By Terry Martin
Updated March 29, 2013
Written or reviewed by a board-certified physician. See About.com's Medical Review Board.
Mainstream smoke is residual cigarette smoke exhaled by smokers.Photo © Stockxpert
The composition of mainstream smoke is affected by how the smoker inhales and exhales, so it will vary from person to person. The frequency of puffs, duration and volume all contribute to the chemical makeup of mainstream smoke.
Secondhand Smoke Facts
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