Tobacco products, including cigarettes, cigars, and smokeless tobacco, contain a complex mix of over 7,000 chemicals. Of these, at least 250 are known to be harmful, and more than 70 can cause cancer. Key toxic chemicals in tobacco smoke include nicotine, tar, formaldehyde, and carbon monoxide. Nicotine is the addictive component, while tar is a mixture of substances that contribute to respiratory diseases and cancer.
