Identification et contribution des sources de COV à Athènes, comparaison avec d'autres zones urbaines du bassin méditerranéén

VOC (Volatile Organic Compounds) are key constituents of atmospheric chemistry and pollution as precursors of harmful compounds like ground ozone and secondary organic aerosols, which in turn have a strong impact on local/regional air quality, climate, vegetation and human health. For that reason and in order to design and implement efficient air pollution control measures, there is a growing interest for their better characterization, as well as the identification, speciation and quantification of their respective sources.Mediterranean basin is a complex environment, favoring the development of severe air pollution events. Despite that, there is a lack of VOC studies in the urban areas of the region, while the existing ones have shown significant uncertainties associated with compounds speciation and the contribution from the different emission sources. Considering this, Athens (Greece) is the ideal place for VOC measurements due to the lack of reported levels for NMHCs the last 15 years, the continuous exceedances of O3 and aerosol concentrations and the increasing emissions from specific pollutant sources (e.g. wood burning for residential heating). In this work, we report the results of an 17-mounth field campaign for NMHCs in Athens (October 2015 – February 2017), under the frame of the international project ChArmEX (The Chemistry – Aerosol Mediterranean Experiment). This was supported by two one-month intensive observation periods (winter and summer) at the same station, and two additional near-source campaigns (tunnel and traffic station). More than 40 VOC with 2 to 16 carbon atoms have been measured giving for the first time a detailed characterization of their temporal and spatial variability on an annual basis, especially for C2 – C3 NMHCs, followed by the determination of its driving parameters. The comparison with other VOC studies in cities worldwide highlighted the role of sources to the observed levels, with significant air pollution for Athens in winter. Furthermore, the analysis indicated that monoterpenes and isoprene, known compounds of biogenic origin, presented a complex variability propably influenced by emissions other than biogenic. The latter provides interesting insights for the assessment of their impact on air quality, as precursors of secondary pollutants. Moreover, the application of the receptor-oriented model Positive Matrix Factorization (PMF) allowed the identification of the main factors related to VOC sources and the quantification of their contribution. Traffic-related emissions and residential heating were determined as the major VOC sources in the city, whereas a second PMF simulation to the intensive observation period gave additional information about sources such as the fuel evaporation from stationary points.Les COV (Composés Organiques Volatils) jouent un rôle majeur dans la problématique de pollution atmosphérique, puisqu’ils interviennent en tant que précurseurs des composés secondaires comme l’ozone troposphérique (O3) et l’Aérosols Organiques Secondaires (AOS) qui ont des impacts sur la santé et le climat. Afin de mettre en place des stratégies efficaces de réduction de la pollution de l’air, il est crucial de caractériser et quantifier la contribution des principales sources d’émission de COV.Le bassin méditerranéen constitue un environnement complexe, favorisant le développement des épisodes de pollution. Cependant, les mesures de COV dans les zones urbaines de la région restent limitées et les études existantes ont montré des incertitudes significatives quant à la contribution des différentes sources d’émission. Dans ce contexte, Athènes (Grèce) est un cas d’étude intéressant notamment pour les COV. Cette zone urbaine fait face à des dépassements des valeurs limites européennes en d’O3 et d’AOS ainsi qu’une augmentation des émissions de polluants pour des sources spécifiques (par exemple, le chauffage résidentiel au bois).Les travaux présentés dans ce manuscrit portent sur l’étude des COV à Athènes, réalisée dans le cadre du projet international ChArMEX (The Chemistry – Aerosol Mediterranean Experiment). La méthodologie s’appuie sur une campagne de mesure de 17 mois (d’octobre 2015 à février 2017) sur un site représentatif proche du centre-ville, sur deux campagnes intensives d’un mois chacune réalisées à la même station ainsi que sur deux campagnes réalisées en champ proche des sources (en tunnel et en station trafic).Plus de 40 COV de 2 à 16 atomes de carbone (C2 à C16) ont été mesurés, permettant la caractérisation détaillée de leur variabilité temporelle et spatiale sur une base annuelle, suivie de la détermination des facteurs d’influence. Les COV de C2 à C3 étaient mesurés pour la première fois à Athènes. La comparaison aux autres études de COV en zones urbaines a mis en évidence la typologie des sources ainsi que l’importance de la pollution atmosphérique en hiver à Athènes. Concernant les monoterpènes et l’isoprène, composés en général d’origine biogénique, l’analyse a mis en évidence des sources anthropiques dans cette atmosphère urbaine, ce qui fournit des informations intéressantes pour l’évaluation de leur impact sur la qualité de l’air en tant que précurseurs des polluants secondaires. L’application du modèle orienté récepteur « Positive Matrix Factorization » (PMF) sur la base de données annuelles, a permis d’identifier et quantifier les contributions des principaux facteurs associés aux sources de COV. Les émissions liées au transport routier et au chauffage résidentiel ont été déterminées comme les sources de COV dominantes. Une seconde analyse PMF sur la base de donnes des campagnes intensives à d’une part corroboré les résultats et, d’autre part, a conduit à l’identification de sources supplémentaires comme l’évaporation de carburants des points stationnaires

Προσδιορισμός πηγών πτητικών οργανικών ενώσεων και αξιολόγηση βάσεων δεδομένων εκπομπών στην ευρύτερη περιοχή των Αθηνών, σύγκριση με άλλες πόλεις της Μεσογείου

VOC (Volatile Organic Compounds) are key constituents of atmospheric chemistry and pollution as precursors of harmful compounds like ground ozone and secondary organic aerosols, which in turn have a strong impact on local/regional air quality, climate, vegetation and human health. For that reason and in order to design and implement efficient air pollution control measures, there is a growing interest for their better characterization, as well as the identification, speciation and quantification of their respective sources. Mediterranean basin is a complex environment, favoring the development of severe air pollution events. Despite that, there is a lack of VOC studies in the urban areas of the region, while the existing ones have shown significant uncertainties associated with compounds speciation and the contribution from the different emission sources. Considering this, Athens (Greece) is the ideal place for VOC measurements due to the lack of reported levels for NMHCs the last 15 years, the continuous exceedance of O3 and aerosol concentrations and the increasing emissions from specific pollutant sources (e.g. wood burning for residential heating). In this work, we report the results of an 17-month field campaign for NMHCs in Athens (October 2015 – February 2017), under the frame of the international project ChArMEX (The Chemistry – Aerosol Mediterranean Experiment). This was supported by two one-month intensive observation periods (winter and summer) at the same station, and two additional near-source campaigns (tunnel and traffic station). More than 40 VOC with 2 to 16 carbon atoms have been measured giving for the first time a detailed characterization of their temporal and spatial variability on an annual basis, especially for C2 – C3 NMHCs, followed by the determination of its driving parameters. The comparison with other VOC studies in cities worldwide highlighted the role of sources to the observed levels, with significant air pollution for Athens in winter. Furthermore, the analysis indicated that monoterpenes and isoprene, known compounds of biogenic origin, presented a complex variability probably influenced by emissions other than biogenic. The latter provides interesting insights for the assessment of their impact on air quality, as precursors of secondary pollutants. Moreover, the application of the receptor-oriented model Positive Matrix Factorization (PMF) allowed the identification of the main factors related to VOC sources and the quantification of their contribution. Traffic-related emissions and residential heating were determined as the major VOC sources in the city, whereas a second PMF simulation to the intensive observation period gave additional information about sources such as the fuel evaporation from stationary points.Παρά τις πρωτοβουλίες για τον περιορισμό και μείωση των ατμοσφαιρικών ρύπων, στη Μεσόγειο και τις πόλεις που την περιβάλλουν εξακολουθούν να καταγράφονται υπερβάσεις των προβλεπόμενων οριακών τιμών για την προστασία της υγείας. Παρόλα αυτά, οι μελέτες στα αστικά κέντρα της περιοχής για Πτητικούς Οργανικούς Υδρογονάνθρακες (Volatile Organic Compounds ή VOC), οι οποίοι είναι πρόδρομοι του τροποσφαιρικού όζοντος (Ο3) και των αερολυμάτων, είναι περιορισμένες, ενώ ορισμένες υποδεικνύουν αβεβαιότητες στις παρατηρήσεις που προκύπτουν από συγκρίσεις με βάσεις δεδομένων εκπομπών, σχετιζόμενες με τη συνεισφορά των πηγών εκπομπής και το χημικό τους αποτύπωμα. Συνεπώς, η Αθήνα αποτελεί ιδανική τοποθεσία για μετρήσεις των ενώσεων αυτών, λόγω της μη-καταγραφής των επιπέδων τους τα τελευταία 15 χρόνια (πλην ελάχιστων εξαιρέσεων), της συνεχούς υπέρβασης των ορίων του Ο3 και των αερολυμάτων, καθώς και της αύξησης των εκπομπών από μέχρι πρότινος ασθενείς πηγές ρύπων (π.χ. καύση ξύλου για οικιακή θέρμανση). Στην παρούσα εργασία παρουσιάζονται τα αποτελέσματα μιας 17μηνης καμπάνιας ατμοσφαιρικών μετρήσεων πεδίου για μη-Μεθανικούς Υδρογονάνθρακες (non-Methane Hydrocarbons ή NMHCs) στην Αθήνα (Οκτώβριος 2015 - Φεβρουάριος 2017), στο πλαίσιο του διεθνούς προγράμματος ChArMEX (The Chemistry - Aerosol Mediterranean Experiment). Παράλληλα, εκπονήθηκαν δύο εντατικές περίοδοι εποχικών μετρήσεων (χειμώνα και καλοκαίρι) στον ίδιο σταθμό και επιπλέον, δύο εκστρατείες συλλογής δειγμάτων αέρα σε γνωστές πηγές ρύπανσης (σήραγγα και αστικός σταθμός μετρήσεων).Τα δεδομένα περισσότερων από 40 VOC με 2 έως 16 άτομα άνθρακα, που συλλέχθηκαν κατά τη διάρκεια της καμπάνιας, χρησιμοποιήθηκαν για τη μελέτη της ημερήσιας και εποχιακής διακύμανσης τους σε ετήσια βάση και των παραγόντων που την επηρεάζουν, ενώ τα επίπεδα C2 - C3 NMHCs στην Αθήνα παρουσιάζονται για πρώτη φορά. Η εποχικότητα παρουσιάζει σαφή διακύμανση, με μέγιστο το χειμώνα και ελάχιστο το καλοκαίρι για την πλειονότητα των ενώσεων, ενώ η ημερήσια διακύμανση επηρεάζεται από την ένταση των εκπομπών των πηγών, την ταχύτητα του ανέμου και το ύψος του στρώματος ανάμειξης. Η σύγκριση των αποτελεσμάτων αυτών με παρόμοιες έρευνες σε άλλες πόλεις ανέδειξαν το ρόλο των πηγών στα παρατηρούμενα επίπεδα, όπου για την Αθήνα αυτή η επίδραση είναι πιο έντονη τον χειμώνα. Επιπρόσθετα, τα μονοτερπένια και το ισοπρένιο, γνωστές ενώσεις βιογενούς προέλευσης, παρουσίασαν μία μοναδική μεταβλητότητα επηρεασμένη από ανθρωπογενείς εκπομπές, η οποία δεν λαμβάνεται υπόψη κατά την εκτίμηση της ποιότητας του αέρα. Τέλος, η χρήση του στατιστικού μοντέλου Positive Matrix Factorization (PMF) επέτρεψε τον προσδιορισμό των κύριων πηγών NMHCs στην Αθήνα και την εκτίμηση της συνεισφοράς τους στα επίπεδα των συγκεντρώσεων. Από αυτές, οι εκπομπές από την κίνηση οχημάτων και την οικιακή θέρμανση επικρατούν, ενώ μια δεύτερη PMF προσομοίωση στα δεδομένα της εποχικής εντατικής περιόδου παρατήρησης επιβεβαίωσε τα αποτελέσματα, δίνοντας επίσης πληροφορίες για πρόσθετες πηγές.Les COV (Composés Organiques Volatils) jouent un rôle majeur dans la problématique de pollution atmosphérique, puisqu’ils interviennent en tant que précurseurs des composés secondaires comme l’ozone troposphérique (O3) et l’Aérosols Organiques Secondaires (AOS) qui ont des impacts sur la santé et le climat. Afin de mettre en place des stratégies efficaces de réduction de la pollution de l'air, il est crucial de caractériser et quantifier la contribution des principales sources d’émission de COV. Le basin Méditerranée constitue un environnement complexe, favorisant le développement des épisodes de pollution. Cependant, les mesures de COV dans les zones urbaines de la région restent limitées et les études existantes ont montré des incertitudes significatives quant à la contribution des différentes sources d'émission. Dans ce contexte, Athènes (Grèce) est un cas d’étude intéressant notamment pour les COV. Cette zone urbaine fait face à des dépassements des valeurs limites européennes en d’O3 et d’AOS ainsi qu’à une augmentation des émissions de polluants pour des sources spécifiques (par exemple, le chauffage résidentiel au bois). Les travaux présentés dans ce manuscrit portent sur l’ étude des COV à Athènes, réalisée dans le cadre du projet international ChArMEX (The Chemistry - Aerosol Mediterranean Experiment). La méthodologie s’appuie sur une campagne de mesure de 17 mois (d’octobre 2015 à février 2017) sur un site représentatif proche du centre-ville, sur deux campagnes intensives d’un mois chacune réalisées à la même station ainsi que sur deux campagnes réalisées en champ proche des sources (en tunnel et en station trafic). Plus de 40 COV de 2 à 16 atomes de carbone (C2 à C16) ont été mesurés, permettant la caractérisation détaillée de leur variabilité temporelle et spatiale sur une base annuelle, suivie de la détermination des facteurs d'influence. Les COV de C2 à C3 étaient mesurés pour la première fois à Athènes. La comparaison aux autres études de COV en zones urbaines a mis en évidence la typologie des sources ainsi que l’importance de la pollution atmosphérique en hiver à Athènes. Concernant les monoterpènes et l’isoprène, composés en général d'origine biogénique, l'analyse a mis en évidence des sources anthropiques dans cette atmosphère urbaine, ce qui fournit des informations intéressantes pour l’évaluation de leur impact sur la qualité de l’air en tant que précurseurs des polluants secondaires. L’application du modèle orienté récepteur « Positive Matrix Factorization » (PMF) sur la base de données annuelles, a permis d’identifier et quantifier les contributions des principaux facteurs associés aux sources de COV. Les émissions liées au transport routier et au chauffage résidentiel ont été déterminées comme les sources de COV dominantes. Une seconde analyse PMF sur la base de donnes des campagnes intensives a d’une part corroboré les résultats et, d’autre part, a conduit à l’identification de sources supplémentaires comme l’évaporation de carburants des points stationnaires

Primary Duodenal Melanoma: Challenges in Diagnosis and Management of a Rare Entity

Primary melanoma of the duodenum is an extremely rare, aggressive and life-threatening malignant neoplasm. Published data regarding the effectiveness of current treatment strategies is limited, and our knowledge relies mostly on sporadic case reports. The diagnosis of primary duodenal melanoma is challenging and is based on the patient’s medical history and findings from physical examination and radiological and endoscopic imaging as well as proper and careful pathological examinations of the tumor. Despite the many advances in cancer treatment, the prognosis for patients with this type of melanoma remains extremely poor. Delayed diagnosis at advanced disease stage, the general aggressive behavior of this neoplasm, the technical difficulty in achieving complete surgical resection, along with the rich vascular and lymphatic drainage of the intestinal mucosa, all have a negative impact on patients’ outcome. In the present review, we aimed to collect and summarize the currently available data in the literature regarding the pathogenesis, clinical features, diagnosis, management and long-term outcomes of this rare, malignant tumor, in order to expand knowledge of its biological behavior and investigate optimal therapeutic options for these patients. Additionally, we present our experience of a case involving a 73-year-old female with primary duodenal melanoma, who was successfully treated with complete surgical resection

Emergence of VIM-12 in Enterobacter cloacae ▿

Detection of the blaVIM-12 gene within the originally described Inh12 integron in a clinical isolate of Enterobacter cloacae is reported for the first time worldwide. Integron Inh12 was carried on a conjugative plasmid of approximately 85 kb which also conferred resistance to aztreonam, likely due to AmpC production

Study of Antiphospholipid Antibodies in Patients with Arterial Hypertension

Antiphospholipid syndrome (APS) is a multifactorial, autoantibody-mediated disease. Antiphospholipid antibodies (aPL) directed against negatively charged phospholipids or various combinations of phospholipid-binding proteins seem to be an independent pathogenic factor that plays a critical role in APS. Unfortunately, their role in hypertension is not fully elucidated. The aim of our study was to determine aPL titers in hypertension patients and investigate the association of aPL with renal impairment parameters. Forty-seven patients with arterial hypertension (22 males, 46.8% and 25 females, 53.2%), aged 41⁻85 years old (mean 65.9 ± 10.1 years), and 21 age-sex-matched subjects without severe hypertension as control group (8 males, 13 females, 38.1% vs. 61.9%), mean age 61 ± 11.3 years, were enrolled in this study. Patients with other risk factors like Rheumatoid Arthritis and Systematic Lupus Erythematosus (SLE), both viral and bacterial acute infections, and cancer were excluded from the study. The aPL (anticardiolipin (ACA) and anti-b2GPI antibodies, IgG and IgM) were measured by ELISA (Aesculisa, Aesku Diagnostics, Wendelsheim, Germany) with a cutoff of 15 GPL/MPL for ACA and 15 U/mL for b2GPI. Serum Neutrophil gelatinase-associated lipocalin (sNGAL) was measured by ELISA kits (BioVendor, Brno, Czech Republic). Biochemical analysis such as serum creatinine (Cr), were measured by automated analyzer and finally estimated glomerular filtration rate (e-GFR) was calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). Fifteen patients were positive for ACA IgG (31.9%), two for anti-b2GPI IgM (4.2%), and three for anti-b2GPI IgG (6.3%). Furthermore, three persons from control group were positive in anti-b2GPI IgG (14.27%). The serum level of anti-b2GPI IgG was significantly higher in patients compared to healthy controls (p = 0.013). The level of sNGAL (59.63 ± 41.5 ng/mL vs. 45.5 ± 21.5 ng/mL, p = 0.14) was not higher in hypertensive patients than in the age-sex-matched control group. Additionally, the sNGAL level was found to be directly and positively correlated in patients with positive ACA IgG (r2 = 0,945, p < 0.0001). These results demonstrate that autoimmunity may be one of the pathogenetic factors of hypertension and aPL antibodies might be a potential marker of renal involvement

Variability and sources of non-methane hydrocarbons at a Mediterranean urban atmosphere: The role of biomass burning and traffic emissions

International audienceLevels and sources of non-Methane Hydrocarbons (NMHCs) were investigated at the urban background Thissio station, close to the historical center of Athens (Greece) from March 2016 to February 2017 (12 months), by means of an automated GC-FID. Alkanes dominated over aromatics and alkenes, with hourly mean levels ranging from detection limit up to 60 μg m−3 for i-pentane and 90 μg m−3 for toluene. Higher levels were recorded in the cold period relative to the warmer one. In addition, NMHCs seasonal diurnal cycles were characterized by a bimodal pattern, following the trend of tracers of anthropogenic sources. The Positive Matrix Factorization (PMF) was used for the allocation of NMHC to their sources. Five factors were identified and quantified, with traffic-related sources being the main one contributing up to 60% to total NMHCs, while biomass burning contributes up to 19%. A supplementary PMF assimilation was applied on a seasonal basis further including α-pinene, C6-C16 alkanes and aromatics. This PMF resulted to a seven-factor solution that allowed the examination of two additional sources, in addition to five already identified, highlighting the main contribution of anthropogenic sources (70%) to α-pinene

Non-methane hydrocarbon variability in Athens during wintertime: the role of traffic and heating

International audienceNon-methane hydrocarbons (NMHCs) play an important role in atmospheric chemistry, contributing to ozone and secondary organic aerosol formation. They can also serve as tracers for various emission sources such as traffic, solvents, heating and vegetation. The current work presents, for the first time to our knowledge, time-resolved data of NMHCs, from two to six carbon atoms, for a period of 5 months (mid-October 2015 to mid-February 2016) in the "greater Athens area" (GAA), Greece. The measured NMHC levels are among the highest reported in the literature for the Mediterranean area during winter months, and the majority of the compounds demonstrate a remarkable day-today variability. Their levels increase by up to factor of 4 from autumn (October-November) to winter (December-February). Mi-croscale meteorological conditions, especially wind speed in combination with the planetary boundary layer (PBL) height, seem to contribute significantly to the variability of NMHC levels, with an increase of up to a factor of 10 under low wind speed (< 3 m s −1) conditions; this reflects the impact of local sources rather than long-range transport. All NMHCs demonstrated a pronounced bimodal, diurnal pattern with a morning peak followed by a second peak before midnight. The amplitude of both peaks gradually increased towards winter, in comparison to autumn, by a factor of 3 to 6 and closely followed that of carbon monoxide (CO), which indicates a contribution from sources other than traffic, e.g., domestic heating (fuel or wood burning). By comparing the NMHC diurnal variability with that of black carbon (BC), its fractions associated with wood burning (BC wb) and fossil fuel combustion (BC ff), and with source profiles we conclude that the morning peak is attributed to traffic while the night peak is mainly attributed to heating. With respect to the night peak, the selected tracers and source profiles clearly indicate a contribution from both traffic and domestic heating (fos-sil fuel and wood burning). NMHCs slopes versus BC wb are similar when compared with those versus BC ff (slight difference for ethylene), which indicates that NMHCs are most likely equally produced by wood and oil fossil fuel burning

Yearlong measurements of monoterpenes and isoprene in a Mediterranean city (Athens): Natural vs anthropogenic origin

International audienc

Molecular Epidemiology of Multi-Drug Resistant Pseudomonas aeruginosa Isolates from Hospitalized Patients in Greece

Resistant Pseudomonas aeruginosa isolates are one of the major causes of both hospital-acquired infections (HAIs) and community-acquired infections (CAIs). However, management of P. aeruginosa infections is difficult as the bacterium is inherently resistant to many antibiotics. In this study, a collection of 75 P. aeruginosa clinical isolates from two tertiary hospitals from Athens and Alexnadroupolis in Greece was studied to assess antimicrobial sensitivity and molecular epidemiology. All P. aeruginosa isolates were tested for susceptibility to 11 commonly used antibiotics, and the newly introduced Double Locus Sequence Typing (DLST) scheme was implemented to elucidate the predominant clones. The tested P. aeruginosa isolates presented various resistant phenotypes, with Verona Integron-Mediated Metallo-&beta;-lactamase (VIM-2) mechanisms being the majority, and a new phenotype, FEPR-CAZS, being reported for the first time in Greek isolates. DLST revealed two predominant types, 32-39 and 8-37, and provided evidence for intra-hospital transmission of the 32-39 clone in one of the hospitals. The results indicate that DLST can be a valuable tool when local outbreaks demand immediate tracking investigation with limited time and financial resources

Ubiquity of anthropogenic terpenoids in cities worldwide: Emission ratios, emission quantification and implications for urban atmospheric chemistry

International audienc