Photochemical and particulate pollution characteristics above the greater Athens area after 2004

The purpose of the present thesis is the study of the photochemical and particulate pollution above the Greater Athens area (GAA) which was achieved with the development of an emission inventory for Greece and the GAA and the use of the photochemical model CAMx coupled by the meteorological model MM5.The primary objective of this thesis was to construct a practical methodology for the calculation of emissions for Greece and the GAA, for the period 2006-2010, with the use of local coefficients for the spatial and temporal allocation of emissions. The final database was named F.E.I. - GREGAA (Flexible Emission Inventory for GREece and the GAA). The comparative study of the contribution of different sources to the total emissions for the year 2010 for the GAA showed that the road transport, stationary combustion sources and navigation contribute most to the CO, NOx and PM10 emissions. The meteorological and photochemical simulations performed for a pollution episode revealed that the model managed to reproduce the afternoon peak ozone concentrations recorded by monitoring stations. Concerning PM10, the numerical simulation revealed high concentrations at the city centre and the southeastern suburbs. In conclusion, the development of the new emission inventory system with official and reliable data led the model to simulate satisfactorily the characteristics of pollutants dispersion above the GAA.Αντικείμενο της συγκεκριμένης διδακτορικής διατριβής είναι η διερεύνηση της κατανομής της φωτοχημικής και σωματιδιακής ρύπανσης στην Ευρύτερη Περιοχή των Αθηνών (ΕΠΑ) η οποία πραγματοποιήθηκε με τη λεπτομερή καταγραφή και χωροχρονική αποτύπωση των εκπομπών για την Ελλάδα και την ΕΠΑ σε ωριαία κλίμακα και τη χρήση του συστήματος μοντέλων MM5/CAMx. Πρωταρχικός στόχος ήταν η ανάπτυξη μιας πρακτικής μεθοδολογίας υπολογισμού των εκπομπών για την Ελλάδα και την ΕΠΑ, για την περίοδο 2006 - 2010, με χρήση τοπικών συντελεστών χωρικού και χρονικού καταμερισμού η οποία οδήγησε στη δημιουργία της βάσης δεδομένων εκπομπών F.E.I. – GRΕGAA (Flexible Emission Inventory for GREece and the GAA). Η μελέτη των εκπομπών για την ΕΠΑ για το έτος 2010 ανέδειξε ότι η πλειοψηφία των εκπομπών CO, ΝΟx και των σωματιδίων ΡΜ10 προέρχεται από τις οδικές μεταφορές, τις σταθερές πηγές καύσης και τη ναυτιλία. Η φωτοχημική προσομοίωση ενός θερινού επεισοδίου ρύπανσης για την ΕΠΑ ανέδειξε την ικανότητα του μοντέλου CAMx να αναπαράγει τη μεσημεριανή μέγιστη συγκέντρωση όζοντος που καταγράφηκε από τους σταθμούς μέτρησης τόσο ως προς τη χρονική στιγμή εμφάνισης, τη χρονική διάρκεια όσο και ως προς το μέγεθος στους περισσότερους σταθμούς. Όσον αφορά στα αιωρούμενα σωματίδια ΡΜ10, υψηλές συγκεντρώσεις εμφανίστηκαν στην αστική περιοχή του λεκανοπεδίου. Συμπερασματικά, η δημιουργία του συστήματος απογραφής εκπομπών με νέα, επίσημα και αξιόπιστα δεδομένα βοήθησε στη βελτιωμένη προσομοίωση των χαρακτηριστικών διασποράς των ρύπων στην ΕΠΑ

Optimizing the Knowledge on Residential Heating Characteristics in Greece via Crowd-Sourcing Approach

Households have been pointed out as a significant source of air pollution and climate change. In Europe, the 60% of energy used by households is for space heating. The present work focuses on improving the knowledge on residential heating characteristics in Greece. The full causal chain, from the appliances used to the pollutants emitted, is examined at thelocal scale. A crowdsourcing approach was followed for the collection of the necessary data for performing the emissions calculations. With the use of a Geographic Information System (GIS), dynamic maps were produced for each Greek region, providing the information produced in this study in gridded form. In terms of energy demands, it was found that Greece relies mainly on oil and biomass and secondarily on gas and electricity. The use of biomass burning as a main heating fuel is quite high inthe colder and rural areas, while it is popular as a secondary heating fuel inthe urban areas. The residential heating period in Greece lasts from October to April and it is even shorter in southern Greece. In terms of emissions, CO and PM10 had the highest values since they are related to biomass burning. NOx emissions are mainly emitted by the oil burned in boilers

Investigation into Atmospheric Pollution Impacts on Hospital Admissions in Attica Using Regression Models

Research in the field of air pollution epidemiology is crucial for identifying and enhancing quality of life by taking measures to manage adequately related medical emergencies. The aim of this paper is to investigate how the occurrence of certain respiratory and cardiovascular diseases in the urban population of the Attica region is affected by the existence of air pollution. The study takes into consideration the daily hospital admissions from two hospitals in central and western Attica as well as the air quality status from the neighboring monitoring stations. The Generalized Linear Models with Poisson Distribution were applied because of the distribution followed by the medical data. Preliminary results from the regression analysis revealed the relationship between pollutants’ concentrations and the associated health effects derived from public hospitals in Attica. The effects of the pollution episodes on health are closely related to factors such as the gender and age of patients, as well as the length of their hospital stays

Estimating the Biogenic Non-Methane Hydrocarbon Emissions over Greece

Biogenic emissions affect the urban air quality as they are ozone and secondary organic aerosol (SOA) precursors and should be taken into account when applying photochemical pollution models. The present study presents an estimation of the magnitude of non-methane volatile organic compounds (BNMVOCs) emitted by vegetation over Greece. The methodology is based on computation developed with the aid of a Geographic Information System (GIS) and theoretical equations in order to produce an emission inventory on a 6 × 6 km2 spatial resolution, in a temporal resolution of 1 h covering one year (2016). For this purpose, a variety of input data was used: updated satellite land-use data, land-use specific emission potentials, foliar biomass densities, temperature, and solar radiation data. Hourly, daily, and annual isoprene, monoterpenes, and other volatile organic compounds (OVOCs) were estimated. In the area under study, the annual biogenic emissions were estimated up to 472 kt, consisting of 46.6% isoprene, 28% monoterpenes, and 25.4% OVOCs. Results delineate an annual cycle with increasing values from March to April, while maximum emissions were observed from May to September, followed by a decrease from October to January

Estimating the Biogenic Non-Methane Hydrocarbon Emissions over Greece

Biogenic emissions affect the urban air quality as they are ozone and secondary organic aerosol (SOA) precursors and should be taken into account when applying photochemical pollution models. The present study presents an estimation of the magnitude of non-methane volatile organic compounds (BNMVOCs) emitted by vegetation over Greece. The methodology is based on computation developed with the aid of a Geographic Information System (GIS) and theoretical equations in order to produce an emission inventory on a 6 × 6 km2 spatial resolution, in a temporal resolution of 1 h covering one year (2016). For this purpose, a variety of input data was used: updated satellite land-use data, land-use specific emission potentials, foliar biomass densities, temperature, and solar radiation data. Hourly, daily, and annual isoprene, monoterpenes, and other volatile organic compounds (OVOCs) were estimated. In the area under study, the annual biogenic emissions were estimated up to 472 kt, consisting of 46.6% isoprene, 28% monoterpenes, and 25.4% OVOCs. Results delineate an annual cycle with increasing values from March to April, while maximum emissions were observed from May to September, followed by a decrease from October to January

Field Evaluation of Low-Cost PM Sensors (Purple Air PA-II) Under Variable Urban Air Quality Conditions, in Greece

Recent advances in particle sensor technologies have led to an increased development and utilization of low-cost, compact, particulate matter (PM) monitors. These devices can be deployed in dense monitoring networks, enabling an improved characterization of the spatiotemporal variability in ambient levels and exposure. However, the reliability of their measurements is an important prerequisite, necessitating rigorous performance evaluation and calibration in comparison to reference-grade instrumentation. In this study, field evaluation of Purple Air PA-II devices (low-cost PM sensors) is performed in two urban environments and across three seasons in Greece, in comparison to different types of reference instruments. Measurements were conducted in Athens (the largest city in Greece with nearly four-million inhabitants) for five months spanning over the summer of 2019 and winter/spring of 2020 and in Ioannina, a medium-sized city in northwestern Greece (100,000 inhabitants) during winter/spring 2019–2020. The PM2.5 sensor output correlates strongly with reference measurements (R2 = 0.87 against a beta attenuation monitor and R2 = 0.98 against an optical reference-grade monitor). Deviations in the sensor-reference agreement are identified as mainly related to elevated coarse particle concentrations and high ambient relative humidity. Simple and multiple regression models are tested to compensate for these biases, drastically improving the sensor’s response. Large decreases in sensor error are observed after implementation of models, leading to mean absolute percentage errors of 0.18 and 0.12 for the Athens and Ioannina datasets, respectively. Overall, a quality-controlled and robustly evaluated low-cost network can be an integral component for air quality monitoring in a smart city. Case studies are presented along this line, where a network of PA-II devices is used to monitor the air quality deterioration during a peri-urban forest fire event affecting the area of Athens and during extreme wintertime smog events in Ioannina, related to wood burning for residential heating