Asbestos health

Acheson, E. D., and M. J. Gardner (1983). Asbestos The Control Limit for Asbestos. Health and Safety Commission, Her Majesty s Stationery Office, London. 

Nicholson, W. J. (1985). Airborne Asbestos Health Assessment Update. EPA Document No. 600-8-84-003F. Office of Health and Environmental Assessment, Washington, DC. 

The Toxicological Profile for asbestos reflects a comprehensive and extensive evaluation, summary, and interpretation of available toxicologic and epidemiologic information on asbestos. Health care providers treating patients potentially exposed to asbestos will find the following information helpful for fast answers to often-asked questions. 

EPA. 1986a. Airborne asbestos health assessment update. Washington, DC U.S. Enviromnental Protection Agency, Office of Health and Environment Assessment. EPA/600/8-84/003F. 

Sturm W, Menze B, Krause J, et al. 1994. Use of asbestos, health risks and induced occupational diseases in the former East Germany. Toxicol Lett 72 317-324. 

Churchill RK, Higgins CT, Hill RL. 2001. A pilot project to map areas likely to contain natural occurrences of asbestos - El Dorado County, California. Poster presentation. 2001 Asbestos Health Effects Conference. Sponsored by U.S. Environmental Protection Agency. May 24-25, 2001. San Francisco, CA. 

Summary of Main Features of Asbestos / Health Regulations at the Workplace, AIA Information Memorandum (AIM) No. 3/80, Asbestos International Association, Epson, Surrey, UK, Nov. 1990. 

Sanders C. 1975b. Dose distribution and neoplasia in the lung following intratracheal instillation of 23gPu02 and asbestos. Health Phys 28 383-386. 

Fiber-Reinforced Cementitious Material. Use of asbestos (qv) has been legally restricted in Europe and the United States as being ha2ardous to health. In asbestos cement, which had consumed 70—80% of total asbestos, PVA fiber has been used in large amount as a replacement for asbestos. PVA fiber has a strength of at least 0.88 N/tex (9 gf/dtex) and can therefore provide the necessary reinforcement for cement the fiber has excellent adhesiveness to cement (qv) and alkaU resistance, and is not a health ha2ard. 

Lipoproteins may denature on heating and if present during pasteurization can result in the formation of haze or turbidity in the final product. This material was removed traditionally by filtration through asbestos (qv) sheets (6) however, health hazards associated with asbestos have led to its replacement by alternative filter materials (23,37,193). These media have been less effective than asbestos and further measures have been required to ensure the visual clarity of albumin products, eg, further filtration developments for Hpid removal (194), preferential denaturation of contaminants using in-process heat treatment, and anion-exchange chromatography (49). 

Inhalation of certain fine dusts may constitute a health hazard. Eor example, exposure to siUca, asbestos, and beryllium oxide dusts over a period of time results ki the potential risk of lung disease. OSHA regulations specify the allowable levels of exposure to kigestible and respkable materials. Material Safety Data Sheets, OSHA form 20, available from manufacturers, provide information about hazards, precautions, and storage pertinent to specific refractory products. 

E. Stem, personal communication. Occupational Safety and Health Administration Asbestos Advisor (Expert System software). Release 1.0, OSHA, Washington, D.C., 1996 (available at http //www.osha.gov). 

During the late 1960s and 1970s, the finding of health problems associated with heavy exposure to airborne asbestos fibers led to a strong reduction (or ban) in the use of asbestos fibers for thermal insulation. In most of the current applications, asbestos fibers are contained within a matrix, typically cement or organic resins. 

Loose asbestos fibers, or formulations containing asbestos fibers for spray coatings, have been widely used in the building industry for fire protection and heat or sound insulation. Such applications used mainly chrysotile or amosite but, because of health concerns, this practice has been discontinued. 

Considerable effort has been devoted to finding alternative fibers or minerals to replace asbestos fibers ia their appHcations. Such efforts have been motivated by various reasons, typically, avadabihty and cost, and more recendy, health concerns. During Wodd War I, some countries lost access to asbestos fiber suppHes and had to develop substitute materials. Also, ia the production of fiber reiaforced cement products, many developiug countries focused on alternatives to asbestos fibers, ia particular on cellulose fibers readily available locally at minimal cost. Siace the 1980s however, systematic research has been pursued ia several iudustrialized countries to replace asbestos fibers ia all of their current appHcations because of perceived health risks. 

The search for asbestos replacement materials is obviously an ongoing process and further developments in this area are to be expected. The extent of substitution of asbestos fibers by other fibers or other materials has been limited by several factors, typically the availabiHty of adequate replacement materials, the cost performance ratio of such materials, and the uncertainty of long-term health risks of these replacement materials. From the data currendy available, it may be estimated that between 10—20% of the industrial consumption of asbestos fibers was diverted to other materials during the 1980s. 

The relationship between workplace exposure to airborne asbestos fibers and respiratory diseases is one of the most widely studied subjects of modern epidemiology (37—39). Asbestos-related health concerns were first raised at the beginning of the century in the UK and the latter appears to have been the first country to regulate the asbestos-user industry (40). However, at that time, infectious respiratory diseases were a much greater concern than those arising from poor industrial hygiene practices. 

The replacement of asbestos fibers by other fibrous materials has raised similar health issues in relation to substitute materials. However, since lung cancer has a latency period of approximately 25 years, and since the fiber exposure levels in contemporary industries is far lower than those which prevailed half a century ago, the epidemiological data on most substitutes is insufficient. A possible exception is slag fibers for which several studies on worker populations are available over extended periods (44) some results show a substantial increase in lung cancer occurrence. Consequentiy, the toxicity of asbestos substitute fibers remains a subject of active investigation. 

Asbestos and Other MaturalMineralFibers, WHO Environmental Health Criteria 53 World Health Organization, Geneva, Switzerland, 1986. 

After the mid-1970s, the downsizing of North American vehicles and the introduction of front wheel drive vehicles brought about the widespread usage of a new class of friction materials (4) called semimetallics, also called semimets and carbon—metaUics. Because of the allegedly adverse health effects associated with asbestos [1332-21 -4] (qv) fibers, a second new class of friction materials called nonasbestos organics (NAOs) came about (5). Such materials are called either asbestos-free or nonasbestos friction materials (2). 

Future brakes must satisfy health standards and most vehicle manufacturers have moved toward removing all asbestos from brakes. Lighter weight rotors and caUpers based on aluminum-based metal-matrix materials are also on the horizon for lighter vehicles requiring a whole new family of compatible friction materials. 

Brake Linings. Substantial amounts of crystalline flake, lump, and amorphous graphite are used in brake and clutch finings, mostly in heavier duty nonautomotive situations. The graphite has been substituted for asbestos because of health considerations. The graphite proportion of the part has risen from 2 to 15% in some instances. The graphite lubricates, transfers the heat of friction away from the fining, and lowers the rate of wear. 

Modem liners are aU asbestos free because of the health risk associated with asbestos (qv). 

Asbestos and Mica Asbestos is no longer mined in the United States because of the severe health hazard, but it is still mined and processed in Canada. See previous editions of this handbook for process descriptions. 

Airborne particles with diameters less than 1 micron, as in the case of asbestos, are potentially respirable therefore, the manufacture of all submicron diameter carbon particles includes a responsibility to ensure that no health hazards arc... 

In Great Britain the COSHH Regulations cover virtually all substances hazardous to health. (Excluded are asbestos, lead, materials dangerous solely due to their radioactive, explosive, or flammable properties, or solely because of high or low temperatures or pressures, or where risk... 

SI 1999/2977 Health and Safety - The Asbestos (Prohibitions)(Amendment)(No. 2) Regulations 1999... 

Work with asbestos insulating board (superseded by EH 71j Ozone health hazards and precautionary measures Occupational exposure limits (annual)... 

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