From the article:
Secondhand smoke has a direct, measurable impact on the brain similar to what's seen in the person doing the smoking, according to a new study. The finding highlights the importance of limiting exposure to secondhand smoke in cars and other enclosed spaces.
When not exposed to smoke (top image), brains show high levels (red and yellow) of a tracer molecule that binds to empty nicotine receptors. After 1 hour of exposure to secondhand smoke (bottom), nicotine displaces and reduces the level of tracer molecules.Image courtesy of Brody et al., Archives of General Psychiatry.
Tobacco is the leading cause of preventable death nationwide. People who smoke are up to 6 times more likely than non-smokers to suffer a heart attack. Tobacco is also one of the strongest cancer-causing agents. Up to 90% of lung cancer deaths are attributed to smoking.
But the smoker isn't the only one harmed by cigarette smoke. According to the U.S. Centers for Disease Control and Prevention, almost 50,000 deaths per year can be attributed to secondhand smoke. A Surgeon General's Report in 2006 concluded that secondhand smoke causes heart disease and lung cancer in nonsmoking adults. It also causes serious health conditions in children, including sudden infant death syndrome, respiratory infections and more severe asthma.