Effects of HEPA air cleaners on unscheduled asthma visits and asthma symptoms for children exposed to secondhand tobacco smoke.

Abstract

OBJECTIVE:

The goal was to test the effects of high-efficiency, particulate-arresting (HEPA) air cleaners on unscheduled asthma visits and symptoms among children with asthma exposed to secondhand smoke.

METHODS:

We enrolled 225 eligible children who were 6 to 12 years of age, had physician-diagnosed asthma, and were exposed to ≥5 cigarettes per day. We conducted a double-blind, randomized trial. Children were assigned randomly to receive 2 active or inactive HEPA air cleaners.

RESULTS:

Of 225 enrolled children, 110 (49%) were assigned to the intervention group and 115 (51%) to the control group; 215 (95%) completed the trial. During the trial, there were 42 fewer unscheduled asthma visits among children in the intervention group (18.5% [95% confidence interval: 1.25%-82.75%]; P = .043), compared with those in the control group, after adjustment for baseline differences. There was a significant difference in the reductions of levels of particles of >0.3 μm according to group assignment; there was a 25% reduction in particle levels in the intervention group, compared with a 5% reduction in the control group (P = .026). There were no significant differences in parent-reported asthma symptoms, exhaled nitric-oxide levels, air nicotine levels, or cotinine levels according to group assignment.

CONCLUSIONS:

These results hold promise for using HEPA air cleaners as part of a multifaceted strategy to reduce asthma morbidity, but further research is necessary before they can be recommended routinely for the medical management of asthma.

• Authors: Bruce P Lanphear, Richard W Hornung, Jane Khoury, Kimberly Yolton, Michelle Lierl, Amy Kalkbrenner
• Journal: Pediatrics (Pediatrics) Vol. 127 Issue 1 Pg. 93-101 (Jan 2011) ISSN: 1098-4275 [Electronic] United States
• PMID: 21149427 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural)

Chemical References

• Tobacco Smoke Pollution

Topics

• Air Conditioning (instrumentation)
• Asthma (diagnosis, epidemiology, etiology, prevention & control)
• Child
• Child, Preschool
• Double-Blind Method
• Environmental Exposure (adverse effects, prevention & control)
• Female
• Humans
• Male
• Tobacco Smoke Pollution (adverse effects, prevention & control)