Carbon Monoxide and Human Health

To prevent adverse effects on human health as exposure to carbon monoxide (CO) increases adequate programs and policies must be adopted. Their formulation will require deliberate scientific judgment based on adequate information and the consideration of certain hypotheses which are reviewed here. Exposures to CO are widespread. For the U.S. urban population cigarette smoking is probably the most important source followed in importance by motor vehicle exhaust occupational sources and home heating and cooking devices. The median carboxyhemoglobin (COHb) concentration for those who smoke 1 pack of cigarettes daily and who inhale is 5.9% - a concentration sufficient to imply a serious threat to health in persons with underlying vascular insufficiency. This level of exposure may be responsible for some of the excess mortality from cardiovascular disease observed among cigarette smokers. Community air pollution may produce COHb concentrations in nonsmokers similar to those observed in smokers and the effects of these concentrations will be greater at high altitude. There has been considerable documentation of endogenous production of CO from home catabolism. Such production provides a tool for the study of hemolytic disorders is a hazard to infants in respirators and to men in submersibles and space capsules and may increase the risk of closed-circuit anesthesia. Low and commonly occurring CO exposures may impair accurate estimation of time intervals as well as the performance of more complex psychomotor tasks. A possible role of CO in motor vehicle accidents is suggested by data showing higher levels of COHb in drivers involved in accidents than in policemen and in other occupationally exposed populations.(AUTHORS MODIFIED)