If you have risk factors for a disease, this means you have a greater probability for developing the disease based on statistical data of people like you. Risk factors are about probability, not prediction: being at risk for mesothelioma does not mean you will develop it. If you are concerned, check with your doctor. Though no longer exactly rare, mesothelioma is still not a very common disease.

Malignant mesothelioma, the cancer of the mesothelium--the tissue that surrounds many organs in the body--is believed to be caused by a number of factors, the main one being exposure to asbestos. Patients with mesothelioma usually have been exposed to asbestos fibers. Asbestos exposure in workers whose occupations put them at risk for breathing in or ingesting certain types of asbestos has been demonstrated as a major risk factor for developing pleural mesothelioma cancer and other types of mesotheliomas.

• Smoking. Smoking alone hasn't been shown to increase a person's chances of developing mesothelioma. But in combination with asbestos exposure, the risk goes up significantly.
• Exposure to asbestos. When workers are exposed to asbestos-containing materials, particularly in a dry environment where the particles might be inhaled, the asbestos exposure is a major risk factor. When old insulation, plumbing or electrical fittings are disturbed, the risk of exposure to asbestos exists. Read more about asbestos and mesothelioma.
• Age is a mesothelioma risk factor. Three quarters of all mesothelioma cases occur in people older than 65 years of age.
  
• Sex is a risk factor for mesothelioma in the United States. Men are 4.5 times more likely to get mesothelioma than women.
• Ethnicity is a risk factor in the U.S. Whites and people of Latino / Hispanic ethnicity have a greater risk of being diagnosed with mesothelioma than African Americans or Asians.

The main group of people at risk are people who worked or work in environments or job sites where they were / are exposed to asbestos.

Also at risk are:

• these workers' family members, since tiny asbestos particles were possibly carried home on the workers' hair, skin, boots and clothing.
• those living in an area where asbestos particles are in the air

Possible, but not well-established, risk factors include:

• exposure to SV40 (Simian Virus 40)
• exposure to radioactive thorium dioxide

For more information on these and other possible risk factors, see What Causes Mesothelioma.

In particular, individuals who were exposed to

• high levels of asbestos for a short time
• high levels of asbestos for a long time, and
• low levels of asbestos for a long time

are at risk for developing pleural mesothelioma. However, the first group--people with a longterm exposure to high asbestos levels--are at the greatest risk.

People especially at risk include:

• Auto mechanics
• Electricians
• Insulation workers
• Metal workers such as iron, sheet metal, or refinery workers and welders
  
• Insulation workers
• Pipe fitters
• Gas mask producers
• Steam fitters
• Construction workers
• Shipbuilders
• Shipyard workers
• Navy and merchant marine veterans
• Railroad workers
• Power plant workers
• Miners
• Factory workers
• Boiler makers
• Bricklayers
• Building inspectors
• Carpenters
• Demolition workers
• Drywallers
• Hod carriers
• Glazers
• Painters
• Plasterers
• Roofers
  
• Longshoremen
• Tile setters
• Oil workers

Contact your doctor to determine your risk and get advice on how to lower the chances that you will develop malignant mesothelioma.

In general, the recommendation is to:

• Reduce your exposure to asbestos. If you work with asbestos, always take the necessary occupational safety precautions in your work. Wear all protective equipment available to you. Follow prescribed procedures. Always take a shower and change clothes before taking a break or leaving work.

• Unless you're qualified to do so and using the proper equipment and procedures, don't disturb old asbestos-containing structures and fixtures, like old insulation. Doing so can lead to airborne asbestos, which is much more of a risk factor than asbestos left intact. Find help at the Environmental Protection Agency.