Toxicity of carbon dioxide: a review.

The toxicity of carbon dioxide has been established for close to a century. A number of animal experiments have explored both acute and long-term toxicity with respect to the lungs, the cardiovascular system, and the bladder, showing inflammatory and possible carcinogenic effects. Carbon dioxide also induces multiple fetal malformations and probably reduces fertility in animals. The aim of the review is to recapitulate the physiological and metabolic mechanisms resulting from CO2 inhalation. As smokers are exposed to a high level of carbon dioxide (13%) that is about 350 times the level in normal air, we propose the hypothesis that carbon dioxide plays a major role in the long term toxicity of tobacco smoke.