Stagnant Conditions Research Articles

Concurrent Collection of Ammonia Gas and Aerosol Ammonium in Urban Beijing During National Celebration Days Utilizing an Acid-Coated Honeycomb Denuder in Combination with a Filter System

Since 2013, the Chinese government implemented the Air Pollution Prevention and Control Action Plan. As a result, the atmospheric concentrations of sulfate reduced significantly, whereas the nitrate concentrations remain relatively high due to the excess of ammonia (NH3). To date, there is no official observation network monitoring NH3 concentrations in China. Previous studies have focused on NH3 or ammonium (NH4+) separately. These limitations hinder a complete understanding of their dynamic changes due to the rapid gas-to-particle conversion. In this study, the concentrations of NH3 and NH4+ were measured concurrently in urban Beijing during autumn 2019 utilizing an acid-coated denuder-filter combination with a time resolution from 2 h (PM2.5>35 μg·m-3) to 5 h (PM2.5<35 μg·m-3). The mean concentrations of NH3 and NH4+ during the study were (4.1±2.9)μg·m-3 and (1.7±1.4) μg·m-3, respectively. The temporal patterns of NH3 or NH4+ coincided with that of PM2.5, CO, and NO2 throughout the sampling period. The diurnal distributions of NH3 were bimodal, both on polluted (PM2.5>75 μg·m-3) and non-polluted (PM2.5<75 μg·m-3) days, peaking at 21:30-05:30 and 05:30-08:30, respectively. The NH3 concentrations on polluted days were relatively lower during 17:30-21:30, which may be related to higher wind speeds. In contrast to NH3, NH4+ had an obvious peak during 17:30-21:30 due to the formation of ammonium nitrate. The meteorological conditions favor the gas-to-particle conversion on polluted days, resulting in a lower NH3/NH4+ ratio of 0.8. However, this value may reach 2.8 on non-polluted days. The concentrations of NH3, CO, NO2, SO2, and PM2.5 in the emission control period showed a significant increase greater than or comparable to those in the non-control period by 54.2%, 40.4%, 33.3%, 0%, and 49.4%, respectively. This result shows that the stagnant conditions offset the benefit of emission control actions implemented during and before the National Celebration Day.

Impact of data assimilation and aerosol radiation interaction on Lagrangian particle dispersion modelling

Lagrangian particle dispersion models (LPDMs) have been widely used in air pollution studies. However, substantial uncertainties still exist in LPDM simulations due to biased meteorological data, especially under stagnant and highly-polluted conditions. In this work, to better investigate the source contribution and formation of winter haze pollution in eastern China, we conduct a sensitivity study of WRF-FLEXPART by using different reanalysis data, applying observational meteorological nudging, and considering aerosols' radiative feedback on meteorology. We find that simulations driven by reanalysis datasets generally underestimate pollutant concentration, especially during periods with heavy haze pollution. The underestimation is directly caused by overestimated planetary boundary layer (PBL) height and lower PBL horizontal wind speeds. By assimilating meteorological data from surface and radiosonde observation, the WRF model can well represent the PBL dynamics and wind fields, especially those near the ground surface, which then substantially improves particle tracing in the LPDM. In addition, by including aerosols' radiative feedback in the WRF-Chem model, which significantly influences PBL evolution, the biases between LPDM modelling and observations are notably narrowed, particularly when the haze pollution is severe. Quantitatively, the accuracy increase of the simulations with aerosols’ radiative effect accounted for 48% of the improvement produced by assimilating meteorological data. Overall, meteorological input is of great importance in LPDM modelling. In regions with intensive pollution like China and India, applying observational data assimilation or considering the feedbacks of aerosols to meteorology serve as an effective way to reduce the biases of LPDMs and better understand the source contributions as well as the formation and accumulation of pollution.

Study of Temporal Variations of Equivalent Black Carbon in a Coastal City in Northwest Spain Using an Atmospheric Aerosol Data Management Software

Light-absorbing carbonaceous aerosols (including black carbon (BC)) pose serious health issues and play significant roles in atmospheric radiative properties. Two-year measurements (2015–2016) of aerosol light absorption, combined with measurements of sub-micrometric particles, were continuously conducted in A Coruña (northwest (NW) Spain) to determine their light absorption properties: absorption coefficients (σabs) and the absorption Ångström exponent (AAE). The mean and standard deviation of equivalent black carbon (eBC) during the period of study were 0.85 ± 0.83 µg m−3, which are lower than other values measured in urban areas of Spain and Europe. High eBC concentrations found in winter are associated with an increase in emissions from anthropogenic sources in combination with lower mixing layer heights and frequent stagnant conditions. The pronounced diurnal variability suggests a strong influence from local sources. AAE had an average value of 1.26 ± 0.22 which implies that both fossil fuel combustion and biomass burning influenced optical aerosol properties. This also highlights biomass combustion in suburban areas, where the use of wood for domestic heating is encouraged, as an important source of eBC. All data treatment was gathered using SCALA© as atmospheric aerosol data management support software program.

A New Ray-Tracing-Assisted Calibration Method of a Fiber-Optic Thickness Probe for Measuring Liquid Film Flows

A ray-tracing-assisted (RTA) method for calibrating a fiber-optic thickness probe (FOTP) that enables the measurement of thickness in micrometers in wavy liquid-film flow is described herein. This technique calibrates the device more quickly than other liquid-film measurements and more efficiently than conventional fiber-optic methods. First, the emission natures of the multimode optical fiber were investigated through ray tracing. The step-index multimode fiber was observed to be superior to the graded-index multimode fiber regarding the thickness resolution and the uncertainty avoidance of the liquid-film shape. Second, the RTA calibration method for pseudo-thickness measurement under stagnant conditions was validated. The measured thickness of the calibrated FOTP was compared to that of visualization. Agreement between the two resulted in a maximum difference of 10% for over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$200~\mu \text{m}$ </tex-math></inline-formula> and 20% for under <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$200~\mu \text{m}$ </tex-math></inline-formula> . Finally, the numerical verification of this method in virtual liquid-film flow was demonstrated. The applicable thickness range and measurement uncertainty of the FOTP, which are unattainable by experiments alone, are discussed.

Rheo-NMR to investigate fat crystallization under shear

It is well known that shear has an effect on fat crystallization. Whereas rheo-NMR has been used to study the impact of shear on the crystallization kinetics in the past, these methods mostly used a simple Teflon mixing shaft inside a sophisticated NMR instrument to apply shear to the sample. However, this method did not enable the determination of rheological parameters. In this work, a custom made low-field rheo-NMR device was evaluated, consisting of a commercial rheometer combined with a low-field permanent magnet to enable simultaneous rheological and NMR measurements. Two fats, i.e. partially hardened sunflower oil (PHSO) and soft palm mid fraction (sPMF), were submitted to several rheo-NMR experiments. The results of these experiments clearly indicated that these fats crystallized differently. First, PHSO crystallized faster than sPMF. Moreover, the latter seemed to crystallize in two steps. Initially a weak structure was formed when a low amount of solids was present, but this structure was replaced by a stronger network once more crystals were present. Both fats were studied under stagnant conditions, but also when submitted to low shear rates (1 s−1 and 5 s−1). It was shown that the amount of solids necessary to obtain a viscosity of 10 ​Pa ​s was higher when the shear rate was higher. The strength of the formed crystal network at a given percentage of solids was also weaker as the shear rate during crystallization increased. Whereas these experiments were done non-isothermally, it was shown that rheo-NMR can also perfectly be used for isothermal measurements.

Instagram Influencer Selection Analysis on the SME’s Brand Campaign in Indonesia using Correlation Analysis (Case Study: IAM.ID)

The number of Small Medium Enterprises (SMEs) in Indonesia reached 64,194,057 units in 2018 and made a good impact on Indonesia’s economy. However, it turns out that SMEs face various problems, such as business strategy, marketing, and branding. Only 12% of SMEs currently use digital as one of their platforms and most of these businesses are still in stagnant condition. Currently, SMEs are starting to use influencers as their marketing strategy on Instagram. However, it is difficult to find a suitable influencer for their product or service due to so many influencers with various categories. The market potential in this field is quite high considering that Indonesia has the largest number of social media users in the world, especially Facebook and Instagram. Globally 5-10 billion USD marketing is done through influencer marketing in 2020, 65% of companies plan to use more influencer marketing and 92% of customers trust personal recommendations more than conventional advertising. An analysis was conducted of the selection of Instagram influencers on the brand campaign in Indonesia through a case study from IAM.ID. This company provides solutions in the fields of influencer marketing and technology with influencers data analytics. IAM.ID services include content creations, endorsement, store visits, and influencer’s community. In this research, the hypothesis is based on the level of engagement and influencer category. Influencers are considered more effective if they match the advertised brand. Influencer data analytics are obtained from engagement rate (ER) influencers, the number of followers, influencer categories, and content analysis. Brand analysis is obtained from brand preferences obtained through questionnaires. Then a correlation analysis was carried out on the ER campaign and the result was that both the number of followers and ER influencers had a strong relationship to the ER campaign. Besides, the suitability of the influencer category can also be checked using content analysis.

Experimental results of the effect of gas composition on void fraction and bubble behavior for gas-liquid two-phase flow under stagnant water condition

Experimental results of the effect of gas composition on void fraction and bubble behavior for gas-liquid two-phase flow under stagnant water condition

Three-dimensional Thermal and Dynamic Structure in Synoptic and Local Scale and its Influence on Haze Formation during Autumn in Beijing

ABSTRACT This study investigates the vertical thermal and dynamic structure of the atmosphere on synoptic and local scales from a three-dimensional perspective and its contribution to haze formation in Beijing during autumn. On a synoptic scale, the occurrence of heavy haze corresponds either to significant horizontal pollutant transport by southerly winds or to strong atmospheric vertical stability with downward air motion at altitudes below ~1500–3000 m; hence, meteorological parameters measured below ~1500 m serve as better indicators of pollutant transport and dispersion than surface observations. When accompanied by increased southerly winds, the upward air motion between the ground and altitudes above ~1500 m can transport pollutants from surrounding areas to Beijing, resulting in a rapid increase in PM2.5 (within several hours) despite weak winds on the surface, which confirms the possibility of regional transport during stagnant surface conditions and its potential role in haze formation. Additionally, the mountain-plain breeze in the Beijing-Tianjin-Hebei (BTH) region during autumn drives strong local wind circulation, influencing the cumulative stage of haze episodes in this season. During the daytime, this breeze pushes pollutants to areas along the mountains and then to Beijing, resulting in a day-by-day increase in pollution. (By contrast, winter haze episodes arise from the accumulation of local pollution under stable meteorological conditions.) The combination of easterly winds and local topography can induce the formation and dissipation of haze, with the orographic effect propelling the haze into higher layers that host the transport of PM2.5 to the southeast. Afterward, southerly winds carry this pollution plume back along the mountain front, where it merges with surface pollutants through vertical mixing, finally this mixed plume arrived Beijing and contributes to the development of the next haze episode.

МОДЕЛИРОВАНИЕ ЗАГРЯЗНЕНИЯ ВОЗДУШНОГО БАССЕЙНА АЛМАТЫ В ПЕРИОДЫ НЕБЛАГОПРИЯТНЫХ МЕТЕОРОЛОГИЧЕСКИХ УСЛОВИЙ

The problem of air pollution in Almaty city in stagnant weather conditions is considered. Such conditions are so frequent, because the city is located at the foothills of the mountain range of Ile Alatau. The WRF-Chem complex model is used for the analysis and allows a high-detail simulation both of the atmospheric circulation and the transport of various pollutants, taking into account their chemical transformations. The results of modeling meteorological processes are compared with observational data. The main attention is paid to the calculation of the sulfur dioxide plume emitted by the pipes of the coal-fired CHP-2. The simulations showed that regional latitudinal wind, whose direction regularly changes to the opposite one, dominates in the northern part of the city atmosphere. During such periods and under unstable atmosphere stratification conditions, the plume dissipates and pollutants penetrate into the surface layer. In some areas, the concentration of SO2 significantly exceeds sanitary standards.

Boosted microbial productivity during the Toarcian Oceanic Anoxic Event in the Paris Basin, France: new evidence from organic geochemistry and petrographic analysis

Abstract The Toarcian Oceanic Anoxic Event (T-OAE) is marked by major palaeoenvironmental and palaeoceanographical changes on a global scale, associated with a severe disturbance of the global carbon cycle and organic-rich facies deposition. Here, a multiproxy approach (petrographic and geochemical techniques) was applied to the study of the organic content of the T-OAE of the Paris Basin, whose phytoplanktonic origin has been previously inferred by its geochemical signature. The top of the tenuicostatum Zone is characterized by palynomorphs and marine phytoplankton-derived amorphous organic matter (AOM), representing a proximal marine environment with emplacement of euxinic conditions at the top (total organic carbon/sulfur content and increase in AOM). At the base of the serpentinum Zone the proliferation of bacterial biomass begins, with phytoplankton playing a secondary role. This indicates the development of stagnant and restrictive conditions in a proximal environment, with water column stratification (neohop-13(18)-ene). The majority of the serpentinum Zone is dominated by bacterial biomass, suggesting a marine environment with bottom-water stagnation, possibly related to basin palaeogeomorphology and circulation patterns, with episodic euxinia. This therefore suggests that the T-OAE organic fraction is dominated by bacterial biomass, not phytoplankton, showing the importance of an integrated approach to the determination of the organic facies.

Surprising Changes in Aerosol Loading over India amid COVID-19 Lockdown

Using ground-based and satellite observation along with aerosol reanalysis products, we show a widespread reduction in aerosol loading over the Indian subcontinent during the COVID-19 (COronaVIrus Disease 2019) lockdown. The pre-lockdown and lockdown period considered in the present study is 20th February–20th March 2020 and 24th March–22nd April 2020. In terms of aerosol optical depth (AOD), loading has reduced up to 40% over the most populated region of India. However, the central part of India shows an unexpected increase (~+20%) in AOD. A simultaneous increase (decrease) in mid-tropospheric relative humidity (wind speed (WS) at 850 hPa) by +85 ± 6.0% (–12 ± 3.9%) occurred during the lockdown. It is found that on a daily scale, the mean AOD is positively (negatively) correlated with mid-tropospheric RH (WS) with a statistically significant linear correlation coefficient of 0.53 (−0.43). An increase (decrease) in RH (WS) of 20% (1 m s–1) was observed to increase AOD by 0.10 (0.04). Thus, we hypothesize that during the lockdown, the increased AOD over central India was due to increased atmospheric moisture coupled with stagnant circulation condition.

Measurement report: dual-carbon isotopic characterization of carbonaceous aerosol reveals different primary and secondary sources in Beijing and Xi'an during severe haze events

Abstract. To mitigate haze pollution in China, a better understanding of the sources of carbonaceous aerosols is required due to the complexity in multiple emissions and atmospheric processes. Here we combined the analysis of radiocarbon and the stable isotope 13C to investigate the sources and formation of carbonaceous aerosols collected in two Chinese megacities (Beijing and Xi'an) during severe haze events of a “red alarm” level from December 2016 to January 2017. The haze periods with daily PM2.5 concentrations as high as ∼ 400 µg m−3 were compared to subsequent clean periods (i.e., PM2.5 less than median concentrations during the winter 2016/2017) with PM2.5 concentrations below 100 µg m−3 in Xi'an and below 20 µg m−3 in Beijing. In Xi'an, liquid fossil fuel combustion was the dominant source of elemental carbon (EC; 44 %–57 %), followed by biomass burning (25 %–29 %) and coal combustion (17 %–29 %). In Beijing, coal combustion contributed 45 %–61 % of EC, and biomass burning (17 %–24 %) and liquid fossil fuel combustion (22 %–33 %) contributed less. Non-fossil sources contributed 51 %–56 % of organic carbon (OC) in Xi'an, and fossil sources contributed 63 %–69 % of OC in Beijing. Secondary OC (SOC) was largely contributed by non-fossil sources in Xi'an (56±6 %) and by fossil sources in Beijing (75±10 %), especially during haze periods. The fossil vs. non-fossil contributions to OC and EC did not change drastically during haze events in both Xi'an and Beijing. However, compared to clean periods, the contribution of coal combustion to EC during haze periods increased in Xi'an and decreased in Beijing. During clean periods, primary OC from biomass burning and fossil sources constituted ∼ 70 % of OC in Xi'an and ∼ 53 % of OC in Beijing. From clean to haze periods, the contribution of SOC to total OC increased in Xi'an but decreased in Beijing, suggesting that the contribution of secondary organic aerosol formation to increased OC during haze periods was more efficient in Xi'an than in Beijing. In Beijing, the high SOC fraction in total OC during clean periods was mainly due to an elevated contribution from non-fossil SOC. In Xi'an, a slight day–night difference was observed during the clean period with enhanced fossil contributions to OC and EC during the day. This day–night difference was negligible during severe haze periods, likely due to the enhanced accumulation of pollutants under stagnant weather conditions.

Yapılarda Kullanılan Alternatif Enerji Kaynakları ve Dalga Enerjisi ile Çalışan bir Jeneratör Önerisi

The decrease in non-renewable resources, and global warming problem in the world is increasing the interest and demand for alternative energy sources. In addition to the investments made in renewable energies such as solar and wind in various countries, regions with coasts to oceans or seas also make new investments in wave energy. In this study, by comparing wave energy with other alternative renewable energy types from various angles, an alternative method is proposed for geographical regions without continuous wave generation, unlike previous studies. The basis of the method is to store the water mass pushed by the wave in a high level when the sea is wavy, and to generate energy by using the potential energy of this water body when it is passed to stagnant weather conditions. It is thought that the method can affect the preference criteria of alternative energy use in buildings.

Living with Legionella and Other Waterborne Pathogens.

Legionella spp. and other opportunistic premise plumbing pathogens (OPPPs), including Pseudomonas aeruginosa, Mycobacterium avium, Stenotrophomonas maltophilia, and Acinetobacter baumannii, are normal inhabitants of natural waters, drinking water distribution systems and premise plumbing. Thus, humans are regularly exposed to these pathogens. Unfortunately, Legionella spp. and the other OPPPs share a number of features that allow them to grow and persist in premise plumbing. They form biofilms and are also relatively disinfectant-resistant, able to grow at low organic matter concentrations, and able to grow under stagnant conditions. Infections have been traced to exposure to premise plumbing or aerosols generated in showers. A number of measures can lead to reduction in OPPP numbers in premise plumbing, including elevation of water heater temperatures.

Characteristics of wintertime VOCs in urban Beijing: Composition and source apportionment

Abstract Characteristics and sources of volatile organic compounds (VOCs) were investigated with highly time-resolved measurements by a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) at an urban site in Beijing in winter 2017. During the measurement period, high mixing ratios of VOCs (48.9 ppbv) and trace gases were observed, with alternating episodes of strong haze pollution and clean air. Ten VOC families showed clear dependence on the VOC concentration. Aromatics increased the most during haze, with significantly elevated benzene concentration at high VOC concentration, while CxHyO3 and CxHy increased the least. The positive matrix factorization (PMF) receptor model was applied to the VOC mass spectra, yielding four major VOC factors: traffic emissions (21.0%), solid fuel combustion (SFC, 24.4%), and two oxygenated VOC (OVOC) factors (32.3% and 22.3%). Traffic and solid fuel combustion were dominant during the periods of high total VOC concentration, while the OVOC1 fraction was reduced. Comparisons with organic aerosol (OA) sources showed increased oxygenated organic aerosol (OOA) concentration during high VOC concentration periods, indicating the importance of OVOCs to secondary organic aerosol formation. Furthermore, trajectory analysis showed that most of the clean days were associated with northerly winds with high ratios of OVOC1. In contrast, the haze periods were not only due to high primary emissions under stagnant conditions, but also influenced by air masses from a more regional scale.

Long Island enhanced aerosol event during 2018 LISTOS: Association with heatwave and marine influences.

The co-occurrence of enhancement in aerosol concentration, temperatures, and ozone mixing ratio was observed between June 29 and July 4, 2018 (enhanced period, EP) on Long Island (LI) and the greater NYC metropolitan area during part of the 2018 Long Island Sound Tropospheric Ozone Study (LISTOS). Two aerosol formation pathways were identified during the EP, the first being the condensation of semi- and intermediate volatility oxidation products of anthropogenic volatile organic compounds (AVOCs) under stagnant synoptic flow conditions, high temperatures and afternoon sea-breeze circulation. While this first pathway was prevalent, the most abundant organic aerosol factor was less oxidized oxygenated organic aerosol or LO-OOA. The second formation pathway occurred during a period of more persistent (synoptic) on-shore flow transporting more aged aerosol which consisted of an internal mixture of more oxidized oxygenated organic aerosol (MO-OOA), methanesulfonic acid (MSA) and sulfate. It was estimated that 35% of the sulfate observed during the mature period (an average of about 1.2μgm-3) originated from oceanic dimethyl sulfide (DMS) emissions. These two formation pathways helped elucidate the sources of fine particle pollution, highlighted the interaction between human emissions and natural DMS emission, and will help our understanding of pollution affecting other urban areas adjacent to large bodies of water during hot and stagnant periods.

Seasonal and temporal factors leading to urea-nitrogen accumulation in surface waters of agricultural drainage ditches.

Urea-nitrogen (N) is commonly applied to crop fields, yet it is not routinely monitored despite its association with reduced water quality and its ability to increase toxicity of certain phytoplankton species. The purpose of this work was to characterize temporal fluctuations in urea-N concentrations and associated environmental conditions to infer sources of urea-N in agricultural drainage ditches. Physicochemical properties and N forms in ditch waters were measured weekly during the growing seasons of 2015-2018. Fertilizer application was only associated with spring peaks of urea-N concentrations in ditches next to cornfields, whereas summer peaks in ditches adjacent to corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields were not associated with fertilizer applications. Environmental conditions of warmer temperatures, lower dissolved oxygen concentrations, and lower redox potentials were correlated with higher urea-N concentrations. In 2018, peaks of urea-N and ammonium-N during the summer co-occurred with peaks of dissolved organic N and total dissolved N, suggesting they might be associated with the breakdown of organic matter and with the turnover of the organic N pool. Although the highest urea-N concentrations occurred when ditch surface waters were hydrologically disconnected from nearby streams, heavy rainfalls can potentially flush accumulated urea-N into coastal waters, where it may affect algal bloom toxicity. Therefore, implementation of available drainage ditch management practices is recommended, but these strategies need to be optimized for targeting periods with high rainfall that coincide with fertilizer additions as well as for periods with low rainfall that promote stagnant water conditions.

Root length is proxy for high-throughput screening of waterlogging tolerance in Urochloa spp. grasses.

C4 perennial Urochloa spp. grasses are widely planted in extensive areas in the tropics. These areas are continuously facing waterlogging events, which limits plant growth and production. However, no commercial cultivar combining excellent waterlogging tolerance with superior biomass production and nutritional quality is available. The objective of this study was to identify root traits that can be used for selecting waterlogging tolerant species of Urochloa. Root respiration, root morphological, architectural and anatomical traits were evaluated in eight contrasting Urochloa spp. genotypes grown under aerated or deoxygenated stagnant solutions. Moreover, modelling of internal aeration was used to relate differences in root traits and root growth in waterlogged soils. Increased aerenchyma formation in roots, reduced stele area and development of a fully suberised exodermis are characteristics improving internal aeration of roots and therefore determining waterlogging tolerance in these C4 forage grasses. Waterlogging-tolerant genotypes had steeper root angles and greater root lengths than the waterlogging-sensitive genotypes. In stagnant conditions, waterlogging-tolerant genotypes had a greater proportion of aerenchyma and reduced stele area in root cross-sections, had deeper roots, steeper root angle and larger root biomass, which in turn, allowed for greater shoot biomass. Total root length had the strongest positive influence on shoot dry mass and can therefore be used as proxy for selecting waterlogging tolerant Urochloa genotypes.

Environmental reservoirs of Vibrio cholerae serogroups in the flowing freshwater environs from the tribal areas of Odisha, Eastern India.

The environmental reservoirs of different serogroups of Vibrio cholerae causing cholera in the flowing freshwater bodies of the tribal areas of Odisha are not known. So the present study was conducted from June 2017 to March 2020 to find out the environmental reservoirs of V. cholerae serogroups in the water and plankton samples collected from the river, nala, stream and chua from Rayagada district. Similarly, rectal swabs were collected from diarrhoea patients and correlation was established among the V. cholerae strains isolated from diarrhoea patients and environmental V. cholerae isolates through routine culture, different multiplex PCR assays and pulse field gel electrophoresis (PFGE) analysis using standard techniques. The multiplex PCR assays on biotypes and different toxic genes exhibited similar correlation between the clinical and water isolates, which was further strengthened by PFGE analysis. The planktonic DNA was positive for ctxA gene which established that the environmental water bodies were the reservoirs for virulence genes of V. cholerae serogroups. The detection of environmental reservoirs of V. cholerae serogroups in temporarily stagnant condition of water; partially encircled by stones, and near the bank of the river, nala and stream were the reservoirs which is a rare report from Odisha, India and Globe.

Health impacts of air pollution in 1027 European urban areas: identification of cities with the highest and lowest preventable mortality burdens.

Most of the health impacts of air pollution (AP) estimates are calculated on global, regional or country levels, evidencing the need for local estimates relevant for policy action. To address this gap, we estimated the premature mortality burden preventable upon the achievement of the WHO recommended and lowest measured AP levels in 1027 urban areas across 31 European countries, and identified the cities with the highest and lowest mortality impacts associated with AP exposure. We retrieved the data for defining cities from the Urban Audit 2018 and identified 978 cities and 49 greater cities based on the OECD-EC city definition. We conducted the Health Impact Assessment (HIA) at the 250m grid cell level (n = 1,135,485) for the reference year 2015. The analysis estimated the impact of AP exposure (PM2.5and NO2) on natural-cause mortality for the urban adult population ≥ 20 years old (n = 168,180,047). Cities were clustered based on the mortality burden associated with AP exposure. Compliance with WHO AP guidelines was estimated to prevent more than 50,000 deaths for the PM2.5 exposure and almost 1000 deaths for the NO2 exposure. The reduction of AP to the lowest measured levels was estimated to prevent more than 120,000 deaths for the PM2.5 exposure and 80,000 deaths for the NO2 exposure. The cluster with the highest PM2.5 mortality impacts included Italian cities in the Po-Valley and cities in Poland and Czech Republic. The cluster with the highest mortality impacts due to NO2 exposure included the bigger and capital cities (i.e. Madrid, Antwerpen, Paris, Torino, Milano and Barcelona). Our results reflect the main factors influencing AP levels across European cities, including stagnant meteorological conditions, domestic fuel burning, diesel car use and high traffic levels, and indicate policy actions needed to reduce AP and its adverse health impacts across European cities.