Ozone (O3), a component of urban smog, causes lung irritation upon inhilation and is a significant public health concern. Studies of the effect of O3 inhalation on humans typically relate exposure directly to response, with little or no consideration of the actual uptake of O3. We hypothesize that duration of exposure, inhaled concentration, and respiratory flow rate are all factors that might affect the uptake of O3 in the respiratory tract, causing a nonlinear relationship between exposure and dose. To test this hypothesis, we have designed a high-speed ozone analyzer which is capable of sampling and monitoring breath-by-breath ozone concentration in real-time in exercising individuals. We measured the fraction of inhaled O3 which was retained, Λ, in eight human subjects during continuous exposure in each of four sessions with O3 concentrations of either 0.2 or 0.4 ppm, exposure duration of 30 or 60 min., and target ventilation rates of 20 or 40 Lpm. Our results indicate that O3 uptake is proportional to ventilation rate, exposure time, and inhaled concentration such that Λ had a value of 0.86 ± 0.06 (mean ± SD) for all the subjects we tested.
|Original language||English (US)|
|Number of pages||4|
|Journal||Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings|
|State||Published - Dec 1 1997|
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