What is mainstream smoke?

Mainstream smoke refers specifically to the smoke that a smoker inhales into their lungs and then subsequently exhales. This smoke contains a variety of harmful chemicals and toxins produced by the combustion of tobacco and other materials in cigarettes. When a smoker takes a puff, the mainstream smoke combines the smoke produced directly from the burning tobacco with the additional compounds that get mixed with it during the inhalation and exhalation process.

In contrast to other types of smoke, such as sidestream smoke, which comes directly from the burning end of a cigarette and contributes to secondhand exposure, mainstream smoke is the result of the smoker's inhalation and can be distinguished by its pathway through the smoker's respiratory system. Understanding mainstream smoke is crucial in discussions about smoking and health, as it plays a significant role in both the health effects on the smoker and the risks posed to those around them from inhaling secondhand smoke.