Asbestos in Settled Dust


In homes throughout the nation built before the 1980s, asbestos containing materials were commonly incorporated. Asbestos was used because of its high durability, fire resistance, and other favorable properties. Asbestos was used in drywall, plasters, floor tiles, HVAC insulation, plumbing insulation, adhesives, and many other products. Asbestos containing materials in the home become a health risk when they are damaged, disturbed, and made friable, which releases the asbestos fibers into the air. Typically asbestos fibers can remain airborne for up to 72 hours in area of low air movement, afterwards falling to the surface and generating dust.


The larger the release of fibers from asbestos containing materials, the more dust it generates once the fibers settle. As a mineral, asbestos can remain in the dust indefinitely and does not degrade. If an asbestos containing material was improperly abated in a home, this could lead to the settled asbestos dust being disturbed in the future.


Unlike asbestos air testing and inspections, there are no federal or state regulations on settled dust sampling. The bulk of our understanding on asbestos dust is based off of industry guidelines. The method we use at Indoor Science for dust sampling is called TEM Microvac. This process involves taking a filter cassette and attaching it to a high volume air pump, which sucks dust onto the filter.  We generally collect dust from a 100 cm2 area. The cassette is then analyzed at an accredited laboratory by an electron microscope which can scan the cassette and identify the amount of asbestos fibers found. This method is called TEM, which stands for Transmission Electron Microscopy).  


The laboratory reports the results as asbestos structures per square centimeter.  As previously stated, there is no governmental regulation for a permissible amount of asbestos fibers in the dust.  Nevertheless, there are industry guidelines that help us interpret if the fibers found in the dust are background levels, elevated, or highly elevated.


If you have concerns about settled asbestos dust in your home. Feel free to contact us.

Jordan Thomas

Jordan Thomas

Jordan Thomas is a Project Manager that performs indoor air quality assessments with a specialty in asbestos and lead. Mr. Thomas holds a Bachelors of Arts degree in Earth Science from DePauw University. Jordan is an ACAC Council-Certified Indoor Environmentalist (CIE), Licensed Lead and Asbestos Inspector, Licensed Air Sampling Professional, and HAZWOPER certified. He also holds an asbestos microscopist certificate from the McCrone Research Institute. Prior to working at Indoor Science, Jordan worked as an Industrial Hygienist at Environmental Analysis, Inc and as an Asbestos/Lead Analyst at Metro Technology Laboratory. In his words… “While not in the field, I’m a Nu-Jazz and movie enthusiast.”

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5 thoughts on “Asbestos in Settled Dust

    An elementary school that had asbestos removed was refurbished and converted into an apartment complex. Also, a brand new apartment addition was built next to the converted elementary school. I’m thinking about moving into the next door new addition building because I think there’s no way I could know that asbestos doesn’t remain in dust form in the renovated part of the complex. Are my concerns legitimate?

    Hello Sammy,

    When asbestos is removed from a school, it is done using a strict protocol called AHERA. While it would not be impossible to find a background amount of asbestos fibers in the dust in the new addition, it would be unlikely to be elevated due to the stringent rules of AHERA clearance criteria.

    I’m glad you pointed out asbestos-containing structures become a health risk in your home if they are damaged or disturbed. My husband and I recently moved into an older home, and we think there may be asbestos in some of the basement fixtures. I don’t want to disturb them and release the asbestos into the air, so I think we’ll call a professional who will know how to safely remove it.

    I’m due to have my house asbestos from ceiling removed.
    My housing have arranged a company to do this but I’m very worried about this being done as i have 2 children with breathing problems asthma and I have just been prescribed an inhaler as im experiencing breathlessness.
    My ceiling has cracks in already and I have 4 children 3 being told im safe to stay here even after but I’m not sure please could u give me some advise as to whether to seek a move.

    Hello Lisa,

    Without inspecting the containment or the site it is difficult to say whether to stay or leave. I would recommend making the decision based on your health concerns. Abatement activities should be performed inside a containment with negative air pressure which if used properly should keep air from breaching the containment. I would recommend that the abatement company conducting the work to set up air samples outside of the containment to see how the work is affecting the air quality in the home.