Research report (Health Effects Institute)
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Res Rep Health Eff Inst · Dec 2004
Comparative StudyEffects of exposure to ultrafine carbon particles in healthy subjects and subjects with asthma.
Increased levels of particulate air pollution are associated with increased respiratory and cardiovascular mortality and morbidity as well as worsening of asthma. Ultrafine particles (UFP; less than 0.1 microm in aerodynamic diameter) may contribute to the health effects of particulate matter (PM) for a number of reasons. Compared with larger particles on a mass basis, UFP have a higher predicted pulmonary deposition, greater potential to induce pulmonary inflammation, larger surface area, and enhanced oxidant capacity. ⋯ However, the observed subtle changes in leukocyte subsets and adhesion molecule expression are consistent with effects on vascular endothelial function. We also found effects on heart rate variability and on cardiac repolarization in healthy subjects. If confirmed, the finding that very low mass concentrations of particles have cardiovascular effects would have important implications for future PM regulatory strategies.