Search Results (5)

The increased concentration of pollutants is a challenge to the health of the population. This work aims to investigate the health risk that is related to the pollutants’ level in the center of Rhodes city. Rhodes Island is a desirable tourist destination with important economic activity over the southeastern Aegean Sea. This analysis covers the (summer) July–August months and the (winter) December month of 2022. Hourly recordings of the concentrations of PM_2.5, NO₂ and O₃ from a mobile air quality monitoring system (AQMS) are analyzed. In order to investigate the effects of pollution level on people’s health, the Air Quality Health Index (AQHI) is calculated. Results show that summer shows an increased health danger compared to winter period, possibly due to increased traffic emissions, tourist density and the different meteorological conditions. In the summer period, the AQHI is classified between the middle and upper-medium health risk class. During the winter month, AQHI is mainly classified in the low-medium health risk class. The summer shows increased health risk despite the AQHI diurnal variability being lower when compared to December. Additionally, the diurnal differences between the two periods show an increased health risk in the summer period for the majority of the hours. Finally, this analysis shows that traffic activities possibly affect the health risk and also highlights that the authorities should adopt green policies to protect human health and the environment. Full article

One of people’s greatest concerns about air quality degradation is its impact on human health. This work is a case study that aims to investigate the air quality and the related impact on people’s health in a coastal city over the eastern Mediterranean. The analysis proceeded during a low-tourist density period, covering the days from 17 to 27 November 2022. Hourly ${\mathrm{PM}}_{2.5}$, ${\mathrm{NO}}_2$ and ${\mathrm{O}}_3$ concentration records from three, mobile, Air Quality Monitoring Systems (AQMS), established in an urban location, port and central area of Rhodes city, are analyzed. To investigate the impact of pollution levels on human health, the Air Quality Health Index (AQHI) is calculated. The daily and diurnal variation of pollutants’ concentration and AQHI among the different areas, as well as the relation among the ambient air pollutants and AQHI, are studied. Additionally, to investigate the impact of wind regime on the variation of pollution and AQHI levels, the hourly zonal and meridional wind-speed components, as well as the temperature at 2 m, the dew point temperature at 2 m, and the height of the boundary layer from ERA5 reanalysis, are retrieved for the region of the southeastern Mediterranean. Results show that the highest pollution level occurs in the city center of Rhodes, compared to the rest of the studied locations. In general, the findings do not show exceedances of the pollutants’ concentration according to the European Directive 2008/50/EC. Moreover, findings show that in some cases, the health risk is classified from Low to Moderate in terms of AQHI. The analysis indicates that the climate conditions affect the pollutants’ concentration due to dispersion, and likely, the atmospheric transport of pollutants. Finally, this work aims to improve the knowledge regarding the air quality of southeastern Greece, promoting the framework for the green and sustainable development of the South Aegean Sea. Full article

In July 2022, strong and high-frequency northern sector winds blew over the Aegean Sea. The low tropospheric circulation in combination with air quality and human comfort is of great importance for the climate and human health. This study investigates the variation in pollutants’ concentrations (PM₁₀, NO₂, O₃ and SO₂), meteorological factors (temperature, relative humidity, wind speed and direction) and the discomfort index in the city of Rhodes during July 2022. Additionally, the impact of Etesians on pollution levels is studied. The strength of the Etesian flow is quantified by calculating a statistical index that takes the July pressure gradient (ΔP) over the Aegean Sea into consideration. For the analysis, pollutants’ concentration recordings from a mobile air-quality-monitoring system during July 2022 and mean sea level pressure (MSLP) data from ERA5 reanalysis during July for the period from 1980 to 2022 are analyzed. The results indicate that traffic affects the pollution level although the pollution limits, according to the European directive for air quality (2008/50/EC), are not exceeded. The findings also reveal an increase in ΔP, about 1.8 hPa, during 2022 compared to the period from 1980 to 2022 and the dipole of high (over Balkans) and low (over eastern Mediterranean) pressure centers also strengthens, leading to stronger winds over the Aegean Sea. The ΔP is strongly correlated (0.8) to the first principal component of MSLP over the eastern Mediterranean. Finally, this study shows that the Etesian flow tends to reduce the concentration of PM₁₀, NO₂ and O₃, and improving the air quality in the city of Rhodes. Full article

Climate and weather conditions have a profound influence on humans’ sense of comfort and discomfort. In addition, the impact of emissions and human activities on air quality seems to be scientifically indisputable. The maintenance of low levels of environmental nuisance in areas of high environmental and cultural interest, such as some Greek islands, is becoming increasingly important. Thus, exploring the combination of the effect of air quality and climate comfort in a high-traffic area falls within the scope of the principles and practices of sustainable development in such areas. The current study aims to shed some light on this field, for the case of Rhodes city, which is located in the eastern Mediterranean, during the summer of 2021. For the analysis, measurements of the concentration of pollutants ($P{M}_{2.5}$, $N{O}_{{\rm X}}$ and $O_3$) and meteorological recordings (wind speed, wind direction and temperature) from a mobile air quality system located in the center of Rhodes city were conducted. Furthermore, meteorological data from the ERA5 reanalysis (wind speed, temperature, relative humidity, precipitation, cloud cover and height of boundary layer) over a geographical domain around Rhodes Island were included in the study. Results show that climate conditions and emissions are closely linked to traffic and tourism activities, which in turn affect the variability of pollutant concentrations. The calculation of the discomfort index shows that during periods of higher levels of air pollution, the population of Rhodes city feels partially comfortable, while the holiday climate index values show that the climatic conditions are suitable for tourist activities. In conclusion, this study could enhance our understanding of climate comfort and air quality by providing some evidence of the benefits of implementing a sustainable development policy in such tourist areas. Full article

This study presents design considerations and an evaluation of a full-scale process chain for methanol and advanced drop-in fuel production derived from lignite/solid recovered fuel (SRF) feedstock. The plant concept consists of a high-temperature Winkler (HTW) gasifier coupled with an air separation unit (ASU), which provides a high-purity (99.55%) gasification oxidant agent. The concept includes the commercially proven acid gas removal (AGR) system based on cold methanol (e.g., Rectisol^® process) for the removal of BTX and naphthalene components. With the involvement of Rectisol^®, an almost pure CO₂ off-gas stream is generated that can be further stored or utilized (CCS/CCU), and a smaller CO₂ stream containing H₂S is recovered and subsequently driven to the sulfur recovery unit (e.g., Claus process). One of the potential uses of methanol is considered, and a methanol upgrading unit is implemented. The overall integrated process model was developed in the commercial software Aspen Plus^TM. Simulations for different feedstock ratios were investigated, ensuring the concept’s adaptability in each case without major changes. A number of parametric studies were performed concerning (a) the oxygen purity and (b) the reformer type, and a comparison against alternative methanol production routes was conducted. Simulations show that the proposed system is able to retain the cold gas efficiency (CGE) in the range of 79–81.1% and the energetic fuel efficiency (EFE) at around 51%. An efficient conversion of approximately 99.5% of the carbon that enters the gasifiers is accomplished, with around 45% of carbon being captured in the form of pure CO₂. Finally, the metrics of EFE and total C for the conversion of methanol to liquid fuels were 40.7% and 32%, respectively, revealing that the proposed pathway is an effective alternative for methanol valorization. Full article