Posted on July 27th, 2020
People who work in certain jobs may be at risk of developing colorectal cancer because of the exposure to asbestos during certain industrial processes. The use of asbestos in various industries was prevalent before 1980 and the menace of asbestos was carefully covered up by companies.
This type of cancer is the third most common malignancy in the United States. Recent studies show that incidence rates have sharply increased lately and males are the most predisposed to develop this form of cancer. Some studies suggest that it is strongly associated with industrial exposure, both occupational and environmental, although these risk factors are generally unrecognized by clinicians. Nowadays, there is a tendency to attribute colorectal cancer to lifestyle and dietary factors, thus neglecting industrially related environmental exposure, including ionizing radiation and polluted drinking water.
Although this type of cancer is not generally considered to be caused by occupational exposure, there have been reported elevated risks for workers in some industries handling asbestos.
Various studies have identified asbestos fibers in the colon when taking biopsy samples from a small group of workers suffering from colon cancer, that have been exposed to the carcinogenic mineral. An explanation as to how the fibers end up attached to colon tissue could be the fact that they can easily travel inside the body, getting trapped in the tissue during the expulsion process. Since 1980, occupational exposure to asbestos was the stimulus for large-scale cancer studies. A conclusive study monitored for 19 years the health of 632 insulation workers who entered the industry before 1943. The authors of the study had expected 5.2 deaths, but data revealed 17 deaths were attributed to it, indicating that asbestos exposure increases the development of colorectal cancers.
A study published in 1994, in the American Journal of Epidemiology found that asbestos workers were 1.4 more predisposed to developing this type of cancer. Gathering data from the available studies and meta-analysis, scientists have come to the understanding that there is a significantly increased risk of colon cancer for workers who have been exposed to asbestos, especially those working directly with the mineral or in environments that were poorly ventilated or didn't take the necessary measures to avoid breathing in large quantities of microscopic fibers. The conclusion was that the lifetime risk of colon cancer and its mortality increases with the level of asbestos exposure.
The hypothesis that occupational risk factors are associated with colorectal cancer is gaining ground, and high risks have been reported among workers in some industries' branches such as:
Asbestos exposure is also a major concern in older buildings, where asbestos fibers can be released indoors and pose a health threat. A case-control study has shown elevated risks identified for workers in occupations and industries including printing machine operators, food manufacturing, communication workers, and workers in the petroleum product trade. U.S. military veterans were directly in contact with asbestos, because of the military's reliance on asbestos products, particularly on Navy ships. 1 in 500 shipyard employees was an asbestos insulator. The succeeding jobs also put shipyard workers to direct exposure to asbestos: shipbuilders, machinists, pipefitters, electricians, and boilermakers.