What is Asbestos?
Asbestos was called "the magic mineral" because its unique chemical composition and physical properties made it suitable for use in thousands of products from floor tiles to road signs, from sewage pipes to insulating mattresses. Asbestos fibres can withstand the fiercest heat but are so soft and flexible that they can be spun and woven as easily as cotton. The term asbestos is derived from a Greek word meaning "inextinguishable, unquenchable or inconsumable." It is a generic name for a group of fibrous silicate minerals, the most common of which are detailed below.
Also known as white asbestos chrysotile is a member of the Serpentine group, so-named because the fibre is curly. Chrysotile fibres are the most flexible of all asbestos fibres and their resistance to alkaline attack makes chrysotile a useful reinforcing material in asbestos-cement building products. Chrysotile and has traditionally been the most widely used of all asbestos types, accounting for approximately 95% of asbestos mined annually. The import and use of chrysotile was banned in the UK in 1999.
Crocidolite is known colloquially as "blue" asbestos and is a member of the Amphibole group. The needle-like fibres are the strongest of all asbestos fibres and have a high resistance to acids. The high bulk volume of crocidolite makes it suitable for use in sprayed insulation. Crocidolite is known to be the most lethal of all the asbestos types. Its import into the UK was banned in 1985.
Amosite is also known as brown asbestos and is, like crocidolite, a member of the Amphibole group. Its harsh, spiky fibres have good tensile strength and resistance to heat. Amosite has been principally used in the UK in the manufacture of insulation boards. The import of amosite into the UK was banned in 1985.
Is Asbestos Still a Problem?
Despite the fact that there has been some regulation on the use of asbestos in Britain since 1931, the death toll from asbestos-related diseases has been appalling. Widely divergent predictions have been made for the number of asbestos-related deaths in Britain over the next thirty years, the most conservative of which forecasts a total of 90,000; another claims that a figure of 500,000 will be reached. Even after a British ban on all types of asbestos was passed in 1999, problems arising from wide-scale asbestos use have not been resolved. Victims in Britain and elsewhere live with the reality which many in the international asbestos industry have sought to deny. The policy of "controlled use" as preached by industry is a fallacy. During the 1990s, the number of younger men dying from one type of asbestos-related cancer more than doubled.
Why All the Fuss?
John Selwyn Gummer, at that time the Under-Secretary of State for Employment, told the House of Commons on 28 July, 1983 that asbestos "is not a substance for which one can set a level below which there is no risk...We must therefore assume that a single fibre could do real damage which may not be seen for 20 years or more." American observers claim that "the United States is suffering from an epidemic of mass murder by the American asbestos industry."
Asbestos has been described as "the grand-daddy of all occupational killers." It affects people who come in contact with it at every level. It contaminated the miners who pulled it from the ground, the millers who processed the raw fibre, the men who transported the Hessian bags of fibre from South Africa, Canada, Australia, the dockers who unloaded the cargo, the factory workers who manufactured asbestos products, the wives who washed their clothes and the children who were present at the time. Children of asbestos factory workers have succumbed to asbestos-related diseases caused by para-occupational exposure: i.e. by breathing the fibres brought home on their parents' workclothes. Building workers used asbestos-containing products in the construction of domestic and commercial properties while D-I-Y enthusiasts used asbestos-containing products in their homes. Asbestos-containing materials in British homes constitute an on-going risk to both amateur and professional workmen.
People who continue to work in, inhabit or maintain buildings which contain deteriorating asbestos products are also at risk. Asbestos deaths among caretakers and maintenance men of such buildings are higher than average. Then there are the people who had the misfortune to live near asbestos factories or mines. Asbestos has resulted in disease in members of the public whose only exposure has been environmental. Studies conducted in Armley, Leeds documented an explosion of asbestos-related deaths among people who lived, worked or visited an area adjacent to a former asbestos textile factory. On 27 October, 1995 June Hancock and Evelyn Margereson were awarded £65,000 and £50,000 respectively for environmental asbestos exposure which occurred near the factory owned by J. W. Roberts Co. Ltd., a subsidiary of Turner & Newall Ltd. Some years earlier, a London man had received a £45,000 out of court settlement from Cape plc after he alleged that he had contracted mesothelioma from living next door to Cape's East London asbestos factory during his childhood.
How Does Asbestos Kill?
As well as being ideally suited for multiple commercial uses, asbestos is also the "perfect carcinogen" as it acts as both a promoter and initiator of cancer. Experiments have shown that when an asbestos fibre enters a lung cell it can attract cancer-causing agents. Asbestos fibres are dangerous when inhaled and the dustiest processes are, in general, the most hazardous. That asbestos is a toxic material has been known for decades. Exposure to asbestos has been linked to several diseases including asbestosis, lung cancer and mesothelioma.
Evidence presented in 1907 to a government enquiry by Dr. Montague Murray described the first diagnosed case of fatal, non-tubercular, diffuse pulmonary fibrosis in an asbestos worker: asbestosis. Asbestosis is an irreversible and progressive lung condition which results from the inhalation of asbestos fibres over an extended period. In asbestosis, lung tissue is scarred and thickened by the abrasive action of the asbestos fibres in the alveoli, the air sacks. The latency period for asbestosis is usually at least ten years and the higher the exposure, the greater the chances of developing the disease. Asbestosis tends to be linked to heavy occupational exposure although cases of asbestosis among those not occupationally exposed have been known.
An article which appeared in The Lancet in 1934 presented evidence of a link between asbestos and lung cancer. Dr. Richard Doll's landmark paper: Mortality from Lung Cancer in Asbestos Workers was published in 1955; Doll's research showed that the incidence of lung cancer among men at an asbestos factory in Rochdale was ten times the national norm. Asbestos-related lung cancer can occur from occupational or environmental exposure: it is virtually incurable. The chances of recovery for those whose lung cancer is caused by asbestos are worse because the lungs may already damaged by the dust. One type of lung cancer asbestos causes, undifferentiated, small-cell type, is the one with the least hope of treatment. The latency period for lung cancer associated with asbestos exposure is usually between fifteen and thirty-five years. An article in the Journal of the American Medical Association estimated that an asbestos insulation worker who smokes had ninety two times the chance of dying from lung cancer as a non-smoking, non-asbestos worker.
Mesothelioma is a formerly rare, but increasingly common cancer of the lung or the abdominal cavity; the only known cause of mesothelioma is exposure to asbestos. Malignant mesothelioma can be contracted from very low exposures to asbestos and accounts for the majority of victims who contract an asbestos-related disease through environmental exposure. The latency period for mesothelioma is generally between thirty to fifty years although British courts have accepted a latency period as short as ten years. On average, mesothelioma patients survive for eighteen months to two years following diagnosis although some poeple survive considerably longer. Currently, there is no known cure.
A scientific paper published in 1960 by Dr. Christopher Wagner established the link between the occurrence of mesothelioma and asbestos exposure in South Africa. Co-written with Dr. Sleggs & Marchard, "Diffuse Pleural Mesothelioma and Asbestos Exposure in the North Western Cape Province" appeared in the British Journal of Industrial Medicine. In 1995 a routine analysis of British statistics by Professor Julian Peto of the Institute of Cancer Research uncovered a rapid acceleration in the number of British mesothelioma deaths which, he predicted, would continue to increase from 1,000 to 3,000 per year by the year 2024. According to Peto, the most worrying aspect is the discovery that the rate of mesothelioma deaths is rising in men aged 50 and younger and that most victims have only had secondary links with asbestos, often as construction workers, carpenters, plumbers or electricians.
How Many British Deaths?
Figures for asbestos deaths in Britain are inaccurate because only two of the asbestos diseases are recorded on death certificates: asbestosis and mesothelioma. Death certificates do not record incidences of lung cancer arising from asbestos exposure. One conservative estimate puts the number of British asbestos deaths at three thousand annually. If this figure was constant for the next thirty years, the result would be 90,000 deaths. According to Professor Peto, at its peak the British asbestos epidemic will claim 10,000 lives per year, producing a mortality of 300,000. Joseph Califano, a former Secretary of Health, Education and Welfare in the US has stated that during a thirty year period 67,000 Americans will die annually from asbestos-caused cancers. Working with these numbers, it is calculated that more than two million American asbestos victims will die. If we were to use the American figures, the number of asbestos-related deaths we could expect in Britain over the next thirty years is 500,000.
Has it Been Regulated?
The British Asbestos Regulations of 1931 constituted the first attempt by a national government to minimise the harmful effects of asbestos and were aimed at limiting occupational exposure within the asbestos industry. Although these regulations governed the British asbestos industry from 1931 until 1970, they failed to prevent the deaths of thousands of British workers from asbestos-related diseases. The main flaw in the 1931 regulations was that they were industry specific. The fact that these regulations did not apply outside the asbestos industry prolonged the period during which insulators, plumbers, boilermakers, shipyard workers and others were exposed to asbestos.
The Asbestos Regulations (1969) revoked the 1931 regulations and expanded the statutory duty of employers to ensure that all staff in factories, power stations, warehouses, institutions and other premises were protected from the dangers of working with asbestos. The 1969 regulations applied to every process which used either asbestos or any article that contained asbestos and sought to minimise exposure to asbestos dust through the use of exhaust ventilation, protective equipment and clothing, the cleaning at regular intervals of machinery, plants and interior surfaces by dustless methods and the introduction of improved handling procedures. Despite the introduction of these controls, the occurrence of asbestos-related occupational disease amongst those working in the premises covered by the 1969 regulations was not eliminated.
Why is Asbestos Still a Hazard?
There are no official estimates of the number of British buildings which contain asbestos. Asbestos products were used on a large scale for fireproofing, acoustic and thermal insulation, condensation protection and reinforcement in asbestos-cement products from about 1900 to the late 1970s. Asbestos-containing materials used in British buildings include: sprayed asbestos coatings, asbestos lagging, insulation partition boards, ropes and yarns, cloth, millboard and paper, asbestos cement sheets and partition boards, flooring, textured coating, mastics, sealants, putties, adhesives, wall plugging compound, pipework and so on. The problems with products which contain asbestos become most severe when they are disturbed, damaged, weathered or old: when this happens, fibres are released into the atmosphere and contamination can occur. In answer to the question: is there still a risk, the answer is a most definite: yes!
What are the Implications for the Future?
Asbestos is a problem which crosses national borders and class divisions. With their long latency periods, asbestos diseases appear to transcend even time itself. Six million tons of indestructible asbestos fibre were imported into Britain during the 20th century. How we identify, locate and deal with this legacy will determine whether future generations will continue to experience the painful deaths caused by exposure to the "magic mineral."
1. Peto J, Hodgson JT, Matthews FE, Jones JR. Continuing increase in mesothelioma mortality in Britain.The Lancet, 1995:Vol. 345: p.535-539.
2. Kazan-Allen L. 1995: Asbestos Update. APIL Newsletter February, 1995:Vol. 5: p.10-13.
3. Hatchwell,P. Asbestos now. Occupational Health Review, 1994: Vol.52: p.25-29.
4. Hatchwell,P. Asbestos-concern abroad. Occupational Health Review, 1995: Vol.54: p.26-31.
August 21, 2004