Asbestos Health Risks
There are no health threats when asbestos-containing building materials remain undisturbed and do not become airborne. Asbestos-containing floor tile is a good example of a building material that is not a health hazard when in good condition. Normal wear will not release fibers, in fact, you would have to burn, grind, or use extreme mechanical methods to release enough fibers to be a health concern. On the other hand, popcorn ceiling texture can easily become airborne. If you simply rub your hand over the surface you will cause a release of fibers.
All asbestos-related diseases have a long latency period, that is, it takes 20 to 40 years for the first symptoms to appear. Given the poor work conditions of the past, the widespread use of amphiboles up until the 70’s, and this long latency period, it is not surprising that new cases of the asbestos-related disease continue to be observed. But this has nothing to do with today’s products containing only chrysotile and work conditions.
Uncontrolled work conditions, work with friable insulation materials and the extensive use of amphibole asbestos fibers in the past have resulted in asbestos-related disease. But times have changed: the types of fibers and products used are different, and dust control technology has evolved. Today, amphiboles are no longer used, the use of low-density friable insulation materials has been banned, and exposure limits for chrysotile are hundreds of times lower than past worker exposures.
Even if these friable products containing chrysotile are present in many commercial buildings, mostly in Europe and North America, removal of asbestos insulation should be considered a measure of last resort and undertaken only when the material is beyond repair or at the time of major renovation work or building demolition. Hasty elimination of asbestos insulation considerably increases the probability that controls will not be adequately enforced, thus presenting a source of risk not only for the workers but for building occupants as well.
An estimated 1.3 million employees in construction and general industry face significant asbestos exposure on the job. The heaviest exposures occur in the construction industry, particularly during the removal of asbestos during renovation or demolition. Employees are also likely to be exposed during the manufacture of asbestos products (such as textiles, friction products, insulation, and other building materials) and during automotive brake and clutch repair work.
Asbestos is well recognized as a health hazard and is highly regulated. OSHA and EPA asbestos rules are intertwined.
Asbestos workers have increased chances of getting two principal types of cancer: cancer of the lung tissue itself and mesothelioma, a cancer of the thin membrane that surrounds the lung and other internal organs. These diseases do not develop immediately following exposure to asbestos but appear only after a number of years. The following documents describe the health hazards of asbestos and how to recognize it.
From studies of people who were exposed to asbestos in factories and shipyards, we know that breathing high levels of asbestos fibers can lead to an increased risk of:
- Lung cancer, Many forms of lung cancer.
- Mesothelioma, a cancer of the lining of the chest and the abdominal cavity.
- Asbestoses, in which the lungs become scarred with fibrous tissue.
The risk of lung cancer and mesothelioma increases with the number of fibers inhaled. The risk of lung cancer from inhaling asbestos fibers is also greater if you smoke. People who get asbestoses have usually been exposed to high levels of asbestos for a long time. The symptoms of these diseases do not usually appear until about 20 to 30 years after the first exposure to asbestos.
Most people exposed to small amounts of asbestos, as we all are in our daily lives, do not develop these health problems. However, if disturbed, asbestos material may release asbestos fibers, which can be inhaled into the lungs. The fibers can remain there for a long time, increasing the risk of disease. Asbestos material that would crumble easily if handled, or that has been sawed, scraped, or sanded into a powder, is more likely to create a health hazard.
Most health information on asbestos exposure has been derived from studies of workers who have been exposed to asbestos in the course of their occupation. Asbestos fiber concentrations for these workers were many times higher than those encountered by the general public.
Because asbestos fibers are naturally occurring and extremely aerodynamic, virtually everyone is exposed to asbestos. To be a significant health concern, asbestos fibers must be inhaled at high concentrations over an extended period of time. Asbestos fibers then accumulate in the lungs. As exposure increases, the risk of disease also increases. Therefore, measures to minimize exposure and consequently minimize the accumulation of fibers will reduce the risk of adverse health effects.
Asbestos is only dangerous if it becomes airborne. As long as asbestos-containing materials are not damaged, the asbestos fibers do not become airborne and do not pose a health threat to the building occupants. During an asbestos building survey, inspectors assess the condition of asbestos-containing materials. These conditions do deteriorate over time. If you find that an asbestos-containing item has been damaged, please contact our office for a hazard assessment.
As asbestos fibers accumulate in the lungs, several types of diseases may occur. Asbestosis is a scarring of the lung tissue. This scarring impairs the elasticity of the lung and hampers its ability to exchange gases. This leads to inadequate oxygen intake to the blood. Asbestosis restricts breathing leading to decreased lung volume and increased resistance in the airways. It is a slowly progressive disease with a latency period of 15 to 30 years.
The next type of disease attributed to asbestos exposure is Mesothelioma. It is a cancer of the pleural lining. It is considered to be exclusively related to asbestos exposure. By the time it is diagnosed, it is almost always fatal. Similar to other asbestos-related diseases, mesothelioma has a longer latency period of 30 to 40 years.
Lung Cancer is a malignant tumor of the bronchi covering. The tumor grows through surrounding tissue, invading and often obstructing air passages. The time between exposure to asbestos and the occurrence of lung cancer is 20 to 30 years. It should be noted that there is a synergistic effect between smoking and asbestos exposure, which creates an extreme susceptibility to lung cancer.
Airborne Fiber Concentrations
Asbestos is known to be hazardous based on studies of high levels of exposure to asbestos workers and laboratory animals. However, the risks associated with low-level, non-occupational exposure are not well established. Therefore, the Environmental Protection Agency (EPA) concludes that there is no safe level of exposure to asbestos fibers. On the other hand, the Occupational Safety and Health Administration (OSHA) has set a Permissible Exposure Limit (PEL) at 0.1 fibers per cubic centimeter (f/cc) for an 8 hour time-weighted average. Similarly, the Minnesota Department of Health (MDH) has set the Clean Indoor Air Standard at 0.01 f/cc.
Controlling the exposure to asbestos can be done through engineering controls, administrative actions, and personal protective equipment. Engineering controls include such things as isolating the source and using ventilation systems. Administrative actions include limiting the worker’s exposure time and providing showers. Personal protective equipment includes wearing the proper respiratory protection and clothing. The following resources contain information to help control asbestos exposures.