Indoor Environmental Quality Daydreams and Nightmares
May 01, 2011
A version of this article appears in the May/June 2011 issue of Home Energy Magazine.
Building performance renovation contractors and Weatherization Assistance program workers daydream of making homes healthy, comfortable, energy efficient, and durable. But sometimes when they are in the middle of a project, they find their dreams have become indoor environmental quality (IEQ) nightmares.
Most contractors are well prepared to deal with some potential IEQ nightmares, such as CO poisoning and building materials that have lead-based coatings. However, there are numerous other sources of IEQ nightmares. These include asbestos; radon; volatile organic compounds; sulfur-containing drywall—typically from China—and even everyday construction dust, which many building performance contractors take no notice of.
The first potential IEQ nightmare is one of the most overlooked, as well as one of the most regulated, indoor environmental hazards: asbestos. Asbestos is regulated at the local, state, and federal levels. All of these laws are intended to protect the public and the construction worker from being harmed by asbestos exposure.
How Is Asbestos Harmful? Asbestos exposure has been known to be harmful for as long as people have used asbestos. The ancient Egyptian nobility knew that the slaves who made the asbestos-fiber shrouds in which the royal mummies were wrapped often died from respiratory ailments.
Asbestos is most harmful when the tiny fibers are inhaled. The fibers are too small to be seen with the naked eye and can be inhaled deep into the lungs, where they remain. The fibers damage lung tissue, causing scar tissue to form; the result is a disease called asbestosis. When the lung surfaces are covered with scar tissue, they cannot function properly, causing problems ranging from shortness of breath to death. Inhaling asbestos fibers can also cause lung cancer.
Workers can be exposed to asbestos when they are working in an area where there are airborne asbestos fibers. Fibers can become airborne when the material containing the asbestos is drilled, cut, abraded, sanded, chipped, or sawed during a home performance renovation. This often happens, for example, when a worker is cutting holes through an asbestos-containing “popcorn ceiling.” The family living in a home that is being renovated can also inhale asbestos fibers. So can the family of the renovation worker who has brought the asbestos fibers home on his or her clothing and equipment.
Why Is Asbestos in Building Materials? Although people have long known that using asbestos can be dangerous, it is so adaptable that they have developed thousands of uses for the fibrous rock that the early Greeks called the miracle mineral.
Asbestos is flame retardant, resistant to chemicals, and insoluble, and the fibers do not break down over time. Because asbestos has these properties, it was used—and is still used—in numerous building materials. Historically, asbestos was added to concrete, roofing, cement pipes, cement boards, sheet flooring, floor tiles, blocks, bricks, drywall, plaster, wall textures, spray-applied acoustic (popcorn) ceilings, ceiling panels, joint compound, fireproofing, stucco, pipe insulation, adhesives, mastics, duct tape, and several other spray-applied or troweled-on building materials. Asbestos also occurs naturally in vermiculite insulation.
In 1978, Congress banned the use of asbestos in some building materials. It did so because more and more workers were being diagnosed with serious diseases attributed to asbestos exposure. Many workers and their families were exposed to asbestos during and after World War II, when hundreds of industrial applications were developed.
It took several years for the damage to the asbestos-exposed workers to become well known. The symptoms of asbestos-related disease usually do not appear until years—even decades—after exposure. Once there was an established history of workers developing asbestos-related disease—and several major corporations were sued and found liable—Congress reacted by banning the use of asbestos in any spray-applied or troweled-on building material, as well as in some industrial applications. But Congress did not ban asbestos in all building materials. Buildings and homes are being constructed today with materials that contain asbestos. In fact, today you can go to your local hardware store and buy roofing mastics and other sealants that contain asbestos.
Public awareness and lawmakers’ attentiveness to the hazards of asbestos exposure led to the mass removal of asbestos-containing building materials in many public structures and institutional buildings. Not all building materials containing asbestos have been banned, but there are many laws and regulations that control asbestos application and disposal.
Asbestos Laws and Regulations. Federal entities that regulate asbestos include EPA and the Occupational Safety and Health Administration (OSHA). EPA administers the National Emissions Standards for Hazardous Air Pollutants (NESHAPs). One goal of NESHAPs is to protect the public from exposure to asbestos when it is released into the air during renovations, including the transport and disposal of construction waste. It applies to any renovation or repair being performed in a building to which the public has access, including schools, hospitals, offices, and retail stores. However, this law exempts work done in single-family properties or multifamily homes with four or fewer units, so it does not affect most residential energy efficiency renovations. Multifamily homes with more than four units do fall under the law.
Nevertheless, all work performed by someone who has been hired to do that work is regulated by OSHA—even work in private homes. OSHA has standards to protect workers from exposure to asbestos in the workplace. Any home in which a weatherization worker or energy efficiency renovation contractor is working is “the workplace.” OSHA enforces the Code of Federal Regulations 29 CFR 1926.1101, which addresses construction work, including the alteration, repair, renovation, and demolition of structures containing asbestos.
The bottom line for OSHA is that any worker’s exposure to asbestos must be at or below established personal exposure limits, or PELs. In order to meet that goal, a contractor must know whether the project will expose the workers to asbestos-containing building materials.
What Homes Must Be Inspected for Asbestos Before Renovations? OSHA requires asbestos testing to be performed by a certified asbestos inspector on any building constructed prior to 1980, regardless of the kind of building or quantity of material disturbed. Alternatively, the contractor or homeowner can assume that all building materials disturbed during the renovations contain asbestos, and can treat them accordingly. But that assumption can be expensive—perhaps unnecessarily so. It makes sense to test for asbestos in the following situations:
- The work will involve a material that is, or was, commonly manufactured with asbestos.
- The residential property was built prior to 1980.
- Anyone doing the renovations was hired to do the work.
Where Do I Start? Most cities, counties, and states have laws that are based on the federal laws. Some local laws are more stringent than the federal laws. So first learn your local laws regarding asbestos, or hire a consultant. The EPA web site has basic information about asbestos. The OSHA web site has an overwhelming amount of information about regulations for contractors. You can get useful asbestos information and find a qualified consultant at the web sites for the Indoor Air Quality Association and the Environmental Information Association.
Another naturally occurring element can wreak havoc on the health of a tightly built home. Radon, like asbestos, occurs naturally; however, unlike asbestos, radon has never intentionally been added to a building. It becomes an IEQ nightmare when a builder or renovator fails to consider that radon can accumulate in a tightly constructed or tightly air-sealed home. Radon is an odorless gas that comes from the natural breakdown of uranium in soil, rock, and water. Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down further, these particles release small bursts of energy. This can damage lung tissue and lead to lung cancer. In fact, radon is the second-leading cause of lung cancer, after smoking cigarettes.
Where Is Radon Found? Radon is found in nearly all soils across North America. In fact, EPA reports that 1 out of every 15 homes in the United States is estimated to have elevated radon levels. EPA has a Map of Radon Zones showing radon levels in various geographic regions. Homes with elevated levels of radon have been found in all zones on the map.
How Does Radon Get In? Radon typically moves up through the ground to the air and into a home through cracks, gaps, and penetrations in the foundation. It can be trapped inside the home, so that a concentration of radon builds up. A few building materials made of stone, such as granite countertops, have been found to emit radon, too. However, building materials alone rarely cause radon problems. It is the gas from the soil coming in through the foundation or basement that poses a threat. Radon becomes dangerous when it accumulates to unsafe concentrations.
An Efficient Home May Have More Radon. Any home built on soils with radon can become unsafe—even a drafty home. But if a home is tightly built or air sealed, there are more opportunities for the radon to become concentrated. Because there is a higher risk for elevated radon in an energy-efficient home, EPA and DOE are including testing for radon as part of the new “Workforce Guidelines for Home Energy Upgrades.” These guidelines are still being developed. EPA also has a draft version of the protocols for addressing radon. “Healthy Indoor Environment Protocols for Home Energy Upgrades” was issued in November 2010.
Although new guidelines and protocols are being developed, the health problems caused by elevated levels of radon in homes are not new. In 1984, an engineer at the Limerick, Pennsylvania, nuclear power plant walked into work and triggered a radiation detector. His exposure to radiation had not occurred at work, since the plant was still under construction and there were no radioactive materials at the site. It turned out that radon concentrations in his home were more than 650 times higher than the PELs for workers in uranium mines. That discovery triggered massive testing of homes in his community, and then the nation.
How Do I Test for Radon?There are short-term and long-term radon tests. Both methods have advantages and disadvantages. The type of test performed will be determined by the needs of the homeowner or the contractor, or both. Both types of test use a radon-detecting device or small canister that is exposed to the ambient air in the home for a specific amount of time. A short-term cassette test is placed in the home for two to three days. However, radon levels will vary based on the season, and on the nature and level of activity taking place in the home. Therefore, a long-term test is more useful for determining a family’s exposure to radon in the home. Long-term tests remain in the home for more than 90 days. These tests give a more reliable measurement of the actual concentrations of radon over time.
If There Is Radon, Then What? EPA recommends radon mitigation in all homes with test results of 4 picocuries per liter (pCi/L) or greater. Radon levels less than 4 pCi/L can still pose a health risk, and in many cases should be reduced.
The type of radon mitigation system installed depends on the radon level and on the characteristics of the house. The most common radon mitigation system is active soil depressurization (ASD). There are different ASD techniques, but they all reduce radon concentrations inside the home by drawing radon-containing soil gas away from the foundation and exhausting it outdoors. There are also passive soil depressurization systems, crawl space depressurization systems, and crawl space ventilation systems. In some cases, positive-pressure ventilation in the home is adequate. There are two American Society for Testing and Materials International (ASTM) standards that address radon mitigation and control. They are:
- ASTM E1465-08a “Standard Practice for Radon Control Options for the Design and Construction of New Low-Rise Residential Buildings,” and
- ASTM E2121-09 “Standard Practice for Installing Radon Mitigation Systems in Existing Low-Rise Residential Buildings.”
Some house characteristic evaluations are performed with a blower door to determine effective leakage area or the equivalent leakage area. The leakage data are used with other testing results to determine the most cost-effective radon mitigation system. Radon mitigation often includes air sealing areas where radon can infiltrate into the home.
After a home is renovated, postimprovement testing should be performed to determine whether radon concentrations are too high or to evaluate the effectiveness of any radon mitigation.
Kirsten Shaw is the vice president of field operations for Advanced Energy Efficiency & Environmental Quality (AE3Q) in Mesa, Arizona. She is a BPI Certified Building Analyst and Envelope Professional and a HERS Rater and Quality Assurance Designee.
>> learn more
For information about asbestos from the U.S. EPA, go to www.epa.gov/asbestos.
For information about asbestos from OSHA, go to www.osha.gov/SLTC/asbestos.
The web site of the Indoor Air Quality Association is www.iaqa.org.
The web site of the Environmental Information Association is www.eai-use.org.
To learn more about radon and home energy retrofits, go to www.epa.gov/iaq/homes/retrofits.html.
To find information about the development of the “Workforce Guidelines for Home Energy Upgrades,” or obtain a copy of “Healthy Indoor Environment Protocols for Home Energy Upgrades,” go to www1.eere.energy.gov/wip/retrofit_guidelines.html.
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