Arterial blood pressure responses to short-term exposure to fine and ultrafine particles from indoor sources - A randomized sham-controlled exposure study of healthy volunteers

Objectives: Particulate air pollution is linked to adverse cardiovascular effects. The aim of the study was to investigate the effect of short-term exposure to indoor particles on blood pressure (BP). Methods: We analyzed the association of particle emissions from indoor sources (candle burning, toasting bread, frying sausages) with BP changes in 54 healthy volunteers in a randomized cross-over controlled exposure study. Particle mass concentration (PMC), size-specific particle number concentration (PNC) and lung-deposited particle surface area concentration (PSC) were measured during the 2 h exposure. Systolic and diastolic blood pressure were measured before, during, directly, 2, 4 and 24 h after exposure. We performed multiple mixed linear regression analyses of different particle metrics and BP. Results: BP significantly increased with increasing PMC, PSC and PNC resulting from toasting bread. For example, an increase per 10 mu g/m(3) PM10 and PM2.5, systolic BP increased at all time points with largest changes 1 h after exposure initiation of 1.5 mmHg (95%-CI: 1.1; 1.9) and of 2.2 mmHg (95%-CI: 1.3; 3.1), respectively. Conclusions: Our study suggests an association of short-term exposure to fine and ultrafine particles emitted from toasting bread with increases in BP. Particles emitted from frying sausages and candle burning did not consistently affect BP.