Mesothelioma is often thought of as a male disease; when most people think of the average mesothelioma patient, they think of a man. This is supported to some extent by the numbers. It is, in fact, true that mesothelioma tends to affect men more than women, by a sizable margin: over 75% of mesothelioma patients are male.
This gender disparity in mesothelioma has often been linked to the primary cause of mesothelioma, which is exposure to asbestos fibers. Asbestos exposure has most commonly, widely and consistently occurred in the workplace, and specifically in traditionally male-dominated workplaces. To fully explain this phenomenon, there are some important things you need to know about this more common form of asbestos exposure, usually referred to as “primary exposure.”
What is Primary Asbestos Exposure?
Primary asbestos exposure is direct exposure to asbestos, which often occurred in the workplace.
Asbestos is a mineral found in many parts of the world. It is especially heat-resistant and is a very effective fire-suppressant, which led to its widespread use as insulation in many fields–especially in mechanical, shipyard, industrial, aeronautic, military, and construction applications.
Asbestos is composed of tiny, microscopic fibers, which are so small that they are individually invisible to the naked eye. The fibers naturally form in bundles, which remain intact unless disturbed. However, if disturbed (as they are in many professional applications of asbestos), the fibers shake loose from the bundles and get sent up into the air.
Those loose, airborne fibers are often inhaled by people handling the asbestos, or people working nearby. Inhaled asbestos fibers can travel to the lungs as well as the pleura, a thin membrane of tissue that covers the lungs. These fibers cannot be broken down or removed by the body, and often lodge in the tissue of the affected organ or tissue lining. Asbestos fibers are harmful to lung and pleural cells, and pleural injury and gene mutation caused by lodged asbestos fibers can lead to pleural mesothelioma over time. Asbestos can also cause other forms of lung cancer, as well as lung scarring (asbestosis).
In addition, asbestos fibers can also travel to, lodge within, and affect other protective tissue linings around the heart and the abdominal organs, leading to pericardial mesothelioma (and associated cancers and heart diseases), and peritoneal mesothelioma (and associated cancers and diseases of the abdominal organs).
Who is at risk for mesothelioma via primary exposure to asbestos?
Out of the total population, there is a relatively small number of people who have been exposed to asbestos in a high enough concentration for a long enough time for mesothelioma to form.
Since the late 1970s, when it became clear that asbestos exposure is directly linked to mesothelioma and associated diseases, asbestos has largely been discontinued in many of the industries in which it was once widely used. This change began in the late 1970s but was not complete for many years. Indeed, asbestos is still not entirely absent from certain fields, though it is handled with increased safety regulations.
Most people who develop mesothelioma are able to trace their asbestos exposure to the workplace, usually workplaces in the fields mentioned above (i.e., shipyards construction, industrial, manufacturing, or military) that widely utilized asbestos before restrictions were put in place in the late 1970s.
Fields in which extensive asbestos exposure leading to mesothelioma were most common include:
- Work related to the merchant marines
- Drywall work and drywall removal
- General construction
- Lathing (making frameworks for buildings)
- Bricklaying and Kiln work
- Mining (especially asbestos-related or asbestos-adjacent mining)
- Steelwork (especially in steel mills)
- Papermill work
- Power plant work
- Foundry work
- Naval yard work
- Millwrighting (repair for industrial machinery)
- Boilermaking, boiler engineering, and boiler repair
- Automotive engineering, production, or repair
- Aircraft engineering, production, or repair
- Manufacturing of products containing asbestos
- Electrical work and electrical repair
- Chemical work (especially in chemical plants)
- Oil work (especially in oil fields and refineries)
- Plumbing and pipefitting
During the time that most dangerous asbestos exposure occurred, these fields were male-dominated, and the jobs which would put a worker at risk of primary asbestos exposure were largely if not entirely held by men. As a result, there has been a general disparity in mesothelioma cases, with more men than women developing mesothelioma.
What is secondary asbestos exposure?
While primary asbestos exposure accounts for around ¾ of all mesothelioma cases, that still leaves a significant percentage of mesothelioma cases unlinked to primary exposure. These cases were almost all the result of secondary asbestos exposure, and account for nearly all of the known cases of mesothelioma in women.
Those subject to secondary exposure did not work in the fields where primary asbestos exposure was most common. Rather, they were often associated with asbestos in less direct–but nonetheless very dangerous–ways. These included:
- Secondary asbestos exposure in the home via primary asbestos workers: Many victims of secondary asbestos exposure were family members living in the same homes as the workers who were victims of primary asbestos exposure. This is sometimes referred to as “take-home asbestos exposure.”
Since asbestos fibers are jagged, the edges snag and can attach easily to surfaces on a worker’s person, whether that surface is an item of clothing (shoes, uniforms, clothes, and/or protective gear) or a part of the body (i.e., skin or hair). Many men who were primarily exposed to asbestos at work often came home with asbestos fibers attached to them. In doing so, they unknowingly exposed the other members of their household to asbestos indirectly, or via “secondary exposure”. The asbestos fibers attached to the workers were shaken loose and cast into the air, where they could then be inhaled or swallowed by other people in their households, especially those who handled he workers’ clothing.
Of course, the people who were most often responsible for washing and maintaining the work clothes of affected workers were women: whether they were wives, mothers, or other female family members.
- Secondary asbestos exposure in the home via household products and construction: Another means of secondary exposure is through asbestos products that were used in home construction, and the disturbance of asbestos fibers via household renovations and construction projects.
aAsbestos was very widely used in home construction, and many products commonly used in home construction contained asbestos. Homes built before the 1980s likely contained (or still contain) asbestos. Spray-on asbestos was widespread, which was especially dangerous since it sent many asbestos fibers up into the air at once. A number of other household construction products also contained asbestos, including:
- Textured paint
- Insulation (especially around boilers and steam pipes)
- Vermiculite (which was often contaminated with asbestos)
- Roofing felt used under shingles
- Vinyl floor tiles
Asbestos fibers were frequently disturbed and sent into the air during home renovations, repairs, and general construction. Sometimes, all it took was drilling into drywall or gathering up insulation to replace. Secondary asbestos exposure through home construction often affected women who identified as homemakers and housewives, as they would be home overseeing or even participating in the repairs or renovations.
- Secondary asbestos exposure via non-conventional workplace: Like most homes built before the 1980s, most larger public use buildings–especially governmental agency buildings, public hospitals, nursing homes, and schools–were built with products containing asbestos. When construction, repairs, and even some forms of dusting were done on these buildings, those who were required to remain inside–namely, teachers and school workers, healthcare workers, and people working in social services–were exposed to the resultant asbestos fibers sent into the air.
This form of asbestos exposure, which is considered secondary exposure, most commonly affected women. Just as the primary exposure fields were mostly male-dominated, the fields of education, public healthcare, and social services were mostly female-dominated.
In addition, some women were subject to secondary workplace exposure because they worked in factories that handled products containing asbestos, or because they worked adjacent to primary asbestos exposure (i.e., at the lunch truck). Though these occupations are not considered primary forms of asbestos exposure, they resulted in extensive secondary exposure, often among women.
- Secondary asbestos exposure via environment: A smaller but still notable number of people endured secondhand exposure to asbestos through asbestos contamination of the environment where they lived. This usually occurred when the person lived close to an industrial facility, factory, oil field, or deposit where asbestos was being mined, refined, or utilized. This sort of environmental contamination can result in secondary asbestos exposure through the air, as well as through food and water.