Blood pressure, spirometry, and indoor fine particulate matter in homes heated by wood stoves: pre-intervention results from the EldersAIR randomized trial

Abstract

Background/Aim: Household air pollution from burning biomass fuels can lead to high concentrations of indoor fine particulate matter (PM2.5) and is associated with many adverse health outcomes. Household heating using wood stoves is common in rural American Indian (AI) communities; however, research on the associations between PM2.5 and health in such communities is limited. Our aims were to assess PM2.5 concentrations and indicators of cardiopulmonary health in older AI adults who use wood stoves for heating, and to evaluate the feasibility of interventions (i.e., education and air filtration) that lower household levels of PM2.5.Methods: EldersAIR was a three-arm pre-post randomized trial in wood stove households from a Northern Rocky Mountain Reservation (n=68) and a Southwestern United States Reservation (n=76). Here, we present pre-intervention concentrations of indoor PM2.5 measured over 2-day sampling periods and measures of peripheral systolic and diastolic blood pressure (SBP; DBP), forced vital capacity (FVC), and forced expiratory volume (FEV1) in older adults.Results: In preliminary analyses, the mean indoor PM2.5 concentration was 38 µg/m3 (standard deviation [sd]=85, median=10) across all homes; 43% of homes had mean PM2.5 concentrations >= 25 µg/m3. Participants were 69 years of age on average (sd=9) with mean body mass index of 30 kg/m2 (sd=6). Participants had mean SBP of 138 mmHg (sd=20) and mean DBP of 77 mmHg (sd=13); 46% had stage-2 hypertension (SBP>=140 or DBP>=90). Mean percent-predicted FVC for participants was 79% (sd=16) and mean percent-predicted FEV1 was 85% (sd=20); 30% had FEV1/FVC ratio < 0.7 or percent-predicted FEV1 < 75%.Conclusions: We observed elevated PM2.5 concentrations inside rural AI homes that used wood stoves for heating. Participants had high SBP and low percent-predicted FVC and FEV1. Our findings highlight the need for interventions that reduce indoor air pollution in an effort to improve health in AI communities.