A great deal of medical and scientific research has been done over the past few decades to study possible connections between second hand smoke and cancer. In general, most of these studies have found a strong correlation between inhalation of second hand smoke and cancer cases in an individual. The causality of the smoke on any resulting cancer is a source of some debate, especially between tobacco industry professionals who wish to minimize responsibility and doctors looking to prevent health problems. Whether second hand smoke directly causes cancer may be somewhat unclear, but evidence does indicate that second hand smoke increases the risk of cancer.
The connection between second hand smoke and cancer is a rather hotly debated subject for many people. Smokers often wish to downplay the affects of second hand smoke, likely because most people may be comfortable knowing their choices impact their own health but do not want to be causing harm to others. Non-smokers, on the other side of the argument, are often concerned with their own health and may want to reduce health problems for others and ensure that the choices of other people will not harm them. Ultimately, however, there is a strong case to be made for a connection between second hand smoke and cancer, at least certain types of cancer.
Second hand smoke is a term used to refer to tobacco smoke that comes from a source other than direct inhalation of a cigarette or other tobacco product. This includes mainstream smoke that is exhaled from someone else who is smoking and sidestream smoke that comes from the tip of a burning cigarette or cigar. Research has indicated that the amount of carcinogens inhaled by a person through second hand smoke is virtually the same as what is inhaled by someone directly smoking. This means that the correlation between second hand smoke and cancer is basically the same as smoking and cancer.
One of the major connections between second hand smoke and cancer is in the increased chance of lung cancer due to exposure to second hand smoke. Tobacco smoke contains thousands of different chemical compounds, dozens of which are known or suspected of being carcinogenic, which means they have been shown to cause cancer. Lung cancer is typically the greatest cancerous threat to a smoker or someone exposed to second hand smoke. There is some evidence, however, that indicates that breast cancer could be a potential risk as well; research has found chemicals from tobacco smoke in breast tissue and breast milk of women who smoke or are exposed to second hand smoke.