Abstract

Currently, the time-weighted exposure value (TWA) for carbon monoxide (CO) is 35 ppm. In response to a CSST request, scientists wanted to estimate the effect of lowering this exposure standard. The project's general objective was to study the influence of various exposure conditions on the percentages of carboxyhemoglobin (% COHb) in the blood. To do this, they developed and used a mathematical model that reproduces the transformation or evolution over time of carbon monoxide by taking into account different processes, mainly absorption and pulmonary elimination, as well as the binding of CO to hemoglobin. They estimated the effect of five factors, namely various CO exposure scenarios involving exposure peaks, or not, during a typical work day, an increase in the workload, the impact of the exposed individuals' weight and of extending the work shift, as well as the use of tobacco. The results of analyzing each of these scenarios are detailed in the report.