AsbestosFrom Wikipedia, the free encyclopedi).Fibrous asbestos on muscoviteaFor other uses, see Asbestos (disambiguationAsbestosAsbestosBlue asbestos (crocidolite) fromWittenoom, Western Australia. The ruler is 1 cm.Blue asbestos showing the fibrous nature of the mineralAsbestos (from Greek ἄσβεστος or asbestinon, meaning "unquenchable" or "inextinguishable") is a set of six naturally occurring silicate mineralsexploited commercially for their desirable physical properties. They all have in common their asbestiform habit, long, (1:20) thin fibrous crystals. Theinhalation of asbestos fibers can cause serious illnesses, including malignant lung cancer, mesothelioma (a formerly rare cancer strongly associated with exposure to amphibole asbestos), and asbestosis (a type of pneumoconiosis). Long exposure to high concentrations of asbestos fibers is more likely to cause health problems, as asbestos exists in the ambient air at low levels, which itself does not cause health problems. The European Union has banned all use of asbestos and extraction, manufacture and processing of asbestos products.Asbestos became increasingly popular among manufacturers and builders in the late 19th century because of its sound absorption, average tensile strength, and its resistance to heat, electrical and chemical damage. When asbestos is used for its resistance to fire or heat, the fibers are often mixed with cement or woven into fabric or mats. Asbestos was used in some products for its heat resistance, and in the past was used on electric oven and hotplate wiring for itselectrical insulation at elevated temperature, and in buildings for its flame-retardant and insulating properties, tensile strength, flexibility, and resistance to chemicals.<br />
Asbestos Ban and Phase Out<br />On July 12, 1989, EPA issued a final rule banning most asbestos-containing products. In 1991, this regulation was overturned by the Fifth Circuit Court of Appeals in New Orleans. As a result of the Court's decision, the following specific asbestos-containing products remain banned: flooring felt, rollboard, and corrugated, commercial, or specialty paper. In addition, the regulation continues to ban the use of asbestos in products that have not historically contained asbestos, otherwise referred to as "new uses" of asbestos. For more information read EPA Asbestos Materials Ban (ABPO Rule): Clarification (PDF) (3 pp., 10 K) - May 1999.<br />Below are four relevant Federal Register notices:<br />Asbestos: Manufacture, Importation, Processing, and Distribution in Commerce Prohibitions; Final Rule (54 FR 29460, July 12, 1989) (FRL-3476-2) (PDF) (55 pp, 8.2MB)<br />Asbestos; Manufacture, Importation, Processing and Distribution Prohibitions; Effect of Court Decision; Continuing Restrictions on Certain Asbestos-Containing Products (57 FR 11364, April 2, 1992) (FRL-4044-2) (PDF) (2 pp, 250K)<br />Asbestos; Manufacture, Importation, Processing and Distribution Prohibitions; Continuing Restrictions on Certain Asbestos-Containing Products (58 FR 58964, November 5, 1993) (FRL-4635-7) (PDF) (5 pp., 588K)<br />Technical Amendment in Response to Court Decision on Asbestos; Manufacture, Importation, Processing and Distribution Prohibitions; Technical Amendment (59 FR 33208, June 28, 1994) (FRL-4776-7) (PDF) (4 pp., 350K)<br />
Asbestos and the law<br />From Wikipedia, the free encyclopedia<br />This article concerns asbestos-related legal and regulatory issues. Litigation related to asbestos injuries and property damages has been claimed to be the longest-running mass tort in U.S. history.Since asbestos-related disease has been identified by the medical profession in the late 1920s, workers' compensation cases were filed and resolved in secrecy, with a flood of litigation starting in the United States in the 1970s, and culminating in the 1980s and 1990s. A massive multi-district litigation (MDL) complex filing has remained pending in the Eastern District of Pennsylvania for over 20 years. As many of the scarring-related injury cases have been resolved, asbestos litigation continues to be hard-fought among the litigants, mainly in individually-brought cases for terminal cases of asbestosis and cancers.<br />Old Wailuku Post Office sealed off for Asbestos Removal.<br />Old Wailuku Post Office sealed off for Asbestos Removal<br />
Asbestos as a contaminant<br /> <br />Asbestos fibers (SEM micrograph)<br />Most respirable asbestos fibers are invisible to the unaided human eye because their size is about 3.0–20.0 µm wide and can be as slim as 0.01 µm. human hair ranges in size from 17 to 181 µm in breadth. Fibers ultimately form because when these minerals originally cooled and crystallized, they formed by the polymeric molecules lining up parallel with each other and forming oriented crystal lattices. These crystals thus have three cleavage planes, just as other minerals and gemstones have. But in their case, there are two cleavage planes that are much weaker than the third direction. When sufficient force is applied, they tend to break along their weakest directions, resulting in a linear fragmentation pattern and hence a fibrous form. This fracture process can keep occurring and one larger asbestos fiber can ultimately become the source of hundreds of much thinner and smaller fibers.<br />As asbestos fibers get smaller and lighter, they more easily become airborne and human respiratory exposures can result. Fibers will eventually settle but may be re-suspended by air currents or other movement.<br />Friability of a product containing asbestos means that it is so soft and weak in structure that it can be broken with simple finger crushing pressure. Friable materials are of the most initial concern because of their ease of damage. The forces or conditions of usage that come into intimate contact with most non-friable materials containing asbestos are substantially higher than finger pressure.<br />
History of health concerns and regulation<br />Until 1900<br />By the first century AD, Greeks and Romans are claimed to have observed that slaves involved in the weaving of asbestos cloth were afflicted with a sickness of the lungs, although this is not confirmed by examination of primary sources.<br />Early concern in the modern era on the health effects of asbestos exposure can be found in several sources. Among the earliest were reports in Britain. The annual reports of the Chief Inspector of Factories reported as early as 1898 that asbestos had "easily demonstrated" health risks.<br />At about the same time, what was probably the first study of mortality among asbestos workers was reported in France. While the study describes the cause of death as chalicosis, a generalizedpneumoconiosis, the circumstances of the employment of the fifty workers whose death prompted the study suggest that the root cause was asbestos or mixed asbestos-cotton dust exposure.<br />1900s—1910s<br /> <br />Micrograph demonstrating asbestosis of the lung (ferruginous bodies). H&E stain.<br />Further awareness of asbestos-related diseases can be found in the early 1900s, when London doctor H. Montague Murray conducted a post mortem exam on a young asbestos factory worker who died in 1899. Dr. Murray gave testimony on this death in connection with an industrial disease compensation hearing. The post-mortem confirmed the presence of asbestos in the lung tissue, prompting Dr. Murray to express as an expert opinion his belief that the inhalation of asbestos dust had at least contributed to, if not actually caused, the death of the worker.<br />The record in the United States was similar. Early observations were largely anecdotal in nature and did not definitively link the occupation with the disease, followed by more compelling and larger studies that strengthened the association. One such study, published in 1918, noted:<br />All of these processes unquestionably involve a considerable dust hazard, but the hygienic aspects of the industry have not been reported upon. It may be said, in conclusion, that in the practice of American and Canadian life insurance companies, asbestos workers are generally declined on account of the assumed health-injurious conditions of the industry.<br />
1920s—1930s<br />Widespread recognition of the occupational risks of asbestos in Britain was reported in 1924 by a Dr. Cooke, a pathologist, who introduced a case description of a 33-year-old female asbestos worker, Nellie Kershaw, with the following: "Medical men in areas where asbestos is manufactured have long suspected the dust to be the cause of chronic bronchitis and fibrosis..." Dr. Cooke then went on to report on a case in 1927 involving a 33-year-old male worker who was the only survivor out of ten workers in an asbestos carding room. In the report he named the disease "asbestosis".<br />Dr. Cooke's second case report was followed, in the late 1920s, by a large public health investigation (now known as the Merewether report after one of its two authors) that examined some 360 asbestos-textile workers (reported to be about 15% of the total comparable employment in Britain at the time) and found that about a quarter of them suffered from pulmonary fibrosis. This investigation resulted in improved regulation of the manufacturing of asbestos-containing products in the early 1930s. Regulations included industrial hygiene standards, medical examinations, and inclusion of the asbestos industry into the British Workers' Compensation Act.<br />The first known U.S. workers' compensation claim for asbestos disease was in 1927. In 1930, the first reported autopsy of an asbestosis sufferer was conducted in the United states and later presented by a doctor at the Mayo Clinic, although in this case the exposure involved mining activities somewhere in South America.<br />In 1930, the major asbestos company Johns-Manville produced a report, for internal company use only, about medical reports of asbestos worker fatalities. In 1932, a letter from U.S. Bureau of Mines to asbestos manufacturer Eagle-Picher stated, in relevant part, "It is now known that asbestos dust is one of the most dangerous dusts to which man is exposed."<br />In 1933, Metropolitan Life Insurance Co. doctors found that 29% of workers in a Johns-Manville plant had asbestosis. Likewise, in 1933, Johns-Manville officials settled lawsuits by 11 employees with asbestosis on the condition that the employees' lawyer agree to never again "directly or indirectly participate in the bringing of new actions against the Corporation." In 1934, officials of two large asbestos companies, Johns-Manville and Raybestos-Manhattan, edited an article about the diseases of asbestos workers written by a Metropolitan Life Insurance Company doctor. The changes downplayed the danger of asbestos dust. In 1935, officials of Johns-Manville and Raybestos-Manhattan instructed the editor of Asbestos magazine to publish nothing about asbestosis. In 1936, a group of asbestos companies agreed to sponsor research on the health effects of asbestos dust, but required that the companies maintain complete control over the disclosure of the results.<br />
Micrograph demonstrating asbestosis of the lung (ferruginous bodies). H&E stain<br />
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