Acceptability of air purifiers to reduce traffic-related particulate exposure near a highway

Background and aim: Traffic-related ultrafine particle pollution near highways has been associated with adverse health. Reducing exposure by use of portable air purifiers in homes is one way to try to reduce this risk. However, acceptability of having air purifiers in homes is not well studied. Methods: We collected data via questionnaires (N=43 surveys at the end of the first month of the intervention), interviews (N=19) and HOBO monitors on air purifiers (N=14) from participants in our randomized crossover trial of air purifiers in homes near a major highway. Results: From survey questions, only 17% and 12% were bothered by noise of the air purifier in the living room and bedroom, respectively. Most survey respondents, 75% and 68%, again for living room and bedroom, reported they set the air purifier to medium air flow. In qualitative interviews, Seventy-four percent (74%) reported that they did not move their air purifiers, but 63% changed the fan speed, many to reduce noise or air flow. Only 21% said that they ever turned it off. Space, noise, airflow and energy consumption were the main concerns from interviews, while cleaner air, improved symptoms and white noise were positives. Data on electricity use indicates >95% compliance of use on a consistent setting (majority choose medium) during our intervention. We have had few participants drop out after their first home data collection visit, with 36 completing the entire intervention, 20 still actively in the intervention and only one lost to follow-up. Conclusions: Evidence from surveys, interviews and HOBO monitors suggests that a small minority of participants were bothered by noise, space issues or air movement from the air purifiers and that they are largely accepted and used by residents near a highway, albeit on settings below maximal air flow.