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Thessaloníki, Greece

Paschalidou A.K.,Democritus University of Thrace | Kassomenos P.A.,University of Ioannina | Kelessis A.,Municipality of Thessaloniki
Science of the Total Environment | Year: 2015

Metro-railways are considered to be a sustainable means of public transportation, as they contribute substantially to the reduction of air pollutant emissions through the decrease in the number of cars and heavy vehicles circulating in the road network. However, the works related to their construction may pose an extra burden in air quality status and consequently in public health. In the present study, we studied the possible effects of the metro-railway construction works in Thessaloniki, Greece, on public health through 2 well-established air quality indices, namely the PI and DAQI. The analysis suggested that there were excess high levels of PM10 measured in the close vicinity of the construction-sites during the period studied (2008-2014). These concentrations are likely to have originated from local construction sources rather than transport or continental secondary dust sources and might have an adverse health impact, as according to the PI index, the majority of days in the construction sites were grouped as "low pollution" or "moderate pollution", while a small percentage of days (1.84%) were suggested to be unhealthy for the most vulnerable groups of the population. Similarly, the DAQI index revealed that the vast majority of days were grouped as "poor" air quality, while 5.50% of the days reflected the most oppressive conditions for public health, as they were characterized as "very poor" air quality. Given the need of reaching a compromise between future transportation sustainability and public health during the construction works, the feasibility of appropriate measures in the area should be examined. © 2015 Elsevier B.V.

Siakavaras D.,University of Aegean | Samara C.,Aristotle University of Thessaloniki | Petrakakis M.,Municipality of Thessaloniki | Biskos G.,The Cyprus Institute | Biskos G.,Technical University of Delft
Atmospheric Environment | Year: 2016

Number size distributions of atmospheric aerosol particles were simultaneously measured at a kerbside and an urban background site in the city of Thessaloniki, Greece, from June to October 2009. New particle formation events were observed ca. 27% of the days at the urban kerbside site and 29% of the days at the urban background site. In almost all the cases the events started between 10:00 and 12:00, and continued for several hours. The total number concentration (TNC) of the particles having diameters from 10 to ca. 500 nm during the events increased from 1.4 × 104 to 6.5 × 104 #/cm3 at the urban kerbside site, and from 0.2 × 104 to 2.4 × 104 #/cm3 at the urban background site. At the urban kerbside site, 9% of the days exhibited class I events (i.e., events followed by a clear growth of the newly formed particles), 10% class II (i.e., events during which the concentration of nucleation mode particles were high but their growth was not continuous), 67% were characterised as non-event days, and 14% of the days exhibited no clear particle formation pattern (undefined). At the urban background site, 15% of the days were classified as class I, 5% as class II, 75% of the days showed no nucleation, whereas only 5% of the days were undefined. While the fraction of event days (both class I and class II) at both sites was similar (ca. 20%), the higher fraction of class I events observed at Eptapyrgio can be attributed to the cleaner environment of the urban background site that allows better identification of the particle concentration increase. The nucleation bursts show a similar pattern at both sites, with the newly formed particles reaching a final size of ca. 80-100 nm. A distinct difference between the two stations was that the smallest particles observed during the new-particle formation events had a diameter of ca. 10 nm (i.e., the smallest particles we could observe) at the kerbside site and ca. 20 nm at the urban background site. This is an indication that the new particles observed at the urban background station are formed elsewhere and are transported to the site. Estimated concentrations of H2SO4 using a proxy model, suggest that these are high enough to explain the nucleation events despite that the available aerosol surface was high, especially at the urban kerbside site. © 2016 Elsevier Ltd.

Samoli E.,National and Kapodistrian University of Athens | Rodopoulou S.,National and Kapodistrian University of Athens | Ostro B.,U.S. Environmental Protection Agency | Ostro B.,Center for Research in Environmental Epidemiology | And 11 more authors.
Environmental Health Perspectives | Year: 2013

Background: Few studies have investigated the independent health effects of different size fractions of particulate matter (PM) in multiple locations, especially in Europe. Objectives: We estimated the short-term effects of PM with aerodynamic diameter ≤ ; 10; μm (PM10), ≤ 2.5; μm (PM2.5), and between 2.5 and 10; μm (PM2.5-10) on all-cause, cardiovascular, and respiratory mortality in 10 European Mediterranean metropolitan areas within the MED-PARTICLES project. Methods: We analyzed data from each city using Poisson regression models, and combined city-specific estimates to derive overall effect estimates. We evaluated the sensitivity of our estimates to co-pollutant exposures and city-specific model choice, and investigated effect modification by age, sex, and season. We applied distributed lag and threshold models to investigate temporal patterns of associations. Results: A 10-μg/m3 increase in PM2.5 was associated with a 0.55% (95% CI: 0.27, 0.84%) increase in all-cause mortality (0-1 day cumulative lag), and a 1.91% increase (95% CI: 0.71, 3.12%) in respiratory mortality (0-5 day lag). In general, associations were stronger for cardiovascular and respiratory mortality than all-cause mortality, during warm versus cold months, and among those ≥ 75 versus < 75 years of age. Associations with PM2.5-10 were positive but not statistically significant in most analyses, whereas associations with PM10 seemed to be driven by PM2.5. Conclusions: We found evidence of adverse effects of PM2.5 on mortality outcomes in the European Mediterranean region. Associations with PM2.5-10 were positive but smaller in magnitude. Associations were stronger for respiratory mortality when cumulative exposures were lagged over 0-5 days, and were modified by season and age.

Samara C.,Aristotle University of Thessaloniki | Voutsa D.,Aristotle University of Thessaloniki | Kouras A.,Aristotle University of Thessaloniki | Eleftheriadis K.,National Center for Radiation Research And Technology | And 3 more authors.
Environmental Science and Pollution Research | Year: 2014

Organic carbon (OC) and elemental carbon (EC) concentrations, associated to PM10 and PM2.5 particle fractions, were concurrently determined during the warm and the cold months of the year (July-September 2011 and February-April 2012, respectively) at two urban sites in the city of Thessaloniki, northern Greece, an urban-traffic site (UT) and an urban-background site (UB). Concentrations at the UT site (11.3 ± 5.0 and 8.44 ± 4.08 14 μg m-3 for OC10 and OC2.5 vs. 6.56 ± 2.14 and 5.29 ± 1.54 μg m-3 for EC10 and EC2.5) were among the highest values reported for urban sites in European cities. Significantly lower concentrations were found at the UB site for both carbonaceous species, particularly for EC (6.62 ± 4.59 and 5.72 ± 4.36 μg m-3 for OC10 and OC2.5 vs. 0.93 ± 0.61 and 0.69 ± 0.39 μg m-3 for EC10 and EC2.5). Despite that, a negative UT-UB increment was frequently evidenced for OC2.5 and PM2.5 in the cold months possibly indicative of emissions from residential wood burning at the urban-background site. At both sites, cconcentrations of OC fractions were significantly higher in the cold months; on the contrary, EC fractions at the UT site were prominent in the warm season suggesting some influence from maritime emissions in the nearby harbor area. Secondary organic carbon, being estimated using the EC tracer method and seasonally minimum OC/EC ratios, was found to be an appreciable component of particle mass particularly in the cold season. The calculated secondary contributions to OC ranged between 35 and 59 % in the PM10 fraction, with relatively higher values in the PM2.5 fraction (39-61 %). The source origin of carbonaceous species was investigated by means of air parcel back trajectories, satellite fire maps, and concentration roses. A local origin was mainly concluded for OC and EC with limited possibility for long range transport of biomass (agricultural waste) burning aerosol. © 2013 Springer-Verlag Berlin Heidelberg.

Voutsa D.,Aristotle University of Thessaloniki | Samara C.,Aristotle University of Thessaloniki | Manoli E.,Aristotle University of Thessaloniki | Lazarou D.,Aristotle University of Thessaloniki | Tzoumaka P.,Municipality of Thessaloniki
Environmental Science and Pollution Research | Year: 2014

This study investigates the water-soluble ionic constituents (Na+, K+, NH4 +, Ca2+, Mg2+, Cl-, NO3 -, SO4 2-) associated to PM2.5 particle fraction at two urban sites in the city of Thessaloniki, northern Greece, an urban traffic site (UT) and urban background site (UB). Ionic constituents represent a significant fraction of PM2.5 mass (29.6 at UT and 41.5 % at UB). The contribution of marine aerosol was low (<1.5 %). Secondary inorganic aerosols (SIA) represent a significant fraction of PM2.5 mass contributing to 26.9 ± 12.4 % and 39.2 ± 13.2 % at UT and UB sites, respectively. Nitrate and sulfate are fully neutralized by ammonium under the existing conditions. The ionic constituents were evaluated in relation to their spatial and temporal variation, their gaseous precursors, meteorological conditions, local and long-range transport. © 2013 Springer-Verlag Berlin Heidelberg.

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