CARBON MONOXIDE.

Abstract

Air concentrations of carbon monoxide (CO) may be determined at relative ease. Yet, the magnitude of a moderate CO exposure is usually more accurately judged by means of biological monitoring methods since the CO body burden depends on several variable factors in addition to the concentration of CO in breathing air. Of these other factors, the most important are the time of exposure, the initial level of carboxyhemoglobin in the blood, alveolar ventilation, and the pulmonary diffusion capacity. Therefore, it is often difficult or misleading to estimate a CO body burden of exposed workers from the air concentrations of CO at work sites. Blood carboxyhemoglobin level serves as a means for monitoring which takes into account not only the variation of CO in air, but also differences in physiological demands of various tasks and other factors that affect CO absorption and elimination. However, at work sites where severe CO hazard may present, e. g. , in the form of massive leakages, biological monitoring of individuals is an ineffective means of prevention. Instead, a continuous air monitoring system with automatic alarms should be installed. Biological monitoring and surveillance of atmospheric CO are, therefore, complementary forms to detect inadvertent exposure to CO. 15 refs.