Effects of short-term exposure to fine and ultrafine particles from indoor sources on arterial stiffness - A randomized sham-controlled exposure study.

OBJECTIVES: Particulate air pollution is linked to adverse cardiovascular effects, including arterial stiffness. The aim of the study was to investigate the effect of short-term exposure to indoor fine and ultrafine particles on augmentation index (AIx), augmentation pressure (AP), and pulse wave velocity (PWV), early signs of vascular damage. METHODS: We analyzed the association of particle emissions from typical indoor sources (candle burning - CB, toasting bread - TB, and frying sausages - FS) with changes in pulse wave analysis indices in 55 healthy adults 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. AIx and AP were measured before, directly, 2, 4 and 24 h after exposure. PWV was measured directly and 24 h after exposure. We performed multiple mixed linear regression analyses of different particle metrics and AIx, AP and PWV. RESULTS: The highest mean PMC was observed during FS reaching a maximum of 210 µg/m3 PM10. The maximal PNC for UFP <100 nm was reached during CB with 2.3 million particles/cm3. PSC was similar across all three exposures (about 3000 µm2/cm³). Strongest associations between different particles metrics and arterial stiffness indices could be observed for UFP from CB and FS and for PMC from TB. The highest mean increase could be observed for the UFP fraction <10 nm, measured during CB, and AIx with an increase of 9.5%-points (95%-CI: 3.1; 15.9). PSC seemed to follow the pattern of PNC. PM10 and PM2.5 from TB led to clear changes in AIx with biggest increases for PM10 of 5.8%-points (95%-CI: 3.2; 8.4) 2 h after exposure and for PM2.5 of 8.1%-points (95%-CI: 2.5; 13.7) directly after exposure. CONCLUSIONS: Our study indicates effects of indoor exposure to fine and ultrafine particles on systemic arterial stiffness indices that depend on the indoor source as well as on particle metric. Differences in size-specific physical characteristics of source-specific particles might account for these differential effects. We did not observe clear and stable associations of indoor particle exposure and PWV.

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 2h exposure. Systolic and diastolic blood pressure were measured before, during, directly, 2, 4 and 24h 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 10µg/m3 PM10 and PM2.5, systolic BP increased at all time points with largest changes 1h after exposure initiation of 1.5mmHg (95%-CI: 1.1; 1.9) and of 2.2mmHg (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.