Mesothelioma affects men more than women. It is rare in people under the age of 45. About 75% of people with mesothelioma are 65 years of age or older. Approximately 3000 people are diagnosed with mesothelioma annually in the United States, accounting for less than 0.3% of the total incidence rate of mesothelioma in the U.S. Department of Agriculture that peaked in the late 1980s and early 1990s, but people exposed to asbestos decades ago are still at risk.
There are no other proven causes of mesothelioma. Researchers continue to investigate other possible causes and risk factors, such as exposure to the SV40 virus or minerals that look like asbestos. Mesothelioma is caused by exposure to asbestos fibers. Exposure to asbestos is more common in the workplace.
However, exposure can also occur through natural asbestos in the environment or through secondary exposure. 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 developing mesothelioma.
Many people with mesothelioma in the abdomen (peritoneal mesothelioma) have also been exposed to asbestos.