Pulmonary Effects of Ozone -generating Air Purifiers

Air purifiers are marketed to asthmatics and others to improve breathing. However, some air purifiers emit harmful ozone—a key component of smog. This study examines the hypothesis that ozone-generating air purifiers and other household devices that generate ozone may have a negative effect on pulmonary function. According to a recent study by the California Air Resources Board, 10% of California households own an air purifier that may produce ozone. No published studies on the direct pulmonary effects of these air purifiers have been found on Medline. The investigator used an ozone sensor to measure the amount of ozone generated from several types of air purifiers, food purifiers, and assorted ionizing household devices in a home environment. A room air purifier, personal air purifier, and food purifier, respectively, produced concentrations of ozone near the device of approximately 15 times, 9 times, and 3 times higher than a Stage 3 Smog Alert (range of error ±20%). A microspirometer was used to measure pulmonary function before and after exposure to each household device (range of error ±3%). A two-hour exposure to a room air purifier caused a statistically significant drop in an important measure of pulmonary function (FEV1/FVC) among asthmatic subjects, but not among the whole study sample (P<0.05) (n=24). There was a mean decrease’ of 11% in the FEV1/FVC ratio among the asthmatics. A three-hour exposure to a personal air purifier resulted in a statistically significant reduction in pulmonary function among the whole study sample, as well as in the asthmatic subset (P<0.05) (n=10). The mean reduction in FEV1/FVC ratio among the whole study sample was 9.6%, while it was 22.8% among the asthmatics. One asthmatic individual experienced a 29% drop accompanied by a severe asthma attack. A food purifier resulted in a reduction in the FEV1/FVC ratio of 4.2 and 9.6% among the whole study sample and the asthmatic subset, respectively (P<0.05) (n=32). Ozone-generating air purifiers and food purifiers that use ozone may impair pulmonary function.