Re-evaluation of the role of carbon monoxide in production or aggravation of cardiovascular disease processes.

As an environmental pollutant carbon monoxide (CO) is without equal with regard to ubiquity. Data suggesting adverse effects on the human cardiovascular system associated with CO exposure have engendered concern. In contrast to previous reviewers, our evaluation of the available studies suggests that this concern is largely unwarranted. We found no convincing evidence to support the conclusion that chronic CO exposure increases the risk of developing clinically significant atherosclerotic disease. Acute, low level, Co exposure has been shown to reduce exercise performance. We believe that this effect does not represent a specific toxic action of CO, but is instead a consequence of the induced hypoxia. Finally, we conclude that low to moderate level CO exposure does not adversely affect cardiac rhythm in man.