Smoking has long been identified as a primary cause of lung cancer. For all types of lung cancer about 90% of cases diagnosed are in people with a smoking history. For small cell lung cancer (SCLC) the smokers represent 98% of all cases diagnosed. The drop in frequency of incidence for lung cancer in the United States can be attributed largely to the drop in tobacco use over the last twenty years. Still, 17,000 – 20,000 non-smokers are diagnosed annually with lung cancer. There are several causes that have been linked to this phenomenon.
So-called “second hand smoke” can be harmful to people who are exposed to it on a regular basis. Non-smokers who live with a smoker are 24% more likely to develop lung cancer than those that reside in a smoke-free environment. The incidence of cancer for non-smokers is higher among women, particularly Asian women. There are a number of statistics that suggest living in a smoker’s environment can be harmful. There is also recent research however that suggests the lung cancer tumors that develop in non-smokers have a very different genetic makeup than for smokers, leading researchers to believe that there may be additional contributing factors to lung cancer.
Aside from second hand smoke there are several industrial and naturally-occurring toxins that can contribute to lung cancer. Radon gas develops when uranium is going through a decaying process; it can be found in many natural settings including well water. It is estimated that radon contributes to 12% of all lung cancer deaths annually, among smokers and non-smokers.
Asbestos is another major cancer-causing element that has impacted many thousands of people over the last several decades. Cigarette smoking is a lethal combination with asbestos exposure, greatly contributing to the likelihood of cancer development among people who have been exposed to asbestos. Nevertheless, people who work around asbestos products and are non-smokers are five times more likely to develop lung cancer. Asbestos has been clearly linked to small cell lung cancer as well. Because almost all cases of SCLC occur among smokers, it is reasonable to assume that a non-smoker who develops the disease may well have been exposed to asbestos.
Non Smokers and Asbestos Exposure
One of the characteristics of an asbestos-related disease – and there are several – is that it has an extraordinarily long period of latency. People who are exposed to deteriorating or worn asbestos products generally inhale or ingest the fibers those products give off without knowing it. Decades later they may develop asbestosis, mesothelioma, or lung cancer. A non-smoker in his or her retirement years who has developed SCLC may well have been exposed to asbestos on the job, during military service, or working on remodeling a home.