Asbestos and Dust
Asbestos is naturally occurring, fibrous silicate minerals mined for their useful properties such as thermal insulation, chemical and thermal stability and high tensile strength. Asbestos is commonly used as an acoustic insulator, in thermal insulation, fire proofing and other building materials. Many products in use today contain asbestos.
When disturbed, microscopic bundles of fibers become airborne. If these fibers get into the air they may be inhaled into the lungs, where they can cause significant health problems.
What are the health effects of Asbestos exposure?
All types of asbestos are hazardous and may cause lung disease and cancer. Health risks to people are dependent upon their exposure to asbestos. The longer a person is exposed to asbestos and the greater the intensity of the exposure, the greater the chances for a health problem. Exposure to airborne friable (dust like, powdery asbestos) asbestos may result in a potential health risk because persons breathing the air may breathe in asbestos fibers. Continued exposure can increase the amount of fibers that remain in the lung. Fibers embedded in lung tissue over time may cause serious lung diseases including: asbestosis, lung cancer or mesothelioma. Smoking increases the risk of developing illness from asbestos exposure. No safe asbestos exposure level has been established for residential areas. The the illnesses caused by asbestos may not be observed for twenty or more years.Three of the major health effects associated with asbestos exposure include:
- Asbestosis – a serious, progressive, long-term non-cancer disease of the lungs. It is caused by inhaling asbestos fibers that irritate lung tissues and cause the tissues to scar. The scarring makes it hard for oxygen to get into the blood. Symptoms of asbestosis include shortness of breath and a dry, crackling sound in the lungs while inhaling. There are no effective treatments for asbestosis.
- Lung Cancer – this disease causes the largest number of deaths related to asbestos exposure. People who work in the mining, milling, manufacturing of asbestos, and those who use asbestos and its products are more likely to develop lung cancer than the general population. The most common symptoms of lung cancer are coughing and a change in breathing. Other symptoms include shortness of breath, persistent chest pains, hoarseness and anemia.
- Mesothelioma – is a rare form of cancer that is found in the thin lining (membrane) of the lung, chest, abdomen, and heart and almost all cases are linked to exposure to asbestos. This disease may not show up until many years after asbestos exposure. This is the primary reason efforts are being made to prevent school children from being exposed.
Exposure to asbestos increases your risk of developing any of the related lung diseases. You can increase your risk to these diseases by smoking. In general, the greater the exposure to asbestos, the greater the chance of developing harmful health effects. Disease symptoms may take several years to develop following initial exposure. If you are concerned about possible exposure, consult a physician who specializes in lung diseases (pulmonologist).
Everyone has some amount of asbestos in their lungs. But measuring how much asbestos is in your lungs will not determine if asbestos-related health effects will occur. Certain methods (sputum tests and lung biopsies) can show whether asbestos is present in your lungs; however, since most people have some asbestos in their lungs, these tests don’t tell whether you’ve been exposed to enough asbestos to cause disease. Other tests can detect asbestos in blood and urine, but these tests only indicate recent exposures and cannot determine risk for asbestos related disease. Chest x-rays can show changes to the lungs caused by asbestos, but not until after many years (usually 20 to 50) have passed. Child lung x-rays are considered to be an unnecessary test because changes to the lung associated with asbestos exposure usually take many years to develop. Additionally, the x-ray radiation could be a greater health risk to children than exposure to asbestos.
Naturally Occurring Asbestos and Dust in Alaska Native Villages
There is significant concern in Tribal Communities of Alaska on the matter of dust mixed with naturally occurring asbestos. The most common type of natural asbestos is chrysotile. Asbestos is commonly found in ultramafic rock, including serpentine, and near fault zones. The amount of asbestos that is typically present in these rocks range from less than 1% up to about 25%, and sometimes more. Asbestos is released from ultramafic and serpentine rock when it is broken or crushed. This can happen when cars drive over unpaved roads or driveways which are surfaced with these rocks, when land is graded for building purposes or at quarrying operations. It is also released naturally through weathering and erosion. Once released from the rock, asbestos can become airborne and may stay in the air for long periods of time.In a study done in May 2005 in the community of El Dorado Hills California with regard to naturally occurring asbestos, the U.S. EPA stated that it is not currently possible to accurately assess the health risk for residents from the types of exposures that were observed in its study. Furthermore, the U.S. EPA has stated that a health assessment was not the purpose of the studies, but the results are of concern because of the potential for long-term development of asbestos-related diseases. A secondary study by the Agency for Toxic Substances and Disease Registry (ATSDR) was restricted to assessing the potential health risks based on activity-based sampling for naturally occurring asbestos at the Oak Ridge High School, in El Dorado Hills. ATSDR has promised to evaluate community exposure and recommended that it would be prudent for people who live in the community to take steps to minimize exposures. It is also presumed that the community at-large may face similar exposures if naturally occurring asbestos is present in the dust and soil of their homes. In consideration of the findings of the U.S. EPA and ATSDR from air sampling studies conducted in El Dorado Hills, there was a demonstrated need for activity-based sampling. In areas where naturally occurring asbestos is known to be present in the soil and in surrounding areas, activity-based sampling would likely indicate an increase in exposures due to dust and soil being disturbed. Currently, as there are no means to evaluate the increased health risk from such increased exposures, little would be gained by the performance of such sampling. It is simpler and more direct for the assumption to be made that asbestos fibers may be present in dust and soil in areas where naturally occurring asbestos is know to be present or more likely to be found, and to direct efforts and available resources into reducing potential exposures to the fibers.
What does this mean in the Tribal Communities of Alaska with naturally occurring asbestos?
Develop a plan to find funding sources not only from EPA IGAP funds but attempt to find other funding sources and monitoring resources.
Some additional sources of funding to contact:
Bureau of Indian Affairs (BIA) Roads,
Bureau of Land Management (BLM),
Centers for Disease Control (CDC)
and Agency for Toxic Substances and Disease Registry (ASTDR).
If a Tribal Community has capacity for implementation and enforcement of an Ordinance, the Tribal Government may wish to develop an Ordinance to decrease the disturbance of soils with naturally occurring asbestos during activities like mining and construction.
The next information is intended for Homeowners who may have naturally occurring asbestos sources, such as dust from unpaved roads or driveways surfaced with ultramafic or serpentine rock, near their homes. Other sources of asbestos dust includes disturbed rock deposits near your home, or nearby construction, quarrying operations and mines. This information does not address asbestos from asbestos-containing products used or found in the home.
Any action to minimize dust generation from naturally-occurring asbestos sources will generally help to reduce your exposure. Some suggestions to consider to reduce dust generation include:
- having crushed ultramafic or serpentine rock in yards/gardens covered with soil;
- having family members and guests remove shoes at the door to reduce track-in (a major entry route of outdoor asbestos fibers);
- keeping windows and doors closed on windy days and during periods when nearby ultramafic or serpentine rock may be disturbed, such as during construction;
- using a wet rag to dust, as opposed to a feather duster;
- using washable area rugs on your floors;
- paving over unpaved walkways, driveways or roadways which contain potential asbestos.
How can testing for asbestos in the ambient (or outdoor) air be conducted and analyzed?
A sampler consisting of a pump and cassette holder containing a filter is used to determine the amount of asbestos in the ambient air. Asbestos is trapped onto the filter as air is drawn through the filter. The filter samples are analyzed by counting the number of asbestos fibers on the filters using transmission electron microscopy (Federal Register, 40 CFR Part 763). The concentration of asbestos in the air is determined by relating the amount of asbestos trapped on a filter to the volume of air pumped through the sampler. Analytical cost can vary per sample for results within 72 hours. For samples to be comparable to each other it is important to use an appropriate sampling method. In addition, laboratories doing the analysis should be certified by the National Institute of Standards and Technology and National Voluntary Laboratory Accreditation Program (NIST/NVLAP.) If you need further information regarding a sampling method or certified laboratory contact the Tribal Air Monitoring Support Center (TAMS) in Las Vegas. Go to: http://www4.nau.edu/tams/, the Institute for Tribal Environmental Professionals or contact the Region 10 IGAP coordinator.The current federal regulatory standards for asbestos contamination are:
- Under the Clean Air Act, the federal National Emission Standards for
Hazardous Air Pollutants (NESHAP) for asbestos defines “friable asbestos material”
generally as greater than 1% measured by polarized light microscopy (PLM) (40 C.F.R. §61.141).
The asbestos NESHAP regulates demolition of buildings containing asbestos, as well as asbestos mining and milling operations, to ensure proper handling, management, and disposal of asbestos-containing materials.
- Occupational Safety and Health Administration (OSHA) regulations define
“asbestos-containing material” to be those materials that include more than 1% asbestos
(29 C.F.R. §1910.1001). The OSHA permissible exposure limit (PEL) is 0.1 asbestos
structures per cubic centimeter of air (29 C.F.R. § 1910.1001(c)). OSHA regulations are
intended to protect workers from inhalation exposure in the workplace.
- The Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) definition of a hazardous substance, while not a regulatory standard for
asbestos, provides authority for taking action under CERCLA where asbestos is present
that presents a threat or potential threat to human health or the environment.
- The Asbestos Hazard Emergency Response Act (AHERA) requires schools to identify materials containing more than 1% asbestos by weight in their school buildings, and to take appropriate actions to control release of asbestos fibers (40 C.F.R. Part 763), including inspection and preparation of management plans. Materials that may contain asbestos include for example: ceiling tiles, insulation, carpet backing and flooring.
Other resources for asbestos and dust issues can be found at:
http://www.juneauempire.com/stories/073105/loc_20050731001.shtml
http://myastm.astm.org/MEETINGS/SYMPOSIAPROGRAMS/D22ID1126.pdf
http://www.agiweb.org/geotimes/nov01/feature_medgeo.html.