Because of its fibrous nature, asbestos can easily
become airborne and can be breathed in. The most prevalent diseases
associated with asbestos exposure are asbestosis , lng cancer,
and mesothelioma - all lung
or respiratory function related. Risk of developing asbestos related
diseases varies with length of time, frequency and concentration
of exposure to asbestos fibers (Agency
for Toxic Substances and Disease Registry, 2007). Asbestos related
disease can have a very long period to manifest after exposure.
The report Chemical-Specific Health Consultation: Tremolite Asbestos
and Other Related Types of Asbestos, ATSDR, 2001 (http://www.atsdr.cdc.gov/asbestos/more
_about_asbestos/health_consultation/) lists the period of time after first occupational exposure to result in asbestosis or lung cancer as 15 years or more and 30 years or more for mesothelioma.
- Asbestosis: Scarring of the lungs and decreased respiratory
function (Ross & Nolan, 2003).
- Lung Cancer: Exposure to asbestos correlates with a greatly
increased risk of lung cancer, particularly in conjunction with
- Mesothelioma: A cancer of the tissues that surround the lungs,
heart, or abdominal cavities. This form of cancer has been linked
to exposure to amphibole asbestos (Ross & Nolan, 2003). There
is still controversy over whether chrysotile asbestos causes
mesothelioma (Osinubi, Gochfeld, & Kipen, 2000).
The first documented asbestos related death was in 1906. An autopsy of an asbestos worker showed lung fibrosis (asbestosis) (Chun, 2004). By the 1930s doctors were noticing a correlation between patients with asbestosis and lung cancer (Chun, 2004). In a 1939 Bureau of Mines report (Harrington, Some Data on Dust in Industrial Work, 1939) it is evident that people were beginning to think of the detrimental effects of exposure to occupational dust, including asbestos.
While other occupational respiratory disease mortality has been decreasing, asbestosis-related mortality has increased and was reported to be 1,493 in 2000 (Centers for Disease Control and Prevention, 2004).
Mesothelioma is the rarest of the asbestos related diseases, however, the incidence rate has increased over the past 20 years. Currently about 2,000 new cases are diagnosed each year (Mesothelioma: Questions and Answers, 2002). Research into the disease continues. In 2007 the U.S. Food and Drug Administration approved a blood test, known as Mesomark, to help with the early diagnosis of mesothelioma (CDRH Consumer Information, 2007).
For smokers exposure to asbestos can be exceptionally risky.
Smokers are 50-84 times more likely to develop lung cancer than
normal (Agency for Toxic Substances and Disease Registry, 2006).
The data documenting asbestos as a human carcinogen is outlined
in the U.S. Environmental Protection Agency Integrated Risk Information
System. Asbestos is listed as a Class A human carcinogen. (U.S.
Environmental Protection Agency, Integrated Risk System, 2008)
While there is no question about the correlation between asbestos exposure and disease, there is controversy over quantifying the risks of low-level asbestos exposure (Osinubi, Gochfeld, & Kipen, 2000). The Code of Federal Regulations Title 40 Section 61.141 defines Asbestos Containing Material (ACM) to be material with greater than 1% asbestos of any regulated type as identified by Polarized Light Microscopy (see Asbestos Structure/Analysis/Abatement). Current asbestos exposure limits set by the U.S. Occupational Safety and Health Administration are 0.1 fibers/cc for an 8 hour period (Occupational Safety and Health Administration, 2002).
Go To Legislation
List of Visuals
- Picture 4: Mortality Rate for Asbestos by State
Centers for Disease Control and Prevention, 2004