“…One important biological mechanism contributing to these associations is an air pollution -mediated pro -hypertensive response (Brook, 2007 ). Epidemiological studies demonstrate that present -day levels of PM are capable of elevating arterial blood pressure (BP) within a period of a few days (Linn et al, 1999 ;Brauer et al, 2001 ;Ibald -Mulli et al, 2001, 2004Zanobetti et al, 2004 ;Chuang et al, 2005 ;Santos et al, 2005 ;Harrabi et al, 2006 ;Madsen and Nafstad, 2006 ;Choi et al, 2007 ;Liu et al, 2007 ;McCracken et al, 2007 ;Auchincloss et al, 2008 ;Dvonch et al, 2009 ;Brook et al, 2010 ). Controlled human and animal experiments have corroborated the veracity of this relationship under certain scenarios whereby BP can increase within only hours of exposure (Gong et al, 2003 ;Mills et al, 2005Mills et al, , 2007Mills et al, , 2008Urch et al, 2005 ;Dales et al, 2007 ;Br ä uner et al, 2008 ;Fang et al, 2008 ;Shah et al, 2008 ;Brook et al, 2009 ).…”