Malignant mesothelioma is a form of asbestos cancer that statistically affects men more often than women. This is not because women are less genetically predisposed to the disease, however. Historically, men, in comparison to women, were more often employed at asbestos jobsites which placed them in direct contact with dangerous asbestos products. Although mesothelioma disease has indeed been diagnosed in women, on-the-job exposure is often not the reason for the development of this disease in this population.
Some studies, including one published in the journal Chest, have also demonstrated that women who develop mesothelioma are much more likely to acquire peritoneal mesothelioma, the abdominal form of the disease, with increasing exposure attributing to as much as a five-fold increase in mesothelioma risk factors. The reasons why this is true are not clear and studies continue in an effort to pursue the answer to this question.
Workplace Exposure to Asbestos for Women
Historically, mesothelioma is a disease that is diagnosed in men much more often than in women. That still holds true today. The major reason for this has nothing to do with genetics or that the male gender is pre-disposed to developing this form of asbestos cancer. Instead, the higher rate of the disease among men is simply due to the fact that, throughout history, men have been much more likely to hold jobs that put them in daily contact with dangerous asbestos.
Nonetheless, there are cases of women who have developed mesothelioma due to on-the-job exposure to asbestos and doctors continue to diagnose the disease in women who likely inhaled dangerous fibers while they worked.
Women and World War II
In the decades prior to World War II, women assumed what was said to be their rightful role in the family. Most married at a fairly young age, tended to their home, and took care of their children. A handful of well-to-do young ladies were given the privilege of attending college and usually became teachers or chose some other profession that generally did not involve workplace hazards. Hence, the men made up the vast majority of the workforce, employed in a wide range of jobs from factory worker to doctor.
When World War II came about and the United States joined the war after the attack on Pearl Harbor in 1941, the face of the workforce in America changed. Tens of thousands of young men, mostly those who were employed in hourly jobs, enlisted in the U.S. Armed Forces and went off to fight the war, either abroad or in a support position somewhere in the U.S. Suddenly, there was no one to “man” the factories or assume the other work that had primarily been done by men, thus exposing them to risks like mesothelioma disease.
At this point, the women of America stepped up and went to work outside the home. Many were involved in industries that helped support the war effort. “Rosie the Riveter” became the cultural icon for the thousands of American women that went to work on the assembly line, many producing munitions and other supplies for the soldiers that fought in the battles of World War II.
But while these women went to work gladly, many of them were suddenly facing hazards they had never before encountered. Asbestos was one of those hazards. Women who worked in the nation’s shipyards were especially susceptible to asbestos exposure as were those who toiled in the factories, where asbestos was not only used as insulation but also in hundreds of war-related, commercial, and household products that were manufactured there. It wasn’t unusual for any of these women to end their day covered in asbestos dust, just as their male counterparts did when they worked the same jobs before they went off to war.
As a result of this war-time exposure, many women developed mesothelioma cancer decades later. That’s because they were rarely given any sort of gear to protect them from inhalation, even though it was already apparent that asbestos was causing health problems among those who worked with it on a regular basis.
On the Job Exposure for Women
Once the war was over, most women went back to their homes. However, some enjoyed their new found freedom and extra income and continued to work. And as the decades progressed, more and more women entered the workforce, assuming not only positions like teacher or secretary, but also factory jobs and others that would continue to expose them to asbestos.
Today, women in the U.S. Armed Forces continue to be at risk for asbestos exposure, particularly those who are serving overseas in places like Iraq and Afghanistan, where asbestos is still in use. Places like old war-torn buildings that are damaged or destroyed can contain asbestos and, often, soldiers encounter the toxic mineral without ever knowing it. In the future, there will likely be a resurgence of cases of pleural mesothelioma caused by military-related exposure among both men and women who served their country in foreign lands.
Women who have served as firefighters, police officers, or emergency personnel also have the potential of encountering asbestos during a fire or other disaster. As a matter of fact, the first person to die of mesothelioma after the World Trade Center attacks was a woman – an emergency responder with the Fire Department of New York who had inhaled large quantities of asbestos during the days and months after the tragedy.
Jobs in laundry facilities where asbestos was present in large commercial dryers put women at risk to develop mesothelioma. Any damaged insulation on these dryers could have resulted in inhalation of the toxic mineral.
Cosmetics manufacturing plants also put women in the workplace at risk for exposure to airborne asbestos. Asbestos may have been used in make-ups and powders, so employees, who were rarely given any kind of protective gear to prevent inhalation of dust, were prime candidates for developing asbestos-caused cancer.
Secondary Exposure to Asbestos in Women
Women are at a much lower risk of developing mesothelioma then men. The major reason for this is that many more men once worked in jobs where asbestos exposure was commonplace and inhalation of the toxic mineral was an everyday occurrence. Though women also worked in factories and shipyards, especially during World War II, they remain much less likely to develop the disease due to on-the-job exposure.
Nonetheless, several cases of asbestos cancer among women (about 8 percent annually) are diagnosed each year and many of these women are discovered to be victims of what is known as “secondary exposure”. That phrase refers to the fact that these women did not directly encounter the material but, rather, were exposed to it in a secondhand fashion that, nevertheless, resulted in inhalation of dangerous fibers.
Secondary Household Exposure
For decades, the most likely way for a woman to develop mesothelioma cancer was through exposure from a husband, father, son, or other household relative who worked directly with hazardous asbestos. Some studies call this “domestic” exposure. A 1997 study conducted by Durham (VA) and Duke University Medical Centers (Roggli et al) involving women with mesothelioma determined that more than half of those diagnosed with the disease had suffered exposure due to household contact with individuals who worked with asbestos.
A common scenario involved a housewife who greeted her asbestos fiber-laden husband (son, father, etc.) each day when he came home from work. Usually, these workers were given no opportunity to change clothes or shower before they headed home; hence, their clothing, hair, and body were often covered with dust when they arrived. The women were charged with the responsibility of shaking out the dust and laundering the clothes. Some did this every night. Once the clothes were shaken, the tiny fibers would become airborne and were easy to inhale, especially in a small enclosed space like a laundry room, where ventilation was likely to be poor. After years of performing this task, the woman would begin to develop some pulmonary distress, like coughing or difficulty breathing. Decades later, she would be diagnosed with mesothelioma disease.
There have also been a number of documented cases of pleural mesothelioma among younger women who recall climbing up on Dad’s lap when he got home from work – before he got cleaned up – snuggling with him while he read a story or they talked about their day. The closeness resulted in exposure to the dust and the inhalation of sharp asbestos fibers. For many of these women, this simple act of affection resulted in a diagnosis of mesothelioma many years later.
While it may seem unlikely that “a little dust” would cause such concern, a 1989 study by Huncharek et al (“Domestic asbestos exposure, lung fiber burden, and pleural mesothelioma in a housewife”) suggested that “household contamination can result in "bystander" exposure levels similar to those found in the industrial setting.” In other words, secondary exposure can be just as intense as direct exposure to toxic asbestos.
Secondary Environmental Exposure
In places like Libby, Montana, where an asbestos-contaminated vermiculite mine caused hundreds of deaths, women also died due to secondary exposure. Those who didn’t work at the mine may have been affected by fibers that commonly circulated in the outside air during the years the mine was in operation. In addition, women who once lived close to a factory that manufactured asbestos-containing products may have also been exposed in this manner.
In some cases, but rarely in the United States, women may be victims of secondary exposure caused by natural deposits of asbestos that may allow dangerous fibers to be released into the air. While there are indeed natural deposits of asbestos in the U.S., primarily in the western portion of the country, only a handful of cases have been attributed to exposure to these deposits.
Studies on Mesothelioma in Women
Though mesothelioma is predominately diagnosed in men, especially older men that worked in trades where asbestos was used extensively, more and more incidences of women touched by this type of cancer have come to the attention of the medical community, prompting additional studies concerning women and the development of the disease. Some studies address why and how women develop mesothelioma cancer, including major risk factors, while others concern the epidemiology of the disease as it relates to women. All have helped shed light on the connection between women and asbestos-caused cancer, helping medical professionals better address the needs of women with mesothelioma.
Karain Village, Turkey and other Turkish studies
One of the most widely read studies concerning women and mesothelioma, was conducted in an area known as the Karain Village in Turkey. Published in 2002, the results shed much light on the plight of those women exposed to naturally occurring asbestos in that part of the world.
The study spanned 10 years and involved 1, 886 villagers in this part of the rural Anatolian Plateau. While the study was being conducted, 377 villagers died and 24 cases of malignant pleural mesothelioma were diagnosed. This was not so startling, given the fact that the incidence of naturally-occurring asbestos in this region was evident. What was noteworthy, however, was that the annual asbestos cancer incidence rates were calculated at 440.9 per 100,000 for women vs. 298.1 per 100,000 for men.
Immediately, questions arose as to the reason for the higher incidence among women. The easiest answer seemed to relate to a local habit of whitewashing one’s home with the “white soil” from the ground in that region. This white soil, also known as aktoprak, contained fibrous zeolite, an asbestos-like mineral. According to reports, this was the procedure that was associated with the highest levels of exposure.
A follow-up study was conducted years later among Karain Village immigrants who had relocated to Sweden. During the time researchers observed these 162 individuals, 18 deaths occurred including 14 from malignant pleural mesothelioma. Five others were still living with mesothelioma. Figures showed that the risk of mesothelioma was 135x and 1,336x greater in males and females from that Karain Village, respectively, than for the same sex and age groups in Sweden natives.
Another observation garnered from these Turkish studies of mesothelioma among women was the fact that lung volume probably influences fiber deposition and retention. Hence, smaller people – which include most women – tend to retain more asbestos fibers at the same exposure level. Hence, they are more likely to develop asbestos-related diseases than their male counterparts, perhaps even at low levels of exposure. The same study stated that people who are taller or have longer trachea are also less likely to develop mesothelioma disease than shorter individuals with shorter tracheas.
Wittenoom, Australia Studies
Dangerous blue (crocidolite) asbestos was mined and milled in Wittenoom in Western Australia from 1943 until 1966. Mine tailings were distributed throughout the town. Today, Wittenoom has been literally wiped off the map due to the high level of contamination there from the asbestos and the deaths of many town residents, including those who did not work at the mine.
A report by Reid et al was designed to determine, in part, if female subjects were more susceptible to asbestos exposure than male subjects among those who resided in Wittenoom. A total of 4,768 residents of the town were followed for the study, which concluded that “the mortality rate with mesothelioma increased with increasing residence duration, time since first exposure, and estimated cumulative exposure. The mesothelioma mortality rate was consistently lower for female subjects when compared with male subjects, but the dose-response curve was steeper for female subjects.” Hence, the study states that it wasn’t necessary for women in Wittenoom to be exposed to as much asbestos as men in order to develop the disease.
The above discovery supports the statements from the Turkish studies which indicate that women’s smaller lungs tend to retain asbestos fibers more easily than men’s larger lungs. Therefore, even low levels of asbestos exposure may cause asbestos cancer in females.
Study Done By Dr. Dorsett D. Smith
Several years ago, Dr. Dorsett D. Smith, Clinical Professor of Medicine, Division of Pulmonary Disease and Critical Care, Department of Medicine, University of Washington at Everett, penned a study that took a look at the relative risk of women vs. men for malignant pleural mesothelioma due to environmental exposure to the amphibole type of asbestos. His study compared a previous study done in Karain Village, Turkey – where women were exposed to erionite (a form of fibrous zeolite) – to the rates of mesothelioma among women in the U.S., Europe, and Australian. Dr. Smith attempted to discern the reason for the difference in mesothelioma risk factors between the Turkish women and those living elsewhere.
An obvious difference, of course, might be due to the fact that the Turkish women engaged in practices that put them at a higher risk, such as whitewashing their homes with a substance that contained asbestos.
However, Smith also noticed other factors that may put women, in general, at higher risk for developing mesothelioma cancer. For example, Smith concluded that “lung volume influences fiber deposition and retention.” Hence, women – who generally have smaller lung capacity than men – are more likely to retain asbestos fibers.
“People who are taller and have longer tracheas and larger lungs have more deposition in the ciliated airways than shorter, smaller people who tend to have greater alveolar deposition at the same level of exposure,” concluded Dr. Smith, noting that more study should be conducted concerning the role of body size and women’s increased susceptibility to mesothelioma cancer.
A similar study was conducted in Wittenoom, Australia, a town that has all but disappeared due to the former presence of a crocidolite asbestos mine and the death of many miners, their family members, and other residents of the town. The study, entitled “Age and Sex Differences in Malignant Mesothelioma after Residential Exposure to Blue Asbestos” (Reid et al) noted that while men accounted for more incidences of the disease, women had a steeper exposure-response relationship, which means that even a small “dose”, i.e. a small amount of exposure to asbestos, elicited a large response, i.e. development of mesothelioma. This may also tie into the aforementioned connection between lung capacity and retention of fibers.
Other Studies of Note
Several studies of note have indicated that women may also be more susceptible to developing the peritoneal form of mesothelioma. Rather than attacking the pleura, this type of the disease forms in the peritoneal, the lining of the abdomen. There may be a number of different reasons for this increased susceptibility. One hypothesis is that because peritoneal mesothelioma and ovarian cancer are very similar, one may be mistaken for the other during diagnosis. Another reason may be women’s use of talc such as that once found in powders, etc. Talc, especially older talc preparations, once contained tremolite asbestos.
Recent Study Gives Some Hope
One of the most recent studies on mesothelioma in women, published in a 2010 issue of The Annals of Thoracic Surgery, indicates that women with malignant pleural mesothelioma appear to experience better mesothelioma survival rate than male victims of the disease. The study, conducted by several faculty members at renowned Brigham and Women’s Hospital in Boston (Wolf et al), concluded that women with the disease should be treated aggressively, especially when no other risk factors exist.Sources
American Cancer Society: Mesothelioma