Lung cancer is primarily caused by tobacco smoking. The data available with the Centers for Disease Control and Prevention, or CDC, indicate that approximately 90 percent of all lung cancer deaths in men and 80 percent in women in the United States are directly linked to cigarette smoking. The National Cancer Institute, or NCI, states that most people are older than 65 years when diagnosed with lung cancer.
Tobacco Smoking and Passive Smoking
The CDC factsheets on smoking and tobacco use reveal that compared to nonsmokers, tobacco smokers have a 10 to 20 times higher probability of getting lung cancer or dying from it. The risk of lung cancer is directly proportional to the number of cigarettes smoked per day. The risk of lung cancer for people who have quit smoking continues to be higher than those who have never smoked. Passive smoking, or inhaling the smoke from other people's cigarettes, is another cause of lung cancer. Second-hand smoke contains over 4,000 chemicals, 60 of which are carcinogenic for human beings. The International Agency for Research on Cancer, or IARC, notes in its report on involuntary smoking that nonsmokers will have some risk of lung cancer if they are exposed to second-hand tobacco smoke.
Other Substances That Cause Lung Cancer
Radon gas causes lung cancer. This gas originates from rocks and dirt, and sometimes it may get trapped in homes and buildings. It is the leading cause of lung cancer among nonsmokers. Other hazardous materials that are known to aggravate the risk of lung cancer include asbestos, arsenic and silica and chromium in some forms. A sustained exposure to such substances can cause lung cancer.
Work Environments
People who may be living or working together in places that have a high exposure to carcinogenic substances such as radon or asbestos are exposed to the risks of lung cancer. The National Office of Public Health Genomics in the U.S. suggests that hereditary factors may also be responsible for an increased risk of lung cancer. Research carried out by the Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, also supports the hypothesis that genetic factors may cause lung cancer in families of nonsmokers.
Dietary Factors
A high-fat and cholesterol-rich diet may contribute to the risk of lung cancer. High consumption of alcohol may also be related to lung cancer risk. Scientific research is still being carried out to establish a clear connection between diet and lung cancer.
References
- Centre for Disease Control and Prevention: Lung Cancer - Risk Factors
- National Cancer Institute: Lung Cancer - Risk Factors
- Mayo Clinic: Lung Cancer - Risk Factors
- Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Connecticut
- IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Tobacco Smoke and Involuntary Smoking
