No organ of the human body goes untouched by regular inhaling of cigarette smoke. Chief among pollutants introduced into the body and lungs by smoking cigarettes is tar, a substance related to several serious and possibly terminal illnesses.
Tar is the collective term describing toxins produced by smoking cigarettes and the coating they place on the lungs. When inhaled, these toxins form a particulate matter that coats lungs much the same way that soot from log fires coats chimneys. But unlike chimneys, which are made of stone or brick, human lungs are made of thin, delicate tissue not intended for toxic smoke intake. Cigarette smoke contains as many as 250 chemicals known to be toxic.
The constant irritation of tar-producing smoke in the lungs can lead to cancer and a breathing disease known as emphysema, which slowly rots lung tissue. The Centers for Disease Control and Prevention reports that smoking causes about 90 percent of lung cancer-related deaths in men and nearly 80 percent of such deaths in women. Those who develop emphysema are more likely to suffer from repeated bouts of bronchitis and from heart and lung failure.
Smoking diseases, many of which are linked to tar, cause about 430,000 U.S. deaths per year, or about one out of every five deaths in the country, according to the CDC. That accounts for more lives claimed than by HIV, illegal drug and alcohol use, motor-vehicle injuries, suicides and homicides combined.
Cigarette manufactures produce "light" cigarettes as an answer to industry critics who contend the products contain unsafe tar levels. The CDC and a study published by Turkish researchers in 2007 contend that the supposed lower-tar cigarettes take as high or higher a toll on health because users of these products tend to draw more heavily on cigarettes, pulling the toxins more deeply into their lungs.
The CDC reports that smokers who kick the habit lower their risk for lung and other types of cancer, coronary heart disease, stroke and vascular diseases. Smokers who quit often experience fewer respiratory illnesses and conditions, such as coughing and shortness of breath. Women who quit reduce the risk of infertility or of having children with low birth weights or other birth defects.