Exposure to asbestos fibers is the only known cause of mesothelioma cancer. Any amount of asbestos exposure is considered dangerous, even for those who do not directly work with or come into contact with the toxin. While the majority of mesothelioma cases are caused by occupational asbestos exposure, secondary exposure to asbestos is also a serious health risk, especially among women and children.
What Is Secondhand Exposure?
Asbestos has been used for decades in the United States, and could once be found in thousands of products. Today, old uses of asbestos products, ranging from brake pads to insulation, still linger in many old homes and buildings and continue to cause exposure, especially in the workplace.
The prevalence of the toxic mineral can also lead to exposure of those not directly working with asbestos, known as secondary asbestos exposure. Secondhand exposure can happen in non-occupational and domestic settings, as well as from the environment. In many instances, victims suffer from para-occupational exposure or secondary asbestos exposure that occurs from living with someone who has been exposed to the carcinogen at work. According to a study, non-occupational exposure to asbestos may explain approximately 20% of the mesothelioma cases in industrialized countries.
Populations Most At Risk For Secondary Asbestos Exposure
Women and children most commonly face secondhand exposure, though the general public is also at risk. Typically, secondary exposure occurs when an individual comes into contact with a person who has experienced occupational exposure and may still have asbestos fibers stuck on their clothing, hair or work tools. When living with asbestos workers, everyday situations can result in exposure to asbestos among household members, like hugs or doing the laundry. This para-occupational or domestic exposure has been shown to increase risk of mesothelioma cancer.
The W.R. Grace asbestos mines in Libby, Montana are one heavily investigated instance of occupational and secondary asbestos exposure. Asbestos-contaminated vermiculite was mined in the town from the 1920s through 1990, and numerous community members were found to have asbestos-related health effects. A study found that townspeople who had never worked with the asbestos in Libby were still impacted by the asbestos dust that contaminated the surrounding environment, as well as from workers unknowingly bringing fibers home.
Researchers concluded that living with a W.R. Grace worker was among the four most strongly associated risk factors for developing an asbestos disease. Historical data shows cases of both pleural mesothelioma (which develops in the lung linings) and peritoneal mesothelioma (which develops in the abdominal linings) from exposure to contaminated work clothes.
Secondhand Asbestos Exposure and Women
Research has shown that women are the most impacted by secondary asbestos exposure. In one study, 64% of the female participants were exposed to asbestos through household exposure, environmental exposure or both. Only 12% of the male patients in the study had secondary asbestos exposure.
Regardless of the source of exposure, the health effects of asbestos present differently in female patients. According to a 2017 study, women are more likely to develop peritoneal mesothelioma than male patients, and female patients typically have longer latency periods than their male counterparts.
Looking at data collected from malignant pleural mesothelioma patients from 2000 to 2017 researchers found:
- 36% of the female patients experienced domestic asbestos exposure, while 67% of the male patients had experienced direct contact with asbestos in industrial settings.
- Mesothelioma symptoms also presented differently. Of the female patients, 82% presented with cough, while only 33% of male patients experienced the symptom.
- 73% of the female patients experienced chest pain, versus 28% of male patients with this symptom.
Because of the longer latency period and differing symptoms, the researchers found the female patients in the study had a worse prognosis than the male patients. Male patients achieved a one-year survival rate of 39%, while only 27% of the female patients survived one year or longer. Female patients may also experience gender bias during their diagnostic process because the majority of malignant mesothelioma cases impact men.
Impact of Secondary Exposure on Mesothelioma Prognosis
Secondhand asbestos exposure typically results in pleural mesothelioma diagnoses, the most common form of the cancer. According to reports, secondary asbestos exposure results in similar asbestos concentrations in the lungs as what researchers have observed in patients with past occupational exposures.
Despite these similarities, patients who have faced secondary or non-occupational exposures may have a more difficult time being accurately diagnosed than those who were exposed to asbestos on the job. In many cases, these patients do not realize they were ever exposed to asbestos in the first place. While those exposed on the job may face a similar situation, doctors may be better able to recognize the potential for past asbestos exposure when discussing work history. Early detection of mesothelioma and other asbestos-related diseases is crucial for patients to have more treatment options and a better prognosis.
Secondary exposure also typically occurs at a younger age compared to occupational exposures, which can lead to younger patients being diagnosed with mesothelioma. Studies have found younger patients often have a longer latency period, which can hinder diagnosis and result in fewer treatment options and a poor life expectancy. However, the effects of secondary exposure during childhood are still unclear. Research is mixed as to whether it’s exposure at a young age or the often prolonged exposure that later leads to asbestos diseases. Prolonged exposure puts anyone, regardless of age, at a higher risk of developing mesothelioma cancer.
Historical Data Can Highlight Future Environmental Risk
Much like the secondary exposure that occurred between asbestos workers and family members, secondary environmental exposure often occurs at a lower concentration than direct exposure. Because the types of exposure are so similar, researchers have seen similar development of asbestos cancer in both cases, with patients typically experiencing longer latency periods.
Researchers have been working to better understand the risks of secondary environmental exposure. Contemporary data shows that the mesothelioma gender gap effectively closes when looking solely at environmental exposures, with equal incidence rates among men and women. Keeping this in mind both male and female patients may experience longer latency periods, resulting in more late-stage diagnoses. Being cognizant of the elevated risk can enable early intervention, which improves patient prognosis. Understanding the magnitude of Americans that may develop mesothelioma as a result of inhaling or ingesting asbestos fibers from their environment can also help prevent exposure.