Long-term exposure to traffic-related air pollution and cardiovascular health in a Greek cohort study Michail Katsoulis a,b , Konstantina Dimakopoulou b , Xanthi Pedeli b , Dimitrios Trichopoulos c,d , Alexandros Gryparis b , Antonia Trichopoulou a,b , Klea Katsouyanni b,e, ⁎ a Hellenic Health Foundation, Athens, Greece b Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, Athens, Greece c Department of Epidemiology, Harvard School of Public Health, Boston MA, USA d Bureau of Epidemiologic Research, Academy of Athens, Greece e Department of Primary Care & Public Health Sciences, Environmental Research Group, King's College London, London, UK HIGHLIGHTS • Use of spatio-temporal LUR models to estimate PM 10 & NO 2 concentrations. • One of the few cohort studies examining the link of PM 10 & NO 2 with CVD incidence. • Traffic related air pollution is linked to increased rates of incidence of CVD. • Need of measures to lower air pollution in urban centers with Mediterranean climate. abstract article info Article history: Received 5 March 2014 Received in revised form 8 May 2014 Accepted 9 May 2014 Available online 6 June 2014 Editor: P. Kassomenos Keywords: Air pollution Longitudinal studies Coronary heart disease Morbidity Cardiovascular incidence Our objective is to evaluate the association of exposure to traffic-related air pollution with the incidence of fatal and non-fatal ischemic heart disease (IHD), stroke and total cardiovascular disease (CVD) events in a Greek cohort. We used data from the European Prospective Investigation on Nutrition and Cancer (EPIC) for 2752 subjects followed from 1997 to 2011, whose residence was in 10 municipalities of the Greater Athens area. Air pollution exposure estimation was based on a spatio-temporal land use regression model linking geo-coded residential addresses to long-term average NO 2 and PM 10 concentrations. We conducted Cox proportional hazards regression analysis, adjusting for potential confounders. Hazard ratios (HR) above 1 (not all statistically significant) were associated with higher PM 10 exposure for all outcomes. Weaker associations were found with NO 2 exposure. Specifically, the estimated HR for a CVD event associated with 10 μg/m 3 increase in long-term exposure to PM 10 was 1.50 (1.05–2.16, p-value: 0.027). The relationship was more evident for subjects ≤50 years old at recruitment. Associations of PM 10 and NO 2 exposure with IHD events were found only among women with HRs respectively of 2.24 (0.89–5.64, p-value: 0.086) and 1.54 (1.01–2.37, p-value: 0.046) associated with 10 μg/m 3 increase in the corresponding pollutant. In conclusion, the present study suggests that long-term exposure to traffic-related air pollution has an impact on CVD and IHD morbidity, particularly among women and younger subjects. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Short and long-term exposure to traffic related air pollution, especial- ly from particulate matter, is a well recognized environmental factor affecting the health of a significant proportion of the population world- wide (Lopez et al., 2006). Long-term exposure appears particularly important for health and especially for cardiovascular diseases (Brook et al., 2010), but appropriate studies are difficult to design and conduct. The Harvard Six Cities Study (Dockery et al., 1993; Laden et al., 2006) and the American Cancer Society (ACS) (Pope et al., 2002; Krewski et al., 2009) first provided compelling evidence that increased all-cause and cardiopulmonary mortality are associated with long-term exposure to fine particles (PM 2.5 ). These were followed by other studies in the US mostly linking exposure to air pollution with mortality (Eftim et al., 2008; Zeger et al., 2008; Ostro et al., 2010) and cardiovascular events (Miller et al., 2007; O'Neill et al., 2011), although studies showing no association have also been reported (Puett et al., 2011). A study from Science of the Total Environment 490 (2014) 934–940 ⁎ Corresponding author at: Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, 75 Mikras Asias Street, 115 27 Athens, Greece. Tel.: +30 210 7462086; fax: +30 210 7462205. E-mail address: kkatsouy@med.uoa.gr (K. Katsouyanni). http://dx.doi.org/10.1016/j.scitotenv.2014.05.058 0048-9697/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv