1. When asbestos fibers are inhaled, most fibers are expelled, but some can become lodged in the lungs and remain there throughout life. Fibers can accumulate and cause scarring and inflammation. Enough scarring and inflammation can affect breathing, leading to disease.
2. People are more likely to experience asbestos-related disorders when they are exposed to high concentrations of asbestos, are exposed for longer periods of time, and/or are exposed more often.
3. Most cases of asbestosis or lung cancer in workers occurred 15 years or more after the person was first exposed to asbestos.
4. Health effects from asbestos exposure may continue to progress even after exposure is stopped.
5. Inhaling longer, more durable asbestos fibers (such as tremolite and other amphiboles) contributes to the severity of asbestos-related disorders.
6. Exposure to asbestos, including tremolite, can increase the likelihood of lung cancer, mesothelioma, and non-malignant lung conditions such as asbestosis (restricted use of the lungs due to retained asbestos fibers) and changes in the lung lining.
7. Changes in the lining of the lungs (pleura) such as thickening, plaques, calcification, and fluid around the lungs (pleural effusion) may be early signs of asbestos exposure. These changes can affect breathing more than previously thought. Pleural effusion can be an early warning sign for mesothelioma (cancer of the lining of the lungs).
8. Most cases of mesothelioma are diagnosed 30 years or more after the first exposure to asbestos.
9. Mesothelioma has been diagnosed in asbestos workers, family members, and residents who live close to asbestos mines.
10. Smoking or cigarette smoke, together with exposure to asbestos, greatly increases the likelihood of lung cancer.

Various factors determine how exposure to asbestos affects an individual:

1. Exposure concentration - what was the concentration of asbestos fibers?
2. Exposure duration - how long did the exposure time period last?
3. Exposure frequency - how often during that time period was the person exposed?

Size, shape and chemical makeup of asbestos fibers:

Long and thin fibers are expected to reach the lower airways and alveolar regions of the lung, to be retained in the lung longer, and to be more toxic than short and wide fibers or particles. Wide particles are expected to be deposited in the upper respiratory tract and not to reach the lung and pleura, the sites of asbestos-induced toxicity. Short, thin fibers, however, may also play a role in asbestos pathogenesis. Fibers of amphibole asbestos such as tremolite asbestos, actinolite asbestos, and crocidolite asbestos are retained longer in the lower respiratory tract than chrysotile fibers of similar dimension.

Individual risk factors, such as a person's history of tobacco use (smoking) and other pre-existing lung disease, etc.

Note, cigarette smoke and asbestos together significantly increase your chances of getting lung cancer. Therefore, if you have been exposed to asbestos you should stop smoking. This may be the most important action that you can take to improve your health and decrease your risk of cancer.

How malignant mesothelioma is treated. There are treatments for all patients with malignant mesothelioma. Three kinds of treatment are used:

1. Surgery (taking out the cancer).
2. Radiation therapy (using high-dose x-rays or other high-energy rays to kill cancer cells).
3. Chemotherapy (using drugs to fight the cancer).

Surgery is a common treatment of malignant mesothelioma. The doctor may remove part of the lining of the chest or abdomen and some of the tissue around it. Depending on how far the cancer has spread, a lung may also need to be removed. Sometimes part of the diaphragm, the muscle below the lungs that helps with breathing, is also removed.

Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes in the area where the cancer cells are found (internal radiation therapy).

If fluid has collected in the chest or abdomen, the doctor may drain the fluid out of the body by putting a needle into the chest or abdomen and using gentle suction to remove the fluid. The doctor may also put drugs through a tube into the chest to prevent more fluid from accumulating.

Chemotherapy uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells throughout the body. In mesothelioma, chemotherapy may be put directly into the chest.

Intraoperative photodynamic therapy is a new type of treatment that uses special drugs and light to kill cancer cells during surgery. A drug that makes cancer cells more sensitive to light is injected into a vein several days before surgery. During surgery to remove as much of the cancer as possible, a special light is used to shine on the pleura. This treatment is being studied for early stages of mesothelioma in the chest.