scholarly journals Spatial Characteristics of PM1 Aerosol Chemical Composition over the Greater Athens Area

2020 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Iasonas Stavroulas ◽  
Georgios Grivas ◽  
Nikolaos Mihalopoulos
Keyword(s):  
Chemical Composition ◽  
Premature Mortality ◽  
Transport Processes ◽  
Secondary Sources ◽  
Local Sources ◽  
Key Factor ◽  
Multi Wavelength ◽  
June July ◽  
Athens Area ◽  
Aerosol Chemical Composition

Airborne sub-micrometer particles (PM1) have been documented to exert adverse impacts on human health, including respiratory and cardiovascular disease and premature mortality. The Greater Athens Area (GAA), characterized by topographic and meteorological conditions which frequently obstruct the effective dispersion of ambient pollutants, hosts approximately 40% of Greece’s population. It can be considered an “ambient laboratory” for studying PM1 pollution events, given the intensity and diversity of submicron aerosol sources and processing. Fine aerosol chemical composition is continuously monitored at the National Observatory of Athens Air Monitoring Station in Thissio, an urban background site in Central Athens. Furthermore, two intensive monthly campaigns were held at a central site in Piraeus, where Greece’s busiest passenger port is located, during both winter (December 2018–January 2019) and summer (June–July 2019) periods. Organic aerosol (OA), sulfate, nitrate, ammonium, and chloride were measured using an aerosol chemical speciation monitor (ACSM), while black carbon (BC and source-specific components) was measured using a multi-wavelength aethalometer (AE-33). The variability of concentrations at different temporal scales was examined, revealing differences for primary aerosol components, depending on site type and location, and related to local sources and transport processes. Biomass burning for domestic heating was found to be a key factor during wintertime, leading to uniform OA and BC levels at both sites, while the local sources in Piraeus (traffic, port activity) lead to substantially increased levels during the summer. Secondary sources were found to affect both sites in a relatively homogeneous manner.

ECOLOGICAL AND PHYSIOLOGICAL ASSESSMENT OF CHEMICAL COMPOSITION OF DRINKING TAP WATER IN KHANTY-MANSIYSK AND SALEKHARD

2020 ◽  
pp. 159-167
Author(s):  
V.V. Lapenko ◽  
L.N. Bikbulatova ◽  
E.M. Ternikova
Keyword(s):  
Drinking Water ◽  
Chemical Composition ◽  
Water Samples ◽  
Tap Water ◽  
Iron Concentration ◽  
Absorption Spectrometry ◽  
Northern Region ◽  
Transport Processes ◽  
Magnesium Concentration ◽  
Geochemical Environment

Water is very important for humans, as it is a solvent for metabolic products. Moreover, it is necessary for metabolism, biochemical and transport processes. The elemental status in persons depends on the geochemical environment and consumption of bioelements with food and water. The aim of the paper is to conduct a comprehensive assessment of chemical composition of drinking tap water in Khanty-Mansiysk and Salekhard. Materials and Methods. The chemical composition of 100 samples of drinking tap water was analyzed by atomic absorption spectrometry, spectrophotometry and capillary electrophoresis. All in all, there were 50 samples from Khanty-Mansiysk and 50 samples from Salekhard. The results were compared with Sanitary Rules and Norms 2.1.4.1074-01. Results. Drinking tap water in Salekhard contains a significantly higher concentration of iron, which is much above the maximum allowable concentration, if compared to water samples in Khanty-Mansiysk (p=0.03). In the cities under consideration, the water undergoes high-quality reagent-free treatment. However, the deterioration of the water supply networks in Salekhard is 3 times as high as in Khanty-Mansiysk. Calcium and magnesium concentration in water samples from Khanty-Mansiysk is 5.6 and 3.9 times lower than the MAC; in water samples from Salekhard calcium concentration is 6.3 (p=0.008) and magnesium concentration 4.6 (p<0.001) times lower than the MAC. Conclusion. The consumption of ultra-fresh drinking water leads to low intake of bioelements, which are a part of enzymes contributing to the human antioxidant defense and can result in manifestation of cardiovascular diseases. This is especially true for Salekhard with very soft drinking water and high iron concentration, which excess can exhibit prooxidant properties. Keywords: tap water, bioelements, northern region, antioxidants. Вода является важнейшим соединением для человека: необходима в качестве растворителя продуктов метаболизма и протекания обменных, биохимических и транспортных процессов. Элементный статус организма человека зависит от геохимического окружения и поступления биоэлементов с пищей и водой. Цель. Провести комплексную оценку химического состава водопроводной воды городов Ханты-Мансийск и Салехард. Материалы и методы. Методами атомно-абсорбционной спектрометрии, спектрофотометрии и капиллярного электрофореза проанализирован химический состав 100 проб водопроводной воды: по 50 из Ханты-Мансийска и Салехарда. Результаты сравнивали с СанПиН 2.1.4.1074-01. Результаты. В водопроводной воде Салехарда установлена превышающая ПДК и достоверно более высокая концентрация железа сравнительно с водой Ханты-Мансийска (р=0,03). При условии качественной безреагентной водоподготовки в изучаемых городах это обусловлено изношенностью водопроводных сетей в Салехарде, более чем в 3 раза превышающей этот показатель в Ханты-Мансийске. Концентрация кальция и магния в воде Ханты-Мансийска в 5,6 и 3,9 раза ниже ПДК; в воде Салехарда – в 6,3 (р=0,008) и 4,6 (р<0,001) раза ниже ПДК соответственно. Заключение. Употребление ультрапресной питьевой воды на фоне очень малого поступления с водой биоэлементов, входящих в состав ферментов антиоксидантной защиты организма человека, может привести к манифестации кардиоваскулярных заболеваний. Это особенно актуально для г. Салехарда с очень мягкой питьевой водой с повышенным содержанием железа, избыток которого может проявлять прооксидантные свойства. Ключевые слова: водопроводная вода, биоэлементы, северный регион, антиоксиданты.

Aerosol chemical composition and light scattering during a winter season in Beijing

2015 ◽  
Vol 110 ◽  
pp. 36-44 ◽  
Author(s):  
Jun Tao ◽  
Leiming Zhang ◽  
Jian Gao ◽  
Han Wang ◽  
Faihe Chai ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Winter Season ◽  
Aerosol Chemical Composition

Aerosol chemical composition over Istanbul

2010 ◽  
Vol 408 (12) ◽  
pp. 2482-2491 ◽  
Author(s):  
C. Theodosi ◽  
U. Im ◽  
A. Bougiatioti ◽  
P. Zarmpas ◽  
O. Yenigun ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Aerosol Chemical Composition

scholarly journals CCN activity of organic aerosols observed downwind of urban emissions during CARES

2013 ◽  
Vol 13 (4) ◽  
pp. 9355-9399 ◽  
Author(s):  
F. Mei ◽  
A. Setyan ◽  
Q. Zhang ◽  
J. Wang
Keyword(s):  
Chemical Composition ◽  
Water Solubility ◽  
Volume Fraction ◽  
Field Studies ◽  
High Water ◽  
Carbonaceous Aerosols ◽  
Mass Spectral ◽  
Least Squares Fit ◽  
The Relationship ◽  
Aerosol Chemical Composition

Abstract. During the Carbonaceous Aerosols and Radiative Effects Study (CARES), activation fraction of size-resolved aerosol particles and aerosol chemical composition were characterized at the T1 site (~60 km downwind of Sacramento, California) from 10 June to 28 June 2010. The hygroscopicity of CCN-active particles (κCCN) with diameter from 100 to 171 nm, derived from the size-resolved activated fraction, varied from 0.10 to 0.21, with an average of 0.15, which was substantially lower than that proposed for continental sites in earlier studies. The low κCCN value was due to the high organic volume fraction, averaged over 80% at the T1 site. The derived κCCN exhibited little diurnal variation, consistent with the relatively constant organic volume fraction observed. At any time, over 90% of the size selected particles with diameter between 100 and 171 nm were CCN active, suggesting most particles within this size range were aged background particles. Due to the large organic volume fraction, organic hygroscopicity (κorg) strongly impacted particle hygroscopicity and therefore calculated CCN concentration. For vast majority of the cases, an increase of κorg from 0.03 to 0.18, which are within the typical range, doubled the calculated CCN concentration. Organic hygroscopicity was derived from κCCN and aerosol chemical composition, and its variations with the fraction of total organic mass spectral signal at m/z 44 (f44) and O : C were compared to results from previous studies. Overall, the relationships between κorg and f44 are quite consistent for organic aerosol (OA) observed during field studies and those formed in smog chamber. Compared to the relationship between κorg and f44, the relationship between κorg and O : C exhibits more significant differences among different studies, suggesting κorg may be better parameterized using f44. A least squares fit yielded κorg = 2.04 (± 0.07) × f44 − 0.11 (± 0.01) with the Pearson R2 value of 0.71. One possible explanation for the stronger correlation between κorg and f44 is that the m/z 44 signal (mostly contributed by the CO2+ ion) is more closely related to organic acids, which may dominate the overall κorg due to their relatively high water solubility and hygroscopicity.

Characterization of aerosol chemical composition from urban pollution in Brazil and its possible impacts on the aerosol hygroscopicity and size distribution

2019 ◽  
Vol 202 ◽  
pp. 149-159 ◽  
Author(s):  
Gerson P. Almeida ◽  
Antônio T. Bittencourt ◽  
Marçal S. Evangelista ◽  
Marcelo S. Vieira-Filho ◽  
Adalgiza Fornaro
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Urban Pollution ◽  
Aerosol Hygroscopicity ◽  
Aerosol Chemical Composition

scholarly journals Bone Chemical Composition Analysis Using Photoacoustic Technique

2020 ◽  
Vol 8 ◽  
Author(s):  
Ting Feng ◽  
Yejing Xie ◽  
Weiya Xie ◽  
Dean Ta ◽  
Qian Cheng
Keyword(s):  
Chemical Composition ◽  
Optical Absorption ◽  
Imaging Techniques ◽  
Diagnostic Technique ◽  
High Sensitivity ◽  
Spectral Unmixing ◽  
Chemical Components ◽  
Composition Analysis ◽  
Feasibility Assessment ◽  
Multi Wavelength

Photoacoustic (PA) signal analysis based on ultrasonic wave detection can provide both high-sensitivity optical contrast information and micro-architectural information which is highly related with the chemical composition of tissue. In this study, the feasibility assessment of bone composition assessment was investigated using the multi-wavelength PA analysis (MWPA) method which could reflect the molecular information. By illuminating a bone specimen using a laser light with wavelength over an optical spectrum ranging from 680 to 950 nm, the optical absorption spectrum of the bone was acquired. Then, with the optical absorption spectra of all optical absorption chemical components in the known bone, a spectral unmixing procedure was performed to quantitatively assess the relative content of each chemical component. The experimental results from rabbit bones show that MWPA method can be used to assess chemical components related to bone metabolism. Our study confirmed that PA technique can be used as a novel bone diagnostic technique by providing new information about the quantity of bone and identifying biomarkers of bone that can improve the current diagnostic imaging techniques.

scholarly journals Towards an online-coupled chemistry-climate model: evaluation of trace gases and aerosols in COSMO-ART

2011 ◽  
Vol 4 (4) ◽  
pp. 1077-1102 ◽  
Author(s):  
C. Knote ◽  
D. Brunner ◽  
H. Vogel ◽  
J. Allan ◽  
A. Asmi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Urban Areas ◽  
Climate Model ◽  
Transport Model ◽  
Climate Impacts ◽  
Chemistry Transport Model ◽  
Pm2.5 And Pm10 ◽  
Phase Chemistry ◽  
Aerosol Chemical Composition

Abstract. The online-coupled, regional chemistry transport model COSMO-ART is evaluated for periods in all seasons against several measurement datasets to assess its ability to represent gaseous pollutants and ambient aerosol characteristics over the European domain. Measurements used in the comparison include long-term station observations, satellite and ground-based remote sensing products, and complex datasets of aerosol chemical composition and number size distribution from recent field campaigns. This is the first time these comprehensive measurements of aerosol characteristics in Europe are used to evaluate a regional chemistry transport model. We show a detailed analysis of the simulated size-resolved chemical composition under different meteorological conditions. Mean, variability and spatial distribution of the concentrations of O3 and NOx are well reproduced. SO2 is found to be overestimated, simulated PM2.5 and PM10 levels are on average underestimated, as is AOD. We find indications of an overestimation of shipping emissions. Time evolution of aerosol chemical composition is captured, although some biases are found in relative composition. Nitrate aerosol components are on average overestimated, and sulfates underestimated. The accuracy of simulated organics depends strongly on season and location. While strongly underestimated during summer, organic mass is comparable in spring and autumn. We see indications for an overestimated fractional contribution of primary organic matter in urban areas and an underestimation of SOA at many locations. Aerosol number concentrations compare well with measurements for larger size ranges, but overestimations of particle number concentration with factors of 2–5 are found for particles smaller than 50 nm. Size distribution characteristics are often close to measurements, but show discrepancies at polluted sites. Suggestions for further improvement of the modeling system consist of the inclusion of a revised secondary organic aerosols scheme, aqueous-phase chemistry and improved aerosol boundary conditions. Our work sets the basis for subsequent studies of aerosol characteristics and climate impacts with COSMO-ART, and highlights areas where improvements are necessary for current regional modeling systems in general.

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