Narrator:This is Science Today. New research on the effects of cigarettes may add fuel to anti-smoking campaigns targeting children. One Massachusetts study found symptoms of nicotine addiction can begin within a few days of smoking just a few cigarettes. And University of California, San Francisco epidemiologist, John Weincke found a crucial link between the age a person starts smoking and how much DNA damage is present in the lungs.
Weincke: Our evidence strongly indicates that if a person starts smoking very early in life, before adolescence, the damage that accumulates persists much longer than if a person starts smoking, say when they're 20 years or so. It may actually take many years for it to clear out of the lungs and of course, once mutations are induced, theoretically, they're around forever.
Narrator: Weincke says there's been controversy over whether when a person starts smoking is an independent risk factor for lung cancer, as opposed to how much a person smokes.
Weincke: Because people that start smoking very early in life tend to smoke more cigarettes per day and they tend to be heavier smokers.
Narrator: For Science Today, I'm Larissa Branin.