City Of Athens Research Articles

A case-control study of hopelessness and suicidal behavior in the city of Athens, Greece. The role of the financial crisis

This study aimed to examine the psychometric properties of Beck Hopelessness Scale (BHS) in Greek patients with a recent suicide attempt, the predictive ability of BHS especially in terms of age and the possible effect of the financial crisis on hopelessness as it has been identified as a significant suicide risk factor. The study included a total of 510 individuals, citizens of Athens, Greece. Three hundred and forty individuals (170 attempted suicide patients, and 170 -age and gender- matched healthy individuals used as controls) completed BHS before the financial crisis onset (from 2009 to 2010). A sample of 170 healthy individuals also completed the BHS after the financial crisis onset (from 2013 to 2014), when the impact of the austerity measures was being felt by the Greek society. The Greek BHS version demonstrated good psychometric properties and a sufficient degree of internal consistency. Attempted suicide patients (M = 9) presented higher hopelessness than the controls (M = 3). The patients’ age positively correlated with hopelessness (rs = .35, p < .001), and the ROC curve revealed that the BHS ability to discriminate the individuals with pathological rates of hopelessness from those without, strengthened as age increased. No significant differences were found between the individuals evaluated before (M = 3) and after (M = 3, p > .05) the crisis onset. Nevertheless, regarding the latter group, the women, the younger individuals, the less educated, the unemployed and the participants with low or mediocre self-reported financial status presented increased hopelessness. Our findings suggest that BHS could be a useful instrument especially when screening for suicide risk in people of older age, and that the financial crisis in Greece had a greater impact on subgroups of the population regarding hopelessness.

Real-time monitoring of carbon monoxide using value-at-risk measure and control charting

ABSTRACTOne of the most important environmental health issues is air pollution, causing the deterioration of the population's quality of life, principally in cities where the urbanization level seems limitless. Among ambient pollutants, carbon monoxide (CO) is well known for its biological toxicity. Many studies report associations between exposure to CO and excess mortality. In this context, the present work provides an advanced modelling scheme for real-time monitoring of pollution data and especially of carbon monoxide pollution in city level. The real-time monitoring is based on an appropriately adjusted multivariate time series model that is used in finance and gives accurate one-step-ahead forecasts. On the output of the time series, we apply an empirical monitoring scheme that is used for the early detection of abnormal increases of CO levels. The proposed methodology is applied in the city of Athens and as the analysis revealed has a valuable performance.

Operating Within Legislative Restrictions Marketing Funds for Urban Restoration Supporting the Fight Against Aesthetic Pollution

A novel marketing approach operating within legislative restrictions such as the prohibition of outdoor advertising in a city environment is suggested. The case examined is the city of Athens. The purpose of this study is to present a modified model of internalizing external costs caused by the operation of a manufacturing unit in conjunction with a new reality created. The model is shaped by means of marketing practices. The environment is characterized as a public good. Contingent Valuation Method and expert opinions were used to evaluate the effect of aesthetic pollution and estimate the potential of our proposal. The proposal describes an exemplary collaboration between private and public sector that brings multiple benefits without burdening any social group, on the basis of a Pigouvian subsidy scheme for renovation of city building facades, including motive to encourage advertising on the scaffoldings used for the renovation (which is allowed by law). Advertisers will place advertising screens on the scaffold while revenues from advertising will fund the renovation of the facade of the building. The suggested solution combines two seemingly competing activities of the city, outdoor advertising and the aesthetic reconstruction of building facades. Activity is transferred from micro- to macro-economic level, while at the same time Pareto criterion of optimality is met.

A methodology for the evaluation of the human-bioclimatic performance of open spaces

The purpose of this paper is to present a simple methodology to improve the evaluation of the human-biometeorological benefits of open spaces. It is based on two groups of new indices using as basis the well-known PET index. This simple methodology along with the accompanying indices allows a qualitative and quantitative evaluation of the climatic behavior of the selected sites. The proposed methodology was applied in a human-biometeorology research in the city of Athens, Greece. The results of this study are in line with the results of other related studies indicating the considerable influence of the sky view factor (SVF), the existence of the vegetation and the building material on human-biometeorological conditions. The proposed methodology may provide new insights in the decision-making process related to urban open spaces’ best configuration.

Efficient Metaheuristics for the Mixed Team Orienteering Problem with Time Windows

Given a graph whose nodes and edges are associated with a profit, a visiting (or traversing) time and an admittance time window, the Mixed Team Orienteering Problem with Time Windows (MTOPTW) seeks for a specific number of walks spanning a subset of nodes and edges of the graph so as to maximize the overall collected profit. The visit of the included nodes and edges should take place within their respective time window and the overall duration of each walk should be below a certain threshold. In this paper we introduce the MTOPTW, which can be used for modeling a realistic variant of the Tourist Trip Design Problem where the objective is the derivation of near-optimal multiple-day itineraries for tourists visiting a destination which features several points of interest (POIs) and scenic routes. Since the MTOPTW is a NP-hard problem, we propose the first metaheuristic approaches to tackle it. The effectiveness of our algorithms is validated through a number of experiments on POI and scenic route sets compiled from the city of Athens (Greece).

Revisiting Urban Dynamics through Social Urban Data

The study of dynamic spatial and social phenomena in cities has evolved rapidly in the recent years, yielding new insights into urban dynamics. This evolution is strongly related to the emergence of new sources of data for cities (e.g. sensors, mobile phones, online social media etc.), which have potential to capture dimensions of social and geographic systems that are difficult to detect in traditional urban data (e.g. census data). However, as the available sources increase in number, the produced datasets increase in diversity. Besides heterogeneity, emerging social urban data are also characterized by multidimensionality. The latter means that the information they contain may simultaneously address spatial, social, temporal, and topical attributes of people and places. Therefore, integration and geospatial (statistical) analysis of multidimensional data remain a challenge. The question which, then, arises is how to integrate heterogeneous and multidimensional social urban data into the analysis of human activity dynamics in cities? To address the above challenge, this thesis proposes the design of a framework of novel methods and tools for the integration, visualization, and exploratory analysis of large-scale and heterogeneous social urban data to facilitate the understanding of urban dynamics. The research focuses particularly on the spatiotemporal dynamics of human activity in cities, as inferred from different sources of social urban data. The main objective is to provide new means to enable the incorporation of heterogeneous social urban data into city analytics, and to explore the influence of emerging data sources on the understanding of cities and their dynamics. In mitigating the various heterogeneities, a methodology for the transformation of heterogeneous data for cities into multidimensional linked urban data is, therefore, designed. The methodology follows an ontology-based data integration approach and accommodates a variety of semantic (web) and linked data technologies. A use case of data interlinkage is used as a demonstrator of the proposed methodology. The use case employs nine real-world large-scale spatiotemporal data sets from three public transportation organizations, covering the entire public transport network of the city of Athens, Greece. To further encourage the consumption of linked urban data by planners and policy-makers, a set of webbased tools for the visual representation of ontologies and linked data is designed and developed. The tools – comprising the OSMoSys framework – provide graphical user interfaces for the visual representation, browsing, and interactive exploration of both ontologies and linked urban data. After introducing methods and tools for data integration, visual exploration of linked urban data, and derivation of various attributes of people and places from different social urban data, it is examined how they can all be combined into a single platform. To achieve this, a novel web-based system (coined SocialGlass) for the visualization and exploratory analysis of human activity dynamics is designed. The system combines data from various geo-enabled social media (i.e. Twitter, Instagram, Sina Weibo) and LBSNs (i.e. Foursquare), sensor networks (i.e. GPS trackers, Wi-Fi cameras), and conventional socioeconomic urban records, but also has the potential to employ custom datasets from other sources. A real-world case study is used as a demonstrator of the capacities of the proposed web-based system in the study of urban dynamics. The case study explores the potential impact of a city-scale event (i.e. the Amsterdam Light festival 2015) on the activity and movement patterns of different social categories (i.e. residents, non-residents, foreign tourists), as compared to their daily and hourly routines in the periods before and after the event. The aim of the case study is twofold. First, to assess the potential and limitations of the proposed system and, second, to investigate how different sources of social urban data could influence the understanding of urban dynamics. The contribution of this doctoral thesis is the design and development of a framework of novel methods and tools that enables the fusion of heterogeneous multidimensional data for cities. The framework could foster planners, researchers, and policy makers to capitalize on the new possibilities given by emerging social urban data. Having a deep understanding of the spatiotemporal dynamics of cities and, especially of the activity and movement behavior of people, is expected to play a crucial role in addressing the challenges of rapid urbanization. Overall, the framework proposed by this research has potential to open avenues of quantitative explorations of urban dynamics, contributing to the development of a new science of cities.

Expressway Traffic Demand Forecasts in the Volatile Economic Environment of Greece

The forecasting of expressway traffic demand for existing facilities is not particularly challenging for regions and countries with stable or moderately growing economies. In most cases the objective is to carefully establish a reliable estimate for the average annual growth for the next N years using demographic and macroeconomic inputs. Recent applications for freeways and rural highways in Hawaii indicate that the traditional methods using time series or tracking important trends, such as tourism in Hawaii, work well for horizons between 5 and 20 years. Models relying on growth do not adapt well to substantial decreases in traffic demand. A dramatic case is Greece, where a multitude of changes such as increased fuel taxes, reduced GDP, increased unemployment, increased car registration (or car ownership) taxes, and a collapsed new car market caused substantial reductions of traffic on all toll roads in the country, including the Attica Tollway in the capital city of Athens. Given several series of high quality monthly data from January 2005 to December 2012, a number of estimates and forecasts for Attica Tollway toll transactions were estimated. Toll transactions are a measure similar to average daily traffic. ADT represents a traffic load at a specific location whereas toll transactions are the total daily vehicle entries to the facility. Then the 2013 to mid-2015 actual data were used to evaluate the models. Autoregressive models were employed to arrive at toll transaction forecasts between 2013 and 2024. The models used International Monetary Fund (IMF) and Economist Intelligence Unit (EIU) forecasts of the GDP for Greece, as well as scenarios for future fuel prices. The impacts of the much increased fuel prices and of the economic and business downturns to traffic are obvious and the models capture them successfully. However, errors in the GDP forecasts cause errors in the predicted traffic. The stock market index appears to be a useful leading indicator with a two year lag.

Revisiting Urban Dynamics through Social Urban Data

The study of dynamic spatial and social phenomena in cities has evolved rapidly in the recent years, yielding new insights into urban dynamics. This evolution is strongly related to the emergence of new sources of data for cities (e.g. sensors, mobile phones, online social media etc.), which have potential to capture dimensions of social and geographic systems that are difficult to detect in traditional urban data (e.g. census data). However, as the available sources increase in number, the produced datasets increase in diversity. Besides heterogeneity, emerging social urban data are also characterized by multidimensionality. The latter means that the information they contain may simultaneously address spatial, social, temporal, and topical attributes of people and places. Therefore, integration and geospatial (statistical) analysis of multidimensional data remain a challenge. The question which, then, arises is how to integrate heterogeneous and multidimensional social urban data into the analysis of human activity dynamics in cities? To address the above challenge, this thesis proposes the design of a framework of novel methods and tools for the integration, visualization, and exploratory analysis of large-scale and heterogeneous social urban data to facilitate the understanding of urban dynamics. The research focuses particularly on the spatiotemporal dynamics of human activity in cities, as inferred from different sources of social urban data. The main objective is to provide new means to enable the incorporation of heterogeneous social urban data into city analytics, and to explore the influence of emerging data sources on the understanding of cities and their dynamics. In mitigating the various heterogeneities, a methodology for the transformation of heterogeneous data for cities into multidimensional linked urban data is, therefore, designed. The methodology follows an ontology-based data integration approach and accommodates a variety of semantic (web) and linked data technologies. A use case of data interlinkage is used as a demonstrator of the proposed methodology. The use case employs nine real-world large-scale spatiotemporal data sets from three public transportation organizations, covering the entire public transport network of the city of Athens, Greece. To further encourage the consumption of linked urban data by planners and policy-makers, a set of webbased tools for the visual representation of ontologies and linked data is designed and developed. The tools – comprising the OSMoSys framework – provide graphical user interfaces for the visual representation, browsing, and interactive exploration of both ontologies and linked urban data. After introducing methods and tools for data integration, visual exploration of linked urban data, and derivation of various attributes of people and places from different social urban data, it is examined how they can all be combined into a single platform. To achieve this, a novel web-based system (coined SocialGlass) for the visualization and exploratory analysis of human activity dynamics is designed. The system combines data from various geo-enabled social media (i.e. Twitter, Instagram, Sina Weibo) and LBSNs (i.e. Foursquare), sensor networks (i.e. GPS trackers, Wi-Fi cameras), and conventional socioeconomic urban records, but also has the potential to employ custom datasets from other sources. A real-world case study is used as a demonstrator of the capacities of the proposed web-based system in the study of urban dynamics. The case study explores the potential impact of a city-scale event (i.e. the Amsterdam Light festival 2015) on the activity and movement patterns of different social categories (i.e. residents, non-residents, foreign tourists), as compared to their daily and hourly routines in the periods before and after the event. The aim of the case study is twofold. First, to assess the potential and limitations of the proposed system and, second, to investigate how different sources of social urban data could influence the understanding of urban dynamics. The contribution of this doctoral thesis is the design and development of a framework of novel methods and tools that enables the fusion of heterogeneous multidimensional data for cities. The framework could foster planners, researchers, and policy makers to capitalize on the new possibilities given by emerging social urban data. Having a deep understanding of the spatiotemporal dynamics of cities and, especially of the activity and movement behavior of people, is expected to play a crucial role in addressing the challenges of rapid urbanization. Overall, the framework proposed by this research has potential to open avenues of quantitative explorations of urban dynamics, contributing to the development of a new science of cities.

Pedestrian Risk Taking While Road Crossing: A Comparison of Observed and Declared Behaviour

The objective of this research is the comparative analysis of observed and declared behaviour of pedestrians as regards road crossing in urban areas. A field survey was carried out, in which a panel of 75 young and middle-aged pedestrians (out of which 40 males) were asked to take 8 short walking trips (each one corresponding to a different walking and crossing scenario and involving one road crossing) in the Athens city centre in Greece. This allowed to record their crossing behaviour in different road and traffic conditions, including residential roads, main urban roads and major urban arterials. The same individuals were asked to fill in a questionnaire on their crossing behaviour and preferences at different road and traffic environments, as well as other related questions concerning their travel motivations, their mobility characteristics, their risk perceptions and preferences etc. A comparative analysis of their declared and observed crossing behaviour was carried out. More specifically, for each pedestrian, the rate of mid-block crossing and diagonal crossing during the walking tasks was calculated for the different road and traffic conditions. These were compared to their questionnaire responses on their crossing behaviour in different road and traffic conditions. The results suggest that, overall, pedestrians observed behaviour is in accordance with their declared behaviour. However, there is a non-negligible share of pedestrians, whose observed and declared behaviour were discordant, either at specific road and traffic conditions or overall. For instance, there were pedestrians who declared that they never cross at mid-block on major urban road but did so during the survey. Moreover, there were pedestrians who declared high frequency of mid-block crossing, but did not implement these crossing practices during the survey. The degree of discordance between pedestrian observed and declared behaviour was further analysed in relation to pedestrian demographics. A weak tendency was identified for female pedestrians to have more discordance between observed and declared crossing behaviour on residential roads, and the same was the case for young pedestrians in all road and traffic conditions. Overall, the results suggest that, while most pedestrians appear to have consistent declared and observed behaviour, there may all deviate from their general “profile” under specific conditions.

Introducing human factors in pedestrian crossing behaviour models

The objective of this research is the development of pedestrian crossing choice models on the basis of road, traffic and human factors. For that purpose, a field survey was carried out, in which a panel of 75 pedestrians were asked to take 8 short walking trips (each one corresponding to a different walking and crossing scenario) in the Athens city centre in Greece, allowing to record their crossing behaviour in different road and traffic conditions. The same individuals were asked to fill in a questionnaire on their travel motivations, their mobility characteristics, their risk perceptions and preferences with respect to walking and road crossing, their opinion on drivers, etc. The walking and crossing scenarios’ data were used to develop mixed sequential logit models of pedestrian behaviour on the basis of road and traffic characteristics. The modelling results showed that pedestrian crossing choices are significantly affected by road type, traffic flow and traffic control. The questionnaire data were used to estimate human factors (components) of pedestrian crossing behaviour by means of principal component analysis. The results showed that three components of pedestrian crossing behaviour emerge, namely a “risk-taking and optimisation” component reflecting the tendency to cross at mid-block in order to save time, etc., a “conservative” component, concerning individuals with increased perceived risk of mid-block crossing, who also appear to be frequent public transport users, and a “pedestrian for pleasure” component, bringing together frequent pedestrians, walking for health or pleasure, etc. The introduction of these components as explanatory variables into the choice models resulted in improvement of the modelling results, indicating that human factors have additional explanatory power over road and traffic factors of pedestrian behaviour. Therefore, the development of integrated choice and latent variables models appears to be an appropriate field for further research.

The Olympic Games of Athens: 10 years later

This paper presents the Olympic Games of Athens in 2004 and the legacy they have left to the city of Athens and generally to Greece. It relies mainly on research made after the Olympic Games 2004, as well as on a pan-Hellenic survey conducted through questionnaires to a country-wide sample of 600 respondents, men and women, from urban and non-urban regions. The survey focuses mainly on the sports venues, the impact of the Games on the infrastructures and the quality of life in Athens, the impact of the Games on urban interventions, the social legacy and the economic impact.

Occurrence of Aelurostrongylus abstrusus and Troglostrongylus brevior in domestic cats in Greece.

BackgroundDespite the evidence that Mediterranean Europe offers suitable conditions for the biology of felid respiratory metastrongyloids, no updated data on the presence of felid lungworms are available for Greece. Although the cat lungworm Aelurostrongylus abstrusus is considered as enzootic in domestic cats (Felis silvestris catus) living in some areas of continental Greece, conversely, Troglostrongylus brevior, has only been reported in the island of Crete. The present study aimed to evaluate the occurrence of Aelurostrongylus abstrusus and Troglostrongylus brevior in domestic cats from four different Greek locations including islands where European wildcats (Felis silvestris silvestris), believed to be the natural reservoir of T. brevior, are considered absent.MethodsFaeces were collected from 125 stray cats in the city of Athens, and in Crete, Mykonos and Skopelos Islands, and examined by copromicroscopic techniques for the presence of lungworm larvae. When present, larvae were morphologically and molecularly identified.ResultsThe occurrence of A. abstrusus and T. brevior was confirmed in 10 (8 %) and 7 (5.6 %) of the samples, respectively. In particular, T. brevior was detected in domestic cats in the city of Athens, and in Mykonos and Skopelos Islands, where wildcats are not present.ConclusionsThis information illustrates that T. brevior may infect domestic cats regardless of the presence of the natural host. Considering the relevant clinical impact of this nematode especially in young animals, it is advisable to include troglostrongylosis in the differential diagnosis of cat respiratory diseases also where this parasite is unexpected.

Energy flux parametrization as an opportunity to get Urban Heat Island insights: The case of Athens, Greece (Thermopolis 2009 Campaign)

Energy flux parameterization was effected for the city of Athens, Greece, by utilizing two approaches, the Local-Scale Urban Meteorological Parameterization Scheme (LUMPS) and the Bulk Approach (BA). In situ acquired data are used to validate the algorithms of these schemes and derive coefficients applicable to the study area. Model results from these corrected algorithms are compared with literature results for coefficients applicable to other cities and their varying construction materials. Asphalt and concrete surfaces, canyons and anthropogenic heat releases were found to be the key characteristics of the city center that sustain the elevated surface and air temperatures, under hot, sunny and dry weather, during the Mediterranean summer. A relationship between storage heat flux plus anthropogenic energy flux and temperatures (surface and lower atmosphere) is presented, that results in understanding of the interplay between temperatures, anthropogenic energy releases and the city characteristics under the Urban Heat Island conditions.

From Classic to Classy: Changing Fashions in Street Names

Street names in Athens, Georgia, are of two kinds: older, traditional, central, commemorative, directional = “classic,” and newer, innovative, suburban, evocative, given by real-estate developers for their commercial appeal = “classy.” The city of Athens is the site of the University of Georgia, the State Botanical Garden, the Georgia Museum of Art, and notably a double-barreled cannon, which was supposed to fire two chain-linked cannon balls simultaneously, but which succeeded on its trial shot only in demolishing a fence and killing a cow. The city was consolidated with Clarke County, yielding a population of some 120,000.

The workplace as a factor of job satisfaction and productivity

Purpose– The purpose of this study is to examine degree of job satisfaction of the University of Athen’s (UOA) administrative staff, specifically regarding the workplace and its impact on their productivity.Design/methodology/approach– Questionnaires were distributed to 160 administrative personnel of the UOA. The study entails descriptive analysis, independent samplest-tests, ANOVA, Pearson correlations (two-tailed) and regression analysis of the data collected.Findings– The results indicate that the UOA’s administrative staff is dissatisfied with most aspects of their workplace, which is characterized by an inability to encourage and support new forms of office work. This scenario was also found to have a negative effect on productivity. In addition, regression analysis showed that satisfaction with the workplace is a significant predictor of employee productivity.Research limitations/implications– A limitation of this study is that the sample was not from the UOA administrative staff that works in more recently constructed office buildings away from the Athens city center. Further investigation would also be needed to identify possible differences in satisfaction with the workspace and its impact on productivity, based on demographic characteristics, such as the level of education and years of employment.Practical implications– The research results may be useful to public institution administrations like that of the UOA, as it highlights changes in the workplace which can have significant impact on employee job satisfaction and productivity, and consequently, the efficiency and effectiveness of the services provided.Originality/value– This study examines aspects of the workspace of a public organization regarding their individual attributes. Given that the existing Greek literature in this field does not contain a discussion on the impact of the workplace on job satisfaction and productivity as far as the public sector is concerned, this paper may contribute to a smoother and more efficient provision of services from its organizations/institutions.

Socio-spatial stigmatization and its ‘incorporation’ in the centre of Athens, Greece

Considering stigmatization as a process ingrained into power relations, difference and contexts, this paper focuses on how socio-spatial stigmatization is deployed by specific social actors within a broader context of multiple stigmatization of social groups in the city of Athens, Greece. As such, it discusses imposed stigmatization, whereby stigma is attributed to a group and/or a place by external (to the group) actors and further explores what can be termed as ‘incorporated’ stigmatization whereby socio-spatial stigma becomes the central feature around which a group is formed and/or mobilized. Furthermore, in both cases, it explores the consequences of stigmatization, while raising further questions about (de)legitimization.

Governmentalities of Urban Crises in Inner‐city Athens, Greece

AbstractThrough the notion of “conjuncture” this paper explores the interplay of urban crises that have been unfolding in the city of Athens during the past 7 years (2008–2014). By focusing on specific “critical moments” that have significantly influenced the narratives, discourses and subsequent policies concerning “Athens in crisis”, it examines a number of intertwined approaches and tactics that shaped the governmentality of such crisis. These approaches and tactics, that work in tandem, include emergency‐driven policies and politics; politics of fear that occasionally transform into geographies of fear; processes of defining the “public” and “public enemies”; and redefinitions of (il)legalities. Yet, they have repercussions on people, places and politics. In this context, certain issues are deemed critical or urgent while others do not or are even obscured.

Determinants of driver response to variable message sign information in Athens

Variable message signs – which comprise a type of advanced traveller information systems – can affect driver behaviour, especially considering route choice. Hence, their operation is integrated in traffic management strategies for the mitigation of traffic congestion. This research explores the factors determining driver response to variable message signs (VMSs) in the city of Athens. A stated preference questionnaire survey is undertaken and discrete choice analysis is performed towards this aim. More specifically, a random-effect ordered probit model is estimated that provides insight on the contributory factors that influence driver propensity to divert, when provided with information on incident occurrence via VMSs. Message characteristics, that is, incident type, impact and suggestion for an alternative route, trip characteristics, such as vehicle type, as well as, driver characteristics, such as driver age and income, have been found to affect driver behaviour. Furthermore, appropriate models are also estimated for subsets of the driving population (considering gender and age) and specific similarities and differences between the population behaviours are identified.

Mercury in the Urban Topsoil of Athens, Greece

The present study documents the Hg content in 45 urban topsoil samples from the highly urbanized city of Athens, Greece. The Hg concentrations were quantified by applying aqua regia digestion on the &lt;100 μm soil fraction followed by inductively coupled plasma-mass spectrometry (ICP-MS) with a detection limit of 5 μg·kg−1. The median concentration of Hg in Athens soil is 96 μg·kg−1; ten out of 45 soil samples were found to contain Hg concentrations higher than 200 μg·kg−1, which is the maximum concentration value expected to be present in normal uncontaminated soils. Results obtained by multivariate principal component and hierarchical cluster analysis incorporating a large suite of chemical elements were notably effective for elucidating the anthropogenic origin of Hg in the studied soil. The elevated concentrations are most likely related to site-specific point source contamination rather than to the widely documented influences from the vehicular traffic emissions in urban settings. Given the proximity of urban population to the contaminated urban soils, we suggest the implementation of different soil extraction tests with the aim to evaluate the fraction of soil Hg available for absorption by the human body.

Interdecadal variations and trends of the Urban Heat Island in Athens (Greece) and its response to heat waves

The study explores the interdecadal and seasonal variability of the urban heat island (UHI) intensity in the city of Athens. Daily air temperature data from a set of urban and surrounding non urban stations over the period 1970–2004 were used. Nighttime and daytime heat island revealed different characteristics as regards the mean amplitude, seasonal variability and temporal variation and trends. The difference of the annual mean air temperature between urban and rural stations exhibited a progressive statistically significant increase over the studied period, with rates equal to+0.2°C/decade. A gradual and constant increase of the daytime UHI intensity was detected, in contrast to the nighttime UHI intensity which increases only in summer, after the mid 1980s. UHI phenomenon was found to be related to higher increasing rates of hot days frequency at the urban stations. It was found that the interaction between heat waves and heat island in Athens, results to pronounced amplification of nocturnal UHI intensity under exceptionally hot weather.