The positive association of PM2.5 with CRP and SAA, two inflammation markers that have been related to arteriosclerosis and other cardiovascular diseases (Johnson et al. 2004; Ridker et al. 2000), is consistent with previous reports of associations between air pollution and traffic exposure with acute-phase inflammation (Peters et al. 2001; Riediker et al. 2004; Rioux et al. 2010). Here, CRP is linked to arteriosclerosis.