Exposure to asbestos may increase the risk of several serious diseases:
Asbestosis - a chronic lung ailment that can produce shortness of breath, coughing, and permanent lung damage.
Mesothelioma - a relatively rare cancer of the thin membranes that line the chest and abdomen.
Other cancers, such as those of the larynx, oropharynx, gastrointestinal tract, and kidney.
Information on the health effects of asbestos comes mostly from studies of people who were exposed levels of asbestos fibers (greater than or equal to 5 micro-meter in length) in workplace air that were as high as 5 million fibers/m3 (5 fibers/mL).
Asbestosis: Workers who repeatedly breathe in asbestos fibers with lengths greater than or equal to 5 micro-meter may develop a slow buildup of scar-like tissue in the lungs and in the membrane that surrounds the lungs. This scar-like tissue does not expand and contract like normal lung tissue making breathing difficult. Blood flow to the lungs may also be decreased leading to enlargement of the heart. People with asbestosis have shortness of breath, often accompanied by a cough. This serious disease can eventually lead to disability or death. Changes in the membrane surrounding the lung, called pleural plaques, are quite common in people occupationally exposed to asbestos, and are sometimes found in people living in areas with high environmental levels of asbestos. Effects on breathing from pleural plaques alone are usually not serious. There is conflicting evidence as to whether the presence of pleural plaques accurately predicts the future development of more serious disease. Asbestosis is not usually of concern to people exposed to low (environmental) levels of asbestos.
Cancer: Asbestos workers have increased chances of getting two principal types of cancer: cancer of the lung tissue itself (lung cancer); and, mesothelioma, a rare cancer of the thin membrane that surrounds the lung and other internal organs. These cancers do not develop immediately following exposure to asbestos, but appear only after 10-40 years. Some studies of workers suggest that breathing asbestos can increase the chances of getting cancer in other locations, including the stomach, intestines, esophagus, pancreas, and kidneys, but this evidence is unclear. Members of the public who are exposed to lower levels of asbestos may also have increased chances of getting cancer, but the risks are usually small and are difficult to measure directly. Lung cancer is usually fatal. Mesothelioma is almost always fatal, often within a few months of diagnosis. Some scientists believe that early identification and intervention of mesothelioma may increase survival.
It is well accepted that asbestos causes cancer in humans. Two types of cancer are associated with exposure to asbestos: cancer of the lung tissue itself (lung cancer); and, mesothelioma, a cancer of the membrane that surrounds the lungs and other internal organs. Both of these are usually fatal. These cancers do not develop immediately, but show up only after 10-40 years. Interactions between cigarette smoke and asbestos increase the chances of developing lung cancer. Studies of workers suggest that breathing asbestos can increase the chances of getting cancer in other parts of the body (stomach, intestines, esophagus, pancreas, kidneys), but the evidence is unclear. People who are exposed to lower levels of asbestos may also have an increased risk of developing cancer, but the risks are usually small and are difficult to measure. It is not known whether ingesting asbestos causes cancer. Some people exposed to asbestos fibers in drinking water had higher-than-average death rates from cancer of the esophagus, stomach, and intestines; however, it is unclear whether these cancers were caused by asbestos or due to other factors.
Length of exposure.
Development of lung disease due to asbestos exposure depends on several factors. The most important of these are:
Amount of exposure.
Smoking. Cigarette smoking in combination with asbestos exposure increases the chances of getting lung cancer.
Exposure to asbestos does not guarantee that you will become ill, however, any asbestos exposures are best avoided.
Children, like adults, may be exposed to asbestos when they are in or near buildings that have damaged asbestos containing building materials, or when they live or spend significant time near asbestos-related industrial operations. Children breathe more rapidly and have different lung structures than adults. It is not known if these differences may cause a greater amount of the inhaled asbestos fibers to stay in the lungs of children than for adults. Children drink more fluids per kilogram of body weight than adults, and can thus be exposed through asbestos-contaminated drinking water. Eating asbestos-contaminated soil and dust is another source of exposure for children. Some children intentionally eat soil, and all young children consume soil through hand-to-mouth activities. Historically, young family members have also been exposed to asbestos that was carried home on the clothing of other family members who worked in asbestos mines or mills.
Inhalation of asbestos fibers may result in difficulty in breathing, lung cancer, or mesothelioma (a rare form of cancer associated with asbestos exposure). These diseases usually appear many years following the first exposure to asbestos and are therefore not likely to be seen in children. Since it may take up to 40 or more years for the effects of exposure to be seen, people who have been exposed to asbestos at a young age may be more likely to develop these diseases than those whose first exposure occurs later in life. The small numbers of studies that have specifically looked at asbestos exposure in children do not indicate that younger people might develop asbestos-related diseases more quickly than older people. Developing fetuses and infants are not likely to be exposed to asbestos through the placenta or breast milk of the mother.