The average CO2 concentrations relevant to a motorcyclist wearing an integral helmet were measured twenty years ago and found to be alarmingly high. The present study examined gas concentrations typically inhaled by a motorcyclist. Average concentrations of CO2 for persons (n=4) wearing integral motorcycle helmets were measured in the laboratory and the field to facilitate comparison to previous work, and similarly high average concentrations were found: above 2 percent when stationary, well below 1 percent for speeds of 50 km/h or more. Detailed measurements of the time-dependent CO2 concentrations during normal inhalation showed levels of about half of the corresponding average concentrations, including 1 percent at standstill, though higher concentrations (4 percent or more) are inhaled at the beginning of each breath. Opening the visor at standstill lowered the average inhaled concentration only to about 0.8 percent. The oxygen deficiency is equal to the CO2 concentration, and could also contribute negatively to motorcyclist cognitive abilities. (A) Paper to the 1st International ESAR Conference on 3rd/4th September 2004 at Hannover Medical School (Germany), Poster Session. For the covering abstract see ITRD D355457.
Abstract