Archaeological digs in Finland have found pottery, dating back almost 5,000 years, containing what we now know as asbestos. Asbestos is the name given by the scientific community to a group of six fibrous silicate minerals which display certain qualities, known as asbestiform minerals, and occur naturally alongside rocks as the result of geological processes.
These properties include strength, flexibility and fire-resistance, which explains why humans have called these materials 'asbestos' - meaning 'inextinguishable' in the ancient Greek language - for millennia.
The Wonder Material
Impressive heat-resistance and flexibility made the fibres ideal for weaving into clothing and mixing with building materials, and asbestos use skyrocketed with the Industrial Revolution of the early 1800's. Used in everything from heavy-duty fire blankets and war-time gas masks to vinyl flooring and household pipes, asbestos was ubiquitous in commerce and industry for centuries.
Asbestos nowadays, however, has quite a different reputation. Far from revered, the useful material is now banned from commercial use in much of the developed world (America being a notable exception).
How could a material so remarkable that it propelled civilisation into a new era of technology, whose use was so beneficial that the ancient Greeks, Egyptians and Romans all adopted it from their northern cousins, fall out of fashion so suddenly?
If It Sounds Too Good To Be True...
In short, asbestos was.
Medical journals in the late 1800's began recording cases of asbestos-related illnesses in miners in Quebec following the opening of a local commercial asbestos mine, and these were corroborated by case studies around the world. Even as far back as the Romans, reports can be found recalling slaves working in asbestos mines that developed a 'sickness of the lungs'.
Upon discussing the death of 33 year old asbestos-yarn spinner Nellie Kershaw in 1924, and following decades of sporadic investigations worldwide into the possible health risks related to asbestos exposure, the UK Parliament requested British doctor E. R. A. Merewether conduct a study. For two years, Merewether examined workers at an asbestos-based textile factory, and discovered alarming trends. 85% of long-time workers at the factory were found to have scarring of the lungs, a symptom of what is now termed asbestosis.
The findings presented in 1930 prompted Parliament to change ventilation legislation in industry, but it would take many decades of gradual investigation for asbestiform materials to finally be axed across the European Union in 2003.
Asbestos use in the US didn't begin to slow until 1979, after nine asbestos manufacturers filed a lawsuit against the government having paid thousands in reimbursements to an asbestosis sufferer a few years previously.
In response, the American federal government launched a case which proved that the asbestos industry had been aware of - and deliberately hidden - the damaging effects of asbestos exposure.
Media coverage sent asbestos-related business tumbling, and many people worldwide took it upon themselves to attempt to remove asbestos products, such as tiling, drywall and insulation, from their own homes. This led to a notable increase in asbestosis cases, and governments around the world now advise that remaining asbestos products be left untouched since they pose minimal risk; the tightly-bound fibres are generally only released into the air if the material is disturbed - by a homeowner attempting to remove it, for example.
Toxicity
The source of asbestos' health effects was the study of medicine for many decades, as the number of recorded asbestosis cases increased.
The flexible fibres of asbestiform minerals - the amphiboles asbestiform type in particular - behave like shards when inhaled, scarring the lungs.
Amphibole shards in particular have numerous chemical properties which cause serious health risks:
Their shards are smaller and sharper, so penetrate deeper into lung tissue causing increased inflammation and scarring.
Their fibres are hydrophobic, or 'water-avoiding', so don't dissolve in the mucus which lines the lungs and would otherwise allow them to be coughed up and expelled.
Their fibres contain iron which may react with oxygen in the lungs. This can lead to DNA damage and have a carcinogenic (cancer-causing) effect over long periods of time.
Should You Be Worried?
Chances are, your home will not contain asbestos-related products. Less modern homes may contain some amount of asbestos insulation or construction materials, but if left undisturbed they represent little risk and should be left alone!
If you're worried about the stringy-looking padding leaking out of the drywall, contact an asbestos removal company.
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References:
Hank Green's Sci Show
British Lung Foundation
www.asbestos.com
www.wikipedia.com