The Lethal Legacy of Asbestos- Related Diseases
While even as far back as Ancient Greece the effects of asbestos have been observed and correlated, it wasn’t until the early 20th century that health risks of asbestos exposure in to the pulmonary system. It took until the 1980’s that laws in America were implemented to regulate and limit the use of the material. In that time, an untold score of people were left exposed to the diseases that the insulating material causes.
Asbestos affects the lungs primarily, as its inhaled fibers are too small to be seen by the human eye unaided. The crystalline fibers can remain in the lungs for decades and are recognized by the body’s immune system as foreign bodies. This ultimately causes inflammation of the lung tissue and eventually leads to cell damage. In turn this cell damage can cause pulmonary fibrosis and in some cases malignant growths. Also, shorter fibers can sometimes find their way to the abdominal and pleural cavities, causing further damage.
Differentiating the Diseases
Asbestos related diseases can be put into two distinctive categories: Non-Malignant and Malignant. Non malignant diseases generally involve afflictions of two pleural membranes of the lung (The visceral and parietal). Asbestos-induced diseases of the malignant variety are cancer based, of course, and are generally the most serious and life threatening of the two varieties for obvious reasons.
The most common of the non-malignant diseases are pleural plaques, which is chronic fibrosis of the affected membranes that leads to a partial calcification of the tissues. While not generally life threatening, they can cause chest pain and diminished capacity of the pulmonary system, though certain medical professionals dispute these claims. Pleural plaques are indicative of heighted risk for other asbestos-related diseases in the future.
Diffuse Pleural Thickening (DPT)
Diffuse pleural thickening is more wide spread in area, causing the membranes over one or both lungs to thicken. Like pleural plaques, diffuse pleural thickening develops decades after initial exposure to asbestos. DPT makes up roughly 20% of reported cases of asbestos related diseases world-wide. It can cause shortness of breath, chest pain, and reduced lung capacity. There are few treatments for DPT, but like plaques, those that suffer with the disease are at increased risk for other pulmonary illnesses.
Benign Asbestos Pleural Effusion
The mildest asbestos related disease is benign asbestos pleural effusion. It is a build of fluid between the two pleural membranes following exposure to asbestos. It generally occurs within ten years after initial exposure and lasts for several months before it completely resolves. The effusion can progress to DPT, which means regularly screening is advised for those that are diagnosed.
Folded Lung Syndrome (Rounded Atelectasis)
Folded lung syndrome, also known as rounded atelectasis develops from inward folding of thickened pleura that causes the functional parts of the lung to collapse. It can sometimes be mistaken for a tumor during x-rays or CT scans. It is relatively rare compared to other non-malignant asbestos related diseases and is chronic but generally asymptomatic.
Asbestosis is a chronic non-malignant lung disease, which requires significant exposure to asbestos. It is characterized as diffuse fibrosis, generally around the base of the lungs, causing scarring of the organs. It generally occurs due to either high levels of asbestos or long term exposure. Overall lung capacity is reduced, resulting in shortness of breath and increased risk for heart failure.
The two main malignant diseases associated with asbestos exposure are mesothelioma and lung cancer. Mesothelioma is an incurable tumor that forms in the mesothelial cells of pleura and peritoneum. Pleural mesothelioma is more common than peritoneal, but both generally show at least twenty years after initial exposure. The tumor is aggressive and patients have a poor prognosis, with a survival rate of less than 1 year for most. Mesothelioma can be treated with surgery, radiation, and chemotherapy.
Asbestos can also cause lung cancer identical to lung cancer from any other cause. It can cause all the major forms of cancer, and estimates place asbestos exposure at as the cause for 5% of all lung cancer cases. Like other asbestos related diseases, it has a long latency period that lasts up to twenty to thirty years before the development of the cancer. Asbestos exposure and other risk factors for cancers have a synergistic effect, creating a far greater risk for development than either of them alone.
The one factor that all asbestos related diseases share is the long dormancy period, with ten years at the shortest to up to fifty years or more at the other end of the spectrum. This makes asbestos exposure a continuing health concern in America despite being banned for most uses since the early 80’s and it worldwide will continue to threaten health, especially in developing industrialized nations.