Effectiveness of air purifier on health outcomes and indoor particles in homes of children with allergic diseases in Fresno, California: A pilot study

ABSTRACT

Objective: Epidemiologic studies indicate that indoor air pollution is correlated with morbidity caused by allergic diseases. We evaluated the effectiveness of reducing the levels of indoor fine particulate matter <2.5 micrometer diameter (PM_2.5) in Fresno, California using air purifiers on health outcomes in children with asthma and/or allergic rhinitis. Methods: The active group (with air purifiers) and the control group consisted of eight houses each. Air purifiers were installed in the living rooms and bedrooms of the subjects in the active group during the entire 12-week study duration. Childhood asthma control test, peak flow rate monitoring, and nasal symptom scores were evaluated at weeks 0, 6, and 12. Results: At 12 weeks, the active group showed a trend toward an improvement of childhood asthma control test scores and mean evening peak flow rates, whereas the control group showed deterioration in the same measures. Total and daytime nasal symptoms scores significantly reduced in the active group (p = 0.001 and p = 0.011, respectively). The average indoor PM_2.5 concentrations reduced by 43% (7.42 to 4.28 μg/m³) in the active group (p = 0.001). Conclusions: Intervention with air purifiers reduces indoor PM_2.5 levels with significant improvements in nasal symptoms in children with allergic rhinitis in Fresno.

KEYWORDS:

• Air purifier
• allergic rhinitis
• asthma
• indoor air pollution
• particulate matter

Acknowledgments

The authors would like to thank Vanitha Sampath for assisting with preparation of the manuscript.

Declaration of interest

This study design, data analysis, and interpretation were carried out independently by Stanford University. The authors declare no conflict of interest. The authors alone are responsible for the content and writing of the article.

Funding

This study was supported by Health Home funding from Samsung Electronics, Ltd., Suwon, Korea and the Sean N. Parker Center of Allergy and Asthma Research at Stanford University, Stanford, CA, USA.