Effect of positive ionisation of inspired air on the response of asthmatic children to exercise

To evaluate the effect of positive ionisation of inspired air on bronchial reactivity, 12 asthmatic children were twice challenged by exercise in random order. During one test positively ionised air (5-10 x 105 ions/cm) was breathed. All challenges were matched in terms of basal lung function and exercise tests were matched in terms of ventilation and respiratory heat loss. Exercise induced asthma was significantly aggravated by exposure to positively ionised air, the postexercise fall in FEV1 (δ FEV,) being 247% (SEM and 5.3%) and 35-3% (5%) after the control and ionised air tests respectively (p < 0.04). It is concluded that positive ionisation aggravates the bronchial response to exercise.