Peters and coworkers (2004) in Augsburg, Southern Germany, found a significant
association between exposure to traffic and the onset of a MI 1 h later (OR ¼ 2.92; 95%
CI ¼ 2.22–3.83). Because Europe has large numbers of light-duty diesel vehicles, it was
speculated that diesel exhaust significantly contributed to traffic emissions in that study. In an
additional study in Erfurt, Germany, ambient PM was measured continuously during the
winter of 2000–2001 (Ruckerl et al., 2006). Ultrafine and accumulation modePMwere both
significantly related to increased levels of C-reactive protein (CRP) with a 2-day lag in 57
male patients with coronary heart disease. Associations between CRP and EC were weaker,
butECwas strongly associated with increased levels of intercellular adhesion molecule-1, an
indicator of vascular endothelial cell activation. In a study of nine North Carolina State
troopers observed over 4 days, PM2.5 measured inside the patrol cars was associated with