Tabacco smoke can be divided into three types- Mainstream, Sidestream and Environmental Tabacco Smoke (ETS). Mainstream smoke is the smoke inhaled from the cigarette, Sidestream smoke is the smoke given off by the end of the cigarette, and ETS is the smoke exhaled from smokers’ lungs. Second-hand smoke is a combination of Sidestream smoke and ETS. This second-hand smoke is primarily the issue when it comes to looking at air pollution caused by smoking. Smoky air can cause irritation to the lungs, eyes and throat, and is generally found to be recognized across both business and leisure environments.