scholarly journals Chemical characteristics of size-resolved atmospheric aerosols in Iasi, north-eastern Romania: nitrogen-containing inorganic compounds control aerosol chemistry in the area

2018 ◽  
Vol 18 (8) ◽  
pp. 5879-5904 ◽  
Author(s):  
Alina Giorgiana Galon-Negru ◽  
Romeo Iulian Olariu ◽  
Cecilia Arsene

Abstract. This study assesses the effects of particle size and season on the content of the major inorganic and organic aerosol ionic components in the Iasi urban area, north-eastern Romania. Continuous measurements were carried out over 2016 using a cascade Dekati low-pressure impactor (DLPI) performing aerosol size classification in 13 specific fractions over the 0.0276–9.94 µm size range. Fine-particulate Cl−, NO3-, NH4+, and K+ exhibited clear minima during the warm season and clear maxima over the cold season, mainly due to trends in emission sources, changes in the mixing layer depth and specific meteorological conditions. Fine-particulate SO42- did not show much variation with respect to seasons. Particulate NH4+ and NO3- ions were identified as critical parameters controlling aerosol chemistry in the area, and their measured concentrations in fine-mode (PM2.5) aerosols were found to be in reasonable good agreement with modelled values for winter but not for summer. The likely reason is that NH4NO3 aerosols are lost due to volatility over the warm season. We found that NH4+ in PM2.5 is primarily associated with SO42- and NO3- but not with Cl−. Actually, indirect ISORROPIA-II estimations showed that the atmosphere in the Iasi area might be ammonia rich during both the cold and warm seasons, enabling enough NH3 to be present to neutralize H2SO4, HNO3, and HCl acidic components and to generate fine-particulate ammonium salts, in the form of (NH4)2SO4, NH4NO3, and NH4Cl. ISORROPIA-II runs allowed us to estimate that over the warm season ∼ 35 % of the total analysed samples had very strongly acidic pH (0–3), a fraction that rose to ∼ 43 % over the cold season. Moreover, while in the cold season the acidity is mainly accounted for by inorganic acids, in the warm ones there is an important contribution by other compounds, possibly organic. Indeed, changes in aerosol acidity would most likely impact the gas–particle partitioning of semi-volatile organic acids. Overall, we estimate that within the aerosol mass concentration the ionic mass brings a contribution as high as 40.6 %, with the rest still being unaccounted for.

2017 ◽  
Author(s):  
Alina Giorgiana Galon-Negru ◽  
Romeo Iulian Olariu ◽  
Cecilia Arsene

Abstract. This study assesses the atmospheric aerosol load and behaviour (size and seasonal dependent) of the major inorganic and organic aerosol ionic components (i.e., acetate, (C2H3O2–), formate, (HCO2–), fluoride, (F–), chloride, (Cl–), nitrite, (NO2–), nitrate, (NO3–), phosphate, (PO43–), sulfate, (SO42–), oxalate, (C2O42–), sodium, (Na+), potassium, (K+), ammonium, (NH4+), magnesium, (Mg2+) and calcium (Ca2+), in Iasi urban area, north-eastern Romania. Continuous measurements were carried out over 2016 by means of a cascade Dekati Low-Pressure Impactor (DLPI) performing aerosol size classification in 13 specific fractions evenly distributed over the 0.0276 up to 9.94 µm size range. Fine particulate Cl–, NO3–, NH4+ and K+ exhibited clear minima during the warm seasons and clear maxima over the cold seasons, mainly controlled by corroboration between factors such as enhancement in the emission sources, changes in the mixed layer depth and specific meteorological conditions. Fine particulate SO42– did not show much variation with respect to seasons. Particulate NH4+ and NO3– ions were identified as critical parameters controlling aerosols chemistry in the area. The measured concentrations of particulate NH4+ and NO3– in fine mode (PM2.5) aerosols were found to be in reasonable good agreement with modelled values for winter but not for summer, an observation reflecting actually the susceptibility of NH4NO3 aerosols to be lost due to volatility over the warm seasons. Clear evidences have been obtained for the fact that in Iasi, north-eastern Romania, NH4+ in PM2.5 is primarily associated with SO42– and NO3– but not with Cl–. However, indirect ISORROPIA-II estimations showed that the atmosphere in the investigated area might be ammonia-rich during both the cold and warm seasons, such as enough NH3 to be present to neutralize H2SO4, HNO3 and HCl acidic components and to generate fine particulate ammonium salts, in the form of (NH4)2SO4, NH4NO3 and NH4Cl. ISORROPIA-II runs allowed us estimating that over the warm seasons ~ 35 % of the total analyzed samples presented pH values in the very strong acidity fraction (0–3 pH units range) while over the cold seasons the contribution in this pH range was of ~ 43 %. Moreover, while over the warm seasons ~ 24–25 % of the acidic samples were in the 1–2 pH range, reflecting mainly contributions from very strong inorganic acids, over the cold seasons an increase to ~ 40 %, brought by the 1–3 pH range, would reflect possible contributions from other acidic type species (i.e., organics), changes in aerosols acidity impacting most probably the gas–particle partitioning of semi-volatile organic acids. In overall, it has been estimated that within the aerosol mass concentration the ionic mass brings contribution as high as 40.6 % with the rest being unaccounted yet.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
L Kuzma ◽  
A Kurasz ◽  
E J Dabrowski ◽  
M Swieczkowski ◽  
S Dobrzycki ◽  
...  

Abstract Background Recent studies have reported associations between air pollution and daily mortality. The majority of them are conducted in highly polluted areas. Taking into consideration the scarce number of surveys from cities with moderate air quality we decided to conduct a study in this type of region. Purpose To assess the short-term impact of air pollution on cardiovascular (CVD), coronary artery-related (CAD), and cerebrovascular-related (CbVD) mortality. Methods The analysis with almost 4,500,000 person-years of follow-up with a time-stratified case-crossover design was performed. Results are reported as odds ratio (OR) associated with an increase in interquartile range (IQR). Results The analysed region was inhabited by almost 500,000 residents. From 2008 to 2017 in Bialystok, Lomza, and Suwalki we recorded 49,573 deaths – 34,005, 8,082, 7,486, respectively. The median daily concentrations of PM10 (23.8 μg/m3, IQR=16.9) was the highest in Lomza, Median daily concentration of PM2.5 was the highest in Bialystok (16.2 μg/m3, IQR=15.9). In the case of Suwalki, daily median PM2.5 concentration was 9.8 μg/m3 (IQR=8.7), and PM10 – 18.0 μg/m3 (IQR=14.3). The IQR increase in PM2.5 (OR 1.036, 95% CI 1.016–1.056, P<0.001) and PM10 concentration (OR 1.034, 95% CI 1.015–1.053, P<0.001) was associated with increased CVD mortality on lag 0 and this effect persisted on following days. The effects of PMs were more expressed in association with CAD-related mortality (OR for PM2.5 = 1.045, 95% CI 1.012–1.080, P=0.008), (OR for PM10 = 1.044, 95% CI 1.010–1.078, P=0.011) and CbVD mortality (OR for PM2.5 = 1.046, 95% CI 1.013–1.080, P=0.006), (OR=1.041 for PM10, 95% CI 1.002–1.082, P=0.038). Additionally, IQR increase in NO2 concentration was associated with increased CAD-related mortality at lag 0–1 (OR=1.055, 95% CI 1.004–1.108, P=0.032). The highest OR for PMs was noted in Suwalki compared to Bialystok and Lomza. The trend was noted regardless of the cause of death from lag 0 to lag 0–3. In a comparison of seasons, we noted higher CVD mortality OR in the cold season for PM10 in Suwalki (P=0.047) and Bialystok (p=0.001). However, the impact of NO2 (P=0.02) and PM10 (P=0.03) on CAD related mortality was higher in the warm season. Conclusions The impact of air pollution on CVD mortality is also observed in moderately polluted areas. PMs and NO2 had the greatest impact on CAD-related mortality. Differences in effect size and seasonality may depend on the source of air pollution. FUNDunding Acknowledgement Type of funding sources: None.


Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1357
Author(s):  
Liudmila Golobokova ◽  
Olga Netsvetaeva ◽  
Tamara Khodzher ◽  
Vladimir Obolkin ◽  
Olga Khuriganova

A precipitation monitoring station in Listvyanka was set up to determine the potential impact of the coastal area on the state of the adjacent air environment above Lake Baikal on its southwest coast. This article presents the results of studying the chemical composition of atmospheric deposition (aerosols and precipitation) at this station in 2020, and of their comparison with the data from previous years (from 2000 to 2019). In 2020, the ionic composition of atmospheric aerosols and precipitation had changed compared to previous years. In the modern period, the total amount of ions in aerosols, accounting for 0.46 ± 0.40 μg∙m−3, was lower by an order of magnitude than between 2000 and 2004. The average annual total amount of ions in precipitation in Listvyanka was almost unchanged from the average values in 2000–2010 and was 10% lower than that from 2011 to 2019 (7.3 mg/L). The ratio of major ions of sulphates and ammonium changed in the aerosol composition: compared to the period from 2000 to 2004, in 2020, the contribution of ammonium ions had decreased significantly, from 32% to 24%; the contribution of sulphates had increased to 43%, and the contribution of calcium had increased from 8 to 13%. Since 2010, the contribution of K+ ions has increased to 8–10%, indicating the effect of smoke aerosols from wildfires. In precipitation, despite the dominance of sulphates (26%) and calcium (18%) throughout the year, the contribution of nitrates increases to 19% during the cold season (from October to March), while the contribution of ammonium ions and hydrogen ions increases to 13% and 17%, respectively, in the warm season (from April to September). In 2020, as in previous research years, the acidity of precipitation at the Listvyanka station was elevated (pH 5.1 ± 0.5); 50% of precipitation in 2020 had pH ˂ 5. We quantified ions in atmospheric aerosols and precipitation on the underlying surface of the coastal southwestern part of Lake Baikal. Ion fluxes with precipitation were the highest in the warm season, which corresponds to the annual maximum precipitation. Unlike previous years (from 2000 to 2010 and from 2011 to 2019), wet deposition of most ions—especially calcium, ammonium and nitrates—had decreased in 2020. There was a 35-fold decrease in nitrogen fluxes and a 5-fold decrease in sulphur fluxes in aerosols, as well as 1.6-fold and 1.3-fold decreases, respectively, in precipitation.


2021 ◽  
Vol 13 (10) ◽  
pp. 1884
Author(s):  
Jingjing Hu ◽  
Yansong Bao ◽  
Jian Liu ◽  
Hui Liu ◽  
George P. Petropoulos ◽  
...  

The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.


2005 ◽  
Vol 27 (1-2) ◽  
pp. 255-280 ◽  
Author(s):  
Genevieve LeMoine ◽  
James Helmer ◽  
Bjarne Grønnow

Abstract Late Dorset dwellings from two sites on Little Cornwallis Island (Nunavut) illustrate the diversity of architectural forms from this period. Ten architectural features are described. They include five tent rings, ascribed to warm season occupations, and five rectangular semi-subterranean houses with axial features, including one exceptionally well-preserved example, ascribed to cold season occupations. Variations in size, number of hearths, and construction techniques are examined and the use of both types of structures to house multiple nuclear families is suggested.


Author(s):  
Jiyoung Shin ◽  
Jongmin Oh ◽  
In Sook Kang ◽  
Eunhee Ha ◽  
Wook Bum Pyun

Background/Aim: Previous studies have suggested that the short-term ambient air pollution and temperature are associated with myocardial infarction. In this study, we aimed to conduct a time-series analysis to assess the impact of fine particulate matter (PM2.5) and temperature on acute myocardial infarction (AMI) among adults over 20 years of age in Korea by using the data from the Korean National Health Information Database (KNHID). Methods: The daily data of 192,567 AMI cases in Seoul were collected from the nationwide, population-based KNHID from 2005 to 2014. The monitoring data of ambient PM2.5 from the Seoul Research Institute of Public Health and Environment were also collected. A generalized additive model (GAM) that allowed for a quasi-Poisson distribution was used to analyze the effects of PM2.5 and temperature on the incidence of AMI. Results: The models with PM2.5 lag structures of lag 0 and 2-day averages of lag 0 and 1 (lag 01) showed significant associations with AMI (Relative risk [RR]: 1.011, CI: 1.003–1.020 for lag 0, RR: 1.010, CI: 1.000–1.020 for lag 01) after adjusting the covariates. Stratification analysis conducted in the cold season (October–April) and the warm season (May–September) showed a significant lag 0 effect for AMI cases in the cold season only. Conclusions: In conclusion, acute exposure to PM2.5 was significantly associated with AMI morbidity at lag 0 in Seoul, Korea. This increased risk was also observed at low temperatures.


2007 ◽  
Vol 55 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Eli Ana Traversim Gomes ◽  
Viviane Severiano dos Santos ◽  
Denise Rivera Tenenbaum ◽  
Maria Célia Villac

Much time and resources have been invested in understanding plankton dynamics in Guanabara Bay (Brazil), but no attention has been devoted to the protozooplankton. To fulfill this lacuna, abundance and composition of protozooplankton were investigated from January to December - 2000 in fortnightly surface water samplings at two distinct water quality sites (Urca - closer to the bay entrance, more saline and cleaner waters; Ramos - inner reaches, hypereutrophic waters). The density at Urca (10³ - 10(5) cell.l-1) was one to three orders of magnitude lower than at Ramos (10(4) - 10(5) cell.l-1). A seasonal trend for nanoplankton and protozooplankton was more evident at Urca, but both sites had lower densities during the colder period. Small heterotrophic dinoflagellates (20-30 mm) were dominant in over 50% of the samples. The protozooplankton abundance and composition reflected the distinct trophic conditions states found at the bay. During the wet-warm season, non-oligotrich ciliates were representative of Ramos site with Gymnodiniaceae dinoflagellates, while tintinnids and heterotrophic dinoflagellates were predominantly found at Urca mainly during the dry-cold season. This first descriptive study towards the understanding of the intricate relationships among the microbial food web components reveals that protozooplankton can be a good indicator of water quality conditions at the bay.


2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.


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