Some studies indicate that asbestos exposure also increases a person's risk of developing colorectal cancer. However, the evidence isn't clear enough to say that yes, asbestos exposure definitely causes cancer of the colon and rectum. This is because while some studies establish a clear link between asbestos exposure and colorectal cancer, others find no relationship between the two whatsoever. Let's talk about the ones that have found a relationship since they're more interesting.
Asbestos Exposure from Drinking Water
Most epidemiological studies that tested the incidence of cancer in areas where the drinking water contained high levels of asbestos, found increases in cancer rates and/or deaths. Most of the cancers formed in the gastrointestinal tract (which includes but isn't limited to the colon and rectum).Asbestos Exposure from Insulation
In one study of 17,800 people who worked with insulation containing asbestos, 99 people died from gastrointestinal cancers. The expected death rate (that of members of the general population) was estimated at 59 deaths. This means that the insulation workers were about one and a half times more likely to die of gastrointestinal cancer than non-insulation workers.Asbestos Exposure in the Textile Industry
In a study of 2,500 asbestos textile workers, 26 people died from gastrointestinal cancers. However, only 17 deaths were expected. This means that the asbestos textile workers were about one and a half times more likely to die of gastrointestinal cancer than people who did not work in the asbestos textile industry.See a Pattern?
According to the Agency for Toxic Substances and Disease Registry (ATSDR), several other studies have shown similar patterns. ATSDR stresses however, that there is no consistent relationship between colorectal cancer and asbestos exposure. The Institute of Medicine of the National Academies agrees. After assessing 120 studies of asbestos exposure and cancers of the throat and digestive tract, the Insitute of Medicine determined that the evidence was suggestive but insufficient to infer a link. In English: seems like asbestos exposure might cause colorectal cancer, but they can't say for sure.The Take-Home Message
Nobody says "Hey, there's some asbestos, let me go roll in it!" We know it's bad for us. So really, its potential to cause cancer of the colon and rectum is simply something else to keep in mind. If you've been exposed to asbestos, or work with asbestos on a regular basis, this is one more reason to make sure you adhere to colon cancer screening recommendations.Sources:
- Health Effects: The Incidence of Nonrespiratory Cancers and Exposure to Asbestos. Agency for Toxic Substances and Disease Registry. 8 Jun. 2006. 10 Jun. 2006 [http://www.atsdr.cdc.gov/asbestos/asbestos/health_effects].
- Institute of Medicine of the National Academies. Asbestos Exposure Linked to Cancer of the Larynx; Evidence About Links to Cancer of the Digestive Tract is Less Clear. 6 Jun. 2006. 10 Jun. 2006 [http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=11665].
- Quiller, David M., MD. Ask the Experts about Preventive Health Care: Asbestos Exposure Screening. Medscape Today. 8 Oct. 2004. 10 Jun. 2006 [http://www.medscape.com/viewarticle/490523].
