PREDICTING PERSONAL EXPOSURE LEVELS TO CARBON-MONOXIDE (CO) IN TAIPEI, BASED ON ACTUAL CO MEASUREMENTS IN MICROENVIRONMENTS AND A MONTE-CARLO SIMULATION METHOD

In order to evaluate the severity of carbon monoxide (CO) pollution in Taipei, this study conducted a survey of commuting patterns (in a dis trict) for random samples of primary school students and adult workers , and carried out CO measurements in vehicles and near roadsides. A Mo nte Carlo simulation was then implemented to estimate 1- and 8-h CO ex posure levels for the population. The microenvironment of the roadside included both the sidewalk and the corridor (a sheltered walkway fart her removed from the road than the sidewalk). By computer simulations, this study showed that commuters on motorcycles and public buses were exposed to the highest CO exposure levels among all commuters on the roads in Taipei. This study also demonstrated that the Monte Carlo sim ulation method could better estimate CO exposure levels for the genera l public. It was found that roadside-fixed monitoring stations operate d by the Taipei BEP (Bureau of Environmental Protection) underestimate d the general population's 1-h CO exposure levels. For adult workers, the roadside-fixed monitoring stations reasonably estimated the roadsi de business workers' 8-h CO exposure levels, but overestimated the exp osure levels of general adult workers commuting by public bus, except for bus drivers whose CO exposure levels were underestimated. It is su ggested that the computer simulation method can be used to better guid e air quality management plans instead of only using the fixed-site mo nitoring data. The simulated results indicate that the CO exposure lev els of commuters on motorcycles and public buses are high enough that prompt control measures are warranted in Taipei.