How many cancer-causing chemicals does secondhand smoke contain?
Secondhand smoke contains 69 chemicals known to cause cancer. Tobacco smoke is a Class-A carcinogenic, which means that it is a substance that causes cancer (asbestos is another well-known Class-A carcinogenic). Some other chemicals in tobacco smoke include: tar (used on the streets), arsenic (poison), benzene (used to make gas and pesticides), and formaldehyde (used to preserve dead bodies).
