From: Air ions and respiratory function outcomes: a comprehensive review
Study author and year | Study objective | Study design | Study population | Sample size | Primary outcomes of interest |
---|---|---|---|---|---|
Infants | |||||
[8] | Measure effects of ion exposure to bronchial asthma subjects and comparison to conventional treatment. | Double-blind | Infant patients aged 2–12 months with bronchial asthma. | 19 (13 with bronchial asthma and 6 without asthma); 19 additional subjects at different hospital with same diagnosis. | Respiratory rate and scored degree of bronchospasm severity. |
Child-adolescent (up to 20) | |||||
[6] | Measure therapeutic effect of negative air ions on exercise-or inhaled histamine-induced asthma. | Double-blind randomized | Asthmatic children aged 10–20 yrs recruited from patient population. | 11 (for exercise challenge); 9 (for histamine challenge) | FEV1 |
[15] | Measure efficacy of negative ion treatment for asthma patients. | Double-blind | Asthmatic male students aged 8.8 to 12.6 years at a special school for asthmatics | 24 | Lung function (whole-body plethysmorgraph and nitrogen washout) |
[16] | Measure respiratory effects of positive ions on asthmatic children under physical exertion; follow-up study from [6]. | Double-blind randomized | Asthmatic children aged 9–15 yrs recruited from patient population. | 12; 7 M and 5 F | Lung function (FEV1 and minute ventilation), oxygen consumption, heart rate, and respiratory heat loss. |
[14] | Measure effects of air ions on concentration of airborne dust mite allergen in air and asthmatics | Double-blind crossover | Asthmatic children aged 3–11 yrs recruited from clinic's patient population who's home environments have elevated dust mite allergen air concentration. | 20 | Peak expiratory flow rate (PEFR) morning and night; self-reported symptom scores; self-medication scores; air concentration of Der p I allergen. |
Overlapping child-adult | |||||
[7] | Measure efficacy of negative ion treatment for asthma patients. | Subject-blind | Asthma patients aged 10–54 yrs; Male=6, Female=1. | 7 | Peak expiratory flow rate (PEFR); self-reported symptoms. |
[17] | Measure efficacy of negative ion treatment for patients suffering from respiratory symptoms | N.S. | Patients male and female aged 7 to 59 years | 27 | Relief from hay fever, bronchial asthma, neurogenic asthma, acute rhinitis, allergic rhinitis, subacute rhinitis, urticaria, neurodermatitis |
[18] | Measure effects of positive and negative ions on hay fever symptoms | N.S. | Patients male and female aged 4 to 59 | 123 | Relief from hay fever and asthma |
[10] | Measure physiological and subject effects of breathing ionized air. | N.S. | 60 subjects, 25 F and 35 M, aged 10–68 yrs. 45 were normal, 15 had arthritis, 1 had pulmonary tuberculosis, 1 had hypertension, 2 with extreme nervousness, 1 with anemia, and 2 with undernutrition. | 60 | Pulse rate, blood pressure, respiration rate, mouth temperature, metabolism (oxygen consumption), arterial and finger blood, subjective sensation, subjective impression |
[19] | Measure therapeutic effects of negative ions on asthmatics | Double-blind | Chronic asthma patients from hospital aged 15–53 yrs | 16 | Severity (scored from mild, moderate, or severe) of wheezing, dyspnea, coughing, and septum, and side effects in nose and throat |
[20] | Measure pulmonary effects of negative and positive ions. | Subject-blind | Patients (7 F & 8 M) aged 16 to 48 yrs with bronchial asthma who were hospitalized for an extended allergy testing. | 15 | Lung function (FEV1), histamine threshold for 25% reduction in FEV1, and subjective scoring (air quality, breathing comfort, temperature). |
Adult | |||||
[21] | Measure physiological effects of negative and positive ions. | Subject-blind | Experiment 1: Six healthy women (age range: 20 to 30 years) chosen at random and Experiment 2: 5 women and 7 men (age range: 19 to 45 years) selected from 125 subjects because they appeared to be most sensitive to ionization | Experiment 1: 6 women Experiment 2: 5 women and 7 men | Experiment 1: skin temperature, rectal temperature, comfort temperature, pulse rate, respiratory rate, mental performance, and subjective feelings of comfort Experiment 2: same as in Experiment 1 except for comfort temperature |
[22] | Measure pulmonary, biochemical, emotional, and physical symptom effects of positive and negative ions on asthma. | Double-blind controlled | Asthmatic patients aged 35–64 (8 female and 1 male). | 9 | Pulmonary (FEV1), pulse and blood pressure, serum theophylline, urinary serotonin metabolite (5HIAA), symptom, response to three questionnaires designed to elicit somatic response and mood changes (Sharav #1 and 2, Adjective check) |
[23] | Measure perception of environment, personal comfort, and physical symptom effects of negative ions on workers in a "sick-building" office setting | Subject-blind | Workers in five rooms of office building | 26 | Linear analogue scores on environment and personal comfort; physical symptom. |
[3] | Measure effects on physiological parameter and subjective state from exposure to positive and negative ions. | Subject-blind | Male medical student paid volunteers aged 18–25 yrs; "morning" group N = 6 and "afternoon" group N = 5 to represent different metabolic states during the day. | 11 | Basal or total metabolism/oxygen consumption (depending on morning or afternoon group), blood pressure, pulse rate, respiratory rate, oral temperature, urine volume, and self-reported subjective state. |
[24] | Measure effects of negative ion on physiological parameters and circadian rhythm at rest and during exercise. | Subject-blind cross-over | Male aged 19–25 yrs experienced in physical training and without respiratory ailments. | 8 | Rectal temperature, heart rate, oxygen uptake (VO2) and minute ventilation (VE), state anxiety per Spielberger (1970), and perception of effort per Borg (1970). |
[25] | Measure effects of weather-related positive ions on pulmonary functions of asthmatics | N.S. | 6 F and 6 M aged 41–69 yrs recruited from advertisement for subjects with weather-related asthmatic condition | 12 | Mean peak flow at four times a day measured by subjects using Mini Wright Peak Flow Meter |
[26] | Measure physiologic effects and subjective impressions after exposure to light positive and negative air ions. | Subject- blind | 17 M and 8 F, aged 22–51 yrs recruited from University research students, lab technicians, and faculty members. Secondary experiments among arthritic patients and infants. | 25 | Physiological observations such as, heart rate, blood pressure, metabolic rate, respiration; subjective sensations |
Unspecified adult populations | |||||
[2] | Measure adverse effect of positive air ions and beneficial effect of negative air ions on respiratory allergies. | Double-blind randomized | "Reversible" condition (e.g., hay fever), "partially-reversible" condition (e.g., asthma), and "Irreversible" condition (e.g., pulmonary emphysema) patients; N = 12, 10, and 4, respectively. | 26 | Six pulmonary functions (VC, total VC1, total VC3, MEFR, MBCR, SBT) |
[27] | Measure effects of positive and negative ions on asthmatic, bronchitis, and hay fever patients | N.S. | Patients with mild to moderate asthma, mild bronchitis, or hay fever | 24 | Lung function (FVC, FEV1, and MMFR) |
[28] | Measure pulmonary effects of negative and positive ions. | Not blinded nor randomized | Subjects with severe emphysema/chronic pulmonary disease and/or fibrosis | 46; 26; 79 | VC, FEV0.5, FEV1, FEV3, MBC, MPFR |
[13] | Measure efficacy of negative ion treatment for asthma patients. | Double-blind crossover | Men and women with asthma; 1/20 subject dropped out. | 20 | Peak expiratory flow rate (PEFR); self-reported symptoms; self medication. |
[9] | Measure whether the body is a collector of air ions and biological effects of air ions. | N.S. | 77 individuals (half had cardiovascular disease. Various experiments conducted | 77 | Body as ion collector experiment: electrical current developed between body and ionizer; biological effects study: clinical symptoms (headache, nasal obstruction, husky voice, sore throat, itchy nose, dizziness, congested throat), maximum breathing capacity, and feeling of exhilaration. |