17%), and unilateral plaques (10%). Occupational disease was diagnosed according to the Finnish insurance regulations for three-fourths of those referred for further examinations, 96% being abnormalities in the pleura and 4% being asbestosis.

Conclusions: Exposure to asbestos dust has been common in ordinary construction work, and, consequently, radiographic abnormalities (mostly pleural) occur frequently among active and retired construction workers."

"In a cohort of some 11,000 men born 1891-1920 and employed in the Quebec chrysotile production industry, including a small asbestos products factory, of 9780 men who survived into 1936, 8009 are known to have died before 1993, 38 probably from mesothelioma--33 in miners and millers and five in factory workers. Among the 5041 miners and millers at Thetford Mines, there had been 4125 deaths from all causes, including 25 (0.61%) from mesothelioma, a rate of 33.7 per 100,000 subject-years; the corresponding figures for the 4031 men at Asbestos were eight out of 3331 (0.24%, or 13.2 per 100,000 subject-years). At the factory in Asbestos, where all 708 employees were potentially exposed to crocidolite and/or amosite, there were 553 deaths, of which five (0.90%) were due to mesothelioma; the rate of 46.2 per 100,000 subject-years was 3.5 times higher than among the local miners and millers. Six of the 33 cases in miners and millers were in men employed from 2 to 5 years and who might have been exposed to asbestos elsewhere; otherwise, the 22 cases at Thetford were in men employed 20 years or more and the five at Asbestos for at least 30 years. The cases at Thetford were more common in miners than in millers, whereas those at. Asbestos were all in millers. Within Thetford Mines, case-referent analyses showed a substantially increased risk associated with years of employment in a circumscribed group of five mines (Area A), but not in a peripherally distributed group of ten mines (Area B); nor was the risk related to years employed at Asbestos, either at the mine and mill or at the factory. There was no indication that risks were affected by the level of dust exposure. A similar pattern in the prevalence of pleural calcification had been observed at Thetford Mines in the 1970s. These geographical differences, both within the Thetford region and between it and Asbestos, suggest that the explanation is mineralogical. Lung tissue analyses showed that the concentration of tremolite fibres was much higher in Area A than in Area B, a finding compatible with geological knowledge of the region. These findings, probably related to the far greater biopersistence of amphibole fibres than chrysotile, have important implications in the control of asbestos related disease and for wider aspects of fibre toxicology."

"Objectives The study analyzed the recent trend in the incidence of mesothelioma in Finland and evaluated the coverage of reporting work-related mesothelioma.

Methods The incidence of mesothelioma in 1960--1995 was retrieved from the Finnish Cancer Registry, and the number of asbestos-associated work-related mesotheliomas were taken from the Finnish Register of Occupational Diseases.

Results The annual number of mesotheliomas increased rapidly in 1975--1990. In the 1990s, the age-adjusted incidence remained relatively stable for Finnish men. The annual number of cases still increased among men over 65 years of age, but decreased slightly among men under 55 years of age and among women. About 35 annual cases were diagnosed among the men and 10--15 among women in the mid-1990s. The reporting of work-related mesotheliomas improved during the Finnish asbestos program in 1987--1992. In 1993--1995 about 30 annual cases (ie, about 90% of all pleural and 50% of the peritoneal mesotheliomas in men) were reported to be work-related.

Conclusion The increasing trend in the incidence of mesothelioma in Finland slowed down in the 1990s, and the maximum of asbestos-related cases in the early 2000s will probably be clearly less than the 100 annual cases estimated in the early 1990s. If the observed trend continues up to 2010, about 40--50 cases among men and 10--20 among the women will then be diagnosed annually. Altogether 40--50 of these cases would be related to occupational asbestos exposure."

"BACKGROUND:
The relationship between mesothelioma and exposure to asbestos is well established. As a result, the use of asbestos in buildings, construction sites, and mines, as well as the implications of disease for the workers has received considerable attention. However, asbestos was also used in household equipment and consumer products, including hairdryers.
PURPOSE:
To examine one case of peritoneal mesothelioma in a hairdresser and review the relevant literature on asbestos exposure from hairdryers.
METHODS:
The subject's medical and occupational records were obtained and reviewed and a physical examination was performed.
RESULTS:
The results indicate that the subject developed peritoneal mesothelioma from her occupational exposure to asbestos containing hairdryers in accordance with the literature.
CONCLUSION:
Hairdryers are possible sources of asbestos exposure in patients with mesothelioma, and the asbestos exposure risk is higher for those who use hairdryers occupationally."

"Jusqu'à la moitié des années 1990, l'amiante de type chrysotile a été intentionnellement ajouté dans certains revêtements routiers afin d'assurer une meilleure durabilité de la couche de finition, les chaussées pouvant être sujettes à une usure prématurée selon le taux de fréquentation et de sollicitation des véhicules (Cf. Encadré 1). Or, les travaux de réfection ou de réaménagement des chaussées peuvent déstructurer la matrice du revêtement, émettre des fibres d'amiante et, par conséquent, avoir un effet sur la santé des travailleurs si les mesures de prévention ne sont pas adoptées par les professionnels. Afin de préconiser des mesures de prévention adaptées aux niveaux d'empoussièrement en fibres d'amiante réglementaires observés lors de ces travaux et de permettre aux professionnels de vérifier le respect de la nouvelle VLEP fixée à 10 f/l en moyenne sur 8?h (VLEP-8h) en vigueur depuis le 2 juillet 2015, un recueil des données d'empoussièrement des processus a été effectué auprès des professionnels, de donneurs d'ordre publics et du réseau prévention des Carsat. Cette étude de cas présente des recommandations de prévention établies à partir de l'analyse de 302 mesurages issus de 53 chantiers."

"Background:Coal-fired thermal power plants (TPPs) in Mongolia use various types of asbestos-containing materials (ACMs) in thermal insulation of piping systems, furnaces, and other products.Objective:To investigate the occupational exposure of insulation workers to airborne asbestos in Mongolian power plants.Methods:Forty-seven air samples were collected from four power plants in Mongolia during the progress of insulation work. The samples were analyzed by phase contrast microscopy (PCM) and transmission electron microscopy (TEM).Results:The average phase contrast microscopy equivalent (PCME) asbestos fiber concentration was 0·93 f/cm3. Sixteen of the 41 personal and one of the area samples exceeded the United States Occupational Safety and Health Administration (US OSHA) short-term exposure limit of 1·0 f/cm3. If it is assumed that the short-term samples collected are representative of full-shift exposure, then the exposures are approximately 10 times higher than the US OSHA 8-hour permissible exposure limit of 0·1 f/cm3.Conclusion:Power plant insulation workers are exposed to airborne asbestos at concentrations that exceed the US OSHA Permissible Exposure Limit. Action to mitigate the risks should be taken in Mongolia."

"Part I of this survey confronted the first two Most Pernicious Myths in Asbestos Litigation: the supposed harmlessness of chrysotile asbestos; and so-called idiopathic mesothelioma. Part II discusses the pernicious notions of safe exposure thresholds for asbestos and the unreliability of Tyndall lighting. Defendants' attempts to preclude plaintiffs' experts from testifying about these generally accepted scientific facts are a disservice to the legal system and to plaintiffs who have been harmed by asbestos. These defense tactics attempt to deny reality and to spin scientific facts in order to keep them from the jurors' eyes and ears. This undermines the legal system and harms the integrity of the scientific enterprise. Defendants' efforts to manufacture "controversy" over previously uncontroversial facts are bald attempts to infect the legal process with junk "doubt science." The role of this type of "doubt science" is being steadily exposed as legitimate researchers resist the degradation of their disciplines and the scientific literature by unprincipled purveyors of this insidious brand of junk science."