In certain conditions, asbestos is very dangerous. Largely harmless when undisturbed, it becomes a threat to human health when it is released into the air. This raises the question: “How long does asbestos remain airborne?”
The answer is complex. Several factors can influence how long asbestos fibers stay in the air. For example, indoor and outdoor airborne asbestos behave differently. For indoor asbestos, the size of the room and its airflow can impact how long asbestos stays afloat.
How Long Does Asbestos Stay Airborne Inside?
Asbestos fibers are so small they cannot be seen with the naked eye. These tiny particles mix in with dust and can stay airborne for hours. Many sources suggest fibers can stay airborne for 48 – 72 hours. But the Environmental Protection Agency (EPA) reports a wider range.
The EPA reports a range of 4 – 80 hours for asbestos fibers to settle from a height of 9 feet. The agency also notes how different factors can affect how long asbestos fibers stay airborne, including:
- Airflow: In rooms with air circulation, the asbestos fibers may stay airborne longer. Air conditioners and heaters may create enough airflow to keep asbestos fibers afloat. Some experts note that merely walking by settled asbestos may be enough to disturb it.
- Size of particles: Smaller particles stay airborne longer than larger particles. Research shows that minuscule variations in size can mean the difference between 4 and 80 hours airborne.
EPA reporting suggests asbestos fibers can stay airborne long enough to travel long distances. Other research shows asbestos fibers can travel several miles.
Airborne Asbestos in the Home
Up until the 1980s, many homes were built with asbestos products. Things like drywall, insulation and vinyl floor tiles often contained the mineral. As these products age and begin to break down, the asbestos can become airborne.
Asbestos in residences may create a prolonged risk of inhaling fibers. Airborne asbestos settles more slowly in smaller rooms. In the United States, homes tend to have smaller rooms than public buildings. For instance, the average size of a bedroom in the United States is 132 square feet while a private office can range from 200 to 400 square feet.
Once released, fibers can easily become airborne again. Small movements or a breeze can lift the particles back into the air. This cycle can continue until the area is professionally cleaned.
Any home built before the 1980s may have asbestos products. It’s important to have these homes inspected for asbestos before doing any remodeling.
Schools With Airborne Asbestos
In the 1980s, the EPA estimated roughly 35,000 schools in the United States had asbestos. The agency also noted more than 15 million students and 1.5 million school personnel were at risk of exposure.
Schools, like many homes, were built using asbestos products. Along with drywall, insulation and flooring, schools had acoustical panels, lab equipment and more.
U.S. classrooms are often larger than a lot of rooms in the home—up to 1,100 square feet. Asbestos tends to settle more quickly in larger rooms, but classrooms are highly trafficked. This means fibers can easily become airborne again. The EPA has cited asbestos in schools as “a significant hazard to public health.”
The EPA requires all schools to be inspected for asbestos every three years. The only exception is if the construction company certifies in writing that the building is asbestos-free. All schools must include the inspection results in an asbestos management plan.
Asbestos in the Air of Public Buildings
Public buildings like businesses, hospitals and libraries were built with asbestos-containing materials. Many construction products contained asbestos starting in the early 1900s. The EPA has estimated that 20% of all buildings have asbestos. The agency also notes about half of those buildings have severely damaged asbestos products.
Asbestos products are considered safe when intact. Once those products become damaged, they may be dangerous until removed or encapsulated. Workers and anyone who visits those buildings may come in contact with asbestos.
Airborne Asbestos Protection Tips
People may not have a way to prevent asbestos exposure. But they do have ways to reduce the risk. Some tips to consider include:
- Avoid abandoned buildings. While it may seem like a good adventure, entering these old buildings can be very risky. They may have damaged asbestos products, meaning the asbestos could be airborne.
- Call a professional. Homeowners should call a qualified inspector to check for asbestos in their homes. Renters can contact their building managers with their concerns. If the inspector finds asbestos, it’s time to call an asbestos abatement professional.
- Do not disturb asbestos products. Known asbestos products and suspected products may pose a risk. If you believe your home has asbestos, leave it alone until it can be inspected.
- Follow appropriate guidelines. The Occupational Safety and Health Administration (OSHA) has guidelines to help workers. These guidelines explain how anyone working near asbestos can reduce the risk of occupational exposure.
- Use wet cleaning methods. When dusting, use a damp rag or sponge to help keep asbestos dust from becoming airborne.
Remember, there is no safe amount of asbestos exposure. Exposure can lead to asbestos-related diseases like mesothelioma and other cancers. Being cautious and understanding the dangers can help people reduce their risks.
