Information AboutAsbestos |
| CATEGORIES ABOUT ASBESTOS | |
| asbestos | |
| fibers | |
| hazardous air pollutants | |
| health risksasbestos | |
| fibers | |
| hazardous air pollutants | |
| health risks | |
| minerals | |
| toxicology | |
| fibers | |
|
]] Asbestos (a misapplication of of the Hydrous Magnesium Silicate variety. The name is derived for its historical use in lamp wicks; the resistance of asbestos to fire has long been exploited for a variety of purposes. Asbestos was used in fabrics such as Egypt ian burial cloths and Charlemagne 's tablecloth which according to legend, he threw in a fire to clean. Asbestos occurs naturally in many forms (see below); it is mined from metamorphic rocks. 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 is used in Brake shoes and Gasket s for its heat resistance, and in the past was used on electric oven and hotplate wiring for its electrical insulation at elevated temperature, and in buildings for its flame-retardant and insulating properties, Abestos' Tensile Strength , flexibility, and resistance to chemicals. The Inhalation of some kinds of asbestos fibers however causes various serious illnesses, including Cancer , and thus most uses of asbestos are banned in many countries. Fiberglass has been found to be a suitable substitute for thermal insulation and woven Ceramic fiber performs as well as or better than asbestos as an insulator of high-temperature electrical conductors. Most respirable asbestos fibers are invisible to the unaided human eye because their size is about 3.0-20.0 ic molecules lining up parallel with each other and forming oriented Crystal Lattices . These crystals thus have three cleavage planes as other minerals and gemstones have. But in their case, there are two cleavage planes that are much weaker than the third direction. Thus 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 over and over until they have been broken down to their smallest unit dimensions. For this reason, one larger asbestos fiber can ultimately become the source of hundreds of much thinner and smaller fibers in a normal environment over the course of time. As they get smaller and lighter, they become more mobile and more easily entrained (wafted) into the air, where human respiratory exposures typically result. The released fibers being heavier than air will eventually settle in quiescent conditions only to be resuspended over and over again by any kind of activity or air currents over a period of time. This cyclic re-entrainment has consequences. Consistent with the tenets of the Second Law of Thermodynamics, the smallest sizes of easily mobile asbestos fibers move away from their initial source location in an ever-broadening manner. They disperse both by simple spontaneous airborne diffusion and through mass transport of the fibers. This latter is an energy-driven process that can occur through directed air currents or by "pickup and release" along a pathway of directed movement by persons, mechanical equipment or vehicles. For these reasons, asbestos contamination does not tend to remain localized at its initial release point but will eventually spread throughout all available accessible areas of buildings, even into areas that don't have their own asbestos-containing products. Eventually asbestos from virtually all products that were manufactured from this mineral will invade each and every space within an affected building. This is because during the lifecycle of each asbestos product, microscopic fibers and larger particles or pieces of these products are typically produced during their residency. The lifecycle of an asbestos containing product begins from the initial delivery of the product to the building, followed by its installation, normal usage forces, age-related deterioration, physical or chemical damage that often occurs, to finally its removal either for replacement or demolition. Any small impact or damage to a typical asbestos containing product can easily release billions to trillions of fibers of asbestos into the immediate environment which then add to the pool of similar fibers and particles from other asbestos containing products within that building. Friability of an asbestos containing product 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 due to their ease of damage. But non-friable asbestos containing materials are not necessarily safe. The forces or conditions of usage that come into intimate contact with most non-friable asbestos containing materials are substantially higher than finger pressure. Because of this, non-friable asbestos products can and do release substantial quantities of free asbestos fibers into their environments as well. During normal usage, initially non-friable products slowly change into a quasi-friable condition. Asphalt asbestos floor tiles are typically worn down through a sanding action of the normal floor grit under foot traffic on such floor coverings. Asbestos shingles, siding and roofing materials are eroded through drying, weathering, embrittlement, acid rain leaching and other deteriorative changes to their binder matrix resulting in release of asbestos fibers ("chalk dust") when simple contact is made with their surface or when the wind blows across them. Unfortunately, most government regulations treat such products with much less care than they do when addressing more friable products. Confusingly, the Modern Greek word ''άσβεστος'' means '' Quicklime ''. TYPES OF ASBESTOS
Notes: Serpentine rocks are those with curled fibres. Amphibole s have straight, needle-like fibres. The amphiboles, in their fibrous form, are Friable and therefore the most carcinogenic, although they also exist in safer non-fibrous forms. Asbestos with particularly fine fibers is also referred to as "amianthus". Other asbestos minerals, such as Tremolite , CAS No. 77536-68-6, Ca2Mg5Si8O22(OH)2; Actinolite (or ''smaragdite''), CAS No. 77536-66-4, Ca2(Mg, Fe)5Si8O22(OH)2; and Anthophyllite , CAS No. 77536-67-5, (Mg, Fe)7Si8O22(OH)2; are less-used industrially but can still be found in a variety of construction materials and insulations and occur in a few consumer products, such as talcum powders and vermiculite. In 1989, In the United States, the Environmental Protection Agency (EPA) passed the Asbestos Ban and Phase Out Rule which was subsequently overturned in 1991. This ruling leaves many consumer product that can still legally contain asbestos. For a clarification of products which legally contain asbestos visit the EPA's clarification statement: http://www.epa.gov/asbestos/pubs/asbbans2.pdf USES Historic usage Items made of asbestos were held in so great an esteem as to be of equal value with gold; none but emperors and kings had napkins made of it. Some antiquaries have believed that ancients made shrouds of asbestos, wherein they burnt the bodies of their kings, in order to entirely preserve their ashes, and prevent their being mixed with those of wood, or other combustible materials commonly used in building funeral piles. Others assert that the ancients used asbestos to make perpetual wicks for sepulchral lamps. In more recent centuries, asbestos was indeed used for this purpose. Although asbestos causes skin to itch upon contact, ancient literature indicates that it was prescribed for diseases of the skin, and particularly for the itch. It is possible that they used the term ''asbestos'' for Alumen Plumosum , because the two terms have often been confused throughout history. Modern usage Serpentine group Chrysotile is the form of asbestos from the serpentine group that has been used commercially. In the United States , chrysotile has been the most commonly used type of asbestos. Chrysotile is often present in a wide variety of materials, including but not limited to:
Amphibole group Amosite and crocidolite were used in many products until the early 1980s . The use of all types of asbestos in the amphibole group was banned in the mid-1980s. These products were mainly:
ASBESTOS-RELATED DISEASES Asbestosis and cancer picture)]] Strong concerns about the health hazards associated with asbestos had been described many times over the years. As early as 1898 the Chief Inspector of Factories of the United Kingdom reported to Parliament in his Annual Report about the "evil effects of asbestos dust". He reported the "sharp, glass like nature of the particles" when allowed to remain in the air in any quantity, "have been found to be injurious, as might have been expected" (Report of the Select Committee 1994 ). In 1906 a British Parliamentary Commission confirmed the first cases of asbestos Death s in factories in Britain and recommended better ventilation and other safety measures. In 1918 a US insurance company produced a study showing premature deaths in the asbestos industry in the United States and in 1926 the Massachusetts Industrial Accidents Board processed the first successful compensation claim by a sick asbestos worker. Many American injuries from asbestos exposure came from shipbuilders working during World War II . {Link without Title} The fine asbestos fibres are easily inhaled, and can cause a number of respiratory complaints, including a potentially serious lung fibrosis called '' Asbestosis ''. Exposure to asbestos has also been determined to cause a very serious form of Cancer , Mesothelioma , that occurs in the chest and abdominal cavities. This aggressive disease is improperly referred to as a Lung Cancer , as the malignant cells are derived from the Mesothelium , a tissue found on the inner walls of the chest and abdominal cavities and on the outer surface of the lungs rather than in the lung itself. When inhaled, asbestos is Carcinogen ic (i.e. promotes Cancer ). In the United States alone, it is estimated that ten thousand people die each year of asbestos-related diseases, such as mesothelioma, asbestosis, Lung Cancer , and gastrointestinal cancer. Asbestos has a synergistic effect with Tobacco Smoking in the causation of lung cancer. Other asbestos-related diseases
LITIGATION See Also: Asbestos and the law In the United States, asbestos was one of the first hazardous air Pollutant s regulated under Section 112 of the Clean Air Act of 1970 . One estimate says that, in the 20th century, more than 100 million Americans were exposed to asbestos in the workplace. {Link without Title} Today, lawsuits claiming that asbestos caused plaintiffs' diseases form a gigantic part of the total amount of lawsuits pending in American courts, with a cost of tens of billions of dollars for expenses, settlements, and judgments to date. The original asbestos manufacturers were driven into , asbestos cases result in about 600 to 700 appellate opinions per year (that is, including both federal and state courts); this number does not include other cases that were not appealed, or were settled or otherwise abandoned before trial. Estimates of total American deaths attributable to asbestos range from 200,000 to 265,000 (according to the March 1991 Report of the Judicial Conference Ad Hoc Committee on Asbestos Litigation). The number of suits has increased, although the leading epidemiological study, cited by attorneys on both sides, suggests that deaths peaked in the 1990s. However, others contend that deaths from asbestosis and mesothelioma have not yet peaked. {Link without Title} "Asbestos litigation today is, for the most part, a massively fraudulent enterprise that can rightfully take its place among the pantheon of such great American swindles as the , have become rich because they established lucrative relationships with unions that steered potential asbestos plaintiffs to their law firms in exchange for questionable financial relationships with union executives. [http://www.motherjones.com/news/special_reports/mojo_400/7_angelos.html In the mass screenings that would take place, it is alleged that asbestos-related ailments were systematically overdiagnosed.[http://papers.ssrn.com/sol3/papers.cfm?abstract_id=490682] Because many companies filed for Chapter 11 bankruptcy in view of claims from plaintiffs (some of whom may have been uninjured), and because some of the earlier manufacturer bankruptcy proceedings underestimated future asbestos liability, many seriously injured workers received as little as ten cents on the dollar of the compensation due them. [http://www.newamerica.net/index.cfm?pg=article&DocID=278 Asbestos-related cases were a rare sight on the U.S. Supreme Court Docket prior to 1980, but since then, the Court has dealt with asbestos-injury cases in 1986, 1993, 1995, 1997, 1999, and 2002. The 1997 and 1999 cases both involved giant settlement Class Action s that were designed to stabilize the liability of the largest defendants. Both settlements were ultimately overturned by the Court because they resolved the rights of future claimants who, because they were currently unknown, could not be given the notice that Due Process requires. Texas passed a reform bill requiring neutral medical screening in asbestos claims. Georgia passed a reform bill that requires an out-of-state plaintiff to provide "prima facie evidence of physical impairment" that shows "to a reasonable degree of certainty" that exposure to asbestos was "a substantial contributing factor" to the plaintiff's injuries. Plaintiffs' attorneys in the state complain that this would foreclose "98%" of the pending claims, and that the law is unconstitutional. {Link without Title} Congress is considering legislation, the Fairness In Asbestos Injury Resolution Act Of 2005 , that would establish a $140 billion trust fund to supplant litigation as a means to compensate victims of asbestos. Trial lawyers protest that the trust fund would undercompensate injured workers, while some Conservative s argue that the trust fund does not do enough to prevent fraud; would override state reforms in Texas, Ohio, and Georgia; and would be too "leaky" to prevent future litigation problems. Asbestos liability is one of the largest issues facing the global insurance industry today, with the industry contending that many are suing because they have been exposed but have not as yet contracted asbestos-related lung diseases, which have latency periods of 10-40 years, and because lawyers spend millions each year advertising to promote such lawsuits. [http://www.law.com/jsp/article.jsp?id=1032128856491 , [http://www.theatlantic.com/politics/nj/taylor2002-10-01.htm] In Australia , public attention was drawn in mid-2004 to James Hardie 's handling of its asbestos injury liabilities, following the revelations of a New South Wales government-sanctioned inquiry. In Brazil , prohibition of extraction and use of asbestos is currently under consideration. In Japan too, recently there has been a spurt of lawsuits involving actual or potential damage due to the use of asbestos in schools and public places, following public outcry over asbestos-related deaths. The abuses are not only attributed to the plaintiff's side of such civil cases, but defense-oriented law firms have their own burdens to bear with over-utilization of high-priced "experts" who proffer scientifically untrue or unsound opinions no matter what the facts are in a case. Such defense resources are creating a pool of unethical and disreputable scientists and medical professionals that have muddied the true picture of cause and effect in such courtroom encounters. But personal injury lawsuits are not the only legal issues in this troublesome chapter of human deceit and greed. The asbestos manufacturers engaged in decades of coverup and lying and threatening whistleblowers and others well past the earliest years of the 20th century when asbestos' hazard and disease potential was first recognized by modern medicine. Prior to World War II asbestos insulation was used mainly in high temperature applications and in more specialized products. With the beginnings of WW II preparations in the late 1930s to early 1940s, those same asbestos manufacturers misrepresented the value of their products to the U.S. War Department and convinced the military planners that asbestos was a "Magic Mineral" without any harmful downside. Because of this scam sales job, the U.S. Navy ordered huge amounts of asbestos insulation and products to use in building new warships and asbestos thus got broad recognition from that point on. It's credibility from this scam ballooned its use four-fold during the war years and at the end of the war, there was four times the total asbestos products in the U.S. infrastructure that was present prior to the war. Furthermore, because of the familiarity with it, its use was codified in the U.S. Building code that required its use by law in many applications. This set of circumstances, initiated by the greed of the former asbestos manufacturers and the corruption they instigated in political and governance circles has led to an even more economically outrageous tort on the countries around the world. This is the cost of removing and disposing of the massive amounts of asbestos in a safe fashion from the estimated 70% of all U.S. buildings. This is something that will be required at some point in time for every affected building before it can be finally demolished. It has been estimated that the actual costs of such a massive removal would exceed 4.5 trillion U.S. dollars (1985 dollar estimate). For worldwide removal, no estimates have been made. But in the 1980s, there was a short-lived effort to develop "cost recovery" litigation in the U.S. This involved owners of all kinds of properties that had been impacted by asbestos. To this day, numerous instances of buildings with highly hazardous asbestos products in need of very expensive removal and cleanup occur in every city in the U.S. each year. Many of these instances result in the cost of removal/cleanup exceeding the value of the building! For many building owners, the only way to financially survive such a calamnity which they had not expected or bargained for is to default on their mortgages and walk away from the building and their invested monies. Insurers usually won't cover such conditions. And U.S. bankrupcy laws now shield those companies and individuals who were ultimately responsible. This massive fraud is still unaddressed by the criminal court system and law enforcement. Cost recovery litigation is still an option that becomes more attractive as time brings more people into this crisis of unexpected devaluation of their largest investments. This pendulum of asbestos litigation will be swinging for generations. REMOVAL OF ASBESTOS Many buildings contain asbestos, which was used in spray-applied Flame Retardant , thermal system insulation, and in a variety of other materials. Typically, asbestos was " Flocked " above false ceilings, inside technical ducts, and in many other small spaces where firefighters would have difficulty gaining access. Structural components like asbestos panels were also used. In residences, it was often a component of a type of flocked acoustic ceiling called "popcorn ceiling", until its production was banned in the U.S. in 1978. However, the ban allowed installers to use up remaining stocks, so houses built as late as 1986 could still have asbestos in their acoustic ceilings. The only way to be sure is to remove a sample and have it tested by a competent laboratory. Depending on how and where asbestos was applied, it might not pose any risk to most users of the building. If the fibers cannot dislodge themselves, they cannot be inhaled, and thus the risk is absent. However, with certain ways of applying asbestos, particularly flocking, asbestos fibers may gradually drop off into the air. Furthermore, in all cases, asbestos poses special hazards to maintenance personnel who have to drill holes in walls for installation of cables or pipes. Also, even if the workers are protected, such maintenance operation may release fibers into the air, which may be inhaled by other users later. As a consequence, interventions in areas where asbestos is present often have to follow stringent procedures. The removal of asbestos from a building is quite difficult because of the above constraints. If removal is to be performed when users are still present in the building, it is usually necessary to relocate some of them temporarily. Typically, the part of the building from which asbestos is being removed has to be sealed off in order to prevent contamination of the other areas. Even if the building is closed to normal users, it is necessary to seal it off from outside atmosphere so that no accessible air is contaminated. Accordingly, asbestos removal projects are long and costly. Examples of long asbestos removal enterprises include the Jussieu Campus (begun circa 1996 and still going on As Of 2005 ) and the '' Tour Montparnasse '' (in 2005, projected duration was 3 years if the tower was emptied of its users, and 10 years if it was not). An asbestos-containing building that is to be torn down may have to be sealed, and to have its asbestos safely removed first before ordinary demolition can be performed. The asbestos removal may take longer and cost more than the actual tearing-down of the building. For example, the former seat of parliament of East Germany , the Palast Der Republik was stripped of most of its asbestos between 1998 and 2001, before it was finally decided to tear it down starting in 2006. The demolition process alone is expected to cost between 20 and 60 million Euros. Regarding the automotive industry, asbestos linings were once used in brake pads and shoes. Since the mid-1990s, a majority of brake linings, new or replacement, have been manufactured with Kevlar linings (the same material used in bulletproof vests). CONTROVERSY As with some other environmental prohibitions like DDT and CFC s, the movement to ban asbestos has many critics, some of whom claim either that the substance in question is not harmful, or that the ban does more harm than good {Link without Title} . Among the arguments around asbestos prohibition are:
SEE ALSO REFERENCES |
|
|