Tobacco Toxicity Introduction

Cigarettes, cigars, pipe tobacco, and smokeless tobacco are made up of dried tobacco leaves and hundreds of other components added for flavor and other properties. More than 4000 individual toxic lipophilic and hydrophilic chemical compounds, of which greater than 60 are carcinogens, have been identified in tobacco and tobacco smoke. I35 36 Accordingly, all tobacco and tobacco smoke exposure is, of necessity, to mixtures of toxic chemicals. 

Tobacco and tobacco smoke exposure has been identified with numerous health effects. Each year, almost 450,000 people in the United States and millions worldwide die from tobacco use. Cigarette smoking is associated with cancer of the lung, oral cavity, pharynx, larynx, esophagus, kidney, liver, bladder, stomach, colon, rectum, and some leukemias. Smoking is the cause of at least 30% of all cancers and 87% of lung cancers.I37 38  

Cancers only account for about half of the smoking-related deaths. Smoking is a major cause of bronchitis, emphysema, heart disease, and stroke. Tobacco is associated with female reproductive health, increases in miscarriage rates, early delivery, stillbirth, infant death, and low birth rate. It is estimated that 9 million Americans suffer from tobacco-related illnesses at any given time.  

The complexity of tobacco smoke makes it difficult to ascribe a particular health effect to a single component, though some inroads have been made in this regard. Complicating matters further is the fact that human exposure to tobacco smoke is almost never without co-exposure to other toxic chemicals. It is known, however, that when individuals are co-exposed to tobacco smoke and other chemicals not contained in the smoke, health effects are observed that are different from those seen from tobacco smoke exposure only. The rest of this chapter is devoted to the health effects caused by the combined exposure to tobacco smoke and other chemicals. 

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