Of all people with intense and prolonged exposure to asbestos, 2 to 10% develop pleural mesothelioma. Symptoms of mesothelioma usually do not appear until 20-50 years after exposure to asbestos, which is when tumors have grown and spread. The average life expectancy of patients with mesothelioma is 12 to 22 months. According to the American Cancer Society, 80% of mesothelioma cases are caused by known exposure to asbestos.
Studies have shown that radiation treatment for other types of cancer or certain genetic markers may increase the risk of developing mesothelioma. However, asbestos is still the only proven cause of the disease. The main risk factor for pleural mesothelioma is exposure to asbestos. In fact, most cases of pleural mesothelioma have been linked to high levels of exposure to asbestos, usually in the workplace.
Conclusions Exposure to asbestos confers a long-term risk of developing pleural and peritoneal mesothelioma, which increases after cessation of exposure. While the rate of increase seems to begin to stabilize after 40 to 50 years, no one survives long enough for the excess risk to disappear. Asbestos is a well-established cause of mesothelioma and lung cancer. 1 It is generally accepted that the risk of mesothelioma persists and increases long after exposure to asbestos has ended, 2—6 Less is known if the risk of lung cancer changes when exposure to asbestos ceases.
Some studies indicate that the risk decreases some years after exposure has ended, 7-10 The results of studies based on industrial cohorts are difficult to assess because workers may have been exposed in other industries after leaving the industry because the use of asbestos has been common in many industries, for example, the construction industry and the shipyard industry. The risk of asbestos was highlighted in Sweden in the 1970s, and the import of asbestos fell dramatically (Fig. Some industries, such as the shipyard and construction industry, decreased the use of asbestos in the mid-1970s following agreements between employers and unions. A law banned the use of asbestos in 1982, 11.Subsequently, the exhibition of almost all Swedish workers ended in the early 1980s.
This provides an opportunity to study the risk of lung cancer after cessation of exposure. Even if a Swedish worker changed jobs and employers after the early 1980s, there was almost no exposure to asbestos. A prospective cohort study of 3,893 shipyard workers, mainly exposed to chrysotile, indicated that there was no increased risk of lung cancer 7-15 years after exposure to asbestos had ceased. However, shipyard workers had a higher risk of pleural mesotheliomas with 11 cases observed versus 1.5 expected.
One explanation for these observations may be that asbestos may have different carcinogenic mechanisms in causing lung cancer and mesothelioma. No increased risk of lung cancer a few years after exposure to asbestos has ceased is consistent with asbestos acting as a promoter. The high risk of mesothelioma, on the other hand, may indicate that asbestos acts as a complete carcinogen in the development of this disease. We know that asbestos causes most cases of pleural mesothelioma.
This starts in the two sheets of tissue that cover the lungs, called the pleura. Being exposed to large amounts of asbestos for a long period of time increases the risk of mesothelioma. Many people with mesothelioma in the abdomen (peritoneal mesothelioma) have also been exposed to asbestos. Risk factors for mesothelioma may increase a person's likelihood of developing this deadly cancer.
Exposure to asbestos is the only known cause of malignant (cancerous) mesothelioma, but not everyone exposed to asbestos develops the disease. Certain risk factors, such as levels of exposure to asbestos, age, and genetics, may increase the risk of developing this cancer. While the rate of increase seems to stabilize for pleural mesothelioma after 40 to 50 years, no one survives long enough for the risk to go away. Those who served in the Navy faced the greatest risk of exposure because asbestos was used to prevent fires in shipyards and boats.
Maintaining a healthy weight through diet and regular exercise is one of the best ways to control this risk factor and minimize the likelihood of developing mesothelioma. Asbestos has also been used in roof and floor tiles; paints, coatings and adhesives; and plastics. However, the most important risk factor for mesothelioma is exposure to asbestos, a hazard that millions of Americans were unknowingly exposed to by manufacturers of products containing asbestos. Other potential risk factors that remain unproven causes of mesothelioma include genetic factors and exposure to radiation, zeolite minerals, and the polio vaccine between 1955 and 1963 that was contaminated with simian virus 40 (SV40).
Having multiple risk factors for mesothelioma makes it more likely that a person will develop the fatal cancer. Asbestos fibers are translocated into the pleural space after interstitial fluid, a process intensified by chronic inflammation, which is again related to the amount of fibers retained in the lungs. Around 1.3 million construction and general industry workers remain at risk of asbestos exposure in the U. Smoking alone or in combination with exposure to asbestos does not increase the risk of developing mesothelioma.
We report the case of a 26-year-old male who was exposed to asbestos during his elementary school years between the ages of 6 and 12.Although the risk of mesothelioma is higher in patients who have been treated with radiation, this cancer is still rare in these patients. Because asbestos was used in the construction of the North Tower of the WTC, when the building was attacked, hundreds of tons of asbestos were released into the atmosphere. Most people diagnosed with mesothelioma were exposed to asbestos while doing certain manual labor or serving in the military. The health hazards of asbestos fibres have been recognized for workers exposed in shipbuilding trades, mining and milling asbestos, manufacturing asbestos textiles and other asbestos products, insulation work in construction and construction trades, and a.