Table 4.
Air Cleaner Interventions to Improve Respiratory Health
| Author/Year | Intervention | Location/Participants | Findings |
|---|---|---|---|
| Ward et al. 2017 | Randomized placebo-controlled trial of woodstove change out and air filtration Primary Outcomes: PM2.5 and CO concentration |
Missoula Montana, n=98 households | Homes randomized to the air purifier intervention had a 63% (95% CI 47–75%) reduction in household PM2.5. The air purifier intervention arm was more efficacious and less expensive than a employing a woodstove changeout, which resulted in no significant change in household PM2.5. |
| Butz et al. 2011 | RCT of health coaching and high-efficiency particle air (HEPA) filter vs HEPA filter vs control Primary Outcomes: Change in PM, air nicotine, urine cotinine concentration and symptom-free days |
Baltimore MD, n=125 children with asthma who resided with smokers | Homes randomized to receive an air cleaner observed a 50% reduction in PM2.5, representing a change of ~20ug/m3 for children living in smoking homes. These improvements were observed with only modest adherence (59%) to the intervention itself. No reduction was observed in markers of tobacco exposure; air nicotine levels or cotinine measurements. The intervention still led to an improvement in symptom free days (1.36; P=0.03), though did not result in a significant improvement in nocturnal symptoms or a reduction in acute asthma events |
| Paulin et al. 2014 | RCT of gas stove replacement with electric stoves vs instillation of hood over exisiting stoves vs placement of HEPA and carbon purifiers in the house Primary Outcomes: Indoor NO2 concentrations |
Baltimore MD, n= 100 households | Homes where the air cleaners were placed in the kitchen and bedroom of homes using gas stoves had an immediate decrease in median NO2 concentrations in both the kitchen (27%; P<0.01) and bedroom (22%, P=0.02). However, at 3-month follow-up improvements were only observed in the kitchen (20%; P=0.05). Notably in this study adherence data was missing from the bedroom air purifier, which potentially could account for the lack of long-term benefit |