Tobacco smoke is a complex mixture of chemicals produced when tobacco is burned. It contains over 7,000 substances, including nicotine, tar, and carbon monoxide. Many of these chemicals are harmful and can lead to serious health issues, such as lung cancer and heart disease. When inhaled, tobacco smoke affects both the smoker and those around them, leading to secondhand smoke exposure. This can also cause health problems in non-smokers, particularly children and pregnant women. Efforts to reduce tobacco use and exposure include public health campaigns and regulations on smoking in public places.