Academic literature on the topic 'Asbestos dust'

Investigation of various asbestos-induced lung diseases caused by exposure of chrysotile and chrysotile dust allowed description clinical, radiological, and functional features of occurrence, presentation, course, and outcomes of respiratory pathology, such as chrysotile asbestosis, occupational bronchitis and lung carcinoma in workers at asbestos industry. There is a reduction in morbidity of chrysotile asbestosis together with increasing prevalence of chronic bronchitis in modern asbestos industry. Morbidity of asbestosis-induced lung diseases is strongly and directly related to the length of service and level of pollution at the workplace. Preventive measures should include prevention of development of asbestos-induced diseases and rehabilitation of workers aimed to keeping health and restore adaptive reserve.

In the twentieth century, asbestos was used extensively in Britain’s Royal Naval Dockyards, especially between the mid-1940s and 1960s. In an era of international tension and conflict, it was invaluable for fire protection and thermal insulation on warships. In 1930, it was established that heavy and prolonged exposure to asbestos dust could cause asbestosis, and from 1931, precautions were required to protect at-risk workers in asbestos factories. These precautions did not apply on ships under construction or undergoing refit or repair in HM Dockyards. Until the 1960s, notwithstanding that asbestos dust was by then linked with two more fatal diseases, health precautions in these yards remained inadequate. Surgeon Commander Peter Harries played a crucial part in recognizing and controlling the occurrence of asbestos-related diseases in the yards. As a result, the occurrence of disease among HM dock workers fell at a time when its incidence was increasing in the wider population.

On the basis of investigation and survey on Chinese enterprises manufacturing asbestos friction material, it is concluded through analysis that key operation posts and pollution features of dust hazard during the process of manufacturing asbestos friction material in the way of the application of process management and hazard identification. Transport and feeding of asbestos and packing etc, hot briquetting, polishing and stamping punch are important operation posts of asbestos dust dispersing, characterized by wide distribution of dust producing places, difficulty in the implementation of closeness and ventilating measures, and extensive dispersing of asbestos dust following air and stream of people. According to three-E principle of risk management theory and safety production accident prevention, controlling asbestos dust should, based on the improvement of technology and abandonment of the use of older production equipment, comprehensively adopt engineering technology, individual protection and legal measures to prevent and reduce asbestos dust pollution and occupational hazard of enterprises manufacturing asbestos friction material.

Almost all of the asbestos used in Brazil is mined by an enterprise wholly owned by two European multinational companies, which also produce and market over two-thirds (by weight of asbestos) of the products made from asbestos. About 80 percent of the asbestos used in Brazil is finally consumed in the form of asbestos cement: for roof tiles and roofing panels, wall-board, and domestic and industrial water tanks. A survey of consumer literature and advertising printed by Eternit, S.A., and Brasilit, S.A., disclosed no mention of a potential danger from exposure to asbestos dust, and no recommendations for cutting down exposure to that dust. The situation at smaller, Brazilian-owned firms is reputed to be disastrous from the standpoint of workers' exposure to asbestos dust at the point of production. At a large asbestos-cement manufacturing plant owned by Eternit, however, exposure to asbestos dust (according to company records) seemed to be kept under 2.0 fibers per cc., the present standard for the United States.

The article describes the chemical properties of asbestos-cement dust and its effect on the human body. The main sources of dust emission at the enterprise for the production of asbestos-cement have been determined. Also in this research were determined the aerodynamic properties of particles of asbestos dust at the plant for the production of asbestos by method of fractional sedimentation. In the course of the experiment, the dispersion composition of dust was determined by the method of sedimentometry and analysis by means of a microscope and a PC. The dependence of the dust settling rate on the equivalent diameter of a particle in a probability-logarithmic grid is revealed.

This manuscript provides basic information on the use of asbestos. Some physicochemical properties of the main component of serpentine asbestos (SA, 95% of all used asbestos) and the biological aggressiveness of the following are considered: dust types in the technology of creating asbestos-containing products and during their operation. Attention is also paid to the use of existing asbestos substitutes in similar products. The authors present data verifying that the incidence of asbestos-related diseases, including asbestosis of a professional and unprofessional nature, is increased, especially in the elderly, in the places of production of an SA variety – chrysotile asbestos {CA, aqueous magnesium silicate - Mg6[Si4O10](OH)8}. The authors pay particular attention to the use of CA in the production of asbestos-formed parts/products (AFP), for example, brake linings containing CA and its substitutes. It is known that such products undergo significant zonal stresses during operation. CA fibers lose hygroscopic and constitutional water (H2O = 13.04 – 14.80%) in the process of car braking due to high pressure and increased local temperature. As a result, they almost entirely turn into a non-aggressive (in the biological sense) material called forsterite. Studies of brake dust emitted during the braking of lightweight VAZ vehicles did not reveal similar transformations of СA degradation. They may occur when braking heavy vehicles with a mass of more than 2.5 tons and when braking high-speed trains with a mass of more than 60 tons.

IntroductionHistorical dust concentrations are available for an occupational cohort study of workers active for 12 months or more between 1975 and 2010 in a chrysotile mine and processing factories in Asbest, Russian Federation. Their occupational histories were ascertained back to as early as the 1930s. A cohort specific job-exposure matrix (JEM) to estimate exposure to asbestos dust and fibre was elaborated.MethodsAlmost 1 00 000 recorded dust concentrations were used to develop an asbestos dust JEM and previously derived conversion factors were applied to estimate an asbestos fibre JEM. Where dust concentrations were not available, linear mixed models were used to impute missing data. Both JEMs were applied to the occupational histories of over 30 000 individual workers (over 35% female workers) based on job title and year worked.ResultsAssigned exposures varied over time with higher levels in the earlier years of activity. Approximately 97% of 2 00 000 person-years in the factories and 89% of 3 15 000 person-years in the mine had exposure assigned based on actual measurements. The median cumulative dust exposure for the exposed cohort was almost 50 mg/m3-years, with women slightly lower than men. The median cumulative fibre exposure for was 37 fibres/cm3-years for both men and women.Discussion and conclusionA key strength of this study is the availability of high-quality measurement data covering workers’ occupational histories. The dust and fibre JEMs enable estimation of annual profession-specific exposure levels that will form the basis of quantitative exposure estimates in the study and consequently quantitative exposure-response analyses.

Relevance. Occupational factor nowadays is considered an important condition of cardiovascular risk increase, including arterial hypertension growth. With this, study of work conditions infl uence on probable arterial hypertension development and other cardiovascular risk factors appears topical.Objective. To construct prognostic model of probable arterial hypertension development in workers of asbestos-concentrating plant, who are exposed to higher concentration of fi brogenic dust containing chrysotile.Materials and methods. Main group (161 individuals) comprised patients with diagnosed occupational disease (asbestosis), reference group included workers (222 individuals) with long length of service, without occupational diseases. Th e groups matched in age, sex, length of exposure to hazards, smoking index.Results. Findings are high occupational conditionality of left ventricle hypertrophy (relative risk 3.217, att ributable fraction 54.32%). Revealed factors that promote occupationally conditioned arterial hypertension (asbestosis, obesity, increased serum glucose, coronary heart disease, increased heart rate, lower saturation) served as a basis for prognostic model design by logic regression.Conclusion. Mathematic modelling helps to define contribution of occupational and non-occupational factors into arterial hypertension development in workers exposed to fi brogenic dust. Dust factor is an additional risk factor in arterial hypertension development am ong workers engaged into asbestos-concentrating production.

Asbestos is a mineral that has a naturally formed fibrous structure and has been used in different areas for centuries with its resistance to heat and chemicals. Asbestos, which is called "Magic Mineral" in the world, has been used in the production of many products in the textile, automotive and chemical industries, shipbuilding and construction sectors. In the last century, when respiratory illnesses and cancers have been encountered in those who work with asbestos and those who breathe the air mixed with asbestos fibers, Asbestos is called "The Evil Dust", "Killer Dust" in the world, and now it has been named "Killer Dust" in our country. Uncontrolled building demolitions as a result of the start of the Ship Recycling Sector and then the urban transformation activities in our country brought the issue of asbestos to the agenda. Old buildings are demolished by assuming that no asbestos is used, and construction waste is disposed of uncontrolled. This study was carried out in order to reveal that asbestos is used in old buildings, building demolition and renovation works are a great danger for employees and residents, and to provide suggestions for safe removal and demolition of materials found to be asbestos in buildings, and it is also aimed to increase "Asbestos Exposure Awareness".

Abstract Asbestosis is defined as diffuse pulmonary fibrosis caused by the inhalation of excessive amounts of asbestos fibers. Pathologically, both pulmonary fibrosis of a particular pattern and evidence of excess asbestos in the lungs must be present. Clinically, the disease usually progresses slowly, with a typical latent period of more than 20 years from first exposure to onset of symptoms. Differential Diagnosis: Idiopathic Pulmonary Fibrosis The pulmonary fibrosis of asbestosis is interstitial and has a basal subpleural distribution, similar to that seen in idiopathic pulmonary fibrosis, which is the principal differential diagnosis. However, there are differences between the 2 diseases apart from the presence or absence of asbestos. First, the interstitial fibrosis of asbestosis is accompanied by very little inflammation, which, although not marked, is better developed in idiopathic pulmonary fibrosis. Second, in keeping with the slow tempo of the disease, the fibroblastic foci that characterize idiopathic pulmonary fibrosis are infrequent in asbestosis. Third, asbestosis is almost always accompanied by mild fibrosis of the visceral pleura, a feature that is rare in idiopathic pulmonary fibrosis. Differential Diagnosis: Respiratory Bronchiolitis Asbestosis is believed to start in the region of the respiratory bronchiole and gradually extends outward to involve more and more of the lung acinus, until the separate foci of fibrosis link, resulting in the characteristically diffuse pattern of the disease. These early stages of the disease are diagnostically problematic because similar centriacinar fibrosis is often seen in cigarette smokers and is characteristic of mixed-dust pneumoconiosis. Fibrosis limited to the walls of the bronchioles does not represent asbestosis. Role of Asbestos Bodies Histologic evidence of asbestos inhalation is provided by the identification of asbestos bodies either lying freely in the air spaces or embedded in the interstitial fibrosis. Asbestos bodies are distinguished from other ferruginous bodies by their thin, transparent core. Two or more asbestos bodies per square centimeter of a 5-μm-thick lung section, in combination with interstitial fibrosis of the appropriate pattern, are indicative of asbestosis. Fewer asbestos bodies do not necessarily exclude a diagnosis of asbestosis, but evidence of excess asbestos would then require quantitative studies performed on lung digests. Role of Fiber Analysis Quantification of asbestos load may be performed on lung digests or bronchoalveolar lavage material, employing either light microscopy, scanning electron microscopy, or transmission electron microscopy. Whichever technique is employed, the results are only dependable if the laboratory is well practiced in the method chosen, frequently performs such analyses, and the results are compared with those obtained by the same laboratory applying the same technique to a control population.