Assessing the Impact of Wood Stove Interventions on Air Quality

The investigators will use portable HEPA filters in a single-blind randomized crossover design. Each participant's home will be monitored for two consecutive seven-day periods, during which time two HEPA units (one in the bedroom and one in the main living room) will be operated indoors. During one 7-day period the HEPA filters will be operated normally, and during the other period the HEPA unit will be operated without the internal filter in place (i.e., "placebo filtration"), thus blinding participants to the filters' status. The order of filtration or non-filtration will be random. At the end of each 7-day period microvascular function will be assessed, blood will be collected for assessment of systemic inflammatory markers, and urine will be collected for assessment of oxidative stress markers.