Asbestos or asbestus ( ) is a group of naturally occurring, fibrous silicate minerals that have been used for thousands of years to create flexible fire-resistant objects, such as fireproof fabrics. It is toxic and carcinogenic.
There are six types, all of which are composed of long and thin fibrous crystals, with each fibre (particulate with length substantially greater than width) composed of many microscopic "fibrils" that can be released into the atmosphere by abrasion and other processes. Inhalation of asbestos fibres can lead to various dangerous lung conditions, including mesothelioma, asbestosis, and lung cancer. As a result of these health effects, asbestos is considered a serious health and safety hazard.
Archaeological studies have found evidence of asbestos being used as far back as the Stone Age to strengthen ceramic pots, but large-scale mining began at the end of the 19th century when manufacturers and builders began using asbestos for its desirable physical properties. Asbestos is an excellent thermal and electrical insulator, and is highly fire-resistant, so for much of the 20th century, it was very commonly used around the world as a building material (particularly for its fire-retardant properties), until its adverse effects on human health were more widely recognized and acknowledged in the 1970s.Bureau of Naval Personnel, Basic Electricity. 1969: US Navy. Many buildings constructed before the 1980s contain asbestos.
The use of asbestos for construction and fireproofing has been made illegal in many countries. Despite this, around 255,000 people are thought to die each year from diseases related to asbestos exposure. In part, this is because many older buildings still contain asbestos; in addition, the consequences of exposure can take decades to arise. The latency period (from exposure until the diagnosis of negative health effects) is typically 20 years. The most common diseases associated with chronic asbestos exposure are asbestosis (scarring of the lungs due to asbestos inhalation) and mesothelioma (a type of cancer).
Many developing countries still use asbestos as a building material, and asbestos mining continues, with the top producer, Russia, producing an estimated 790,000 tonnes in 2020.
Etymology The word "asbestos", first used in the 1600s, ultimately derives from the , meaning "unquenchable" or "inextinguishable".. The name reflects use of the substance for wicks that would never burn up.
It was adopted into English via the Old French abestos, which derived the word from Greek via Latin, but in the original Greek, "asbestos" actually referred to quicklime. It is said by the Oxford English Dictionary that the word was wrongly used by Pliny the Elder for what is now called asbestos, and that he popularized the misnomer. Asbestos was originally referred to in Greek as amiantos, meaning "undefiled",. because when thrown into a fire it came out unmarked. "Amiantos" is the source for the word for asbestos in many languages, such as the Portuguese, the Spanish, and the Italian amianto and the French amiante. It had also been called "amiant" in English in the early 15th century, but this usage was superseded by "asbestos". The word is pronounced or .
History
Asbestos has been used for thousands of years to create flexible objects that resist fire, such as napkins and other textiles. Mass production of asbestos-containing consumer goods began in the modern era. Today, the risk of asbestos has been recognized; the use of asbestos is completely banned in 66 countries and strictly regulated in many others.
Early references and uses
Asbestos use dates back at least 4,500 years, when the inhabitants of the Lake Juojärvi region in East Finland strengthened earthenware pots and cooking utensils with the asbestos mineral anthophyllite; archaeologists call this style of pottery "asbestos-ceramic". Some archaeologists believe that ancient peoples made shrouds of asbestos, wherein they burned the bodies of their kings to preserve only their ashes and to prevent the ashes being mixed with those of wood or other combustible materials commonly used in funeral pyres.Pliny the Elder. Ch. 4.—LINEN MADE OF ASBESTOS. In The Natural History Others assert that these peoples used asbestos to make perpetual wicks for sepulchral or other lamps. A famous example is the golden lamp asbestos lychnis, which the sculptor Callimachus made for the Erechtheion. In more recent centuries, asbestos was indeed used for this purpose.
A once-purported first description of asbestos occurs in Theophrastus, On Stones, from around 300 BC, but this identification has been refuted. In both modern and ancient Greek, the usual name for the material known in English as "asbestos" is amiantos ("undefiled", "pure"), which was adapted into the French as amiante and into Italian, Spanish and Portuguese as amianto. In modern Greek, the word ἀσβεστος or ασβέστης stands consistently and solely for lime.
The term asbestos is traceable to Roman naturalist Pliny the Elder's first-century manuscript Natural History and his use of the term asbestinon, meaning "unquenchable"; he described the mineral as being more expensive than pearls. While Pliny or his nephew Pliny the Younger is popularly credited with recognising the detrimental effects of asbestos on human beings, examination of the primary sources reveals no support for either claim.
In China, accounts of obtaining huǒ huàn bù () or "fire-laundered cloth" certainly date to the Wei dynasty (386-535 AD), and there are claims they were known as early as in the Zhou dynasty, though not substantiated except in writings thought to date much later (see huoshu or "fire rat").
Athanasius of Alexandria, a Christian bishop living in 4th-century Egypt, references asbestos in one of his writings. Around the year 318, he wrote as follows:
Wealthy Persians amazed guests by cleaning a cloth by exposing it to fire. For example, according to Tabari, one of the curious items belonging to Khosrow II Parviz, the great Sassanian king (r. 590–628), was a napkin () that he cleaned simply by throwing it into the fire. Such cloth is believed to have been made of asbestos imported over the Hindu Kush.New Encyclopædia Britannica (2003), vol. 6, p. 843 According to Biruni in his book Gems, any cloths made of asbestos (, āzarshost) were called shostakeh ().Dehkhoda Persian Dictionary Some Persians believed the fiber was the fur of an animal called the samandar (), which lived in fire and died when exposed to water;A Brief History of Asbestos Use and Associated Health Risks EnvironmentalChemistry.com website this was where the former belief originated that the salamander could tolerate fire. Charlemagne, the first Holy Roman Emperor (800–814), is also said to have possessed such a tablecloth.
Marco Polo recounts having been shown, in a place he calls Ghinghin talas, "a good vein from which the cloth which we call of salamander, which cannot be burnt if it is thrown into the fire, is made ..."
Industrial era
The large-scale asbestos industry began in the mid-19th century. Early attempts at producing asbestos paper and cloth in Italy began in the 1850s but failed to create a market for these products. Canadian asbestos samples were displayed in London in 1862, and the first companies were formed in England and Scotland to exploit this resource. Asbestos was first used in the manufacture of yarn, and German industrialist Louis Wertheim adopted this process in his factories in Germany. In 1871, the Patent Asbestos Manufacturing Company was established in Glasgow, and during the following decades, the Clydebank area became a centre for the nascent industry.
Industrial-scale mining began in the Thetford Hills, Quebec, from the 1870s. Sir William Edmond Logan was the first to notice the large deposits of chrysotile in the hills in his capacity as head of Geological Survey of Canada. Samples of the minerals from there were displayed in London and elicited much interest. With the opening of the Quebec Central Railway in 1876, mining entrepreneurs such as Andrew Stuart Johnson and William Henry Jeffrey established the asbestos industry in the province.The storied province of Quebec : past and present. Volume V (1931) Wood, WCH; Atherton, WH; Conklin, EP pp. 814–5 The 50-ton output of the mines in 1878 rose to over 10,000 tonnes in the 1890s with the adoption of machine technologies and expanded production.Udd, John (1998) "A Chronology of Minerals Development in Canada" National Resources Canada For a long time, the world's largest asbestos mine was the Jeffrey Mine in the town of Asbestos, Quebec.
Asbestos production began in the Urals of the Russian Empire in the 1880s, and the Alpine regions of Northern Italy with the formation in Turin of the Italo-English Pure Asbestos Company in 1876, although the greater production levels from the Canadian mines soon overtook European production. Mining also took off in South Africa from 1893 under the aegis of the British businessman Francis Oates, the director of the De Beers company. It was in South Africa that the production of amosite began in 1910. The US asbestos industry began in 1858 when fibrous anthophyllite was mined for use as asbestos insulation by the Johns Company, a predecessor to the current Johns Manville, at a quarry at Ward's Hill on Staten Island, New York. US production began in earnest in 1899 with the discovery of large deposits in Belvidere Mountain in Vermont.
The use of asbestos became increasingly widespread toward the end of the 19th century when its diverse applications included fire-retardant coatings, concrete, bricks, pipes, and fireplace cement, heat-, fire-, and acid-resistant gaskets, pipe insulation, ceiling insulation, fireproof drywall, flooring, roofing, lawn furniture, and drywall joint compound. In 2011, it was reported that over 50% of UK houses still contained asbestos, despite a ban on asbestos products some years earlier.Don, Andrew (1 May 2011) Asbestos: the hidden health hazard in millions of homes . The Guardian.
In Japan, particularly after World War II, asbestos was used in the manufacture of ammonium sulfate for purposes of rice production, sprayed upon the ceilings, iron skeletons, and walls of railroad cars and buildings (during the 1960s), and used for energy efficiency reasons as well. Asbestos production in Japan peaked in 1974 and fluctuated until about 1990, when production began to drop dramatically.
Discovery of toxicity
The 1898 Annual Report of the Chief Inspector of Factories and Workshops in the United Kingdom noted the negative health effects of asbestos, the contribution having been made by Lucy Deane Streatfeild, one of the first women factory inspectors.
In 1899, H. Montague Murray noted the negative health effects of asbestos. The first documented death related to asbestos was in 1906.
In the early 1900s, researchers began to notice a large number of early deaths and lung problems in asbestos-mining towns. The first such study was conducted by Murray at the Charing Cross Hospital, London, in 1900, in which a postmortem investigation discovered asbestos traces in the lungs of a young man who had died from pulmonary fibrosis after having worked for 14 years in an asbestos textile factory. Adelaide Anderson, the Inspector of Factories in Britain, included asbestos in a list of harmful industrial substances in 1902. Similar investigations were conducted in France in 1906 and Italy in 1908.