Residential indoor exposure to fine and ultrafine particulate air pollution in association with blood pressure and subclinical central haemodynamic markers of cardiovascular risk among healthy adults living in Perth, Western Australia

Abstract Despite that large percentages of individual daily time is spent in the home, few studies have examined the relationship between indoor particulate matter (PM) exposure in residential settings with subclinical indicators of cardiovascular risk. This cross-sectional study investigated associations between exposure to fine (PM2.5) and ultrafine (UFP) PM in domestic indoor environments, with central blood pressure (BP) and component BP measures (pulse pressure, augmented pressure [AP], augmentation index [AIx], mean arterial pressure, pulse wave velocity [PWV]) in 40 non-smoking, otherwise healthy adults (58% women) living in Perth, Western Australia. Overall, in adjusted models, an interquartile range (IQR) increase in PM2.5 was associated with a 3.2 mmHg (95% confidence interval [CI]: 0.99, 5.45) higher diastolic BP, and a 1.8 mmHg lower AP (95%CI: − 3.63, − 0.01) and 0.4 m/s PWV (95%CI: − 0.80, − 0.08), respectively. For the UFP fraction, an IQR increase was associated with a 5.2% higher AIx (95%CI: 0.51, 9.97) and a 0.6 m/s lower PWV (95%CI: − 1.00, − 0.11).When stratified by sex, higher UFP concentrations were associated with higher DBP and lower PWV among women. Among men, higher UFP concentrations were associated with lower AP. Exposure to domestic indoor fine and ultrafine PM was associated with preclinical indicators of cardiovascular risk and some of these relationships were affected by sex. These findings contribute important evidence linking low-level residential indoor PM exposure with measurable impacts on cardiovascular physiology and may inform preventative recommendations as part of risk profiles for susceptible individuals.