Causes - Radon
There are other less common causes for lung cancer besides the well known relationship with the disease and cigarette smoking. Certain environmental chemicals also have the ability to cause lung cancer. One of these is radon. Radon is a naturally occurring element that is typically released from radioactive decay of uranium in rocks and soil. Radon has the ability to become present in a certain areas groundwater and be released into the air when the water is utilized. Typically, these small exposures are of little consequence, especially in outside areas where radon would most likely be encountered. However, in areas with inadequate ventilation, radon accumulations in the air can be of dangerous enough levels that they substantially increase the risk of lung cancer to the exposed.
The general population is usually exposed to harmful levels of radon because of geologic factors in their home. For instance, if a home is built upon uranium rich soil or bedrock, the sheer quantity of decaying material has the ability to proliferate radon particles in floors and foundations. Because of their proximity to the ground, radon levels are typically higher in basements or first floors of homes. Risk can become elevated in tightly sealed or highly insulated homes, such as those in cold weather climate areas.
Radon first became associated with lung cancer when scientists and physicians took notice of a high incidence of lung cancer patients among underground uranium mine workers. Laboratory studies confirmed higher rates of lung tumors in rodents exposed to high levels of uranium decay.
The process, by which radon causes lung cancer, is fairly simple. When uranium decays, it produces the radon particles. These particles have a very fast radioactive half-life, and decay quite fast. When radon decays it releases tiny radioactive particles. When inhaled, these particles have the ability to damage the lung cells that they encounter. Damaged or mutated lung cells have the propensity to lose their control on mitosis, or normal growth. When body cells reproduce uncontrollably, a tumor is developed in the lung.
The amount of people who develop lung cancer as a result of radon exposure is quite small compared to those who develop cigarette smoking induced lung cancers. Of the 400,000 lung cancer related deaths each year, approximately 20,000 of those are the result of radon exposure. This does represent however, the second leading cause of lung cancer. Although the relationship between radon exposure and smoking is not commonly understood, smokers who are exposed to radon pose a greater risk of developing lung cancer than those exposed to one or the other isolated factors. Most radon related cancer deaths occur in smokers.