Assessing personal exposure to PM using data from an integrated indoor-outdoor experiment in Athens-Greece Assimakopoulos V.D. a, ⁎, Bekiari T. b , Pateraki S. c , Maggos Th. c , P. Stamatis b , Nicolopoulou P. b , Assimakopoulos M.N. d a Institute for Environmental Research and Suitable Development, National Observatory of Athens, 15236 P. Penteli, Greece b Pathology Department, University of Athens, Medical School, Athens, Greece c Environmental Research Laboratory/INT-RP, National Center for Scientific Research “DEMOKRITOS”, 153 10, Aghia Paraskevi Attikis, Athens, Greece d Department of Environmental Physics-Meteorology, Faculty of Physics, University of Athens, University Campus, 15784 Athens, Greece HIGHLIGHTS • The first integrated personal exposure study to PM 1 , PM 2.5 and PM 10 in Athens-Greece in a range of MEs. • PM 2.5 and PM 1 chemical composition is typical of an urban Mediterranean area in all MEs. • Smoking, re-suspension, distance from trafficked streets and lack of proper ven- tilation lead to higher PM levels. • Total personal exposure is lower when spending more than 90% in the residen- tial ME and increases when more MEs are visited. • PM samples chemical analysis showed that people are exposed to higher crustal material concentrations when in public MEs. GRAPHICAL ABSTRACT abstract article info Article history: Received 26 October 2017 Received in revised form 3 April 2018 Accepted 18 April 2018 Available online xxxx Editor: P. Kassomenos An integrated indoor-outdoor 15-day PM sampling campaign in a general area close to the centre of Athens, targeted to examine personal exposure. All microenvironments (MEs) (second and fourth floor flats, cafes, cars, restaurants, underground metro, outdoor etc.) frequented by the residents were included in the study. The instrumentation used was both stationary (low volume samplers) and portable/wearable to be able to mea- sure continuously PM 10 , PM 2.5 , PM 1 and analyze chemically PM 2.5 and PM 1 samples. The study showed that the residences' air quality was determined by the type and intensity of outdoor sources and their vertical distance from the street. Indoor activities such as cooking, cleaning further increased PM levels and formulated the air quality, while particulate accumulation was evident. In general, PM 2.5 concentrations were higher outdoors, 11–43 μg/m 3 , than in the second floor flat as well as on days within different MEs, 13–33 μg/m 3 and 8–35 μg/ m 3 , respectively and finally in the fourth floor 10–18 μg/m 3 . PM 2.5 chemical composition was typical of a Medi- terranean urban area predominantly composed on average of OC/EC (33%), sulfate (13%), ammonium (9%), ni- trate (5%) and crustal material (Cl−, Na + ,K + , Mg 2+ and Ca 2+ ) (5%). On days when other MEs were visited crustal material increased on average to 16%. The PM levels measured with the portable instrumentation at all mEs showed that the persons were exposed to higher PM 10 concentrations in the subway (avg. 218 μg/m 3 ) due to the resuspension of crustal material, while maximum PM 2.5 and PM 1 were experienced in cafes where Keywords: Personal exposure Fine PM sampling Athens Indoor outdoor microenvironment PM chemical speciation Urban area Science of the Total Environment 636 (2018) 1303–1320 ⁎ Corresponding author. E-mail address: vasiliki@noa.gr (V.D. Assimakopoulos). https://doi.org/10.1016/j.scitotenv.2018.04.249 0048-9697/© 2018 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv