In the United States, smoking-related illnesses accounted for an estimated 443,000 deaths each year between 2000 and 2004.[1,2] (Also available online.) On average, these deaths occur 12 years earlier than would be expected, so the aggregate annual loss exceeds 5 million life-years. These deaths are primarily due to smoking's role as a major cause of cancer, cardiovascular diseases, and chronic lung diseases. The known adverse health effects also include other respiratory diseases and symptoms, nuclear cataract, hip fractures, reduced female fertility, and diminished health status. Maternal smoking during pregnancy is associated with fetal growth restriction, low birth weight, and complications of pregnancy. It has been estimated that at least 30% of cancer deaths and 20% of all premature deaths in the United States are attributable to smoking.
Tobacco products are the single, major avoidable cause of cancer, causing more than 155,000 deaths among smokers in the United States annually due to various cancers. The majority of cancers of the lung, trachea, bronchus, larynx, pharynx, oral cavity, nasal cavity, and esophagus are attributable to tobacco products, particularly cigarettes. Smoking is also causally associated with cancers of the pancreas, kidney, bladder, stomach, and cervix and with myeloid leukemia.[4,6]
Avoiding risk factors and increasing protective factors may help prevent cancer.
Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.
The following are risk factors for oral cancer:
Smoking also has substantial effects on the health of nonsmokers. Environmental or secondhand tobacco smoke is implicated in causing lung cancer and coronary heart disease. Among children, secondhand smoke exposure is causally associated with sudden infant death syndrome, lower respiratory tract illnesses, otitis media, middle ear effusion, exacerbated asthma, and respiratory effects such as cough, wheeze, and dyspnea.
Environmental tobacco smoke has the same components as inhaled mainstream smoke, although in lower absolute concentrations, between 1% and 10%, depending on the constituent. Carcinogenic compounds in tobacco smoke include the polycyclic aromatic hydrocarbons (PAHs), including the carcinogen benzo[a]pyrene (BaP) and the nicotine-derived tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Elevated biomarkers of tobacco exposure, including urinary cotinine, tobacco-related carcinogen metabolites, and carcinogen-protein adducts, are seen in passive or secondhand smokers.[7,9,10,11]