By Jeffrey O. and Grace G. Stull
The approach used for dealing with contaminated clothing depends on the nature of the contaminant and the extent of it. Certainly some contaminants are more hazardous than others. But one that seems to be of increasing concern for firefighters is exposure to asbestos.
During a fire, firefighters can be exposed to a broad spectrum of construction materials. In older buildings, especially those built before the 1980s, some of these materials can contain asbestos. The hot air currents at a fire can carry asbestos fibers that are released when cold water hits hot asbestos or when structural failure causes asbestos-containing components to break. Also, fires may cause non-friable asbestos materials (materials in which the asbestos fibers are not easily broken apart) to become friable.
Firefighters are protected from fiber inhalation when they wear their self-contained breathing apparatus. However, SCBA are not always worn during all parts of the fire operations, particularly during overhaul when asbestos, if present, will still be airborne. Activities such as pulling ceilings or pipes or opening walls to be sure fires are completely extinguished pose additional risks to firefighters because the asbestos fibers released during a fire may get on the firefighters’ protective clothing.
Asbestos fibers tend to become entrained in the textile portions of clothing and equipment in contrast to smooth surfaces, where they may more easily be removed. If contaminated clothing is not handled properly, it can pose a risk to anyone who comes in contact with the clothing.
A 1990 study of 226 firefighters in New York City showed 50 percent to have chest X-rays with abnormalities characteristically caused by asbestos exposure. More recently, it was found that tons of asbestos were released into the local atmosphere during the collapse of the World Trade Center North Tower that was constructed in the 1970s and for which all asbestos had not been removed.
In addition to its well-known use as a fire-retardant and heat insulator, asbestos was also used as a reinforcing or binding agent in plastics and cement. This use was continued into the 1980s, where asbestos was used in building materials including plaster, drywall materials, floor tiles, roofing products, wall and ceiling insulation and electric wiring insulation.
Handling asbestos-contaminated clothing
Fire departments often learn of asbestos exposure after the response when it is realized that the particular structure involved in the incident was constructed of asbestos-containing materials. At that time, there is generally no information that characterizes the levels of exposure that may have been encountered. Because this type of contamination is not visible on clothing, it is impossible to determine if asbestos is present without testing the clothing.
Dangers to HealthUntil the mid-1980s, asbestos was widely used in industry and in construction for a variety of fire-retardant and insulation applications. Fortunately, to the best of our knowledge, it was not used in the manufacture of structural firefighters’ coats or trousers. Nevertheless, asbestos is also a naturally-occurring mineral. Thus, almost everyone is exposed to some amount of asbestos during his or her lifetime. The more asbestos one is exposed to, the greater the risk of developing a health complication such as lung cancer or asbestosis. According to the National Cancer Institute, there are a number of issues that impact how a person may be affected by exposure to asbestos. These include the amount of asbestos one was exposed to and over what period of time, the type of asbestos fibers one was exposed to, and the health and lifestyle of the individual, such as whether or not the person smokes. Exposure to asbestos can cause a number of health conditions including lung cancer, malignant mesothelioma (a form of cancer that affects the membrane covering the body’s internal organs), and non-malignant lung conditions. The lung conditions that asbestos exposure can lead to include asbestosis, which is a form of chronic lung disease that leads to coughing, damage to the lungs and shortness of breath. Asbestosis typically affects those who have been exposed to higher levels of asbestos and can take up to 15 years to develop. Exposure also causes people to develop pleural plaque, which can involve calcification of the membrane around the lungs and changes to the membrane around the lungs. The most serious conditions caused by exposure to asbestos are two forms of asbestos cancer: lung cancer, which affects the tissue of the lung; and mesothelioma, a cancer which affects the membrane surrounding the body’s internal organs. These types of cancer develop 15 years or more after the initial exposure. They are aggressive and, particularly in the case of mesothelioma, often fatal. |
Given the health hazards related to asbestos, fire departments must take decisive actions with respect clothing suspected of being contaminated with asbestos. These decisions should involve the following steps:
1. The clothing and equipment must be immediately removed from service and isolated. Ideally, it is best to place this clothing and equipment in a plastic bag; however, if the clothing is wet, this can cause other problems such as the growth of mildew and fungus on the clothing.
2. If possible, the department should attempt to have the response site sampled (wipe or random surface samples can be taken) to confirm that asbestos was present.
3. The protective clothing should be subject to specialized cleaning as described in NFPA 1851. For suspected asbestos contaminated clothing, this cleaning process can be similar to the advanced cleaning procedures, but simply involve isolated handling (away from other clothing in separate machines), additional rinse cycles, use of respirators and sleeved aprons for handlers, and follow-on testing. . Alternatively, the clothing item can be subject to vacuuming with a High Efficiency Particulate Air (HEPA) filter, and then washed using the advanced cleaning procedures provided in NFPA 1851. If this process is followed, it important to select a competent facility to perform this service. Many Hazardous Materials response teams may have information on these service providers.”
4. The follow-on testing should involve sampling of representative clothing items using procedures that will be likely to assess if asbestos fibers are still present on the clothing. One of the best approaches to is to have a qualified facility vacuum the clothing item using a specialized sampling pump that is outfitted with a filter cassette designed to capture asbestos fiber for later analysis. The filter cassette samples can then be subjected to a qualitative (presence/absence) analysis for asbestos using transmission electron microscopy (TEM) by an accredited asbestos analysis laboratory.
If the analysis of cleaned clothing shows the presence of asbestos, then the department may attempt to decontaminate the clothing again, but retesting will also be required. The department must then choose to retire the clothing and properly dispose of the clothing as hazardous waste. On the other hand, if the analyses reveal that no asbestos is present on the selected clothing items, this finding significantly increases the probability that all the clothing items are free of asbestos; however, there is no guarantee that clothing is absolutely and completely free of asbestos fibers. This is because there is no certainty that the sampled items truly represent that all clothing items exposed in the fire where asbestos exposure was suspected.
Firefighter exposure to any hazardous substance that is a known carcinogen warrants special consideration and follow-on procedures. Asbestos is but one substance that fits this category, but with proper procedures, it can be demonstrated that clothing can be cleaned and reused providing the cleaning is supplemented with appropriate forms of testing to increase the probability that the clothing has been decontaminated and is free of asbestos.
