Risk Factors for Mesothelioma
Mesothelioma is a rare but deadly cancer that affects the lining of various organs. Asbestos exposure is the # 1 risk factor for mesothelioma, but other risk factors have also been identified.
Mesothelioma is a deadly cancer that affects the mesothelium. The mesothelium is the membrane, like a net, that covers many organs of the body, such as the lungs and the heart. It has two layers: one covers the organ, the other acts as a bag, leaving the organ move, if necessary.
People who develop mesothelioma have generally been exposed to a substance infiltrating into the mesothelium.
Mesothelioma Risk Factors: Long-Term Exposure to Asbestos
Among the risk factors for mesothelioma, exposure to asbestos dust is by far the most important. About 70% to 80% of mesothelioma patients report a history of asbestos exposure at work.
And since asbestos was widely used in the industry, car manufacturing and construction until just a few decades ago, millions of American workers have been exposed to asbestos in the long term and are still at risk of contracting the disease. . At the top of the list are:
-Manufacturers of asbestos products and textiles
-Workers in the heating and construction industries
Mesothelioma Risk Factors: Short-Term Exposure to Asbestos
Many more people with shorter or less intensive exposure to asbestos face reduced but still real risks. For example, demolition workers, firefighters, plasterboard movers, asbestos removal workers and auto workers may also be exposed to asbestos fibers. Even family members of asbestos workers can be exposed to asbestos dust because workers bring it home with their clothes.
The crews involved in cleaning up the World Trade Center in New York after 9/11 are particularly at risk. Asbestos was used in the construction of the North Tower and it is estimated that hundreds of tons of asbestos were part of the debris.
The risks associated with asbestos exposure can be difficult to quantify, but in general the risks depend on:
-The amount of asbestos to which the person was exposed
-The time during which the person was exposed
-The size, shape and chemistry of asbestos fibers
-Personal risk factors, such as smoking
There are two main forms of asbestos, amphibole (straight fibers) and chrysotile (curly fibers). Although all asbestos is dangerous, recent studies suggest that exposure to amphibole asbestos may pose a higher risk of mesothelioma than chrysotile asbestos because amphibole fibers stay longer in the lungs.
Risk Factors of Mesothelioma: Genetic Opportunities
While it is clear that the risks increase with more intensive exposure over long periods of time, some people have mesothelioma after only brief exposure to asbestos, while others who are exposed intensively are not. .
"A lot of work is being done to try to find links to the genetic predisposition to the disease," said Timothy Winton, MD, associate professor of surgery and divisional director of thoracic surgery, University of Alberta, Edmonton. , Canada. . "There is also often a history of co-morbid smoking or a genetic predisposition to smoking-related problems.With many cancers - and Mesothelioma is one of them - you may need multiple accesses of different carcinogens before to develop the disease. "
Risk Factors for Mesothelioma: Simian Virus 40 (SV40)
In the 1950s, some polio vaccines were contaminated with SV40, which causes mesotheliomas in laboratory animals. In humans, an association between SV40 and mesothelioma has been suggested, as SV40 has been found in human mesothelioma tumors, but no link has been established.
Risk Factors for Mesothelioma: Thorium Dioxide and X-Ray Imaging
Some studies have linked the use of thorium dioxide (Thorotrast), a radioactive X-ray contrast agent, to an increased incidence of cancers, including mesothelioma.
One study found that a group exposed to thorium dioxide had a cumulative incidence of peritoneal mesothelioma (the peritoneum covering the gastric cavity) up to 0.6% higher than that of workers exposed to asbestos. Thorium dioxide has not been used in X-ray imaging for many years.
Risk Factors for Mesothelioma: Zeolites
Zeolites are naturally occurring minerals in volcanic rocks and ash containing hydrated aluminum and silicon. In synthetic forms, zeolites are used in detergents, for purification of water and air and in other uses. Exposure to airborne zeolite dust has been associated with a high incidence of mesothelioma in Turkey. In a Turkish village, a zeolite form used to whiten houses caused an incidence of pleural mesothelioma of 440.9 per 100,000 for women and 298.1 per 100,000 for men.