Asbestos | The History, Types, and Exposure Risks

Asbestos is a fibrous mineral found naturally in rocks and soil. Prior to 1980, asbestos was used commonly in construction materials used in buildings, homes, and schools. Asbestos is the only known cause of mesothelioma.

What Is Asbestos?

Asbestos is made of naturally occurring fibrous minerals found in rocks and soil. These fibers are so small that they cannot be seen. People exposed to asbestos unintentionally inhale or ingest these toxic airborne particles.

Asbestos can be found in many construction materials, such as spray-on insulation and roofing materials. Most mesothelioma cases are due to occupational exposure.

Key Facts About Asbestos

Widely Used Building Material

Asbestos was a critical building component in the military, used in virtually every naval ship from the 1930’s to 1980’s. It was also used in most construction trades during this period.

Used for Thousands of Years

Asbestos has been used since before 3,000 B.C. Records show ancient Egyptians pointing to a related illness that afflicted those who worked with the mineral.

Naturally Occurring

Asbestos is a naturally occurring mineral that was often used in manufacturing for its fire-resistant and insulating qualities. It is still widely used in some countries across the globe.

Types of Asbestos

The use of asbestos was common in the United States until the 1970′s. During this time regulations were made to help protect people from developing mesothelioma and other asbestos-related illnesses.

Some parts of the world still use asbestos because it is cheap and convenient for manufacturing. Asbestos can still be found today and there are several other minerals which also pose a threat to those who breathe in their fibers.

Serpentine vs. Amphibole Asbestos

There are two different kinds of asbestos fibers: serpentine and amphibole.

Serpentine fibers are long and curly. These types of asbestos fibers are considered less harmful to the human body because they are easier to flush out. The only known type of this asbestos is chrysotile.

Serpentine asbestos can be found in:

  • Asphalt
  • Cement
  • Textiles
  • Roofing materials
  • Plastics

According to Penn Medicine, “Because it is the most widely used, chrysotile accounts for the majority of cases of mesothelioma and asbestos diseases including pleural mesothelioma”.

Amphibole fibers are short, straight, rigid and sharp. These types of asbestos fibers are easy to inhale. Amphibole lodges into organs and tissues more easily than serpentine fibers. These types of asbestos fibers are more likely to cause mesothelioma and lung cancer. Amosite and crocidolite asbestos have these types of fibers.

Amphibole asbestos can be found in:

  • Roofing
  • Insulation
  • Plumbing
  • Titles
  • Automobile parts

“…asbestos fibers of greater length and smaller diameter (high length/width ratio) are more carcinogenic, possibly because they can penetrate farther,” claims a passage about malignant pleural mesothelioma in Clinical Respiratory Medicine.

Asbestos Subtypes

There are six different subtypes of asbestos used in products: tremolite, actinolite, anthophyllite, chrysotile, amosite, and crocidolite. The three most commonly used asbestos types are chrysotile, amosite, and crocidolite. These asbestos subtypes can be found in construction materials and automobile parts.


  • Also known as “white asbestos”.
  • Commonly used form of asbestos.
  • Used in products where it is compacted and non-friable.
  • Found in car gaskets, brake pads, brake linings, insulation, and cement.
  • Considered the “safest” form of asbestos, but it still can cause mesothelioma.


  • Also known as “brown asbestos”.
  • Second most commonly used type of asbestos in the United States.
  • More dangerous form of asbestos because it’s easy to crumble and inhale.
  • Used to make ceiling tiles, insulation, fire protections, and cement sheets.
  • Made up of amphibole fibers which have a higher risk of causing cancers.


  • Also known as “blue asbestos”.
  • Least commonly used in materials.
  • Most hazardous type of asbestos.
  • Commonly found in cement.
  • Causes more deaths and asbestos-related diseases than any type of asbestos.

Where Is Asbestos Found?

Asbestos is primarily found in older buildings. Prior to the 1980’s and 1990’s, there weren’t any restrictions on using building materials that contained asbestos. The health risks were known, but not in full detail.

“Even though asbestos production has slowed in the U.S., there are still thousands of buildings (including offices, homes, and schools) containing asbestos materials that could potentially cause mesothelioma”.

Asbestos is extremely flame-resilient and does not corrode. As a result, it was used in many buildings, homes, and schools built prior to the 1990’s. Asbestos was also used in automobile parts.

Some building materials that may contain asbestos are:

  • Tiles
  • Insulation
  • Roofing shingles
  • Paper products

There are approximately 542 locations in the United States where asbestos occurs naturally or in mine deposits.

Asbestos was once mined in the following states:

  • Vermont
  • Arizona
  • North Carolina
  • Georgia
  • California
  • Washington
  • Alaska

Those who have worked directly with asbestos materials, such as miners, have the highest risk of developing asbestos-related cancers. However, secondary exposure can also occur. Many mesothelioma patients were unintentionally exposed by coming into contact with asbestos fibers brought home by their loved ones.

Mining and Importing Asbestos

Mining for asbestos no longer occurs in the United States. It was once popularly mined and a high demand in the country.

Asbestos was mined by using an open-pit (an open area similar to a valley) method. When asbestos is first extracted, it resembles old wood. It is then refined to a fluffy fiber. The refined asbestos is then added to other materials, like cement or insulation, to form an asbestos-containing material.

Mining of asbestos in the United States ended in 2002, but it is still imported into the country today. In fact, over 8 million pounds of asbestos has been imported to the U.S. over the last decade.

The majority of asbestos imported into the United States is raw asbestos. As of today, this type of asbestos is used by the chlor-alkali industry. This industry uses it to aide in the production of chlorine and sodium hydroxide.

The following ports in the United States are known for receiving large shipments of asbestos:

  • New Orleans, LA
    • Amount of Asbestos: 5,249,193 Lb
    • Shipments: 40
  • Houston, TX
    • Amount of Asbestos: 2,375,254 Lb
    • Shipments: 42
  • Newark, NJ
    • Amount of Asbestos: 248,280 Lb
    • Shipments: 7
  • Long Beach, CA
    • Amount of Asbestos: 149,853 Lb
    • Shipments: 3

Is Asbestos Banned in the United States?

The answer is no. Even though there have been efforts made towards officially banning it, asbestos is still legal in the United States.

In 1989 the EPA attempted to ban asbestos. Unfortunately, the result was only banning new uses of the carcinogen. The ways that asbestos was used dating up to 1989 are still legal.

Types of asbestos products officially banned in the United States:

  • Corrugated paper
  • Rollboard
  • Commercial paper
  • Specialty paper
  • Flooring felt

Types of asbestos products not banned in the United States:

  • Clothing
  • Roofing felt
  • Vinyl floor tile
  • Roof coatings
  • Drum brake linings
  • Automatic transmissions

The U.S. Consumer Product Safety Commision in the 1970’s banned the use of asbestos in wallboard patching and gas fireplaces. Also around this same time, asbestos was removed from electric hair dryers.

In the early 2000’s crayon manufacturers refined their recipes when asbestos was discovered in their crayons. During this timespan, the EPA also expressed concern about asbestos contamination in gardening products containing vermiculite. Recently, traces of asbestos have been found in cosmetic products, such as talc powder and makeup.

In 2016 the Toxic Substances Control Act was passed in the United States. Under this law, certain chemicals will undergo a series of tests that address public safety. The EPA included asbestos in the first ten chemicals picked to be reviewed. Unfortunately, as of today, no tests have been completed yet.

Over 50 countries have banned asbestos, but the U.S. isn’t one of them.

History of Asbestos

It is impossible to pinpoint the first uses of asbestos, but archaeologists have found traces of the mineral in Scandinavian excavations (pointing to 3000 B.C.). The Greeks and Romans once used the material to create fire retardant cloth and in their building materials. Asbestos has also been discovered in suits of armor from medieval times and in embalming techniques used in preserving pharaohs in ancient Egypt.

As the Industrial Revolution engulfed America in the early 1800′s, manufacturers found asbestos helped to insulate pipes and fireboxes. Soon, asbestos was mined and used in every facet of construction and manufacturing. It was also used in shipyards, railroad cars, and automotive factories. As time went on, the demand for asbestos increased.

“The United States Geological Survey stated asbestos manufacturing reached an all-time high in 1977 with 4,800,000 tons produced. In 2000, asbestos production decreased to 1,900,000 tons.”

Although health risks were known, asbestos materials were continued to be used in houses, schools, and office buildings up until the 1980’s.

Similar Toxic Fibers That Cause Mesothelioma

There are toxic substances that are similar to asbestos. Vermiculite, erionite, and taconite have similar physical makeup, and they can have the same effects on people. These fibers are all naturally occurring, and some are still mined in the United States today. All of these substances are capable of causing a mesothelioma diagnoses.


  • Heat resistant and light-weight.
  • Primarily used for gardening and construction purposes.
  • Mined along the eastern Appalachian Mountains in the United States.
  • Only hazardous if contaminated by asbestos.


  • Airborne fibers can be up to 800 more times carcinogenic than asbestos.
  • Found in volcanic ash.
  • Is no longer mined in the United States.
  • Has been used in building materials in the Western part of the United States.


  • Used in production and manufacturing of steel beams and sheets.
  • Became a solution to iron mining when high-grade iron ore had become exhausted in the U.S.
  • Famously known for being mined and produced in “Iron Range”, Minnesota.
  • This fiber is distributed to the surrounding Great lakes Region in the United States.

Occupational Asbestos Exposure

It was never a secret that asbestos could cause pulmonary issues. Researchers didn’t discover until the 20th century that asbestos causes mesothelioma.

In the past, exposure to asbestos was associated with individuals that worked directly with the raw material. Some professions associated with this are mining and construction.

According to the Agency for Toxic Substances and Disease Registry, “In the United States, an estimated 27 million workers were exposed to aerosolized asbestos fibers between 1940 and 1979.”

Occupational exposure is not just a thing of the past because it still occurs to many people in the United States today. Exposure can occur to individuals inside their home because asbestos was once used freely in building materials and consumer goods. Secondary exposure has even been known to occur to the loved ones of workers that carry asbestos dust home with them on their clothes.

Asbestos exposure still occurs during:

  • Repairs
  • Renovations
  • Removal
  • Maintenance

Based on research by the American Thoracic Society, as of today,“1.3 million construction workers as well as workers in building and equipment maintenance” are exposed to this harmful carcinogen.

Other professions at risk for exposure are:

  • Firefighters
  • Veterans
  • Auto mechanics
  • Ironworkers
  • Demolition workers
  • Teachers

Asbestos is the only known cause of mesothelioma. Unfortunately, many individuals have been exposed unknowingly in their workplace. Learn more about occupational exposure in our free Mesothelioma Guide.