Issue 2 [June]( Issue on Air Pollution and Atmospheric Processes )Editorial Atmospheric conditions associated with high and low ozone concentrations in the lower troposphere over the Aegean seaKalabokas P.D., Pages:143-151 DOI: https://doi.org/10.30955/gnj.001032Paper Topic: General Issue: Issue 2Get Full Paper AbstractIn this study the vertical ozone profiles during summertime (June to August) of the MOZAIC (Measurement of Ozone and Water Vapor by Airbus in Service Aircraft) Project over the eastern Mediterranean airports of Heraklion and Rhodes in the Aegean Sea, have been analyzed in order to identify the major factors determining the ozone variability in the lower troposphere over this area. In total 42 ozone profiles have been examined, which have been collected during a 10-year period (1996-2006). In addition, the corresponding vertical profiles of temperature, relative humidity, carbon monoxide and wind speed have been also examined in parallel. The vertical summer ozone profiles have been classified into groups of highest and lowest ozone levels in the free troposphere (at the 3000-5000m and 1500-3000m layers) and the corresponding composite weather maps of geopotential heights have been plotted and their examination was focused on the Aegean Sea area. From the data analysis it comes out that for the examined area, in the lower troposphere but also within the boundary layer the role of the synoptic weather conditions and the associated large-scale transport of air masses, especially anticyclonic subsidence, seem to be more important in understanding the ozone variability than the local or regional short-term ozone photochemical production. Model for estimating atmospheric ozone content over Europe for use in solar radiation algorithmsKaravana-Papdimou K. Psiloglou B.E. Lykoudis S. Kambezidis H.D., Pages:152-162 DOI: https://doi.org/10.30955/gnj.001033Paper Topic: General Issue: Issue 2Get Full Paper AbstractPart of the attenuation of the incoming solar radiation by the atmosphere is caused by ozone absorption in the UV and visible portions of the spectrum. Ozone absorption typically accounts for only 2-3 % of the global solar radiation depletion, but it is often 10-20 % of the absorption of the direct component. Thus, broadband solar radiation models require atmospheric ozone content as input in order to correctly calculate the direct component. Van Heuklon in 1979 described the general spatial and temporal characteristics of the ozone column in the atmosphere with an empirical mathematical relationship that can be easily incorporated into solar radiation transmission models (codes). The model requires only the day of the year, the latitude and longitude of the location of interest in order to calculate the total ozone column for that place and time, based upon observed climatological averages. In this study, the validity of van Heuklon’s formula for the atmospheric ozone content estimation is tested against satellite measurements for a number of cities in Europe. A new model based on the van Heuklon formula is fitted, with promising results. Assessment of surface ozone variability in an urban coastal area at the Eastern MediterraneanProias G.T. Larissi I.K. Moustris K.P. Nastos P.T. Paliatsos A.G., Pages:163-168 DOI: https://doi.org/10.30955/gnj.001034Paper Topic: General Issue: Issue 2Get Full Paper AbstractThe surface ozone is a pollutant of major concern due to its impact on receptors, at currently occurring ambient levels in many regions of the world. The aim of this work is to present the results derived from an analysis of hourly surface ozone concentrations, measured at the urban station of Volos, a coastal medium-sized city at the eastern seaboard of Central Greece, during the 8-year period 2001-2008. The regional climate that is characterized by hot and dry summers with intense sunshine plays an important role in the observed exceedances of the air quality ozone limits. The analysis showed that, ozone diurnal patterns depict daytime photochemical ozone built up, during the sunlight hours of the day. It is remarkable that the maximum daily 8-h averages often exceeded the standard value that is assigned by the EU Directive for human health protection, during almost the warm period of the year, mainly at noon and afternoon hours. Effect of the land use change characteristics on the air pollution patterns above the Greater Athens area (GAA) after 2004Fameli K.M. Assimakopoulos V.D. Kotroni V., Pages:169-177 DOI: https://doi.org/10.30955/gnj.001035Paper Topic: General Issue: Issue 2Get Full Paper AbstractThe Attica Peninsula has experienced the rapid expansion of the Athens urban area, prior to the Athens 2004 Olympics. As a result, the distribution of pollutant sources and emission patterns has changed with a subsequent effect on the distribution of photochemical pollutants and aerosols. The purpose of the present work is to perform a comparative study of the land use changes in the rapidly developing Attica Peninsula including the Greater Athens Area (GAA) before and after 2004, the year that the Olympic Games took place, as well as of the effect of these changes on the respective pollutant distribution profiles. The land use data were provided by USGS Global Land Use/Land Cover version 2.0 Database and the updating process was fulfilled with the help of a satellite image. The area was divided into cells using a spatial resolution of 5x5 km2. Results showed that the urban grid has expanded considerably the past fifteen years while a great shift of population has been made to the eastern area of Attica. Also, new towns were created while others expanded and many factories moved out of the center of the city of Athens. Moreover, the forest land has decreased considerably in the Attica Peninsula either by continuous and extended fires or by the residential burst. The Comprehensive Air Quality Model with extensions (CAMx) was used in order to estimate O3 distribution during a recorded pollution episode. Results revealed that land use changes affected slightly the O3 concentrations and the development of a new emission inventory related to the new LULC field is necessary. Investigation of fine particulate pollution in a coastal city with a mobile monitoring platformHoi K.I. Mok K.M. Yuen K.V. Pun M.H., Pages:178-187 DOI: https://doi.org/10.30955/gnj.002538Paper Topic: General Issue: Issue 2Get Full Paper AbstractAbstract Spatial and temporal variation of fine particulate pollution in a complex small coastal city, Macau, was investigated by using a mobile air quality monitoring platform. Real-time street level measurements of aerosol size distribution were carried out three times per day by using an on-board wide-range particle spectrometer along a designed route covering the main area of the city for one week. The measured distributions were then transformed into PM2.5 mass concentrations for assessment based on an empirical relation estimated from a co-located measurement calibration process. Within this week, the averaged PM2.5 mass concentrations of the morning, afternoon, and evening sessions are 51.76 μg m-3, 28.87 μg m-3 and 30.77 μg m-3, respectively. By comparing the spatial statistics of the estimated PM2.5 concentrations with the US 24-hour primary NAAQS as a reference, a significant probability of exceedance (> 86%) was observed in 1/3 of the monitoring sessions, particularly in the morning of high traffic volume. Meanwhile, majority of the hotspots were found in the districts of the Macau peninsula. In addition, by performing analysis of the backward trajectories, daily MODIS images, and comparison of the PM2.5 patterns of the entire route of three selected measuring sessions during weekdays and weekend, it was observed that long range transport of fine particulates may affect Macau in a larger scale. Therefore, regional land source influence could shadow the local one when the ambient conditions are met. The impact of wind on particle mass concentrations in four european urban areasLianou M. Chalbot M-C. Vei I-C. Kotronarou A. Kavouras I.G. Hoek G. Hameri K. Harrison R.M., Pages:188-194 DOI: https://doi.org/10.30955/gnj.001019Paper Topic: General Issue: Issue 2Get Full Paper AbstractThe impacts of wind conditions to fine and coarse particle mass concentrations at four European urban centers, by multivariate regression analysis of particle measurements against categorized wind (direction and speed) conditions were estimated. Statistically significant associations (both positive and negative) were observed for all urban areas. Both fine and coarse particle mass concentrations were decreased for moderate and strong winds (speed > 2.2 m s-1) in Athens and Helsinki. Weak winds had a positive influence on particle mass, accounting for up to 40% of fine particles in Athens. For the three coastal urban areas (Amsterdam, Athens and Helsinki), positive correlations were observed for sectors encompassing ports and areas with intense marine traffic. For Birmingham, the association of both particle fractions with the eastern sector indicated the influence of emissions from central UK and continental Europe. The method described here may be used to screen the orientation of sources near receptor sites. Source-receptor relationships by using dispersion model in a lignite burning area in Western Macedonia, GreeceTriantafyllou A.G. Krestou A. Matthaios V., Pages:195-203 DOI: https://doi.org/10.30955/gnj.001018Paper Topic: General Issue: Issue 2Get Full Paper AbstractQuantifying the contribution of individual sources to air pollution in one area is the first essential step in managing air quality in this region. This is of great interest especially in areas with combined urban and industrial emission sources. The area of Western Macedonia is a very complex in terms of air quality management problem because of large and complex pollution sources operating in the region. The emissions from five lignite power plants (LPP) operating in this region, the corresponding opencast lignite mining, as well as the urban activities in the industrial axis, is a complex problem to quantify the contribution of these sources in a spatial and temporal scale in the region. This paper attempts to quantify the contribution of LPP to the particulate pollution of this region, using PM10 concentrations measurements and simulations. Specifically were used: a) suspended particulate PM10 concentration measurements for a two years period (2009-2010) at various locations in the region and b) simulations of atmospheric dispersion. The results showed that the LPPs contribution to the PM10 concentrations of the regions studied ranged from 27-84% when the background was removed. These results were also confirmed by the corresponding Index of Agreement (IOA) between the mean monthly model calculations and the station measurements after removing the background. The LPPs contribution to the PM10 concentrations was a factor of the distance between the receptor area and the LPP, while the presence of other PM10 sources was found also to contribute at a higher or a lesser extent, depending on the area’s activities (e.g. urban, agricultural etc) and seasonal characteristics. Survey of airborne particulate matter concentration at a marble processing facility - workers’ exposure assessmentDiapouli E. Papamentzelopoulou A. Chaloulakou A., Pages:204-208 DOI: https://doi.org/10.30955/gnj.000953Paper Topic: General Issue: Issue 2Get Full Paper AbstractThe scope of the present work was to examine exposure to airborne particulate matter (PM) at a marble cutting and treatment facility. Measurements were conducted inside all sections of the facility, as well as at selected outdoor locations. PM10 concentrations were monitored continuously, with a 1-min time resolution, by the use of DustTrak (Model 8520, TSI, Inc.). Mean PM10 concentration levels during cutting operations were measured equal to 997 μg m-3, when all machines were in use and 710 μg m-3, when only half of the machines were functioning. Higher levels were measured at the artistic department, where marble is cut and processed manually (mean PM10 concentration equal to 3,860 during a heavy cutting procedure and 1,000 μg m-3during a light duty period). When sampling was conducted next to the workers during the cutting process, mean personal exposure reached up to 63,000 μg m-3. The use of water during cutting operation was found to effectively decrease PM emissions. Significant concentrations were also measured at the different administrative offices. The highest levels (mean concentration equal to 220 μg m-3) were measured at the accounting office which is located at ground level, in close vicinity to the cutting section. Synergies between environmental pressures in the urban climate: combined air quality and noise exposure assessment in Thessaloniki, GreeceVlachokostas Ch. Michailidou A.V. Athanasiadis A. Moussiopoulos N., Pages:209-217 DOI: https://doi.org/10.30955/gnj.000962Paper Topic: General Issue: Issue 2Get Full Paper AbstractThis study offers a combined analysis of personal exposure to noise and air pollution within the metropolitan centre of Thessaloniki, Greece. The area is selected on the grounds that it is considered as one of the most polluted cities in Europe, especially with respect to air pollution. An extensive survey has been designed to provide detailed information on CO and VOC concentrations and noise pollution levels in the main modes of transport and along heavy traffic routes inside the core of the urban area under consideration. Air pollution and noise measurements were performed simultaneously along several commuting routes, during morning and evening rush hours. Personal portable devices were used. The results highlight the magnitude of air and noise urban scale personal exposure, since they depict a considerable environmental burden for the citizens of Thessaloniki, especially for VOCs and noise pollution levels. Furthermore, they provide, for the first time, a combined exposure assessment to these environmental pollutants for Thessaloniki and in this sense they are of importance for local public authorities and decision makers. The material herein points out the importance of micro-environmental monitoring and the necessity of considering environmental pollution in urban areas in a more holistic way. TVOCs emissions from disinfectants, bonding agents and acrylic substances in a controlled dental office Halios C.H. Helmis C.G. Sgouros G. Tzoutzas J. Antoniadou M. Kostopoulos V., Pages:218-226 DOI: https://doi.org/10.30955/gnj.000954Paper Topic: General Issue: Issue 2Get Full Paper AbstractThe aim of this study, which took place in a dental environment located at the centre of Athens, Greece, is to quantify the amount of Total Volatile Compounds (TVOCs), which were emitted from commonly used dental substances in a controlled dental micro-environment (8 surface disinfectants including both sprays and tissues, 8 bonding agents and 4 acrylic substances). TVOCs concentrations were monitored at three distances from the source (right above the source, 50cm and 100 cm distance from the source) for a period of minutes using a ppbRAE monitor. The environmental factors were complementary assessed using a prototype experimental setup consisted of a sonic anemometer and a hygrometer right above the source. Ventilation rates were estimated via CO2 concentrations. High TVOCs concentrations were found to be emitted from three out of the four acrylic substances, with average values as high as 42.000 ppb. Concentrations were substantially reduced away from the source (average values below 500 ppb for all substances). For disinfectants, above the source the concentrations ranged between 30.430 ppb and 10 ppb with an average value of 5.393 ppb. Significant differences were observed between TVOCs emitted from sprays which in general, were substantially higher than TVOCs emitted from wipes (average TVOCs conc. from sprays 8.327 ppb, while the respective value for tissues is 496 ppb). An effort was made to assess the dependence of the measured TVOCs concentrations on environmental factors such as wind speed and ventilation rates. It was found that the influence of environmental factors is not traceable, indicating the importance of emission patterns. Pages1 2 next › last »