Effect of negative ionisation of inspired air on the response of asthmatic children to exercise and inhaled histamine.

Abstract

AssTRAcr To evaluate the effect of negative ionisation of inspired air on bronchial reactivity, 11 asthmatic children were challenged twice by exercise and 10 were challenged twice by histamine inhalation. The children breathed negatively ionised air (4 x 105 -10 X 105 ions/cm3) or control room air in random order in a double-blind fashion. All challenges were matched in terms of basal lung function and the exercise tests were matched in terms of ventilation and respiratory heat loss. Exercise-induced asthma was significantly attenuated by exposure to negatively ionised air, the mean postexercise fall in one-second forced expiratory volume (FEVy) being 29% (SE 5%) of the initial value after the control and 21% (3%) after the ionised air test (p < 0.02). Ten of the 11 subjects developed less exercise-induced asthma while breathing ionised air. Although the median dose of histamine (cumulative breath units) which caused a constant fall in FEV, for each individual was higher with the ionised air challenge than with the control challenge the difference was not significant. Five of the 10 subjects were less sensitive to histamine and the other five more sensitive when breathing ionised air. It is concluded that negative ionisation of inspired air can modulate the bronchial response to exercise but the effect on the response to histamine is much more variable.Asthmatic patients show increased airway responsiveness when exposed to various stimuli, both specific stimuli such as antigen inhalation and nonspecific ones such as histamine inhalation or physical exertion.

Can Ionisers in Bedrooms Help Asthmatics?

“…This is in contrast with a study with a statistically significant but rather small increase in FEY 1 after inhalation of both negative and positive ions in a cabin facing the ion generator [19]. Two similarly designed infant studies on exercise-induced asthma con cluded that positive ions may aggravate [20] and negative ions attenuate [21] the fall in FEVi. Another infant study showed a significant reduction in the absences of infants from kindergarten or school as a result of wheezy bronchi tis or asthma during periods in which active ionisers were used [22].…”

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

“…' 2 The ionic charge of the air has for long been thought to affect various biological systems,34 including the respiratory system, which is highly exposed to air constituents.56 Uncontrolled studies in the past have suggested a beneficial effect of negative ions on lung function in asthmatics but the observed changes were always minor.78 Recently we studied the effect of negative ionisation of inspired air on the response of asthmatic children to exercise and inhaled histamine. 9 We found that negative ionisation significantly attenuated the response to exercise but the effect on histamine responsiveness was more variable. To investigate this further we decided to study the response of asthmatic children to exercise while they were breathing positively ionised air under similarly controlled conditions.…”

The control of allergens of dust mites and domestic pets: a position paper

“…It has been shown that exercise-induced asthma can be attenuated significantly by the exposure of patients to negatively ionized air-mean post-exercise fall in forced expiratory volume in 1 second (FEVi) was significantly less than that of a control group [142]. But double-blind cross-over studies, using active and placebo ionizers in homes, have showed no improvement of asthmatic symptoms during the period of active ionization [143], even though significant reduction in amounts of airborne Der p I during the active period was achieved in one study [82].…”