Lung Adenocarcinoma at 20x Magnification

In addition to smoking, chronic exposure to secondhand smoke has become generally acknowledged as a lung cancer risk factor in recent years. A number of other factors are known to increase the likelihood of developing the disease as well, including living in an urban region, exposure to asbestos or radon, lung scarring from an earlier medical condition or injury, and working in certain high-risk manufacturing jobs that entail exposure to paints, gases, and other materials that contain carcinogens. There also appears to be a genetic component to the disease, and having a close relative with lung cancer is another notable risk factor. It is important to remember, however, that no one yet knows exactly what causes cancer, and many people that are diagnosed with the disease have no known risk factors.