scholarly journals Characteristics, seasonality and sources of inorganic ions and trace metals in North-east Asian aerosols

2015 ◽  
Vol 12 (3) ◽  
pp. 338 ◽  
Author(s):  
Chandra Mouli Pavuluri ◽  
Kimitaka Kawamura ◽  
Nikolaos Mihalopoulos ◽  
Pingqing Fu
Keyword(s):  
Trace Metals ◽  
Atmospheric Aerosols ◽  
East Asian ◽  
Fungal Spores ◽  
Inorganic Ions ◽  
Early Spring ◽  
Anthropogenic Sources ◽  
Inorganic Aerosols ◽  
North East ◽  
Northern Japan

Environmental context Atmospheric aerosols affect the Earth’s climate system and can cause adverse effects on human health depending on their loading and chemical composition. This study presents the chemical characteristics and seasonality of inorganic ions and trace metals in atmospheric aerosols from Sapporo, northern Japan, and explores their possible sources. The work is relevant for our understanding of atmospheric composition and climate change. Abstract To better understand the characteristics, seasonality and sources of inorganic aerosols in North-east Asia, we studied total suspended particulate samples collected in Sapporo, northern Japan for inorganic ions and trace metals over a 1-year period. SO42– was found as the most abundant ionic species, which accounted for on average 43±15% of the measured total ionic mass followed by Cl–≈NO3–≈Na+. Among the metals determined, Ca was found as the most abundant (45±5.2% of the measured total metals) followed by Fe. Temporal variations of methanesulfonate (MS–) and SO42– showed a clear seasonal pattern with a maximum in summer followed by spring. Cl–, NO3–, NH4+ and K+ showed increasing trends from mid autumn to winter. Na+, Ca2+ and Mg2+ and crustal metals (Al, Ca, Fe, Ti and Mn) peaked in early spring. Na+ and Mg2+ and Ni, Cu and As were abundant in autumn whereas Zn was in spring. However, Cd and Pb did not show any seasonality. Based on comparisons of such seasonal trends with those of organic tracers as well as the air mass trajectories, we infer that the seasonality in inorganic aerosols in the North-east Asian atmosphere is mainly controlled by their season-specific source(s): soil dust in early spring, biogenic emissions in spring–summer, microbial activities in autumn and forest fires and biomass burning in autumn–winter. However, contributions from anthropogenic sources are significant in all seasons. This study also suggests that fungal spores partly contribute to some trace metals (i.e. Ni, Cu and As) whereas pollen contributes to Zn in aerosols.

scholarly journals Trace element contamination in the mine-affected stream sediments of Oued Rarai in north-western Tunisia: a river basin scale assessment

2021 ◽  
Author(s):  
Jamel Ayari ◽  
Maurizio Barbieri ◽  
Yannick Agnan ◽  
Ahmed Sellami ◽  
Ahmed Braham ◽  
...  
Keyword(s):  
Trace Elements ◽  
Ecological Risk ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Stream Sediments ◽  
Anthropogenic Sources ◽  
Contamination Level ◽  
North East ◽  
Basin Scale ◽  
North Western

AbstractHigh-quality and accurate environmental investigations are essential for the evaluation of contamination and subsequent decision-making processes. A combination of environmental geochemical indices, multivariate analyses and geographic information system approach was successfully used to assess contamination status and source apportionment of trace elements (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, V and Zn) in surface stream sediments from the Oued Rarai basin in north-western Tunisia, containing various metal and metalloid ores. The contamination level reported in this study indicates a non-negligible potential ecological risk, mainly related to sediment transport along the river. Antimony (concentrations ranged from 0.02 to 297 mg kg−1 and Igeo > 5), arsenic (from 0.5 to 1490 mg kg−1 and Igeo > 5), lead (from 2.9 to 5150 mg kg−1 and Igeo > 5) mercury (from 0.05 to 54.4 mg kg−1 and Igeo > 5) and silver (from 0.05 to 9.4 mg kg−1 and Igeo > 5) showed the most crucial contamination. Besides, potential ecological risk index values were maximum for arsenic with a median of 302, indicating a very high to serious ecological risk (> 160). Results from correlation analysis and principal component analysis revealed three main geochemical associations related to lithologic, tectonic and anthropogenic sources. V, Cr and Cu mainly originated from natural bedrock and soil. Ag and Cd were more controlled by both natural and mining enrichments. Mercury and Pb were mostly influenced by the ancient ore-related activities at the Oued Rarai site and north-east–south-west trending faults. Finally, Sb, As, Ni and Zn were largely controlled by the siliciclastic continental Neogene sequences. Finally, the physical and chemical dynamics of the watershed system, lithological properties, mineralisation, tectonic settings and mobilisation of subsurface sediments largely controlled both concentrations and spatial patterns of trace elements in the study basin. These results need to be considered in the strategies of suitable environmental management at former and current mining sites in north-western Tunisia.

Arctic policy of the North East Asian countries

2017 ◽  
Vol 8 (1) ◽  
pp. 69-86 ◽  
Author(s):  
Viatcheslav Gavrilov ◽  
Alexandra Kripakova
Keyword(s):  
East Asian ◽  
Asian Countries ◽  
North East ◽  
The North ◽  
Arctic Policy

scholarly journals Chemical Composition and Source Apportionment of PM2.5 in Urban Areas of Xiangtan, Central South China

2019 ◽  
Vol 16 (4) ◽  
pp. 539 ◽  
Author(s):  
Xiaoyao Ma ◽  
Zhenghui Xiao ◽  
Lizhi He ◽  
Zongbo Shi ◽  
Yunjiang Cao ◽  
...  
Keyword(s):  
Source Apportionment ◽  
South China ◽  
Urban Areas ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Total Carbon ◽  
Anthropogenic Sources ◽  
Vehicle Exhaust ◽  
Industrial Emissions ◽  
Wind Speeds

Xiangtan, South China, is characterized by year-round high relative humidity and very low wind speeds. To assess levels of PM2.5, daily samples were collected from 2016 to 2017 at two urban sites. The mass concentrations of PM2.5 were in the range of 30–217 µg/m3, with the highest concentrations in winter and the lowest in spring. Major water-soluble ions (WSIIs) and total carbon (TC) accounted for 58–59% and 21–24% of the PM2.5 mass, respectively. Secondary inorganic ions (SO42−, NO3−, and NH4+) dominated the WSIIs and accounted for 73% and 74% at the two sites. The concentrations of K, Fe, Al, Sb, Ca, Zn, Mg, Pb, Ba, As, and Mn in the PM2.5 at the two sites were higher than 40 ng/m3, and decreased in the order of winter > autumn > spring. Enrichment factor analysis indicates that Co, Cu, Zn, As, Se, Cd, Sb, Tl, and Pb mainly originates from anthropogenic sources. Source apportionment analysis showed that secondary inorganic aerosols, vehicle exhaust, coal combustion and secondary aerosols, fugitive dust, industrial emissions, steel industry are the major sources of PM2.5, contributing 25–27%, 21–22%, 19–21%, 16–18%, 6–9%, and 8–9% to PM2.5 mass.

scholarly journals Ion-molecule interactions enable unexpected phase transitions in organic-inorganic aerosol

2020 ◽  
Vol 6 (47) ◽  
pp. eabb5643 ◽  
Author(s):  
David S. Richards ◽  
Kristin L. Trobaugh ◽  
Josefina Hajek-Herrera ◽  
Chelsea L. Price ◽  
Craig S. Sheldon ◽  
...  
Keyword(s):  
Air Quality ◽  
Inorganic Ions ◽  
Climate Projections ◽  
Atmospheric Models ◽  
Inorganic Aerosols ◽  
Low Mass ◽  
Inorganic Aerosol ◽  
Semi Solid ◽  
Molecule Interactions ◽  
Inorganic Fraction

Atmospheric aerosol particles are commonly complex, aqueous organic-inorganic mixtures, and accurately predicting the properties of these particles is essential for air quality and climate projections. The prevailing assumption is that aqueous organic-inorganic aerosols exist predominately with liquid properties and that the hygroscopic inorganic fraction lowers aerosol viscosity relative to the organic fraction alone. Here, in contrast to those assumptions, we demonstrate that increasing inorganic fraction can increase aerosol viscosity (relative to predictions) and enable a humidity-dependent gel phase transition through cooperative ion-molecule interactions that give rise to long-range networks of atmospherically relevant low-mass oxygenated organic molecules (180 to 310 Da) and divalent inorganic ions. This supramolecular, ion-molecule effect can drastically influence the phase and physical properties of organic-inorganic aerosol and suggests that aerosol may be (semi)solid under more conditions than currently predicted. These observations, thus, have implications for air quality and climate that are not fully represented in atmospheric models.

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