Why is asbestos harmful to your health? How can I tell If I've been exposed to asbestos fibers?
Lung disease from exposure to asbestos can be divided into three main types: 1) asbestosis, 2) disease of the lining of the lung (pleura), and 3) lung cancer.
- Asbestosis is a process of widespread scarring of the lungs.
- Disease of the lining of the lungs, called the pleura, has a variety of signs and symptoms and is the result of inflammation and the hardening (calcification) and/or thickening of the lining tissue.
- Lung cancer, either of the internal portions of the lungs or the outer lining (pleura).
All of the commonly available commercial forms of asbestos have been linked to cancerous and non-cancerous lung disease.
Depending on their shape and size, asbestos fibers deposit in different areas of the lung. Fibers less than 3 mm easily move into the lung tissue and the lining surrounding the lung (pleura). Long fibers, greater than 5 mm (1/5 inch), cannot be completely broken down by scavenger cells (macrophages) and remain in the lung tissue. These asbestos fibers can cause inflammation. Substances damaging to the lungs are then released by the cells of inflammation that are responding to the foreign asbestos material. The persistence of these long fibers in the lung tissue and the resulting inflammation seem to initiate the process of cancer formation.
As inflammation and damage to tissue around the asbestos fibers continues, the resulting scarring can extend from the small airways to the larger airways and the tiny air sacs (alveoli) at the end of the airways. Some of these fibers can move to the surface of the lung where they form plaques (white-gray regions of scarred tissue) in the tissue lining of the lung (pleura). In severe cases of asbestosis, scarring of both the lung and its lining tissue can occur.
Asbestos-related lung disease occurred at very high rates toward the middle of the 20th century, when patients who were exposed decades earlier to asbestos eventually developed disease. British asbestos workers were among the first who were observed to have lung cancer related to asbestos.
About 125 million people worldwide are exposed to asbestos in the workplace, and most people with lung disease from asbestos exposure were exposed to it from:
- factories, or
- homes with asbestos, either in the process of carrying, installing, or removing asbestos, or while cleaning items laden with asbestos dust.
Some workers have been exposed to high concentrations of asbestos in:
- automotive repair,
- launderers of asbestos-containing clothing.
Continuing sources of exposure are asbestos removal and general construction industries. The delay between exposure to asbestos and the development of cancer can be anywhere from 10 to 40 or more years.
Despite not using asbestos in construction materials for the last 30 years, the number of deaths from asbestosis has increased over the past two decades. A 2009 study to assess the incidence of asbestos-related deaths concluded that the death rate is not expected to decrease sharply in the next 10 to 15 years. Each year in the US, asbestos exposure kills about 12,000 to 15,000 people. Some World Trade Center rescue and recovery workers have asbestos exposure lung disease.