No level of smoking, or exposure to second-hand smoke, safe: researcher

(This report might as well be about pot, not tobacco---makes no difference. Smoke is smoke is toxic fume---there's no such thing as "harmless" toxic fume. Disagree? Then let your children smoke all the pot they want --poster )   
By Neil Haesler, Postmedia News, August 21, 2010
Casual smokers may think a few puffs a week are nothing to worry about, but new research in the United States claims having even an infrequent cigarette, or being exposed to second-hand smoke, could be doing more harm than people believe.

According to a study published in the American Journal of Respiratory and Critical Care Medicine, exposure to low levels of cigarette smoke may put people at risk for lung disease in the future.

"Even at the lowest detectable levels of exposure, we found direct effects on the functioning of genes within the cells lining the airways," said Dr. Ronald Crystal, senior author of the study and chief of the division of pulmonary and critical care medicine at New York-Presbyterian/ Weill Cornell and chairman of the department of genetic medicine at Weill Cornell Medical College in New York City.