For more than 150 years, asbestos was the wonder material of construction and engineering. It had excellent insulation and fire resistant properties, it was easy to work, and it was cheap. The versatile mineral was welcomed everywhere and quickly became as indispensible in shipbuilding and heavy construction as it was later for vital components in cars, railway locomotives and electrical goods.
Domestic construction was a huge market for the material throughout most of the 20th century, and any structure in the UK that was refurbished or constructed before the year 2000 is likely to contain some form of asbestos. It masquerades as floor tiles and decorative finishes, and lurks in wall cavities and lofts as insulation material, or in old fuse boxes or boiler housings. It was widely used by plumbers and roofers and is clearly identifiable when presented as guttering or sheet roofing, but less so when used in a resin composite and shaped into toilet cisterns and water tanks.
Asbestos was an important insulating material for electric oven and hotplate wiring, and widely used in construction for its tensile strength, flexibility and its resistance to heat, flame and chemical erosion. Its fibres were woven into fabric or mats or mixed with cement; it was a universal material with almost limitless applications.
But the full story began long before the industrial revolution in Europe, and asbestos was given its name by the ancient Greeks. Wealthy Persians are said to have amazed guests by cleaning the mystical cloth by simply exposing it to fire, and Marco Polo wrote of garments he saw in China that were also cleaned by flame. The cloths and garments were undoubtedly early examples of woven asbestos, but the modern material didn’t appear in the UK until 1857, and a few years later the first manufacturing plants were opened.
It was used in Canadian and American construction from the 1860’s and the earliest commercial asbestos mines were developed in the Appalachian foothills of Quebec. Canadian asbestos was first spun into cloth in the UK by Samuel Turner in the late 1870’s on second hand cotton machinery. This simple business was founded to manufacture packings with cotton cloth as the fabric base, but was the genesis of Turner and Newell, the Lancashire manufacturer which became the world’s largest asbestos conglomerate.
The company’s early products were hampered by the limitations of cotton, but when the first consignment of raw asbestos arrived from Canada they began to experiment with it, spinning and weaving the fibrous mineral in a region of England with a long textiles tradition. In the early decades of the 20th century Turner and Newell founded an asbestos cement plant and bought asbestos mining properties in Southern Rhodesia.
In the midst of this growth and optimism, a former employee called Nellie Kershaw died in 1924 of what was described as asbestos poisoning, becoming one of the first recorded asbestos related fatalities in the country.
Concerns about the material were first voiced as early as 1898 when a microscopic examination of the mineral dust was made by an HM Medical Inspector. This revealed the jagged, glass-like nature of the particles, and it was noted in an Annual Report of the UK’s Chief Inspector of Factories that were ‘they allowed to rise and remain suspended in the air of a room, in any quantity, the effects have been found to be injurious.’ In 1918 the Prudential Insurance Company of New York refused to sell personal life insurance to asbestos workers, and in 1931 the Asbestos Industry Regulations were drafted in the UK to set a ‘safe’ level of exposure; this level was set so high that one in three workers still developed asbestosis after 15 – 20 years of exposure.
Demand grew through the Second World War and for decades afterwards despite concerns about its safety. But alarmed by the huge number of claimants for asbestos related disease which seemed to grow unchecked, governments began restricting its use from 1980 and the market started to decline.
The days of Turner and Newall, now the world’s largest asbestos manufacturer, were numbered. In 1998 the group was bought by the American company Federal Mogul despite it facing no fewer than 263,000 claims for industrial injury. Partly because of this huge and increasing burden, the new owners went into a Chapter 11 bankruptcy administration in 2001.
Respiratory diseases associated with exposure
However, the asbestos story was far from over. Today more than 200 people are killed in the UK in accidents at work each year, but more than fifteen times that number die as a result of past exposures to asbestos. The lethal qualities of this common material take decades to develop into the many respiratory diseases associated with it, and the annual toll of 4,000 UK deaths will continue to rise in step with the peak in asbestos consumption 40 years before. Many of the earlier work activities which resulted in exposure such as shipbuilding and boiler making have long ceased, but a quarter of the people currently dying have backgrounds in building maintenance and construction.
Whatever the circumstances of the original exposure, the diseases of mesothelioma, asbestosis and lung cancer kill without remorse, while other less fatal lung conditions associated with asbestos merely disable their victims. Caused only by asbestos, mesothelioma is a cancer that grows on the lining of the lung and kills sufferers between six and eighteen months after diagnosis. The non-mesothelioma lung cancers in asbestos-exposed and unexposed individuals are clinically indistinguishable and the signs and symptoms are the same. Some authorities believe that the death rate could be much higher than the Health and Safety Executive (HSE) UK estimate of 4,000, and Professor Rory O’Neill of Stirling University’s Occupational and Environmental Research Group told the BBC last year that the HSE lacked resources to carry out necessary checks and that its figures were a woeful underestimation: ‘A more realistic figure would be 5-6,000,’ he said.
The lung cancer risk increases dramatically if the person smoked, and some studies show that heavy smokers with asbestos exposure have a lung cancer risk that is 16 times greater than that of unexposed smokers. When asbestos exposure was at its height 35 years ago, tobacco use was also widespread.
Asbestosis is a form of pneumoconiosis, a general term for a type of damage done to the interior of the lung by inhaled dust. The lung consists of millions of minute pockets called alveoli where oxygen and carbon dioxide are transferred to and from the blood. Microscopic dust that reaches the alveoli can damage its walls, causing scar tissue which then puts pressure on the neighbouring alveoli which break and scar, and so the disease progresses. Over time this reduces the lung’s ability to get oxygen into the blood resulting in shortness of breath, which can be extreme.
The heart works harder to compensate, and in the worst cases death comes from heart failure. Mild asbestosis may not cause any noticeable symptoms but once scarring has taken hold the disease will get worse. Seriously debilitating asbestosis mainly affects people who worked unprotected with lots of the raw fibre, and such cases are becoming rarer.
Another type of lung disease linked to asbestos exposure involves the lining of the lungs, called the pleura. Diffuse pleural thickening occurs when the lining of the lung hardens as a reaction to inhaled asbestos fibres. It can develop in one or both lungs and restrict breathing; in extreme cases the condition is life threatening, and as an indicator of previous asbestos exposure it may be the harbinger of other asbestos diseases.
The fibres behind all this suffering fall into two main groups, chrysotile and amphiboles. The most widely used of all asbestos types was chrysotile, also known as white asbestos, which has long curly fibres that can be spun and woven like cotton. White asbestos was banned in the UK in 1999 long after the more dangerous amphiboles types, amosite (brown asbestos) and crocidolite (blue asbestos), were outlawed. Crocidolite (blue) was used as yarn and rope lagging from the 1880’s and later in spraying insulation; it is the most lethal member of the asbestos family. Amosite (brown) was used in preformed thermal insulation, pipes, slabs and moulded pipe fitting covers. Both the crocidolite and amosite types had been strictly regulated in the UK since 1969, but not actually banned until the Asbestos (Prohibitions) Regulations 1985.
Amphiboles have long straight fibres that are much more likely to cause cancer of the lung lining, but all types of asbestos dust will cause diseases of the lung such as asbestosis. Studies of patients exposed to chrysotile show only a moderately increased risk, while exposure to the amphibole types double the risk of lung cancer.
In Europe all of these asbestosminerals were widely used in almost every type of construction and manufacturing industry.
There had been concerns about the safety of asbestos for more than fifty years, and by the 1950s it was known that asbestos exposure could cause lung cancer. In 1963 firm medical evidence emerged that exposure to low levels of asbestos could cause mesothelioma, and this knowledge became widespread when the Sunday Times published the results of their investigations, prompting calls for action. The Asbestos Regulations 1969 were directed at those who worked with asbestos or manufactured asbestos products and aimed to reduce or eliminate exposure to it by workers. These regulations and other measures greatly reduced the extent to which asbestos was used in the construction and insulation industries.
Fourteen years later the Asbestos (Licensing) Regulations came into effect, requiring an HSE (Health license to be held by anyone working with asbestos coating or asbestos insulation products. In 1985 the UK’s Asbestos (Prohibition) Regulations banned the import and use of the more dangerous crocidolite (blue asbestos) and amosite (brown asbestos). And two years later the original 1969 regulations were replaced by the Control of Asbestos at Work Regulations, which tightened controls with the aim of reducing the risk of exposure to asbestos at work.
In 1992 (white) chrysotile asbestos was added to the Asbestos (Prohibition) Regulations that were originally drafted to control the use and importation of the more dangerous blue and brown asbestos. And the following year the Control of Asbestos at Work Regulations of 1987 were amended to enforce the substitution of any material containing asbestos wherever this was possible.
With the use and import of blue and brown material already banned, a 1999 ruling saw the complete prohibition concerning use and import of chrysotile. While there would be no further asbestos introduced into the UK, millions of domestic and commercial properties already contained the material in its many forms, and this still presents a constant risk of exposure to anyone who might disturb it.
To reduce this risk as much as possible the “duty to manage” policy was introduced in 2002 to protect further against instances of asbestos exposure in the workplace, and in 2003 the Asbestos (Licensing) Regulations were again amended, to ensure that details of any asbestos work requiring a license were communicated to the relevant authority at least 14 days in advance of the work starting.
The statute books were a mass of asbestos legislation, and so in 2006 the three previous sets of regulations covering the prohibition, licensing and control of asbestos at work were brought together in the Control of Asbestos Regulations 2006, which came into effect in November that year.
- 1931 Asbestos Regulations limited the exposure of asbestos of workers within the asbestos industry
- 1969 Asbestos Regulations revoked the earlier regulations and expanded the statutory duty of employers to ensure their workers were protected from the dangers of working with asbestos
- 1983 Asbestos (Licensing) Regulations introduced strict guidance on how asbestos should be removed
- 1985 Asbestos (Prohibitions) Regulations banned Crocidolite (Blue asbestos) and Amosite (Brown asbestos
- 1987 Control of Asbestos at Work regulations introduced to protect workers from fibre exposure when working with asbestos containing materials
- 1992 Asbestos (Prohibitions) Regulations amended to include ban on rarer forms of Amphibole asbestos (Tremolite, Actinolite and Anthophylite
- 1999 Asbestos (Prohibitions) Regulations amended again to include ban on Chrysotile
- 2002 Control of Asbestos at Work Regulatations (2002) introduced regulation 4 where businesses are obliged to identify and manage asbestos in their properties
- 2006 Control of Asbestos Regulations (2006) introduced. This was an amalgamation of previous key asbestos regulations
The Control of Asbestos Regulations (2006) require employers to prevent exposure of employees to asbestos, and If this is not reasonably practicable the law says that their exposure should be controlled to the lowest possible level. Before any work with asbestos is carried out, the regulations require employers to make an assessment of the likely exposure risk to asbestos; and this should include a description of the precautions planned to control dust release and to protect workers and others who may be affected by the work.
Regulation 4 of this legislation gave the person responsible for a commercial property the duty to manage asbestos in the building, requiring them to establish whether asbestos is present and if so where, what type it is and in what condition. In many cases the building manager needed to survey the premises for asbestos and record the information in a register that would be available for anyone having to work on the building, such as maintenance staff. No work can now be carried out on premises containing asbestos without first preparing written plans detailing how that work is going to be conducted.
The regulations introduced a new, lower control limit of exposure, and mandated that employers can no longer carry out work on asbestos with their own workers without a licence. The legislation also made working on asbestos textured coatings a licensed task, and clarified the need for asbestos awareness training for anyone who may be exposed to it. The control limit is 0.1 fibres per ml for all types of asbestos and this is the maximum concentration averaged over a four hour period that must not be exceeded. Areas are routinely monitored by sampling known volumes of air onto a gridded membrane filter. This filter is then sent to accredited analysts for optical analysis, where the number of fibres are identified and /or counted. Once levels are below the required level, areas can be deemed clear and can then be re – occupied.
Short term exposures must also be strictly controlled and worker exposures should not exceed 0.6 fibres per ml of air averaged over any continuous 10 minute period. Personal air sampling pumps can be used in this instance, again samples made onto filters and a fibre count obtained. Appropriate actions can then be made in response to the fibre count.
Respiratory protective equipment must be used if exposure cannot be reduced sufficiently by other means. Respiratory protective equipment is an important part of the control regime but it must not be the sole measure to reduce exposure and should only be used to supplement other measures. Respiratory protective equipment must be suitable, must fit properly and must ensure that worker exposure is reduced as low as is reasonably practicable.
With the legislation in place, the HSE has set about enforcing it with gusto. Recent prosecutions include that of an Essex building company that was fined £150,000 this year with £30,000 costs for allowing workers in a refurbishment project to become contaminated with asbestos. Another company was recently fined £70,000 with costs of £14,000 for breaches of regulations 15 and 7 of the Control of Asbestos at Work Regulations.
Directive 1999/77/EC of the European Union banned all types of utilization of asbestos from 1st January 2005, and the earlier 2003/18/EC directive banned the extraction of asbestos and the manufacture and processing of related products. The entire EU is now free of new asbestos materials and products, but as in the UK the problem of exposure to asbestos in the course of removal, demolition, servicing and maintenance activities remain. Its legacy is the projected 250,000 asbestos related deaths in Europe over the next 25 years; some authorities predict that the fatalities will peak in 2010 and others estimate that it will not start to decline until 2020.
In the US, there are 2,000 expected cases of mesothelioma a year and 2,000 to 3,000 other asbestos related tumours (American Journal of Epidemiology); the use of asbestos is still legal although tightly controlled. However, there are many countries, particularly in the third world, where asbestos continues to be imported and used in various industries, and for these countries the number of exposed workers and asbestos-related deaths are unknown.
Published: 10th Jul 2009 in Health and Safety International