I'm only a social smoker, what's the big deal?

Melanie considered herself a social smoker. Her husband smoked and she would bum a couple of his cigarettes when she was drinking, usually at a party or out to dinner, She considered herself healthy because she ate a low-fat diet and exercised daily; yet she had a high risk for heart disease. She had a family history of heart disease, her father had died from a heart attack in his fifties. She