Exposure of children to aerosol during PE lessons

The indirect method of transferring heart rate (HR) to minute ventilation (VE) through the exponential regression curve was used to measure pulmonary ventilation. HR was measured by sport-testers during PE lessons. Results of rest and ventilation load values were compared with the values of aerosol weight concentrations, measured continually by a photometer Dust Track and by the Personal Cascade Impactor Sampler.

Results have shown that the average VE multiple during exercising reached 3.8 times in the observed group. The average HR of respondents in the measured exercise unit was 150.6 beats·min-1 and the estimated x̄ VE 24.4 litres·min-1. VE multiple values of individual pupils in an exercise unit correlate significantly (r = 0.78) with average HR values in the time unit. Aerosol concentrations reached in measured PE lessons from PM2.5 22.4 to 24.4 [μg·m-3] and from PM10 60.14 to 101.12 [μg·m-3]. If the tested pupils raised their ventilation to the estimated 3.8 times their resting value, exposure to PM would exceed the sanitary limits set by WHO guidelines for school environments. Out of 112 observed days, in three Prague primary schools, 89% of days in school gyms and 46% of days outdoors were over the limit (under the above stated conditions of VE multiple).

The study results indicate that during increased physical load inhalation exposure exceeds pollutant limit concentrations. We recommend that indoor areas, in which pupils exercise, should be cleaned with more care than places in which pupils stay in rest.