Asbestos Exposure in Buildings

 

Part 1

Asbestos is a pale-colored, fibrous mineral formation with a storied history. It is perhaps the fact that it was once so popular as a building material that colors our current sense of urgency regarding its toxicity. Asbestos was known to the ancient world, named in a variety of sources as a material useful for lamp wick’s, fireproof clothing, and in buildings as a source for fireproof curtains. Prior to the 19th century asbestos boom, the material had a limited use in domestic goods (Alleman & Mossman, 1997), (Competition Commission, 1975), although Peter the Great did operate an asbestos industry. Its application in building throughout the nineteenth century was mainly restricted to Chrysotile fibres designed for insulation reasons (Competition Commission, 1975).

Case Study:

When meeting Robert Hamilton for the first time, one might be excused for thinking he is terminally sick. He has wonderful energy, a strong will to live, and a fantastic sense of humour. Since being diagnosed with mesothelioma in July 2006, Robert’s optimistic attitude has helped him get through some of his darkest moments.

Mesothelioma is a terminal cancer of the lungs caused by exposure to asbestos fibres.

Robert, of Polmont, Falkirk Central Region, worked for 28 years as an assistant foreman at I.C.I. in Grangemouth, and despite not handling asbestos himself, he was exposed to the fibres every day at work during the maintenance and refurbishment works going on around him – the entire building and all the pipes were insulated with deadly asbestos.

Robert’s job included guiding maintenance personnel across the I.C.I. building to areas where asbestos cladding and lagging needed to be repaired or replaced.

“When the boys put the lagging on, the dust would go everywhere. You could feel the dust in your throat and we used to go for a couple of pints after work to wash the dust out!

“Nobody told us anything about asbestos. The staff were given different items of protective clothing for other chemicals that they worked with, but not for asbestos.”

Robert Hamilton, now 66 years old, is supporting the national campaign “Asbestos – the Hidden Killer” launched by the Health and Safety Executive (HSE). The program seeks to educate tradespeople about the dangers they confront in order to combat the increasing incidence of asbestos-related fatalities.

Asbestos may be present in any structure constructed or renovated before to 2000. It is believed that asbestos is present in approximately 500,000 working buildings, with the possibility of asbestos being present in many more residential locations.

The first symptom Robert noticed was a chesty cough, which he assumed he caught from the air conditioning while on vacation. When the chest infection didn’t go away, his doctor diagnosed pneumonia and subsequently tuberculosis, for which Robert was treated for six months.

“It took a year before I was correctly diagnosed with mesothelioma. On diagnosis they gave me six to nine months to live. It does knock the breathe out of you when you are diagnosed.

“It takes a while to sink in, it’s as if you are talking about someone else. A lot of crying goes on and asking ‘Why me – what have I done to deserve it?’

“Telling the family was devastating and my wife is very scared at being left on her own.”

Mesothelioma may take anywhere between 15 and 60 years to become active and begin destroying the lungs’ exterior lining. The majority of people who are diagnosed with cancer die within one or two years after being diagnosed.

Robert has been suffering from this terrible illness for more than three years. There is no cure for mesothelioma; only symptomatic relief is available. He’s undergone three rounds of chemotherapy, the most recent of which was in March of this year, and he’s had significant surgery to remove a lung, as well as radium treatment. Robert’s recovery after surgery took a long time, and he had a stroke and suffered from despair at that period.

Living daily with mesothelioma has had a huge effect on Robert’s life he explained:

“The life that you know is gone. I can’t walk for more than 20 minutes and I easily become breathless when I do something energetic, I can’t swim anymore and I struggle to walk up the steps in the football stand now when I go to watch Falkirk play.”

Robert used to live a very full and active life, spending time with family and friends. He used to volunteer as a coach driver for several charities and was an officer with the Boys Brigade for 25 years.

Robert now takes life day by day and explains how he copes and manages to look on the bright side of life:

“There are lots of things I took for granted that I used to be able to do, but now I just can’t. But you’ve got to put a face on. You can’t go and lie in a wee corner, you’ve got to be positive and get on with things

“Although I do say to some of my close friends that it’s going to get me one day.

“Now that I’ve had chemo my hair grows straight up! You’ve got to laugh; otherwise you’d sit there crying all the time.”

(Health and Safety Executive, 2012)

Robert’s story is intended to alert modern tradesmen to the dangers of working with asbestos. He also wishes to remind them to employ protective equipment in any situation involving contact with asbestos. Proper training is essential. Presently, there are still reports that attribute Asbestos-related disease to approximately 4,000 deaths per year. (Health and Safety Executive, 2012)

Asbestos may be extracted from six distinct mineral kinds. Long chains of oxygenated silicon create fibrous structures that may be used in building, according to the mineral’s characteristics. The precise behavior of the minerals, as well as the distinction between the six kinds, is determined by the presence of other elemental components such as calcium, magnesium, or iron. (Alleman & Mossman, 1997; Alleman & Mossman, 1997; Alleman & Mossman Few people dispute that Asbestos is a dangerous occupational and environmental hazard. Based on the prognosis of reported occurrences of lung cancer, asbestos has been connected to over 200,000 fatalities in the United States (La Dou, et al. 2001), and it is feasible to estimate millions more deaths globally. (According to Lilienfeld et al., 1988.) One of the most alarming elements of the asbestos pandemic is the evidence that all asbestos-related cancers and fatalities are completely avoidable.

Safer substitutes for asbestos exist, and they have been utilized successfully in many countries around the world. ,( La Dou, et al. 2001) After the 1950s, the asbestos industry in the United Kingdom faced challenges from alternative products made in some cases from plastic or glass fibres. More restrictive regulatory requirements as a result of concerns during the 1960s relating to health risks has since seriously contracted the market for asbestos products in the United Kingdom. (Competition Commission, 1975)

For decades, health concerns linked to asbestos exposure, as well as the availability of some safer replacement materials, have prompted a growing number of nations to ban asbestos imports and usage. The usage of asbestos in the United States has been drastically reduced. (2001, LaDou) Most European nations, as well as Saudi Arabia, have outlawed asbestos. By 1998, the European Union had enacted laws prohibiting the use of asbestos in the future, as well as regulations governing the safety of workers who remove asbestos from older structures. Laborers involved in the dismantling or destruction of structures containing Chrysotile are required to get special training. (European Union Publications Office, 2010) The seriousness of the health effects of using asbestos as a building material in contemporary industry has been well established in worldwide scientific literature. Simply put, the issue is how much is too much. Even decades later, a burden of disease and death among asbestos workers in mining, heavy industries, and construction is all but apparent. (1955, Doll)

            It is the great resiliency of asbestos that also creates a danger; the fibres are fireproof, may be stronger than steel, and can penetrate living tissue where their prolonged presence may result in cancers. According to the United States Environmental Protection Agency, fibres between 0.5 to 1.5 micrometers are respirable by humans, are able to reach the respiratory zone of the lungs, and thus pose a health hazard. (Berman et al, 2003) It is for this reason that suspicion and restriction of the material is prevalent throughout much of the industrialized world. Many countries criminalize the use of the substance, especially where it might come in direct contact with people. (Turner, 2012), (Alleman & Mossman, 1997)

Due to the carcinogenic effects of tissue penetration, a correlation is suspected between the strongest fibre-types that exhibit the greatest risk to humans. These are known as the amphibolic varieties, and are thus the most dangerous. They may be informally known as ‘brown’, or ‘blue’ asbestos, and have been mixed with cement and utilized for insulation purposes before health dangers restricted their use. 95% of worldwide asbestos usage employed the mineral known as Chrysotile, or serpentine-asbestos. Its softness and flexibility permit the human body to degrade it more easily; making it less damaging to body tissues. Specifically, tougher amphibole fibres have a 5-fold greater carcinogenicity across multiple analyses when inhaled than Chrysotile. (Hodgson & Darnton, 2000) In the United States, 20% of shingles, pipes, and insulation layers still use this variety. (Berman et al. 2003

But the material still sees considerable use outside of the UK and US, and much modern demand for asbestos comes from Asian markets. The properties and resiliency of the substance has excited humans for centuries, but Marco Polo – upon visiting an asbestos mine in China correctly deduced that it was a type of rock, not the hair of a ‘wooly lizard’. But examples such as this illustrate the ongoing human fascination with the substance. (Alleman & Mossman, 1997)

Risk assessment for asbestos is important; in part for the purpose of tracing patterns of lung cancer back to a potential source. But an in-depth understanding of carcinogenicity associated with asbestos will provide insight on ways to develop safe construction techniques. An analysis on the rates of cancer with a particular type of asbestos at what particle size might enable the material to be used safely in the future. Asbestos is not some unnatural chemical invader; it is a real, natural substance. Thus is cannot be ‘destroyed’ in its entirety. It is worthwhile to explore methods to employ it without risk.

That task is complex, asbestos exposure standards have not always exhibited consistency with risks reported in the scientific literature. (Berman & Crump, 2001) It is vital that the minimum exposure standards of environmental regulatory agencies be as accurate as possible; to be protective of the populace.

While it is generally accepted that amphibole fibres yield a greater risk for cancer, the exact estimates vary from 5-fold, to 50-fold. Some of the discrepancy may be due to differing toxicity parameters resulting from animal studies, or deviations based on calculations used to determine average exposure compared with severity of exposure. This creates a challenge in the standardization of exposure levels to be mandated by government for use in construction. (Hodgson & Darnton, 2000) Other researchers believe that the risk levels do not differ in a statistically relevant way between different asbestos varieties, (amphibole, vs. Chrysotile)

There is little doubt that asbestos fibres do entail considerable carcinogenic risk; not only for lung cancer, but also malignant mesothelioma. The disagreement concerning the exact nature of the risk posed by how much of which subtype does not fundamentally change the debate. The question becomes one of thresholds and standards.

The earliest initial attempt to project cancer from asbestos exposure is attributed to a 1978 study. The objective was to quantify the proportion of cancers occupationally induced by industry and construction efforts utilizing asbestos. (Gough, 1984) But similar to other studies, there remains uncertainty concerning the exact tendencies of what asbestos levels to inflict what form of cancer.

Recent studies show that even at the lowest levels of exposure, 0.1 fiber per millimeter of air is linked to a lifetime risk of lung cancer of 5/1000. The danger exists regardless of whether the fibers are 0.5 to 1.5 micrometers in diameter. (LaDou and colleagues, 2001)

Industries manufacturing health-hazardous products may survive stringent standards in the industrialized world by increasing sales to developing countries. In these regions, exposure risk is likely to be far higher; with nearly epidemic exposure rates possible amongst the work force. (Giannasi & Thebaud-Mony, 1997), (Izmerov et al, 1998) For this reason, there is considerable support for an international ban on asbestos. This juggling action has shifted the problem, rather than permitted the elimination of the health risks.

The asbestos industry still retains influence throughout the world. Even in the United States, the asbestos industry was able to overturn a 1992 mandate for the phasing out of asbestos by a legal technicality. (LaDoe et al, 2001)

Exporters of asbestos, such as Canada and Russia, have established strong commercial interests in the newly industrializing countries. Asbestos contamination levels in emerging nations are now similar to those in developed ones before the health concerns were identified. Despite the impact of these commercial interests, exporters are not immune to them. A study of women living in towns near asbestos mines in Canada found a seven-fold increase in the incidence of pleural cancer death. (Meek & Camus, 1998) These ladies did not work as miners. A remarkable rise in morbidity has been seen in areas where significant industrial activities using asbestos have taken place. Even with the most rigorous working regulations, some exposure seems to be unavoidable.

A description of mesothelioma might be helpful in a discussion of pleural malignancies. Malignant mesothelioma is a malignancy that affects the thin layer of cells that lines the body’s internal organs, known as the mesothelium. Mesothelioma is classified into three kinds. The most prevalent kind of mesothelioma is called pleural mesothelioma. Pleural forms, which develop in the lining of the lung termed the pleura, account for about 70% of cases. Peritoneal mesothelioma affects the peritoneum, which borders the abdominal cavity, while pericardial mesothelioma affects the pericardium, which lines the heart. (2012, Mesothelioma.com)

Asbestos exposure in the job or at home may put people at risk of developing mesothelioma. Mesothelioma is a cancer caused by asbestos exposure and inhalation of asbestos fibers or particles. In most cases, mesothelioma symptoms do not appear until years after a person has been exposed to asbestos. Those who have had previous asbestos exposure and are having symptoms should see a doctor who is experienced in correctly diagnosing mesothelioma. The importance of early detection cannot be overstated. Various therapy methods are available at early stages of mesothelioma development that will lead to a better prognosis. (2012, Mesothelioma.com)

In Summary:

1. While asbestos has been used since ancient times, for more than 50 years there have been suspicions concerning the risk of carcinogenicity from inhalation of asbestos fibres.
2. Different researchers have given different estimates concerning the risk of what number of fibres of a particular concentration, but there is abundant evidence that the fibres cause cancer.
3. The most common form of asbestos is Chrysotile, which is less physically resilient. The more resilient fibres with higher concentrations of iron or magnesium carry a greater risk of cancer.
4. Asbestos leads to different diseases depending upon the severity of concentration, asbestosis at higher levels. Mesothelioma can result from long exposure to low levels of airborne fibres.
5. Asbestos is still useful in heavy industrial operations requiring resistance to extreme heat, but it is becoming increasingly scarce for residential use.

Part 2

Due to its resilience, asbestos shows significant resistance to heat and degradation in building applications, and has therefore been used for a variety of commercial and industrial applications in the past. When asbestos is crushed, it splits into millions of tiny, sometimes microscopic threads rather than dissolving into dust. (Asbestos and Lead Management Program, 1997; Asbestos and Lead Management Program, 1998; Asbestos and Lead Management Program,

Large amounts of asbestos remain in thousands of schools and residential areas, as well as commercial structures, throughout the industrialized world, and are currently collecting in thousands of communities in emerging nations, owing to the needs of previous construction techniques.

Due to the fact that many cancers are slow-developing diseases, and given estimations of morbidity rates based upon levels of exposure, researchers have been able to project future deaths from asbestos exposure out to many years in the future. (Lilienfeld. et al, 1988). Such as projections that Western European deaths from exposure will increase from 5,000 in 1998, to 9,000 by the year 2018. (Peto et al. 1999)

Every year in the U.S. for instance, 2,500 to 3,000 people are diagnosed with mesothelioma, due to these long latency periods, many such victims suffered exposure to asbestos decades ago. (Finley, 2011)

Other items, even in more recent times, may contain asbestos. Finley discusses a new research that found mesothelioma-causing tremolite in hundreds of consumer goods. Tremolite is a kind of asbestos mineral that causes mesothelioma. An study of the exposure-response connection in two high-risk settings, such as the Thetford Chrysotile mine in Canada and the vermiculite mine in Libby, Montana, was another method to evaluate mesothelioma risk. The lowest-observed-adverse-effect level (LOAEL) for mesothelioma in these employees was 35-73 fibres per cubic centimeter (f/cc) per year. (2011, Finley)

Researchers calculated levels of exposure in different settings using estimates of airborne tremolite asbestos concentrations associated with the use of tremolite-containing goods and structures. When working on brakes, gearboxes, and engine components, auto technicians may come into contact with asbestos-containing materials. According to studies, a 0.028 f/cc per year exposure level is expected.

 Consumers who buy vermiculite-containing gardening goods on a regular basis have an annual tremolite exposure risk of 0.034 f/cc. (2011) (Finley)

These levels also include remediation/removal actions concerning asbestos. Complicating the matter of asbestos usage and replacement as a building material are the risk factors – not only in the long-term consequences of residential exposure, but also the issue of removing asbestos from older buildings. Finley describes additional risks from homeowner removal of Zonolite insulation. This yields probable exposures of homeowners to levels equal to 0.0002 f/cc of tremolite each year. (Finley, 2011)

The Finley research cautions that there are still hundreds of goods and construction materials on the market that include Chrysotile and talc-containing consumer products, even if the morbidity figures are modest compared to the mesothelioma danger to asbestos miners. The greater the exposure to the tremolite asbestos variety and the higher the lifelong risk of health problems like mesothelioma and lung malignancies, the more of these items a customer uses on a regular basis.

            There is abundant evidence presented above concerning health dangers from inhalation of Asbestos fibres, and it is reasonable to conclude that while a single fibre may not cause cancer, in light of the above studies, and the considerable research on the subject, it is reasonable to conclude that there is no known safe exposure. Where disagreement exists concerning the fibre size that may result in carcinogenicity, and uncertainty regarding the numbers thereof, the only truly safe standard would be none at all. The risks rise as exposure increases. (American Lung Association Fact Sheet, 2010). The amount of time between exposure and the first signs of disease can be measured in decades. This factor makes studies performed decades ago potentially still relevant, given future morbidity projections.

However, it may be premature to say that no asbestos should ever be used in construction anywhere ever; it is hardly safe for instance, to allow unshielded persons to handle uranium, but it still has its uses. It is worthwhile to explore the question of safe utilization of asbestos minerals. While alternatives are possible, asbestos is still very useful for industrial processes that require specialist materials that exhibit tolerance to extremely high temperatures. It is also useful for applications where high friction is involved. (Competition commission, 1975)

Because Asbestos has been widely used in building projects throughout the decades, replacement will take time. Acoustic insulation, thermal system insulation, floor and ceiling tiles, assorted floor coverings, counter tops, and various kinds of shingles and siding were all made using asbestos until the 1970s (Asbestos and Lead Management Program, 1997). As previously stated, asbestos may be found in a number of consumer products that benefit from heat/fire resistance.

Public buildings often contain Friable asbestos, 20% in the United States as of the early 1990’s. (Gaensler, 1992). Even if those levels change, the fact that they did exist in the past creates an exposure risk; which implies a certain level of contamination that will lead to future diseases. To be specific, Friable asbestos are materials that easily release asbestos fibres into the air when subjected to pressure. Non-friable varieties have asbestos contained in a seal that binds particles in a stable mesh to prevent their release. Other sealing methods include binding asbestos into cement, vinyl, or resins. Non-friable materials can still pose a risk if the mesh is damaged or stripped in some way. Nuclepore filter technology can be useful in the determination of airborne concentration of fibres; often in offices and industrial buildings. (Altree-williams & Preston, 1985)

The discovery of environmental asbestos fibres and particulates in the course of autopsies has increased awareness concerning asbestos exposure in buildings. Since asbestosis results from high levels of exposure, some building occupants may dismiss the risks. While respiratory asbestosis occurs as a result of higher levels of exposure, even faint amounts of fibres can cause mesothelioma; amounts typical of household conditions.

Presently, there is little risk of the asbestosis of the past; dependent upon the exposure doses in the higher ranges. It was largely a disappearing disease by the 1990’s; and that illness in particular is of almost no concern as a factor in modern buildings. (Gaensler, 1992) Gaensler’s study also strengthens the premise that Different pathologies can be associated with different levels of exposure.

Gaensler’s Epidemiologic data includes alveolar inflammation, fibrogenesis, and respiratory carcinogenesis, in addition to the long-known respiratory carcinogenesis. However, mesothelioma has been a major source of worry in recent years because to the fact that it has been linked to much lower levels of exposure in the home and neighborhood than lung cancer and asbestosis. Because of their prevalence in autopsies and the showing of a linear connection between exposure and lung cancer risk in occupational groups, asbestos fibres are an increasing source of worry. Legislative and regulatory requirements, abatement businesses’ advertising efforts, and adverse court decisions have increased the pressures on asbestos and asbestos products and their manufacturers. All of it stems from a fear of a “mediagenic disease pandemic” (Gaensler, 1992), and these concerns, both genuine and overblown, have led to a panic among building owners, schools, and those who insure them. The actual clinical probability of asbestos illness or asbestos-related disease from building occupancy alone, particularly when non-friable materials are used, is disputed. As a result, certain risk estimates were extrapolated from previous data derived from higher-dose, occupation-related exposure. When asbestos particles are breathed by workers who are actively working with the material, we know that it causes illness, but the actual disease risk from casual occupation is unknown.

The Gaensler study’s risk estimations in the United States based on 0.001 f/mL exposure show lifetime cancer risks ranging from 2 to 20 per 1 million participants. These calculations, however, are based on the assumption of mixed fiber exposure. Chrysotile, which is less poisonous than amphibole fibres owing to its lesser stiffness, accounts for the majority of exposure from casual occupation. Gaensler (Gaensler, 1992)

Following a comprehensive examination of these risks, comparisons between various regulatory methods for the management of asbestos illnesses in construction should be made. In the case of asbestos and other hazardous materials, UK legislation mandates a certain degree of risk management. All forms of asbestos are subject to a control limit of 0.1 fibres per cm3 under British legislation. A Control Limit is the maximum concentration of asbestos fibres in the air that must not be exceeded at any point throughout the workday (averaged over any continuous 4-hour period). Short-term exposure levels must also be carefully regulated, with worker exposure levels not exceeding 0.6 fibres per cm3. 2006 (legislation.gov.uk).

The United States code differs slightly from England with less reliance on hard limitations for the control of certain substances. Such limitations do exist as basic safety measures; but the United States Code contains language that permits Inspectors some leeway. Language includes powers for the Investigator to deem whether a hazardous chemical or mixture poses a threat. There are laws that can be used to penalize various businesses that are involved in the production or spread of hazardous materials, but in certain cases the Investigator can issue judgments on if an how to impose penalties. An administrator is also permitted to judge whether actions short of the maximum penalties allowable could moderate the detected risk. (United States Code, 2009)

In terms of mitigating these risks there are a number of recommendations that should prove effective. The use of asbestos should be reduced where possible, but valid industrial processes are a legitimate purpose. Heavy Industries need the ability to work with a variety of dangerous substances, including acids, explosives, and to some extent radioactive agents. As mentioned above, Asbestos is useful in extremely high-temperature operations involving heavy friction.

Policies should be in place to reduce its prevalence in any residential setting, or business settings where employees do not habitually don heavy protective gear. For the short-term, non-friable production methods should be employed wherever possible. These techniques are not entirely without risk, if the mesh or seal is damaged, some fibers can still be released. But for use in cement, and paneling secured between walls, the risk appears negligible. In terms of absolute banning, amphibole fibres appear to carry too great a risk to be worth the benefit, when alternatives are available. Non-friable asbestos should serve as an effective substitute in construction until technological advancement produces alternatives that are fully equivalent in terms of protection, yet also cost-effective. This method should retain structural benefits and feasibility in terms of fire resistance, while making inhalation a non-issue.

In Summary:

1. While the dangers have been known for decades, buildings constructed before the 1990’s are still likely to contain asbestos.
2. Friable asbestos can separate into airborne fibers are threaten respiratory health, as well as cause mesothelioma.
3. Non-friable asbestos is safer if the structure is not damaged or altered.
4. Glass and Plastic alternatives exist, but asbestos is still needed in high-temperature, high-friction operations.

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