Lessons from in-home air filtration intervention trials to reduce urban ultrafine particle number concentrations. (December 2017)

• Record Type: Journal Article
• Authors: Brugge, Doug; Simon, Matthew C.; Hudda, Neelakshi; Zellmer, Marisa; Corlin, Laura; Cleland, Stephanie; Lu, Eda Yiqi; Rivera, Sonja; Byrne, Megan; Chung, Mei; Durant, John L.
• Is Part Of: Building and environment. Volume 126(2017)
• Page Start: 266
• Page End: 275
• Publication Date: 2017-12
• Subjects: Urban air pollution -- Air filtration -- HEPA -- Ultrafine particles -- Intervention -- Puerto Rican -- Community-based; Buildings -- Environmental engineering -- Periodicals; Building -- Research -- Periodicals; Constructions -- Technique de l'environnement -- Périodiques; Electronic journals; 696
• DOI: 10.1016/j.buildenv.2017.10.007
• Languages: English
• ISSNs: 0360-1323

Abstract

Abstract: Background: Exposure to airborne ultrafine particle (UFP; <100 nm in aerodynamic diameter) is an emerging public health problem. Nevertheless, the benefit of using high efficiency particulate arrestance (HEPA) filtration to reduce UFP concentrations in homes is not yet clear. Methods: We conducted a randomized crossover study of HEPA filtration without a washout period in 23 homes of low-income Puerto Ricans in Boston and Chelsea, MA (USA). Most participants were female, older adults who were overweight or obese. Particle number concentrations (PNC, a proxy for UFP) were measured indoors and outdoors at each home continuously for six weeks. Homes received both HEPA filtration and sham filtration for three weeks each in random order. Results: Median PNC under HEPA filtration was 50–85% lower compared to sham filtration in most homes, but we found no benefit in terms of reduced inflammation; associations between hsCRP, IL-6, or TNFRII in blood samples and associations with indoor PNC were inverse and not statistically significant. Conclusions: Limitations to our study design likely contributed to our findings. Limitations included carry-over effects, a population that may have been relatively unresponsive to UFP, reduction in PNC, even during sham filtration, that limited differences between HEPA and sham filtration, window opening by participants, and lack of fine-grained (room-specific) participant time-activity information. Our approach was similar to other recent HEPA intervention studies of particulate matter exposure and cardiovascular risk, suggesting that there may be a need to improve study designs. Highlights: A randomized intervention study of HEPA filtration in homes was conducted. Ultrafine particle number concentrations were monitored indoors and outdoors. We assessed whether residents had lower blood biomarkers during filtration. Blood biomarkers were not reduced during filtration. Study's limitations include limited contrast between filtration and sham scenarios.