On the effect of land use change on the meteorological parameters above the greater Athens area

The rapid land use changes that took place in the Greater Athens Area (GAA) the past decades, due to the expansion of the urban grid, have changed the landscape of Attica significantly. Areas that were covered by low vegetation in the past are now replaced by roads (e.g. Attiki Odos) and new towns. On the other hand, accurate and updated data of land use are necessary for simulating the meteorological fields above urban areas, which in turn are given as input to photochemical models in order to study the dispersion of pollutants above urban areas. The purpose of the present work is to study the effects of land use changes on the meteorological parameters, such as wind speed profiles and temperature. For this reason, the meteorological mesoscale model MM5 was applied, using updated land use data. The model ran with the grid nesting method using two grids, the fine one covering the GAA with a spatial resolution of 5 × 5 km2. Results showed that the land use changes affected wind and temperature fields. Wind velocities decreased above areas covered by urban grid that were previously characterised as shrub land, while above the rapidly developing eastern suburbs of Attica an increase in velocities appeared

Development of a road transport emission inventory for Greece and the greater Athens area: Effects of important parameters

Traffic is considered one of the major polluting sectors and as a consequence a significant cause for the measured exceedances of ambient air quality limit values mainly in urban areas. The Greater Athens Area (located in Attica), the most populated area in Greece, faces severe air pollution problems due to the combination of high road traffic emissions, complex topography and local meteorological conditions. Even though several efforts were made to construct traffic emission inventories for Greece and Attica, still there is not a spatially and temporally resolved one, based on data from relevant authorities and organisations. The present work aims to estimate road emissions in Greece and Attica based on the top down approach. The programme COPERT 4 was used to calculate the annual total emissions from the road transport sector for the period 2006–2010 and an emission inventory for Greece and Attica was developed with high spatial (6 × 6 km2 for Greece and 2 × 2 km2 for Attica) and temporal (1-hour) resolutions. The results revealed that about 40% of national CO2, CO, VOC and NMVOC values and 30% of NOx and particles are emitted in Attica. The fuel consumption and the subsequent reduction of annual mileage driven in combination with the import of new engine anti-pollution technologies affected CO2, CO, VOC and NMVOC emissions. The major part of CO (56.53%) and CO2 (66.15%) emissions was due to passenger cars (2010), while heavy duty vehicles (HDVs) were connected with NOx, PM2.5 and PM10emissions with 51.27%, 43.97% and 38.13% respectively (2010). The fleet composition, the penetration of diesel fuelled cars, the increase of urban average speed and the fleet renewal are among the most effective parameters towards the emission reduction strategies

Effect of the land use change characteristics on the air pollution patterns above the greater Athens area (GAA) after 2004

The 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

Assimilation of numerical study of the distribution of ozone above the greater Athens area (GAA)

Air pollution is considered to be a critical environmental problem of large urban areas posing a threat to human health because of elevated concentrations of pollutants such as O3, NOx, VOCs and PM. In the past decades the GAA has experienced rapid expansion of the urban grid. Thus, the current study aims to examine the distribution of ozone above the GAA, with the help of the photochemical model CAMx, and assess the contribution of multiple geographical source areas, boundary and initial conditions to ozone formation. Results showed that the transport of primary and secondary pollutants can affect the air quality of the receptor area. Many pollution episodes reported to ground stations are often due to the development of a local circulation system (sea breeze) that disperses intense pollutant emissions. Moreover, the boundary and initial conditions used in numerical studies play a significant role to the ozone formation

Particulate matter and airborne fungi concentrations in schools in Athens

Indoor Air Quality degradation is of exceptional concern due to the potential adverse effects indoor air pollutants have on human’s health. Students are a susceptible group of people, who spend a lot of their time within classrooms. The purpose of this study is to investigate the concentration levels of particulate matter (PM) and total airborne fungi, in school classrooms. Further objective is to examine possible correlations between PM10, PM2.5, PM1, ultrafine particles (UFPs, diameter<100 nm), and airborne fungi. The measurements were performed using fully automated instrumentation. The results indicate that a lot of PM10 concentrations exceeded the proposed daily limit of 50μg/m3. Also, in some cases the concentration of the total airborne fungi indoors, exceeded their concentration outdoors. There is evidence that certain correlations exist between PM and airborne fungi

Covid-19 disease, women’s predominant non-heparin vaccine-induced thrombotic thrombocytopenia and kounis syndrome: A passepartout cytokine storm interplay

Coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitute one of the deadliest pandemics in modern history demonstrating cardiovascular, gastrointestinal, hematologic, mucocutaneous, respiratory, neurological, renal and testicular manifestations and further complications. COVID-19-induced excessive immune response accompanied with uncontrolled release of cytokines culminating in cytokine storm seem to be the common pathogenetic mechanism of these complications. The aim of this narrative review is to elucidate the relation between anaphylaxis associated with profound hypotension or hypoxemia with pro-inflammatory cytokine release. COVID-19 relation with Kounis syndrome and post-COVID-19 vaccination correlation with heparin-induced thrombocytopenia with thrombosis (HITT), especially serious cerebral venous sinus thrombosis, were also reviewed. Methods: A current literature search in PubMed, Embase and Google databases was performed to reveal the pathophysiology, prevalence, clinical manifestation, correlation and treatment of COVID-19, anaphylaxis with profuse hypotension, Kounis acute coronary syndrome and thrombotic events post vaccination. Results: The same key immunological pathophysiology mechanisms and cells seem to underlie COVID-19 cardiovascular complications and the anaphylaxis-associated Kounis syndrome. The myocardial injury in patients with COVID-19 has been attributed to coronary spasm, plaque rupture and microthrombi formation, hypoxic injury or cytokine storm disposing the same pathophysiology with the three clinical variants of Kounis syndrome. COVID-19-interrelated vaccine excipients as polysorbate, polyethelene glycol (PEG) and trometamol constitute potential allergenic substances. Conclusion: Better acknowledgement of the pathophysiological mechanisms, clinical similarities, multiorgan complications of COVID-19 or other viral infections as dengue and human immunodeficiency viruses along with the action of inflammatory cells inducing the Kounis syndrome could identify better immunological approaches for prevention, treatment of the COVID-19 pandemic as well as post-COVID-19 vaccine adverse reactions

Measurement of the neutron capture cross section of the s-only isotope 204Pb from 1 eV to 440 keV

The neutron capture cross section of 204Pb has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range could be reliably determined from the measurement of a 208Pb sample. Other systematic effects in this measurement could be investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for 204Pb at kT=30 keV of 79(3) mb, in agreement with previous experiments. However our cross section at kT=5 keV is about 35% larger than the values reported so far. The implications of the new cross section for the s-process abundance contributions in the Pb/Bi region are discussed.Comment: 8 pages, 3 figures, article submitted to Phys. Rev.

New measurement of neutron capture resonances of 209Bi

The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19(3)% of the solar bismuth abundance, resulting in an r-process residual of 81(3)%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target.Comment: 10 pages, 5figures, recently published in Phys. Rev.