Reduced Fine Particulate Matter Air Pollution Exposures Using In-Home Portable Air Cleaners

PURPOSE: Fine particulate matter (PM2.5) air pollution is a leading risk factor for cardiovascular disease. Even low levels common to millions of Americans pose health risks. However, no study has tested protective measures such as in-home portable air cleaners (PACs) among at-risk cardiac patients. We conducted a pilot phase of the Cardiac Rehabilitation Air Filter Trial (CRAFT)-a randomized, double-blind, crossover study of outpatient cardiac rehabilitation patients at Michigan Medicine. METHODS: During a routine visit, patients were provided with 2 PACs to run continuously for 5 d in both the bedroom and the main living space. PACs were randomized as active (with HEPA filter) versus sham. On day 4, subjects wore a personal PM2.5 monitor for 24-hr without activity restrictions. After a 1-wk washout, patients crossed over to the opposite mode. RESULTS: Patients (n = 20; 4 women) were elderly (70.8 ± 9.6 yr) nonsmokers with cardiovascular disease living near the facility (10.7 ± 6.0 mi). Compared with sham, active in-home PAC use significantly lowered personal-level 24-hr PM2.5 exposures by 43.8% (-12.2 μg·m; 95% CI, -24.2 to -0.2). Sensitivity analyses corroborated the reductions in most patients. CONCLUSION: An inexpensive in-home PAC can effectively lower personal PM2.5 exposures in cardiac patients. These benefits occurred even in a region with overall good air quality and if maintained over the long-term could translate into major reductions in cardiovascular events.