Nicotine is one of more than 4,000 chemicals found in tobacco smoke and is the primary component that acts on the brain. Smokeless tobacco products such as snuff and chewing tobacco also contain high levels of nicotine as well as other toxins.
Nicotine is absorbed through the skin and mucosal lining of the mouth and nose or by inhalation into the lungs. Depending on how tobacco is taken, nicotine can reach peak levels in the bloodstream and brain rapidly. Cigarette smoking, for example, results in rapid distribution of nicotine throughout the body, reaching the brain within 10 seconds of inhalation. Cigar and pipe smokers, on the other hand, typically do not inhale the smoke, so nicotine is absorbed more slowly through the mucosal membranes of their mouths, the same as for smokeless tobacco.
A typical smoker will take 10 puffs on a cigarette over a period of 5 minutes that the cigarette is lit. Thus, a person who smokes about 1-1/2 packs (30 cigarettes) daily, gets 300 “hits” of nicotine to the brain each day. These factors contribute considerably to nicotine’s highly addictive nature.
HEALTH EFFECTS: Smoking tobacco is the chief avoidable cause of death in our society. Smokers are more likely than nonsmokers to contract heart disease – some 170,000 die each year from smoking-related coronary heart disease. Lung, larynx, esophageal, bladder, pancreatic, and kidney cancers also strike smokers at increased rates. Some 30 percent of cancer deaths (130,000 per year) are linked to smoking. Chronic, obstructive lung diseases such as emphysema and chronic bronchitis are 10 times more likely to occur among smokers than among nonsmokers.
PREGNANCY: Smoking during pregnancy also poses serious risks. Spontaneous abortion, preterm birth, low birth weights, and fetal and infant deaths are all more likely to occur when the pregnant woman is a smoker.
SECOND HAND SMOKE: Exposure to secondhand smoke is thought to cause heart disease. In addition, each year an estimated 3,000 nonsmoking Americans die of lung cancer. Exposure to secondhand smoke also causes respiratory tract infections in up to 300,000 children annually.