Search

Outdoor air pollution and especially particulate matter pollution is a major environmental health issue that raises concerns of scientists and policy makers. This study focuses on air quality perception in relation to particulate matter in order to find potential patterns. Field questionnaire-based surveys were conducted among pedestrians on two central sites in the city of Athens, Greece, during the winter period while particulate matter of 10 μm or less in diameter (PM 10 ) were concurrently measured on-site at 1-min resolution. The participants were asked to evaluate the dust and the overall pollution-related air quality based on 5-point bipolar scales. Air quality perception patterns were explored considering PM 10 concentration, meteorological and thermal conditions, and subjective variables including gender, age, smoking status, and health status. An effect of PM 10 on dust perception was identified, suggesting that dusty air quality conditions are reported more frequently when particulate concentration increases. Health status, exposure time, smoking status, and gender were found to affect air quality perception. Participants experiencing health symptoms, exposed to outdoor conditions for more than 30 min, smokers, and females were more likely to report unfavorable air quality conditions. The comparison with the results of a previous study obtained using air pollution station data confirmed the dependence of air quality perception on participants’ characteristics and particularly on their health status. Ordinal logistic regression models showed that for pedestrians who were neither smokers nor experiencing health symptoms and were exposed to outdoor conditions for more than 30 min, a PM 10 concentration around 64 μg·m −3 could be a threshold, to perceive dusty air quality conditions. © 2018, ISB.

Perception plays a significant role on people's response to preventive measures. In the view of public awareness, the aim of this study was to explore factors that affect air quality perception and to reveal its potential patterns. Air quality perception of individuals, in terms of dust and overall air quality, was examined in relation to air pollutants concentrations, meteorological variables, personal characteristics as well as their thermal sensation and health condition. The data used were obtained from environmental measurements, in situ and from stations, and questionnaire surveys conducted in an outdoor urban Mediterranean area, Athens, Greece. The participants were asked to report their air quality perception and thermal sensation based on predefined scales. A thermal index, Physiological Equivalent Temperature (PET), was estimated to obtain an objective measure of thermal sensation. Particulate matter (PM10) and nitrogen oxide (NO) were associated with dust perception. Nitrogen oxides (NOx) and carbon monoxide (CO) were associated to air quality perception. Age, area of residence, health symptoms and thermal sensation also affected the perception of air quality. Dusty or poor air quality conditions were more likely to be reported when pollutants’ concentrations were increased. Younger people, participants residing in the city center, experiencing health symptoms or warm thermal sensation showed a trend towards reporting more unfavorable air quality conditions. © 2016 Elsevier B.V.

A time series of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images (AST08) have been processed to allow radiative heat flux estimations of the Nisyros volcano. ASTER night-time images were acquired on four different dates: 7 April 2001, 13 June 2002, 26 October 2002 and 23 July 2005. The results show a steady state energy release with heat fluxes ranging from 15 to 30 W m-2 over the craters of Kaminakia, Polyvotis and Stefanos, respectively. It is suggested that this range of values indicates a background heat flux of this volcano following the unrest of 1995-1997, and that the volcano has entered again into the quiet phase. Also, on the basis of the average spatial extent of the thermal anomaly a total radiative heat flux of 36 MW was estimated at the moment of ASTER overpass. Heat flux values for Nisyros are in good agreement with other published estimates derived from low-temperature fumarolic volcanoes (Stromboli and Vulcano, Italy) using Landsat TMdata. It is also evidenced that the ASTER radiometer can be used as an important imaging tool for the monitoring of geophysical properties associated to volcanic activity, as is the volcanic heat flux. © 2010 Taylor & Francis.

In this study the potential of satellite remote sensing coupled with Geographical Information Systems (GIS) for the assessment of fire risk in and around the National Park of Vikos-Aoos, a mountainous area in Northern Greece, is examined. In order for this to be accomplished, recent satellite images of varying spatial resolutions (from 5-30 m) have been selected for processing, whereas satellite products as well as in-site information were integrated in a Geographic Information System. Subsequently, a fire risk GIS model was developed taking into account factors favouring the ignition of a forest fire, such as combustion parameters, inflammable material, slope, proximity to the road network, and urban areas and distance from water sources. It was found that despite the relatively small size of the National Park of Vikos-Aoos and its pronounced topography, the integration of satellite remote sensing with GIS techniques, can substantially support in terms of fire prevention management of the Park. © 2005 Inderscience Enterprises Ltd.

In this paper, measurements of benzene, toluene, p, mxylene, ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2) made using the differential optical absorption spectroscopy (DOAS) technique during a 4-month period of summer 2000 (June–September) in Athens, Greece, are presented. An assessment of benzene mean value concentrations during this 4-month period exceeded 10 µg/m3, which is 2 times greater than the average yearly limit proposed by European authorities. Toluene measurements present mean values of approximately 33 µg/m3Benzene and especially toluene measurements are highly correlated with NO2 and anticorrelated with O3High values of benzene, NO2, and toluene are also correlated with winds from the southeast section, an area of industrial activity where emissions of volatile organic compounds (VOCs) have been recorded in previous studies. O3 is correlated with winds from the south-southwest section affected by the sea breeze circulation. Diurnal variations of O3, NO2, and SO2 concentrations are compatible with measurements from the stations of the Ministry of Environment’s network. Outliers are combined with weak winds from the south-southwest. As far as p, m-xylene measurements are concerned, there is a poor correlation between gas chromatography (GC) and DOAS Opsis measurements, also observed in previous relevant campaigns and eventually a criticism in the use of the DOAS Opsis model for the measurement of p, m-xylene. © 2003 Air & Waste Management Association.

The use of renewable energy sources is a fundamental factor for a responsible energy policy in the future. Taking into account the sustainable character of the majority of renewable energy technologies, they are able to preserve resources and to provide security, diversity of energy supply and services, virtually without environmental impact. The present paper deals with the description of several applications of renewable energy sources in the area of the South Aegean Sea islands. The potential of the most important forms of renewable energy such as solar and wind energy, biomass, photovoltaics and geothermal energy, is investigated and analysed for the majority of the South Aegean Sea islands, while alternative scenarios are assessed and discussed. © 2001 Elsevier Science Ltd. All rights reserved.

Three methods for analyzing and modeling the global shortwave radiation reaching the earth's surface are presented in this study. Solar radiation is a very important input for many aspects of climatology, hydrology, atmospheric sciences, and energy applications. The estimation methods consist of an atmospheric deterministic model and two data-driven intelligent methods. The deterministic method is a broadband atmospheric model, developed for predicting the global and diffuse solar radiation incident on the earth's surface. The intelligent data-driven methods are a new neural network approach in which the hourly values of global radiation for several years are calculated and a new fuzzy logic method based on fuzzy sets theory. The two data-driven models, calculating the global solar radiation on a horizontal surface, are based on measured data of several meteorological parameters such as the air temperature, the relative humidity, and the sunshine duration. The three methods are tested and compared using various sets of solar radiation measurements. The comparison of the three methods showed that the proposed intelligent techniques can be successfully used for the estimation of global solar radiation during the warm period of the year, while during the cold period the atmospheric deterministic model gives better estimations. Three methods for analyzing and modeling the global shortwave radiation reaching the earth's surface are presented in this study. Solar radiation is a very important input for many aspects of climatology, hydrology, atmospheric sciences, and energy applications. The estimation methods consists of an atmospheric deterministic model and two data-driven intelligent methods. The deterministic method is a broadband atmospheric model, developed for predicting the global and diffuse solar radiation incident on the earth's surface. The intelligent data-driven methods are a new neural network approach in which the hourly values of global radiation for several years are calculated and a new fuzzy logic method based on fuzzy sets theory. The two data-driven models, calculating the global solar radiation on a horizontal surface, are based on measured data of several meteorological parameters such as the air temperature, the relative humidity, and the sunshine duration. The three methods are tested and compared using various sets of solar radiation measurements. The comparison of the three methods showed that the proposed intelligent techniques can be successfully used for the estimation of global solar radiation during the warm period of the year, while during the cold period the atmospheric deterministic model gives better estimations.

This study investigates the effects of the total solar eclipse of 29 March 2006 on surface air-quality levels over Greece based on observations at a number of sites in conjunction with chemical box modelling and 3-D air-quality modelling. Emphasis is given on surface ozone and other photooxidants at four Greek sites Kastelorizo, Finokalia (Crete), Pallini (Athens) and Thessaloniki, which are located at gradually increasing distances from the path of the eclipse totality and are characterized by different air pollution levels. The eclipse offered the opportunity to test our understanding of air pollution build-up and the response of the gas-phase chemistry of photo-oxidants during a photolytical perturbation using both a photochemical box model and a regional air-quality offline model based on the modeling system WRF/CAMx. At the relatively unpolluted sites of Kastelorizo and Finokalia no clear signal of the solar eclipse on surface O3, NO2 and NO concentrations can be deduced from the observations while there is no correlation of observed O3, NO2 and NO with observed global radiation. The box and regional model simulations for the two relatively unpolluted sites indicate that the calculated changes in net ozone production rates between eclipse and non eclipse conditions are rather small compared to the observed short-term ozone variability. Furthermore the simulated ozone lifetime is in the range of a few days at these sites and hence the solar eclipse effects on ozone can be easily masked by local and regional transport. At the polluted sites of Thessaloniki and Pallini, the solar eclipse effects on O3, NO2 and NO concentrations are revealed from both the measurements and modeling with the net effect being a decrease in O3 and NO and an increase in NO2 as NO2 formed from the reaction of O3 with NO while at the same time NO2 is not efficiently photolysed. This result is also supported by a positive correlation of observed global radiation with O3 and NO and a negative correlation with NO2. It is evident from the 3-D air quality modeling over Greece that the maximum effects of the eclipse on O3, NO2 and NO are reflected on the large urban agglomerations of Athens, and Thessaloniki where the maximum of the emissions occur.