An irreversible health effect is a permanent change in the structure and/or function of an
organ system or a permanently increased risk of suffering from a disease or some other
threat to health. Irreversible effects vary in intensity and are related both to the amount and
duration of exposure and the age at which the person is initially exposed. A risk or effect
may diminish over time, but it may also increase; some risk may remain many years after
exposure has ended.
This report examines the irreversible effects of cigarette smoking on various organ systems
and challenges the notion that a few years of exposure to smoking will have no lasting
adverse consequences. Our hope is to discourage young people from taking up this deadly
habit by appealing to their common sense and better judgment, thereby allowing them to
choose for themselves not to smoke. We will not recite the familiar litany of
smoking-related health problems such as emphysema, cancer, and heart disease. Rather,
we will show that smoking cigarettes for as few as five years can have a permanent effect
on the lungs, the heart, the eyes, the throat, the urinary tract, the digestive organs, the bones
and joints, and the skin—even if the smoker quits.
We do not mean to dishearten long-term smokers. Despite smoking's irreversible effects, it
would be foolish for a smoker to conclude that, after years of smoking, quitting would do
him no good. Many studies prove that tobacco-related health effects decline substantially
as time away from smoking increases; some of the benefits begin within months after
quitting. But after years of exposure to the damaging effects of tobacco, quitting smokers
must realize that they have to be realistic in their expectations of recouping their health.