Is outdoor tobacco smoke really toxic?

Yes. Tobacco smoke contains over one hundred recognized toxic chemicals, hazardous air pollutants, or known carcinogens -- including benzene, arsenic, hydrogen cyanide, cadmium, 1,3-butadiene, and benzo-a-pyrene. In addition to being a strong irritant and potential annoyance, tobacco smoke can have adverse effects on the human respiratory and cardiovascular systems.