Asbestos is a group of silicate minerals known to cause a rare form of cancer called mesothelioma.
Key Points about Asbestos
- Asbestos is the only scientifically proven cause of mesothelioma, a rare form of cancer.
- Asbestos is a general term that refers to six specific fibrous minerals (asbestiform minerals).
- All types of asbestos share common properties, including a fibrous texture and resistance to fire, heat, and electricity.
- Since the late 19th century, asbestos has been used in an abundance of construction materials and household products.
- Although it is a known carcinogen, asbestos has yet to be banned in the United States.
What Is Asbestos?
Asbestos refers to a number of unique substances that are members of the serpentine and amphibole mineral groups. Asbestos is very resistant to chemicals, electricity, and water, making it a good insulator for a number of Industrial Age products such as steam engines, ovens, electrical generators, turbines, and boilers. Because it is malleable, it is useful for building materials (roofs, tiles, wall board, etc.) as well as binding and strengthening other products.
In the 1960s, asbestos was shown by researchers to cause a rare form of cancer, known as mesothelioma, that can form in the lining of the lungs, abdomen, heart, or testes. Although some forms of asbestos may be more harmful than others, the United States Department of Health and Human Services, EPA, and the International Agency for Research on Cancer declare that all types of asbestos are cancer-causing materials. That is to say that all currently known forms can cause mesothelioma, lung cancer, asbestosis, laryngeal cancer, ovarian cancer as well as a number of other diseases and conditions.
While asbestos has been banned in 52 countries due to its status as a known carcinogen, the United States has not yet implemented absolute ban. The recently passed Frank R. Lautenberg Chemical Safety for the 21st Century Act may provide the EPA with a path to fully banning asbestos once and for all.
Asbestos as a Health Concern
Asbestos has long been known to be a health hazard, and the effects of exposure are well documented. Asbestos fibers in the air can easily be inhaled and become embedded in the lungs, where they can cause mesothelioma, a deadly form of cancer, and other diseases like asbestosis.
This asbestos-related cancer grows on the thin protective linings that cover the lungs (pleura), abdomen (peritoneum), and heart (pericardium). If you inhale or swallow asbestos fibers, they can become lodged in the pleural, peritoneal, or pericardial lining. Over a period of time, the embedded asbestos fibers cause biological changes that bring about inflammation, scarring, and genetic damage to the cells, which can lead to cancer. Studies have shown a slightly increased risk of developing mesothelioma for those who are exposed to crocidolite or amosite asbestos over other forms.
Another asbestos-related lung disease from breathing in asbestos particles, asbestosis is a severe form of fibrosis – the development of fibrous connective tissue around the lung cavity. Symptoms of asbestosis include shortness of breath and lung scarring. This happens after many years of exposure and is an irreversible scarring of the lungs. This is an industrial disease from exposure to high levels of any type of asbestos.
The pleural cavity around the lungs contains a small amount of fluid. This fluid is kept in balance by the normal mechanics of breathing. However, changes in the rate of production or removal of the fluid can produce an excess amount of fluid, which is known as pleural effusion. Pleural effusions can be an early manifestation of asbestos-related diseases and can appear within 10 years of exposure, or it may be benign.
Unlike other asbestos-related diseases, asbestos warts appear on the outside of the body rather than internally. They can occur on the surface of the skin where asbestos fibers have been embedded, forming calluses.
Other Asbestos-Related Conditions
Lung cancer is an abnormal growth of cells in the lungs, generally of cells that line the air passageways. The most common cause of lung cancer is smoking tobacco products. However, in a small number of cases, the presence of asbestos has also been shown to be a factor in the development of lung cancer, especially in combination with tobacco smoking.
These are thickened areas which can be seen on the surface of the pleura. The pleura is made up of two membranes that cover the lungs and line the chest cavity. Pleural plaques don’t become cancerous or generally cause breathing problems; however, they can be an indication of other conditions, such as mesothelioma. They often form 20 to 30 years after exposure. Over time they calcify.
This occurs when air has accumulated in the thoracic (chest) cavity that causes the lung to collapse. This can occur spontaneously or as a result of injury or lung disease. Mesothelioma can sometimes be misdiagnosed as pneumothorax.
Types of Asbestos
Asbestos refers to the unique fiber composition shared by six different minerals, known as “asbestiform” minerals. In the U.S., the legal definition of asbestos is provided in the Toxic Substances Control Act (TSCA), and this definition was adopted by the U.S. Environmental Protection Agency (EPA) in 1976. The TSCA guides the EPA in administering national compliance rules in regulating these six forms of asbestos.
Chrysotile – This form of asbestos (white) is the most common form used and often found in homes particularly in floors, walls, ceilings and roofs. This mineral has also been used in brake linings, gaskets, pipe insulation, and boiler seals. This mineral is the only member of the serpentine group and has somewhat curly fibers unlike amosite, crocidolite, tremolite, actinolite, and anthophyllite which have needle-like fibers.
Amosite – Known as brown asbestos (needle-like fibers), most of the amosite comes from Africa and most often used in pipe insulation, cement sheets, and ceiling tiles.
Crocidolite – Commonly know as blue asbestos and has best heat resistance. Much of the crocidolite is mined in Australia, South Africa, and Bolivia. It is found in cement materials, spray-on coatings, pipe insulation and steam engines.
Tremolite – This asbestos form can be found in a number of colors such as gray, green, white, and transparent. This mineral is not used commercially but is frequently found as a contaminate in talc powders, vermiculite, and chrysotile. So, it is found in insulation products, roofing materials, paints, and sealants.
Anthophyllite – This asbestos tends to be grayish-brown in color. It is not used commercially but found as a contaminant in flooring products.
Actinolite – This form of asbestos is not used commercially but is found as a contaminant. It can be colorless to pale or deep green. This form of asbestos can have a harsh texture and is less flexible.
Minerals Related to Asbestos
Since 1976, hundreds of other minerals either sharing similar properties as asbestos or containing traces of asbestos themselves have been recognized. However, these materials are not regulated.
Erionite – This is a fibrous mineral forming white wool-like mats and is a member of the zeolites. Often found in volcanic ash, it is not regulated by the EPA. Erionite is found in Oregon, Nevada, Utah, South Dakota, Montana and Arizona. The hazard here is road dust (generating atmospheric contamination) for those who mine erionite and local residents.
Vermiculite – This is a mica mineral and has a brown or yellowish color. It is commonly used in insulation materials for open fireplaces, acoustic panels, fireproofing of steel and pipes, wall board, brake linings, hand warmers, flooring, roofing, and as a medium to grow plants. Some vermiculite products prior to the early 1990s contained asbestos, however vermiculite mined today is tested and if it contains asbestos it is not supposed to be sold.
Taconite – This rock contains a significant amount of iron mixed with a variety of minerals, including carbonate, quartz, and chert. Named for the State of New York’s Taconic Mountains, which contains similar iron-bearing rock formations, taconite was mined, crushed, and formed into pellets for use in the steel industry. The waste product from this process (known as the “tailings”) has been shown to contain asbestos-like particles. Most mining and production of taconite occurred in Minnesota, where the tailings would flow into Lake Superior, until 1973 when a U.S. District Court judge ordered mining companies to implement safer waste practices. Although taconite itself has not been linked to cancer, the large amounts of asbestos used in the processing of taconite have caused northeastern Minnesota to have almost double the expected occurrence of mesothelioma.
Talc – A magnesium-heavy clay mineral, in its powder form talc is often used as baby powder (talcum powder). It can be green, gray or white. Soapstone – which has historically been used to make sinks, countertops, stoves, sculptures, and other items – is primarily made of talc. Talc is found in the Western United States, Western Europe, Italy, Himalayas, Pakistan, India, Nepal, and Bhutan, where it often occurs naturally with or very near to asbestos deposits. Although regulations and quality control practices were put in place in the 1970s to help make sure food- and cosmetic-grade talc does not contain asbestos, there is still some potential for asbestos to find its way into talcum powder and other products. Talc may also be linked to other forms of cancer: A recent court case against Johnson & Johnson awarded tens of millions of dollars to the family of a woman who died of ovarian cancer, claiming that the cancer was caused by the company’s talcum powder.
Primary Uses of Asbestos
Humans have used asbestos as far back as prehistoric times. Asbestos was used in funeral shrouds, candle wicks and pottery. In modern times, asbestos became important for the automotive and construction industries. Asbestos has also been used in shipbuilding, clothing and in domestic items such as small appliances.
Ancient Uses of Asbestos
Asbestos has been used since prehistoric times. Interestingly, archeologists have found asbestos fibers at sites dating as far back as the Stone Age (750,000 years ago). Around 4000 BCE, asbestos fibers were used as wicks in candles and lamps. Even the Egyptians used asbestos. Around 2000 – 3000 BCE, embalmed bodies were wrapped with asbestos cloth.
In 2500 BCE, Northern Europeans were using asbestos fibers to strengthen their clay pots also making them more resistant to fire. Circa 450 BCE, the Romans wrapped their dead in asbestos shrouds before placing them onto a funeral pyre to prevent their ashes from being mixed with the fire. It is believed that the Romans used asbestos to weave tablecloths and napkins. It is claimed that these cloths were cleaned by throwing them in a fire and apparently coming out unharmed.
Both the Romans and the Greeks were aware of the dangers of asbestos. They observed individuals who mined and wove asbestos come down with “a sickness of the lungs.” Even though asbestos was used early in human development, it was more of a novelty than a major industry.
Growth of Asbestos in the Industrial Age
Not until the 19th century CE, during the beginning of the Industrial Age, did asbestos mining begin to grow and become widespread.
Asbestos has been used in just about all public and commercial buildings since before the 1900s in the United States, primarily because of its effectiveness as a fireproofing material for steel beams and columns.
Due to the strength and malleability of asbestos, it is added to adhesives, concrete, roof shingles, asphalt, pipes, wall board, and floor tiles. Since it is heat resistant, it is good for thermal insulation.
For the modern world, asbestos was the hottest item for the construction industry. However, over time the industry realized that asbestos becomes dangerous to your health when damaged, crumbled, or degenerates into a state of ill-repair.
In the early part of the 1800s, crocidolite was found in Africa, and in the late 1800s chrysotile was found in Quebec. Canada established the first commercial asbestos mines, and by 1870, Scotland, Germany, and England joined them in the global asbestos industry. In the 1880s, Australia began mining asbestos, and in the 1890s Finland joined in.
In the 1800s, asbestos mining was not mechanized, which made it a slow, manual process. Once it was industrialized and manpower increased, production increased dramatically, allowing new applications to be realized. The first asbestos brake linings for the horseless carriage were made in 1896 in England. Then, came asbestos cement sheets from Germany and high pressure gaskets from Austria.
By 1913, the first asbestos pipes were being produced by Italy. World War I and World War II brought about an even greater need for asbestos products, and later the car industry because of the need for more durable roads with asbestos. By the middle of the 20th century, the asbestos mining became an unstoppable machine.
The United States Navy specified the use of asbestos in submarines in 1922, using South African chrysotile asbestos for gaskets, insulation, packing, and tape. By 1939, the United States defined asbestos as a critical material and began stockpiling it.
During World II, the British Admiralty had control of merchant shipbuilding, including the distribution of asbestos. Asbestos resists corrosion and high temperature making it very useful for shipbuilding. However, asbestos accumulation in the air, skin, and clothing makes naval shipyard workers the most frequently exposed to its harmful effects.
Asbestos has so many applications such that it can be found in almost every industry, and the automobile industry is no exception. Asbestos is found in internal combustion parts, brake pads, gaskets, and a myriad of other car parts. Due to the ubiquity of the mineral in automobile parts, many workers in the automotive industry – including mechanics, technicians, and factory employees – are at risk of asbestos exposure.
Clothing and Textiles
Due to its fibrous nature, asbestos can be used to make protective clothing and textiles, such as jackets and fire blankets for firefighters or the overalls worn by racecar drivers. Workers in industries that use open flames and/or high heat also may wear specialized clothing made with asbestos, such as protective gloves (such as gauntlets or mitts) and aprons. This includes industries such as glass making, foundries, the steel industry, welding, or even cooking.
In addition to clothing and protective gear, asbestos has been used in other textile applications, including carpeting, drapes and curtains, upholstery, and covers for ironing boards.
There are a number of domestic items made with asbestos because of its durability and fire- and heat-resistant properties. These include toys, personal items, appliances, and home construction materials. Other items include fire starters, gaskets, toasters, hair dryers, ironing board covers, electric blankets, burner pads, portable heaters, dishwashers, and much more.
In the 1930s to 1950s, artificial snow made of asbestos was a big hit, having been marketed for use in homes across the country. It was also used in such movies as The Wizard of Oz. Recently, asbestos has been found in children’s toys and tools, such as crayons.
Alternatives to Asbestos
Since the hazards associated with asbestos are well understood, there are a number of alternative products currently available. Most of these alternatives are readily available at the store or through a contractor.
This foam is used in roofing and insulation and is a petroleum byproduct; however, some environmentally friendly polyurethane foams are made from soy byproducts. All polyurethane foam contain millions of tiny closed cells filled with one of two gases known as hydrochlorofluorocarbons (HCRC) or chlorofluorocarbons (CFC).
To create the foam, a blowing agent agitates the plastic, which causes bubbles to form. The foam then hardens quickly and forms a water-resistant barrier that completely blocks air flow. Make sure to buy a polyurethane that is free of polybrominated diphenyl ethers (PBDEs), as this chemical has been known to be toxic to developing brains in animals and potentially cause harm to humans.
This foam differs from polyurethane in that it is based on castor oil and it doesn’t trap gas inside cells, as it has an open cell structure. Icynene is used primarily for insulation applications and is meant to be applied by a professional. This insulator is generally used when some air or vapor needs to pass through the foam.
Safer alternatives to asbestos fillers, which are used to fill in cracks and crevices, can be made of wheat, rice flour, or pecan shell flour. These are great green alternatives; however, they might be difficult to find as they are not as common as other varieties of fillers.
Made of shredded newspaper, this is another green alternative to asbestos and has become very popular in recent years. It is chemically treated to reduce mold and increase fire resistance. Cellulose fiber has been used in roofing materials, partitions, and as a mixture for cement.
Thermoset Plastic Flour
Made of plastic, this material popular in the building and construction industry as a heat, cold, and sound insulator. This plastic flour can be mixed with other fillers to lower the cost.
Amorphous Silica Fabrics
These materials are used in insulation and protection where high temperature fabrics are required such as in aerospace shipyards, molten metals, and electric power generation. These materials contain fiberglass which can be a health hazard but is far better than asbestos.
When Was Asbestos Banned?
By the 1930s, medical evidence was mounting that linked asbestos to mesothelioma; however, the federal government didn’t pass any legislation to limit exposure until the 1970s. The following decade brought about further guidelines.
The EPA formally sent out a rule banning most asbestos products on July 12, 1989. Unfortunately, this rule was overturned by the Fifth Circuit Court of Appeals, allowing established uses prior to 1989. However, The Toxic Substances Control Act (TSCA) banned the manufacture, importation, processing and distribution in commerce of certain asbestos materials in:
- Commercial paper
- Corrugated paper
- Specialty paper
- Flooring felt
Domestic asbestos production finally came to a grinding halt in 2002 with the closing of the last mine in the United States.
Major Hurdles in Banning Asbestos
Despite the overwhelming medical and scientific evidence that asbestos is dangerous in any amount, there have been a number of significant hurdles to banning asbestos in the U.S. If the ban in 1990 had gone through, that would have been the end of the asbestos problem. However, since it did not occur back then, there is still an ongoing effort to ban asbestos in the U.S. and other countries.
In May 2016, one of the biggest hurdles preventing a ban on asbestos was cleared when Congress passed the Frank R. Lautenberg Chemical Safety for the 21st Century Act. Although this bill does not ban asbestos outright, it empowers the EPA to review and ban substances that it deems to be toxic. While it may take several years for such a ban to be put in place – and perhaps many more years after that to fight asbestos industry interests in the court system – the passage of this bill brings the U.S. one step closer to banning asbestos for good.