Medicine: second-hand cancer

Those crazy Canadians and their anti-smoking propaganda, I mean, er, rigorous statistical analysis.

Long-term regular exposure to passive smoking was associated with an overall 27-percent increased risk of breast cancer among women who had never smoked.

"More importantly, among the studies that collected the most complete measures of passive smoking, the observed breast cancer risk was increased by 90 percent," Johnson said in an interview with Reuters Health. "Studies with less complete second-hand smoke measures only observed an eight-percent increase in risk."

"The relationship with premenopausal breast cancer risk was stronger -- elevated 68 percent with long-term regular passive smoking exposure among life-long non-smokers based on 14 studies," Dr. Johnson explained. "The premenopausal risk was up 119 percent for the five studies with more complete second-hand smoke measures."

Compared with women with neither active nor regular passive smoke exposure, those who smoked had a 46-percent increased risk of breast cancer. The risk was raised 108 percent in studies with more complete passive exposure assessment. For studies with less complete passive exposure assessment, the risk was increased by 15 percent.

No studies yet assessing second hand smoke exposure while yelling that you have a bomb on an airplane.