Source: Texas Department of State Health Services
Information on human health effects of asbestos comes mostly from long-term studies of people exposed to asbestos in the workplace. Asbestos workers who breathe in asbestos may develop a slow build-up of scar-like tissue in the lungs called asbestosis. This scarred tissue state impairs the ability of the lungs and heart to adequately provide oxygen to the body. This is a serious disease, and can eventually lead to disability or death in people exposed to high amounts of asbestos. Asbestos workers also have increased chances of developing two types of cancer: Lung cancer starts within the respiratory tissues, and mesothelial cancer grows from the thin membranes that surround the lung or the abdominal cavities. Both lung cancer and mesothelioma are usually fatal. These asbestos-related diseases do not appear immediately, but may develop 20 to 50 years after exposure.
The health effects from oral asbestos exposures are unclear. In some areas where the residents are exposed to asbestos fibers in the drinking water, cancers of the esophagus, stomach, and intestine may be a greater concern. After reviewing the scientific evidence from human experience and animal testing; however, health authorities are still unsure of asbestos links to cancer in the digestive system.
Source: CDC, Agency for Toxic Substances and Disease Registry (ATSDR)
Significant exposure to any type of asbestos will increase the risk of lung cancer, mesothelioma and nonmalignant lung and pleural disorders, including asbestosis, pleural plaques, pleural thickening, and pleural effusions. This conclusion is based on observations of these diseases in groups of workers with cumulative exposures ranging from about 5 to 1,200 fiber-year/mL. Such exposures would result from 40 years of occupational exposure to air concentrations of 0.125 to 30 fiber/mL. See Detecting Asbestos, for typical levels of concentration. The conclusion is supported by results from animal and mechanistic studies.
Diseases from asbestos exposure take a long time to develop. Most cases of lung cancer or asbestosis in asbestos workers occur 15 or more years after initial exposure to asbestos. Tobacco smokers who have been exposed to asbestos have a "far greater-than-additive" risk for lung cancer than do nonsmokers who have been exposed, meaning the risk is greater than the individual risks from asbestos and smoking added together. The time between diagnosis of mesothelioma and the time of initial occupational exposure to asbestos commonly has been 30 years or more. Cases of mesotheliomas have been reported after household exposure of family members of asbestos workers and in individuals without occupational exposure who live close to asbestos mines.
If you would like to find out more about the potential health effects of asbestos exposure, review any of the following resources: