Sidestream smoke refers to which part of tobacco smoke?

• A. Smoke from the burning end of a cigarette or pipe
• B. Smoke exhaled by the smoker
• C. Fresh air near the smoker
• D. Smoke filtered by the filter

Answer: (A)

Sidestream smoke is the smoke that comes directly from the burning end of a cigarette or pipe. It rises into the surrounding air as the tobacco burns, and it enters the environment without being inhaled by the smoker. This type of smoke is a major source of secondhand smoke exposure because it is released constantly during burning. In contrast, the smoke exhaled by the smoker is called mainstream smoke. Fresh air near the smoker is not smoke, and smoke filtered by the filter refers to what has passed through the filtering during inhalation, not the burning end.