Background: Drive-through mass vaccination clinics are an increasingly popular component of public health emergency response plans. One potential disadvantage, however, is the exposure of clinicians, volunteers, public health responders, and the public to carbon monoxide (CO) from vehicle exhaust emissions when clinics are held within garages or other enclosed structures.
Methods: CO levels were monitored during indoor drive-through clinics held on the same day at 2 separate locations in a rural upstate New York county. Each clinic was operated for 2 hours during which seasonal influenza vaccines were administered to county residents as they remained within their vehicles. At each location, vehicle engines remained operating indoors within multiple lanes of traffic. No mechanical ventilation was used, but wind speeds through the buildings were relatively strong and consistent. CO was measured at breathing-zone height throughout the clinic sessions using direct-reading instruments.
Results: CO levels remained below detection for the majority of the clinic sessions. Short-term, high CO exposures, however, were found to be associated with a small number of individual vehicles that were in apparent disrepair.
Conclusions: The findings from this study indicate that CO exposures may be minimized by identifying and separately processing problematic vehicles before they enter the clinic. Direct reading CO monitors can help to identify these vehicles. (Disaster Med Public Health Preparedness. 2009;3:158–162)