43 results on '"Long-Range Transport"'
Search Results
2. Aerosol Vertical Structure and Optical Properties during Two Dust and Haze Episodes in a Typical Valley Basin City, Lanzhou of Northwest China.
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Ma, Junyang, Bi, Jianrong, Li, Bowen, Zhu, Di, Wang, Xiting, Meng, Zhaozhao, and Shi, Jinsen
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MINERAL dusts , *AEROSOLS , *OPTICAL properties , *AIR pollutants , *HAZE , *PARTICULATE matter , *VOLCANIC eruptions - Abstract
The vertical profiles of aerosol optical properties are vital to clarify their transboundary transport, climate forcing and environmental health influences. Based on synergistic measurements of multiple advanced detection techniques, this study investigated aerosol vertical structure and optical characteristics during two dust and haze events in Lanzhou of northwest China. Dust particles originated from remote deserts traveled eastward at different altitudes and reached Lanzhou on 10 April 2020. The trans-regional aloft (~4.0 km) dust particles were entrained into the ground, and significantly modified aerosol optical properties over Lanzhou. The maximum aerosol extinction coefficient (σ), volumetric depolarization ratio (VDR), optical depth at 500 nm (AOD500), and surface PM10 and PM2.5 concentrations were 0.4~1.5 km−1, 0.15~0.30, 0.5~3.0, 200~590 μg/m3 and 134 μg/m3, respectively, under the heavy dust event, which were 3 to 11 times greater than those at the background level. The corresponding Ångström exponent (AE440–870), fine-mode fraction (FMF) and PM2.5/PM10 values consistently persisted within the ranges of 0.10 to 0.50, 0.20 to 0.50, and 0.20 to 0.50, respectively. These findings implied a prevailing dominance of coarse-mode and irregular non-spherical particles. A severe haze episode stemming from local emissions appeared at Lanzhou from 30 December 2020 to 2 January 2021. The low-altitude transboundary transport aerosols seriously deteriorated the air quality level in Lanzhou, and aerosol loading, surface air pollutants and fine-mode particles strikingly increased during the gradual strengthening of haze process. The maximum AOD500, AE440–870nm, FMF, PM2.5 and PM10 concentrations, and PM2.5/PM10 were 0.65, 1.50, 0.85, 110 μg/m3, 180 μg/m3 and 0.68 on 2 January 2021, respectively, while the corresponding σ and VDR at 0.20–0.80 km height were maintained at 0.68 km−1 and 0.03~0.12, implying that fine-mode and spherical small particles were predominant. The profile of ozone concentration exhibited a prominent two-layer structure (0.60–1.40 km and 0.10–0.30 km), and both concentrations at two heights always remained at high levels (60~72 μg/m3) during the entire haze event. Conversely, surface ozone concentration showed a significant decrease during severe haze period, with the peak value of 20~30 μg/m3, which was much smaller than that before haze pollution (~80 μg/m3 on 30 December). Our results also highlighted that the vertical profile of aerosol extinction coefficient was a good proxy for evaluating mass concentrations of surface particulate matters under uniform mixing layers, which was of great scientific significance for retrieving surface air pollutants in remote desert or ocean regions. These statistics of the aerosol vertical profiles and optical properties under heavy dust and haze events in Lanzhou would contribute to investigate and validate the transboundary transport and radiative forcing of aloft aerosols in the application of climate models or satellite remote sensing. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Assessment of the Temporal and Seasonal Variabilities in Air Pollution and Implications for Physical Activity in Lagos and Yaoundé.
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Popoola, Olalekan A. M., Alani, Rose, Assah, Felix, Lawanson, Taibat, Tchouaffi, Awah K., Mapa-Tassou, Clarisse, Blanche, Nfondoh, Odekunle, Damilola, Unuigboje, Richard, Onifade, Victor A., Ogunro, Toluwalope, Thondoo, Meelan, Jones, Roderic L., and Oni, Tolu
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PHYSICAL activity , *AIR pollution , *PUBLIC spaces , *CITIES & towns , *SEASONS , *AIR quality - Abstract
Physical activity (PA) can reduce the risk of non-communicable diseases like heart diseases and diabetes. However, exposure to poor air quality (AQ) when engaging in PA could negate the health benefits. The risk associated with air pollution is relatively severe during physical activities because a higher inhaled pollution dose is experienced during PA compared to when sedentary. We conducted a yearlong AQ monitoring using a commercial low-cost AQ device. The devices were deployed near a public space used for PA as part of a study to understand the health risks encountered by people informally appropriating public spaces for PA in Lagos, Nigeria and Yaoundé, Cameroon. The parameters monitored included CO, NO, NO2, O3, PM2.5, PM10, CO2, pressure, temperature and relative humidity. We detected unique pollutant temporal profiles at the two locations, with a distinct weekday-to-weekend effect observed for the gaseous pollutants but not for the PM. Transboundary emissions related to the Harmattan haze dominated the background PM concentration in both cities in the dry season. Our findings underscore the importance of long-term AQ monitoring to inform action and offer insights into simple behavioural changes that can maximise the health benefits of PA while minimising the risk of air pollution exposure. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Assessment of Spatio-Temporal Variations in PM 2.5 and Associated Long-Range Air Mass Transport and Mortality in South Asia.
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Islam, Md Sariful, Roy, Shimul, Tusher, Tanmoy Roy, Rahman, Mizanur, and Harris, Ryley C.
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SPATIO-temporal variation , *AIR masses , *AIR travel , *AIR quality standards , *PARTICULATE matter , *COVID-19 - Abstract
Fine particulate matter (PM2.5) is associated with adverse impacts on ambient air quality and human mortality; the situation is especially dire in developing countries experiencing rapid industrialization and urban development. This study assessed the spatio-temporal variations of PM2.5 and its health impacts in the South Asian region. Both satellite and station-based data were used to monitor the variations in PM2.5 over time. Additionally, mortality data associated with ambient particulate matter were used to depict the overall impacts of air pollution in this region. We applied the Mann–Kendall and Sen's slope trend analysis tool to investigate the trend of PM2.5. At the same time, clustering of backward trajectories was used for identifying the long-range air mass transport. The results revealed that the mean annual PM2.5 mass concentration was the highest (46.72 µg/m3) in Bangladesh among the South Asian countries during 1998–2019, exceeding the national ambient air quality standards of Bangladesh (i.e., 15 µg/m3) and WHO (10 µg/m3), while lower PM2.5 was observed in the Maldives and Sri Lanka (5.35 µg/m3 and 8.69 µg/m3, respectively) compared with the WHO standard. The trend analysis during 1998–2019 suggested that all South Asian countries except the Maldives experienced an increasing trend (p < 0.05) of PM2.5. The study showed that among the major cities, the mean annual PM2.5 value was the highest in New Delhi (110 µg/m3), followed by Dhaka (85 µg/m3). Regarding seasonal variation, the highest PM2.5 was found during the pre-monsoon season in all cities. The findings of this research would help the concerned governments of South Asian countries to take steps toward improving air quality through policy interventions or reforms. Moreover, the results would provide future research directions for studying the trend and transport of atmospheric PM2.5 in other regions. [ABSTRACT FROM AUTHOR]
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- 2023
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5. The Identification and Analysis of Long-Range Aerosol Transport Pathways with Layered Cloud-Aerosol Lidar with Orthogonal Polarization Datasets from 2006 to 2016.
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Wang, Lingyu, Wang, Wensheng, Lyu, Baolei, Zhang, Jinghua, Han, Yilun, Bai, Yuqi, and Guo, Zhi
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TROPOSPHERIC aerosols , *AEROSOL analysis , *ATMOSPHERIC boundary layer , *TROPOSPHERIC ozone , *LIDAR , *AEROSOLS - Abstract
In this study, we used Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol products acquired from 2006 to 2016 to identify global long-range aerosol transport pathways, including the trans-Atlantic, the trans-Pacific, and the trans-Arabian Sea pathways. Deep analyses were subsequently conducted focusing on two significant paths within the range of the trans-Pacific transport pathway, from which we generated a three-stage conceptual model mainly identifying aerosols from the Taklimakan Desert and aerosols from the North China Plain. The results show that in the first stage of the model, the dust or polluted-dust aerosols were emitted, raised, and mixed within the planetary boundary layer (PBL), characterized by high percentages (>70%) of aerosols in the PBL (AODPBL), while in the second stage, some aerosols were further raised into the free troposphere where the AODPBL percentages decreased to less than 40%, driven by vertical movements and turbulences; in the last stage, the aerosols gradually settled back to the surface layer due to gravity and wet deposition, inferred by increasing AODPBL percentages. We demonstrated that the proposed model is capable of characterizing different aerosol types and climate conditions on spatiotemporal scales, providing a straightforward and evident approach to exploring long-range aerosol transport pathways. [ABSTRACT FROM AUTHOR]
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- 2023
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6. How Do Aerosol Influence Cloud Formation and Evolution?
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Mamouri, Rodanthi-Elisavet, Ansmann, Albert, Nisantzi, Argyro, Ene, Dragoş, and Hadjimitsis, Diofantos Gl.
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CLOUDS ,ATMOSPHERIC aerosols ,LIDAR ,ICE clouds ,STRATOSPHERIC aerosols - Abstract
The remote sensing ground-based platform for atmospheric research hosted by the ER-ATOSTHENES Centre of Excellence will be the key research infrastructure of the Cyprus Atmospheric Remote Sensing Observatory (CARO) in Limassol, Cyprus. Between the 27th of October to the 1st of November 2020, the lidar system observed a pronounced and well-aged stratospheric aerosol layer with a backscatter maximum around 10 km asl and clear wildfire smoke signatures. The observed smoke plume was caused by extreme wildfires on the west coast of the U.S. Long-range aerosol transport events observed over Limassol are used for the study of the influence of organic aerosol particles (serving as ice-nucleating particles, INPs) in a cirrus formation in the upper troposphere. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Assessment of Present-Day Heavy Metals Pollution and Factors Controlling Surface Water Chemistry of Three Western Siberian Sphagnum-Dominated Raised Bogs.
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Kharanzhevskaya, Yulia, Gashkova, Lyudmila, Sinyutkina, Anna, and Kvasnikova, Zoya
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WATER chemistry ,HEAVY metal content of water ,SURFACE chemistry ,BOGS ,HEAVY metal toxicology ,ATMOSPHERIC deposition ,HEAVY metals - Abstract
This study investigated the heavy metal concentrations in bog and stream water compared to present-day atmospheric deposition, and concentrations in peat and vegetation within three typical raised bogs in Western Siberia located in urban area, close to oil and gas facilities and in the natural background area. Our data showed that elevated heavy metals deposition occurs not only near industrial centres but also in remote areas, which is a sign of regional atmospheric deposition of heavy metals associated with long-range transport and wildfires. Present-day atmospheric depositions of heavy metals are not always consistent with their contents in waters, and the content of Zn, Pb, Cu and Cd in waters is more correlated with their concentrations in vegetation and in the upper peat layer; this indicates a significant role of biological processes in heavy metal cycling. Temperature plays an important role in increasing the mobility and vegetation uptake of heavy metals. Heavy metals removal is largely determined by the size of the bog and its stage of development, which determines bog–river interaction. The seasonal catchment-scale budget indicated that 80–97% of Zn and Pb and 47–74% of Cu and Cd from atmospheric inputs remained within the catchments. [ABSTRACT FROM AUTHOR]
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- 2023
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8. Influence of the Long-Range Transport of Siberian Biomass Burnings on Air Quality in Northeast China in June 2017.
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Sun, Li, Yang, Lei, Wang, Dongdong, and Zhang, Tiening
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BIOMASS burning , *TRACE gases , *PHOTOSYNTHETICALLY active radiation (PAR) , *AIR travel , *FOREST fires , *AEROSOLS , *CARBONACEOUS aerosols - Abstract
Biomass burning (BB) emits a large volume of trace gases and aerosols into the atmosphere, which can significantly affect the earth's radiative balance and climate and has negative impacts on air quality and even human health. In late June 2017, an intense BB case, dominated by forest and savanna fires, occurred in Siberia, and it affected the air quality of Northeast China through long-range transport. Here, multisatellite remote-sensing products and ground-based PM2.5 measurements are used to evaluate the influence of the Siberian smoky plume on Northeast China. The results show that the BB was intense at the early stage when the daily fire count and average fire radiative power exceeded 300 and 200 MW, respectively. The maximum daily fire count reached 1350 in Siberia, and the peak value of instantaneous fire radiative power was as high as 3091.5 MW. High concentrations of CO and aerosols were emitted into the atmosphere by the BB in Siberia. The maximum daily mean values of the CO column concentration and aerosol optical depth (AOD) increased by 3 × 1017 molec·cm2 and 0.5 compared with that during the initial BB stage. In addition, the BB released a large number of absorptive aerosols into the atmosphere, and the UV aerosol index (UVAI) increased by five times at the peak of the event in Siberia. Under the appropriate synoptic conditions and, combined with pyroconvection, the smoky plume was lifted into the upper air and transported to Northeast China, affecting the air quality of Northeast China. The daily mean values of CO concentration, AOD, and UVAI in Northeast China increased by 6 × 1017 molec·cm2, 0.5, and 1.4, respectively, after being affected. Moreover, the concentration of the surface PM2.5 in Northeast China approximately doubled after being affected by the plume. The results of this study indicate that the air quality of Northeast China can be significantly affected by Siberian BBs under favorable conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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9. A Review of Atmospheric Aerosols in Antarctica: From Characterization to Data Processing.
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Anzano, Jesús, Abás, Elisa, Marina-Montes, César, del Valle, Javier, Galán-Madruga, David, Laguna, Mariano, Cabredo, Susana, Pérez-Arribas, Luis-Vicente, Cáceres, Jorge, and Anwar, Jamil
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ATMOSPHERIC aerosols , *PARTICULATE matter , *AIR pollution , *ELECTRONIC data processing , *AIR quality , *AIR pollutants , *SUBGLACIAL lakes - Abstract
One of the major problems of the present era is air pollution, not only for its impact on climate change but also for the diseases provoked by this scourge. Among the most concerning air pollutants is particulate matter, since it can travel long distances and affect the entire globe. Antarctica is extremely sensitive to climate change and essential for regulating temperature and permitting life on Earth. Therefore, air quality studies in this region are extremely important. The aim of this review is to present the work conducted on the identification and detection of aerosols and particulate matter in the Antarctic region in the last 20 years. These studies revealed a large number of organic and inorganic species. Organochlorine pesticides or polychlorinated biphenyls represent almost 50% of the organic fraction detected in Antarctica. Furthermore, heavy metals such as Hg and Pb were also found in the region related to anthropogenic activities. To summarize, this work detailed different analytical techniques and data processing to help characterize Antarctic aerosols and their potential sources. [ABSTRACT FROM AUTHOR]
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- 2022
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10. Insights into Variations and Potential Long-Range Transport of Atmospheric Aerosols from the Aral Sea Basin in Central Asia.
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Wu, Na, Ge, Yongxiao, Abuduwaili, Jilili, Issanova, Gulnura, and Saparov, Galymzhan
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ATMOSPHERIC aerosols , *ATMOSPHERIC transport , *STRATOSPHERIC aerosols , *TROPOSPHERIC aerosols , *ATMOSPHERIC models , *GEOCHEMICAL modeling - Abstract
The dramatic shrinkage of the Aral Sea in the past decades has inevitably led to an environmental calamity. Existing knowledge on the variations and potential transport of atmospheric aerosols from the Aral Sea Basin (ASB) is limited. To bridge this knowledge gap, this study tried to identify the variations and long-range transport of atmospheric aerosols from the ASB in recent years. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) data were used to gain new insight into the types, variation and long-range transport of atmospheric aerosols from the ASB. The results showed five types of tropospheric aerosols and one type of stratospheric aerosol were observed over the ASB. Polluted dust and dust were the dominant subtypes through the year. Sulfate/other was the only stratospheric aerosol detected. The occurrence frequency of aerosols over the ASB showed obvious seasonal variation. Maximum occurrence frequency of dust appeared in spring (MAM) and that of polluted dust peaked in summer (JJA). The monthly occurrence frequency of dust and polluted dust exhibited unimodal distribution. Polluted dust and dust were distributed over wide ranges from 1 km to 5 km vertically. The multi-year average thickness of polluted dust and dust layers was around 1.3 km. Their potential long-range transport in different directions mainly impacts Uzbekistan, Turkmenistan, Kazakhstan and eastern Iran, and may reach as far as the Caucasus region, part of China, Mongolia and Russia. Combining aerosol lidar, atmospheric climate models and geochemical methods is strongly suggested to gain clarity on the variations and long-range transport of atmospheric aerosols from the Aral Sea Basin. [ABSTRACT FROM AUTHOR]
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- 2022
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11. Large-Scale Saharan Dust Episode in April 2019: Study of Desert Aerosol Loads over Sofia, Bulgaria, Using Remote Sensing, In Situ, and Modeling Resources.
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Peshev, Zahari, Deleva, Atanaska, Vulkova, Liliya, and Dreischuh, Tanja
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MINERAL dusts , *REMOTE sensing , *AEROSOLS , *DUST , *CLIMATE change , *AIR masses , *REMOTE-sensing images - Abstract
Emissions of immense amounts of desert dust into the atmosphere, spreading over vast geographical areas, are in direct feedback relation with ongoing global climate changes. An extreme large-scale Saharan dust episode occurred over Mediterranean and Europe in April 2019, driven by a dynamic blocking synoptic pattern (omega block) creating conditions for a powerful northeastward circulation of air masses rich in dust and moisture. Here, we study and characterize the effects of related dust intrusion over Sofia, Bulgaria, using lidar remote sensing combined with in situ measurements, satellite imagery, and modeling data. Optical and microphysical parameters of the desert aerosols were obtained and vertically profiled, namely, backscatter coefficients and backscatter-related Ångström exponents, as well as statistical distributions of the latter as qualitative analogs of the actual particle size distributions. Dynamical and topological features of the dust-dominated aerosol layers were determined. Height profiles of the aerosol/dust mass concentration were obtained by synergistic combining and calibrating lidar and in situ data. The comparison of the retrieved mass concentration profiles with the dust modeling ones shows a satisfactory compliance. The local meteorological conditions and the aerosol composition and structure of the troposphere above Sofia during the dust event were seriously affected by the desert air masses. [ABSTRACT FROM AUTHOR]
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- 2022
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12. Different Transport Behaviors between Asian Dust and Polycyclic Aromatic Hydrocarbons in Urban Areas: Monitoring in Fukuoka and Kanazawa, Japan.
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Pham, Kim-Oanh, Hara, Akinori, Zhao, Jiaye, Suzuki, Keita, Matsuki, Atsushi, Inomata, Yayoi, Matsuzaki, Hiroshi, Odajima, Hiroshi, Hayakawa, Kazuichi, and Nakamura, Hiroyuki
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POLYCYCLIC aromatic hydrocarbons ,OPTICAL radar ,CITIES & towns ,LIDAR ,DUST - Abstract
To clarify different effects of Asian dust (AD), long-range transported from Asian continent, on total suspended particles (TSP) and polycyclic aromatic hydrocarbons (PAHs) in Japan, TSP were simultaneously collected during AD periods (from 1 March to 31 May 2020 and 2021) in Fukuoka and Kanazawa. During AD days, decided by Light Detection and Ranging and Japan Meteorological Agency, TSP concentrations increased significantly (p < 0.001) at two sampling sites. PAH concentrations increased in Kanazawa (p < 0.001) but not in Fukuoka on AD days. Correlation coefficients (r) between daily TSP and total PAHs concentrations were weak in Kanazawa: 0.521 (non-AD) and 0.526 (AD) (p < 0.01), and in Fukuoka: 0.321 (non-AD) and 0.059 (AD). However, correlation between seasonal (average monthly) TSP and total PAH concentrations were stronger: 0.680 (Kanazawa) and 0.751 (Fukuoka). The reasons might be that seasonal variations of TSP and total PAHs in two cities depend equally on planetary scale westerly, while daily TSP and total PAHs variations in each city varied by different transportation distances from AD and PAHs sources in the Asian continent to Japan. Different local sources and meteorological conditions were considered. These results are important for elucidating the causes of chronic and acute respiratory diseases. [ABSTRACT FROM AUTHOR]
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- 2022
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13. Changes in Ambient Bacterial Community in Northern Taiwan during Long-Range Transport: Asian Dust Storm and Frontal Pollution.
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Chen, Nai-Tzu, Tam, Lai-Man, Wu, Jer-Horng, Cheong, Ngok-Song, Lin, Chuan-Yao, Tseng, Chun-Chieh, and Su, Huey-Jen
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DUST storms , *BACTERIAL communities , *RESTRICTION fragment length polymorphisms , *POLLUTION , *BACILLUS (Bacteria) , *MICROBIOLOGICAL aerosols , *BACTERIAL population - Abstract
Long-range transport (LRT) can carry air pollutants to downwind areas. However, studies about the impacts of LRT on bacterial communities are few. This study investigated the influence of Asian dust storms (ADS) and frontal pollution (FP) on bacterial communities in ambient air using next-generation sequencing (NGS) and Terminal Restriction Fragment Length Polymorphism (T-RFLP). Air samples were collected at Cape Fugui (CF) and National Taiwan University (NTU) in northern Taiwan before (or background days), during, and after LRTs from November 2013 to March 2015. The richness, H index, and evenness increased during FPs and then decreased after FPs. During and after ADS and FP, the prevalence of the phylum Proteobacteria decreased, but that of Firmicutes increased. The dominant class of Proteobacteria changed from Alphaproteobacteria on background days to Betaproteobacteria during LRTs. At the genus level, the high abundance of Ralstonia and Bacillus during FP and Clostridium during ADS were detected at both locations. Additionally, Ralstonia was dominant at CF during ADS. In conclusion, FP and ADS both changed the bacterial community. The indicator genus was Clostridium and Ralstonia for ADS as well as Bacillus and Ralstonia for FP. Given the potential health threats posed by the bioaerosols transported, people should avoid outdoor activities during LRTs. [ABSTRACT FROM AUTHOR]
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- 2022
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14. Investigation of Policy Relevant Background (PRB) Ozone in East Asia.
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Lam, Yun Fat and Cheung, Hung Ming
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OZONE , *AIR pollution control , *AIR pollutants , *WEATHER - Abstract
The concept of Policy Relevant Background (PRB) ozone has emerged in recent years to address the air quality baseline on the theoretical limits of air pollution controls. In this study, the influence of Long-range Transport (LRT) of air pollutants from North America and the effect of Stratosphere-Troposphere Transport (STT) on PRB ozone was investigated using GEOS-Chem coupled WRF-CMAQ modelling system. Four distinct seasons in 2006 were simulated to understand better the seasonal and geographical impacts of these externalities on PRB ozone over East Asia (EA). Overall, the LRT impact from North America has been found to be ~0.54 ppbv, while the maximum impacts were found at the mountain stations with values of 2.3 ppbv, 3.3 ppbv, 2.3 ppbv, and 3.0 ppbv for January, April, July, and October, respectively. In terms of PRB ozone, the effect of STT has enhanced the surface background ozone by ~3.0 ppbv, with a maximum impact of 7.8 ppbv found in the northeastern part of East Asia (near Korea and Japan). Springtime (i.e., April) has the most vital STT signals caused by relatively cold weather and unstable atmospheric condition resulting from the transition of the monsoon season. The simulated PRB ozone based on the mean values of the maximum daily 8-h average (MDA8) is 53 ppbv for spring (April) and 22 ppbv for summer (July). Up to ~1.0 ppbv and ~2.2 ppbv of MDA8 ozone were attributed to LRT and STT, respectively. Among the selected cities, Beijing and Guangzhou have received the most substantial anthropogenic enhancement in MDA8 ozone in summer, ranging from 40.0 ppbv to 56.0 ppbv. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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15. The Impact of Solid Fuel Residential Boilers Exchange on Particulate Matter Air Pollution.
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Koval, Silvie, Vytisk, Jiri, Ruzickova, Jana, Raclavska, Helena, Skrobankova, Hana, and Hellebrandova, Lucie
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AIR pollution ,AIR pollution control ,PARTICULATE matter ,BOILERS ,INDUSTRIAL location ,AIR quality - Abstract
Combustion processes, including the use of solid fuels for residential heating, are a widespread custom for many households. Residential heating is a significant source of ambient air pollution, yet it varies greatly by geography, meteorologic conditions, the prevalence of the type of solid fuel and the technologies used. This study evaluates whether residential heating affects the air quality through modelling three given scenarios of solid fuel boiler exchange at selected locations and comparing the results with measured data. The findings of this study suggest that according to the modelled data, the main air pollution contributor is residential heating since Dolni Lhota (daily average of PM
10 = 44.13 μg·m−3 ) and Kravare (daily average of PM10 = 43.98 μg·m−3 ) are locations with no industry in contrast to heavily industrial Vratimov (daily average of PM10 = 34.38 μg·m−3 ), which were modelled for the heating season situation. Nevertheless, actual measurements of PM10 during the same period suggest that the average levels of air pollution were significantly higher than the modelled values for Dolni Lhota by 64% and for Kravare by 51%. Thus, it was assumed that PM long-range or/and transboundary transports were involved. [ABSTRACT FROM AUTHOR]- Published
- 2021
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16. Monthly and Diurnal Variation of the Concentrations of Aerosol Surface Area in Fukuoka, Japan, Measured by Diffusion Charging Method.
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Miho Kiriya, Tomoaki Okuda, Hana Yamazaki, Kazuki Hatoya, Naoki Kaneyasu, Itsushi Uno, Chiharu Nishita, Keiichiro Hara, Masahiko Hayashi, Koji Funato, Kozo Inoue, Shigekazu Yamamoto, Ayako Yoshino, and Akinori Takami
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ATMOSPHERIC aerosols , *SOOT , *POLLUTANTS , *SEA breeze - Abstract
Observation of the ambient aerosol surface area concentrations is important to understand the aerosol toxicity because an increased surface area may be able to act as an enhanced reaction interface for certain reactions between aerosol particles and biological cells, as well as an extended surface for adsorbing and carrying co-pollutants that are originally in gas phase. In this study, the concentration of aerosol surface area was measured from April 2015 to March 2016 in Fukuoka, Japan. We investigated the monthly and diurnal variations in the correlations between the aerosol surface area and black carbon (BC) and sulfate concentrations. Throughout the year, aerosol surface area concentration was strongly correlated with the concentrations of BC, which has a relatively large surface area since BC particles are usually submicron agglomerates consisting of much smaller (tens of nanometers) sized primary soot particles. The slopes of the regression between the aerosol surface area and BC concentrations was highest in August and September 2015. We presented evidence that this was caused by an increase in the proportion of airmasses that originated on the main islands of Japan. This may enhance the introduction of the BC to Fukuoka from the main islands of Japan which we hypothesize to be relatively fresh or "uncoated", thereby maintaining its larger surface area. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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17. Characterization, Long-Range Transport and Source Identification of Carbonaceous Aerosols during Spring and Autumn Periods at a High Mountain Site in South China.
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Hong-yan Jia, Lei Wang, Peng-hui Li, Yan Wang, Li-qiong Guo, Tao Li, Lei Sun, You-ping Shou, Tian-yu Mao, and Xian-liang Yi
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PARTICULATE matter , *CARBONACEOUS aerosols , *PARTICLES , *AIR masses , *ATMOSPHERIC circulation - Abstract
PM10 (particulate matter) samples were collected at Mount Lu, a high elevation mountain site in south China (August and September of 2011; and March, April and May of 2012). Eight carbonaceous fractions of particles were analyzed to characterize the possible carbonaceous emission sources. During the sampling events, daily average concentrations of PM10 at Mount Lu were 97.87 μg/m³ and 73.40 μg/m³ in spring and autumn, respectively. The observed mean organic carbon (OC) and element carbon (EC) concentrations during spring in PM10 were 10.58 μg/m³ and 2.58 μg/m³, respectively, and those in autumn were 6.89 μg/m3 and 2.40 μg/m³, respectively. Secondary organic carbon concentration was 4.77 μg/m³ and 2.93 μg/m³ on average, accounting for 28.0% and 31.0% of the total OC in spring and autumn, respectively. Relationships between carbonaceous species and results of principal component analysis showed that there were multiple sources contributing to the carbonaceous aerosols at the observation site. Through back trajectory analysis, it was found that air masses in autumn were mainly transported from the south of China, and these have the highest OC but lowest EC concentrations. Air masses in spring transported from northwest China bring 7.77 μg/m³ OC and 2.28 μg/m³ EC to the site, with lower levels coming from other sites. These air mass sources were featured by the effective carbon ratio (ECR). [ABSTRACT FROM AUTHOR]
- Published
- 2016
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18. Long-Range Transport of SO2 from Continental Asia to Northeast Asia and the Northwest Pacific Ocean: Flow Rate Estimation Using OMI Data, Surface in Situ Data, and the HYSPLIT Model.
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Junsung Park, Jaeyong Ryu, Daewon Kim, Jaeho Yeo, and Hanlim Lee
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OZONE , *LAGRANGIAN functions , *ATMOSPHERIC ozone , *OZONE generators - Abstract
This present study suggests a method to calculate the SO2 flow rate from a source area to receptor areas on a regional scale using Ozone Monitoring Instrument (OMI) SO2 products, surface in situ SO2 data, and the hybrid single particle Lagrangian integrated trajectory (HYSPLIT) model. The method was implemented to calculate the SO2 flow rate from continental Asia to northeast Asia and the Northwest Pacific Ocean. For the high SO2 events when SO2 was transported from continental Asia to Japan via the Korean Peninsula on 22-24 December 2006, the long-range transported SO2 flow rates were 14.0 (21.0) Mg·h-1 OMI·gird-1 at Gangneung (Seoul) in Korea and 4.2 (5.3) Mg·h-1 OMI·gird-1 at Hiroshima (Kumamoto) in Japan. For the long-range transport of SO2 from continental Asia to the Northwest Pacific Ocean on 6-7 October 2008 (9-11 October 2006), the flow rates were 16.1 (16.2) Mg·h-1 OMI·gird-1 at Hokkaido, Japan (Vladivostok, Russia) and 5.6 (16.7) Mg·h-1 OMI·gird-1 at the Aleutian Islands, Northwest Pacific Ocean (Bering Sea). The mean rates of decrease in the SO2 flow rate per 1000 km were also calculated between continental Asia and the receptor areas. Uncertainties in the flow rate estimates were also assessed and discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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19. Influence of Trans-Boundary Air Pollution on the Urban Atmosphere in Fukuoka, Japan.
- Author
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Ayako Yoshino, Akinori Takami, Kei Sato, Atsushi Shimizu, Naoki Kaneyasu, Shiro Hatakeyama, Keiichiro Hara, and Masahiko Hayashi
- Subjects
- *
AIR quality research , *TRANSBOUNDARY pollution , *AIR pollution , *RADIOACTIVE aerosols , *MASS spectrometers - Abstract
To understand the influence of trans-boundary air pollution on the air quality of Fukuoka, the mass concentration and chemical composition of fine particulate matter (PM) were observed at urban (Fukuoka) and rural (Fukue Island) sites in the northern Kyushu area in Japan. Chemical composition was measured using an aerosol mass spectrometer. Organic aerosol (OA) data were analyzed by the positive matrix factorization (PMF) method. Sulfate and low-volatile oxygenated OA (LV-OOA) were dominant for all of the PM2.5 mass variations on Fukue Island, where the trans-boundary air pollution is dominant in the winter-spring season. In Fukuoka, however, sulfate accounted for the largest fraction of total chemical species under high PM2.5 mass concentrations (>35 μg.m-3), while organics and nitrate made up a large fraction under low PM2.5 (<10 μg.m-3). Under the high PM2.5 condition, LV-OOA was also dominant. This indicates that high PM2.5 mass concentrations were attributed to the long-range transport of air pollution. Although the trans-boundary air pollution prevails in the winter-spring season, high sulfate concentrations were observed in the summer of 2012. In addition to the volcanic activities and photochemical reactions, long-range, trans-boundary air pollutions are influential factors not only in winter-spring but also in summer. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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20. The Influence of Sandstorms and Long-Range Transport on Polycyclic Aromatic Hydrocarbons (PAHs) in PM2.5 in the High-Altitude Atmosphere of Southern China.
- Author
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Minmin Yang, Yan Wang, Qiang Liu, Aijun Ding, and Yuhua Li
- Subjects
- *
SANDSTORMS , *POLYCYCLIC aromatic hydrocarbons , *UPPER atmosphere , *MOLECULAR weights - Abstract
PM2.5 (Particulate Matter 2.5) samples were collected at Mount Heng and analyzed for polycyclic aromatic hydrocarbons (PAHs). During sampling, a sandstorm from northern China struck Mount Heng and resulted in a mean PM2.5 concentration of 150.61 μg/m3, which greatly exceeded the concentration measured under normal conditions (no sandstorm: 58.50 μg/m3). The average mass of PAHs in PM2.5 was 30.70 μg/g, which was much lower than in the non-sandstorm samples (80.80 μg/g). Therefore, the sandstorm increased particle levels but decreased PAH concentrations due to dilution and turbulence. During the sandstorm, the concentrations of 4- and 5-ring PAHs were below their detection limits, and 6-ring PAHs were the most abundant. Under normal conditions, the concentrations of 2-, 3- and 6-ring PAHs were higher, and 4- and 5-ring PAHs were lower relative to the other sampling sites. In general, the PAH contamination was low to medium at Mount Heng. Higher LMW (low molecular weight) concentrations were primarily linked to meteorological conditions, and higher HMW (high molecular weight) concentrations primarily resulted from long-range transport. Analysis of diagnostic ratios indicated that PM2.5 PAHs had been emitted during the combustion of coal, wood or petroleum. The transport characteristics and origins of the PAHs were investigated using backwards Lagrangian particle dispersion modeling. Under normal conditions, the "footprint" retroplumes and potential source contributions of PAHs for the highest and lowest concentrations indicated that local sources had little effect. In contrast, long-range transport played a vital role in the levels of PM2.5 and PAHs in the high-altitude atmosphere. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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- View/download PDF
21. Temporal Variability of Atmospheric Total Gaseous Mercury in Windsor, ON, Canada.
- Author
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Xiaohong Xu, Akhtar, Umme, Clark, Kyle, and Xiaobin Wang
- Subjects
- *
MERCURY , *COMBUSTION , *ACTIVE combustion control , *LIQUID metals , *DIURNAL atmospheric pressure variations ,ENVIRONMENTAL aspects - Abstract
Atmospheric Total Gaseous Mercury (TGM) concentrations were monitored in Windsor, Ontario, Canada, during 2007 to 2011, to investigate the temporal variability of TGM. Over five years, the average concentration was 2.0 ± 1.3 ng/m³. A gradual decrease in annual TGM concentrations from 2.0 ng/m³ in year 2007 to 1.7 ng/m³ in 2009 was observed. The seasonal means show the highest TGM concentrations during the summer months (2.4 ± 2.0 ng/m³), followed by winter (1.9 ± 1.4 ng/m³), fall (1.8 ± 0.81 ng/m³), and spring (1.7 ± 0.73 ng/m³). Diurnal patterns in summer, fall, and winter were similar. A different diurnal pattern was observed in spring with an early depletion in the morning. The TGM concentrations were lower on weekends (1.8 ± 0.77 ng/m³) than on weekdays (2.0 ± 1.5 ng/m³), suggesting 10% of TGM in Windsor was attributable to emissions from industrial sectors in the region. Directional TGM concentrations also indicated southwesterly air masses were TGM enriched due to emissions from coal-fired power plants and industrial facilities. Correlation and principal component analysis identified that combustion of fossil fuel, ambient temperature, wind speed, synoptic systems, and O3 concentrations influenced TGM concentrations significantly. Overall, inter-annual, seasonal, day-of-week, and diurnal variability was observed in Windsor. The temporal patterns were affected by anthropogenic and surface emissions, as well as atmospheric mixing and chemistry. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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22. Comparative Analysis of PM2.5-Bound Polycyclic Aromatic Hydrocarbons (PAHs), Nitro-PAHs (NPAHs), and Water-Soluble Inorganic Ions (WSIIs) at Two Background Sites in Japan
- Author
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Ayako Yoshino, Naoki Kaneyasu, Wanli Xing, Kei Sato, Akira Toriba, Lu Yang, Akinori Takami, Lulu Zhang, Atsushi Shimizu, Hao Zhang, Xuan Zhang, Kazuichi Hayakawa, Ning Tang, Quanyu Zhou, and Atsushi Matsuki
- Subjects
China ,food.ingredient ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,polycyclic aromatic hydrocarbons ,lcsh:Medicine ,PM2.5 ,010501 environmental sciences ,Inorganic ions ,Monsoon ,01 natural sciences ,Article ,Atmosphere ,food ,Japan ,Combustion process ,water-soluble inorganic ions ,Humans ,0105 earth and related environmental sciences ,Ions ,long-range transport ,Air Pollutants ,nitro-polycyclic aromatic hydrocarbons ,Sea salt ,lcsh:R ,Public Health, Environmental and Occupational Health ,Water ,Particulates ,Aerosol ,Water soluble ,Environmental chemistry ,Environmental science ,background sites ,Particulate Matter ,Seasons ,Environmental Monitoring - Abstract
Daily PM2.5 (particulate matter with aerodynamic diameter &le, 2.5 &mu, m) samples were simultaneously collected at two background sites (Wajima Air Monitoring Station (WAMS) and Fukue-Jima Atmosphere and Aerosol Monitoring Station (FAMS)) in Japan in the East Asian winter and summer monsoon periods of 2017 and 2019, to compare the characteristics of air pollutants among different regions and to determine the possible variation during the long-range transport process. Polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and water-soluble inorganic ions (WSIIs) were analyzed. Despite the PM2.5 concentrations at FAMS (8.90 &ndash, 78.5 µ, g/m3) being higher than those at WAMS (2.33 &ndash, 21.2 µ, g/m3) in the winter monsoon period, the average concentrations of &sum, PAHs, &sum, NPAHs, and &sum, WSIIs were similar between the two sites. Diagnostic ratios indicated PAHs mainly originated from traffic emissions and mostly aged, whereas NPAHs were mostly secondarily formed during long-range transport. WSIIs at WAMS were mainly formed via the combustion process and secondary reactions, whereas those at FAMS mainly originated from sea salt and dust. Backward trajectories revealed the air masses could not only come from Asian continental coastal regions but also distant landlocked areas in the winter monsoon period, whereas most came from the ocean in the summer monsoon period. These findings can provide basic data for the establishment of prediction models of transboundary air pollutants in East Asia.
- Published
- 2020
23. Analysis of Ozone Concentrations between 2002–2020 in Urban Air in Northern Spain.
- Author
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García, M. Ángeles, Villanueva, Javier, Pardo, Nuria, Pérez, Isidro A., and Sánchez, M. Luisa
- Subjects
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OZONE , *TROPOSPHERIC ozone , *SOLAR radiation , *NITROGEN oxides , *CITIES & towns , *SURFACE analysis - Abstract
This paper analyses surface ozone measurements at five stations in an urban area (Valladolid) in the upper Spanish plateau over the period 2002–2020. Temporal evolutions, the relationship between ozone and other pollutants such as nitrogen oxides, and the assessment of the ozone concentration trend during the study period were analysed. Daily evolution of ozone at all the stations showed mean maximum concentrations in the afternoon, 15:00 GMT, with values ranging between 73.8 and 80.9 µg m−3, evidencing the influence of photochemical processes favoured by solar radiation in ozone formation. The lowest levels were recorded at night and in the early morning, 7:00 GMT, and were between 23.4 and 32.3 µg m−3, related with the reduction by NO reactions and deposition processes. A broad spring–summer peak between May and July was seen, with the highest values in the latter, with a mean value of up to 73.8 µg m−3. The variation in the monthly mean ozone concentrations of the different percentiles was analysed using a harmonic model. The empirical equation described the experimental values satisfactorily, with a confidence level of 95% and coefficients of determination above 80%, confirming the major decreasing trend in the ozone peak values over the study period. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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24. Effect of Error in SO 2 Slant Column Density on the Accuracy of SO 2 Transport Flow Rate Estimates Based on GEMS Synthetic Radiances.
- Author
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Park, Junsung, Choi, Wonei, Lee, Hyung-Min, Park, Rokjin J., Kim, Seong-Yeon, Yu, Jeong-Ah, Lee, Dong-Won, and Lee, Hanlim
- Subjects
- *
ATMOSPHERIC boundary layer , *RADIANCE , *DENSITY , *STANDARD deviations - Abstract
This study investigates the uncertainties associated with estimates of the long-range transport SO2 (LRT-SO2) flow rate calculated hourly using Geostationary Environment Monitoring Spectrometer (GEMS) synthetic radiances. These radiances were simulated over the Korean Peninsula and the surrounding regions using inputs from the GEOS-Chem model for January, April, July, and October 2016. The LRT-SO2 calculation method, which requires SO2 vertical column densities, wind data, and planetary boundary layer information, was used to quantify the effects of the SO2 slant column density (SCD) retrieval error and uncertainties in wind data on the accuracy of the LRT-SO2 estimates. The effects were estimated for simulations of three anthropogenic and three volcanic SO2 transport events. When there were no errors in the GEMS SO2 SCD and wind data, the average true LRT-SO2 flow rates (standard deviation) and those calculated for these events were 1.17 (± 0.44) and 1.21 (± 0.44) Mg/h, respectively. However, the averages of the true LRT-SO2 flow rates and those calculated for the three anthropogenic (volcanic) SO2 events were 0.61 (1.17) and 0.64 (1.20) Mg/h, respectively, in the presence of GEMS SO2 SCD errors. In the presence of both errors in the GEMS SO2 SCD and wind data, the averages of the true LRT-SO2 flow rates and those calculated for the three anthropogenic (volcanic) SO2 events were 0.61 (1.17) and 0.61 (1.04) Mg/h, respectively. This corresponds to differences of 2.1% to 23.1% between the simulated and true mean LRT-SO2 flow rates. The mean correlation coefficient (R), intercept, and slope between the true and simulated LRT-SO2 flow rates were 0.51, 0.43, and 0.45 for the six simulated events, respectively. This study demonstrates that SO2 SCD accuracy is an important factor in improving estimates of LRT-SO2 flow rates. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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25. Arctic Freshwater Environment Altered by the Accumulation of Commonly Determined and Potentially New POPs.
- Author
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Kosek, Klaudia and Ruman, Marek
- Subjects
POLLUTANTS ,FRESH water ,PERSISTENT pollutants ,TUNDRAS ,WATERSHEDS ,GEOMORPHOLOGY ,ANIMAL health ,POLLUTION - Abstract
Chemical composition of Arctic freshwater ecosystems depends on several factors. They include characteristics of the surrounding landscape, its lithology, geomorphology, vegetation, and hydrological features, as well as accumulation of anthropogenic pollution. In the Arctic, the problem of environmental contamination is widespread. That is why research on lakes and river catchments in terms of their chemical composition has enjoyed increasing interest among scientists worldwide. The freshwater reservoirs of the Arctic are fragile and particularly vulnerable to the uptake of pollutants that become trapped in the water and sediments for an extended period. This review summarises selected studies of freshwater bodies in the Arctic to highlight the problem of the accumulation of pollutants in these reservoirs. Moreover, it emphasises the possible negative impact of chemical pollutants on both animal and human health. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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26. Effects of Meteorological Conditions on PM2.5 Concentrations in Nagasaki, Japan
- Author
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Jianhua Wang and Susumu Ogawa
- Subjects
Pollution ,PM2.5 ,Health, Toxicology and Mutagenesis ,media_common.quotation_subject ,correlation analysis ,lcsh:Medicine ,Atmospheric sciences ,Wind speed ,Article ,Statistics, Nonparametric ,Japan ,Mass concentration (chemistry) ,meteorological variables ,Precipitation ,Cities ,Particle Size ,Visibility ,Weather ,media_common ,Pollutant ,long-range transport ,Air Pollutants ,lcsh:R ,Public Health, Environmental and Occupational Health ,Particulates ,Wind direction ,Linear Models ,Environmental science ,Particulate Matter ,Seasons ,Environmental Monitoring - Abstract
The fine particulate matter (PM2.5) problem has attracted much scientific and public attention, due to its effects on visibility, human health, and global climate. There are three factors that have important effect on PM2.5 mass concentration: domestic pollutant emission sources, external sources outside of the country, and the meteorological conditions. Nagasaki is a coastal prefecture located at the westernmost part of Japan, which is an ideal location to study pollutants from long range transport and correlation between PM2.5 and meteorological conditions. In this paper, PM2.5 concentration data and meteorological data were obtained during 1 January 2013~31 December 2013. The spatial distribution depicts that the western part of the study area has the most serious PM2.5 pollution. The correlation analysis results between PM2.5 concentration and meteorological data showed that temperature had a negative, and precipitation had a positive, correlation with PM2.5. There was a threshold in the correlations between humidity and wind speed and PM2.5. The correlation was positive or negative depending on the meteorological variable values, if these were lower or higher than the threshold. From the relationship with wind direction, it can be depicted that the west wind might bring the most pollutants to Nagasaki., International Journal of Environmental Research and Public Health, 12(8), pp.9089-9101; 2015
- Published
- 2015
27. Concentrations and Sources of Atmospheric PM, Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Kanazawa, Japan.
- Author
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Hayakawa, Kazuichi, Tang, Ning, Xing, Wanli, Oanh, Pham Kim, Hara, Akinori, Nakamura, Hiroyuki, and Wakamatsu, Shinji
- Subjects
- *
POLYCYCLIC aromatic hydrocarbons , *AROMATIC compounds , *DUST , *CARBONACEOUS aerosols - Abstract
PM2.5 (fine particles with diameters 2.5 micrometers and smaller) and PM>2.5 were separately collected in Kanazawa, Japan in every season, from the spring of 2017 to the winter of 2018, and nine polycyclic aromatic hydrocarbons (PAHs) and six nitropolycyclic aromatic hydrocarbons (NPAHs) were respectively determined using high-performance liquid chromatography (HPLC) with fluorescence and chemiluminescence detections. The atmospheric concentrations of both the PAHs and NPAHs showed seasonal changes (highest in the winter and lowest in the summer), which differed from the variations in the total suspended particulate matter (TSP) and PM2.5 amounts (which were highest in the spring). The contributions of major sources to the combustion-derived particulate (Pc) in the PM2.5 were calculated using the 1-nitropyrene-pyrene (NP) method, using pyrene and 1-nitropyrene as the representative markers of PAHs and NPAHs, respectively. The annual average concentration of Pc accounted for only 2.1% of PM2.5, but showed the same seasonal variation as PAHs. The sources of Pc were vehicles (31%) and coal heating facilities/industries (69%). A backward trajectory analysis showed that the vehicle-derived Pc was mainly from Kanazawa and its surroundings, and that coal heating facilities/industry-derived Pc was transported from city areas in central and northern China in the winter, and during the Asian dust event in the spring. These results show that large amounts of PAHs were transported over a long range from China during the winter. Even in the spring, after the coal heating season was over in China, PAHs were still transported to Japan after Asian dust storms passed through Chinese city areas. By contrast, the main contributors of NPAHs were vehicles in Kanazawa and its surroundings. The recent Pc concentrations were much lower than those in 1999. This decrease was mostly attributed to the decrease in the contribution of vehicle emissions. Thus, the changes in the atmospheric concentrations of Pc, PAHs and NPAHs in Kanazawa were strongly affected not only by the local emissions but also by long-range transport from China. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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28. Establishment of a CoMFA Model Based on the Combined Activity of Bioconcentration, Long-Range Transport, and Highest Infrared Signal Intensity and Molecular Design of Environmentally Friendly PBB Derivatives.
- Author
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Yang, Luze, Li, Minghao, Liu, Miao, and Bara, Jason
- Subjects
- *
COMPARATIVE molecular field analysis , *BIOCONCENTRATION , *POLYBROMINATED biphenyls , *ELECTROSTATIC fields - Abstract
In the current study, a comparative molecular field analysis (CoMFA) model with the combined activity of polybrominated biphenyls (PBBs) bioconcentration, long-range transport, and the highest infrared signal intensity (weight ratio of 5:4:1) was constructed based on the threshold method and was further evaluated and analyzed. PBB-153 derivatives with improved combined activity values of bioconcentration, long-range transport, and the highest infrared signals intensity were designed based on contour maps of the CoMFA model. The environmental stability and functionality of the derivatives were also evaluated. The constructed model showed good prediction ability, fitting ability, stability, and external prediction ability. The contribution rates of electrostatic and steric fields to the combined activity of PBBs were 53.4% and 46.6%, respectively. Four PBB-153 derivatives with significantly improved bioconcentration, long-range transport and the highest infrared signal intensity (the combined activity value of these three parameters decreased) were screened with good environmental stability and functionality. Results validated the accuracy and reliability, and ability of the generated model to realize the simultaneous modification of the three activities of the target molecule. The binding ability of the designed derivatives to food chain biodegradation enzymes increased, thereby verifying the improvement in the bioconcentration. The half-lives of the derivatives in air and their ability to be absorbed by the plants significantly improved compared to the target molecule, further showing that the long-range transport of derivatives was reduced. In addition, the introduction of the –NO group caused the N =O stretching vibration of the derivatives to increase the infrared signal intensity. The present model provides a theoretical design method for the molecular modification of environmentally friendly PBBs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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29. Investigation of Volcanic Emissions in the Mediterranean: "The Etna–Antikythera Connection".
- Author
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Kampouri, Anna, Amiridis, Vassilis, Solomos, Stavros, Gialitaki, Anna, Marinou, Eleni, Spyrou, Christos, Georgoulias, Aristeidis K., Akritidis, Dimitris, Papagiannopoulos, Nikolaos, Mona, Lucia, Scollo, Simona, Tsichla, Maria, Tsikoudi, Ioanna, Pytharoulis, Ioannis, Karacostas, Theodore, and Zanis, Prodromos
- Subjects
- *
VOLCANIC plumes , *GEOPHYSICAL observatories , *MEDITERRANEAN climate , *LAVA flows , *LIDAR , *DUST , *OBSERVATORIES - Abstract
Between 30 May and 6 June 2019 a series of new eruptions occured in the south-east flanks of Mt. Etna, Italy, forming lava flows and explosive activity that was most intense during the first day of the eruption; as a result, volcanic particles were dispersed towards Greece. Lidar measurements performed at the PANhellenic GEophysical observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), in Greece, reveal the presence of particles of volcanic origin above the area the days following the eruption. FLEXible PARTicle dispersion model (FLEXPART) simulations and satellite-based SO2 observations from the TROPOspheric Monitoring Instrument onboard the Sentinel-5 Precursor (TROPOMI/S5P), confirm the volcanic plume transport from Etna towards PANGEA and possible mixing with co-existing desert dust particles. Lidar and modeled values are in agreement and the derived sulfate mass concentration is approximately 15 μg/m3. This is the first time that Etna volcanic products are monitored at Antikythera station, in Greece with implications for the investigation of their role in the Mediterranean weather and climate. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
30. Microbial Ecology of the Planetary Boundary Layer.
- Author
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Tignat-Perrier, Romie, Dommergue, Aurélien, Vogel, Timothy M., and Larose, Catherine
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- *
ATMOSPHERIC boundary layer , *MICROBIAL ecology , *ATMOSPHERIC physics , *ATMOSPHERIC chemistry , *MICROBIOLOGICAL aerosols , *WEATHER , *MICROBIAL communities , *IONIZING radiation - Abstract
Aerobiology is a growing research area that covers the study of aerosols with a biological origin from the air that surrounds us to space through the different atmospheric layers. Bioaerosols have captured a growing importance in atmospheric process-related fields such as meteorology and atmospheric chemistry. The potential dissemination of pathogens and allergens through the air has raised public health concern and has highlighted the need for a better prediction of airborne microbial composition and dynamics. In this review, we focused on the sources and processes that most likely determine microbial community composition and dynamics in the air that directly surrounds us, the planetary boundary layer. Planetary boundary layer microbial communities are a mix of microbial cells that likely originate mainly from local source ecosystems (as opposed to distant sources). The adverse atmospheric conditions (i.e., UV radiation, desiccation, presence of radicals, etc.) might influence microbial survival and lead to the physical selection of the most resistant cells during aerosolization and/or aerial transport. Future work should further investigate how atmospheric chemicals and physics influence microbial survival and adaptation in order to be able to model the composition of planetary boundary layer microbial communities based on the surrounding landscapes and meteorology. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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31. Insoluble Particles in the Snowpack of the Ob River Basin (Western Siberia) a 2800 km Submeridional Profile.
- Author
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Shevchenko, Vladimir P., Vorobyev, Sergey N., Krickov, Ivan V., Boev, Andrey G., Lim, Artyom G., Novigatsky, Alexander N., Starodymova, Dina P., and Pokrovsky, Oleg S.
- Subjects
- *
WATERSHEDS , *SNOW cover , *SCANNING electron microscopes , *SOIL particles , *PARTICULATE matter , *SNOW accumulation - Abstract
Snowpack exhibits properties that make it a unique natural archive of airborne pollution. The data on insoluble particles in the Ob River catchment (Western Siberia) snowpack are limited. Insoluble particles in the snowpack of Western Siberia were studied at 36 sites on a 2800 km submeridional profile from the city of Barnaul to Salekhard in February 2020. Snow samples were collected over the full depth of the snow core, from the surface of the snow cover to the boundary with soil, except for the lower 1–2 cm. After the filtration of melted snow through a 0.45-µm membrane, the particle composition was studied using a scanning electron microscope with an energy microprobe. In the background areas, the concentration of insoluble particles in the snow was below 2 mg/L. Significantly higher particle concentrations were encountered near cities and hydrocarbon production areas. Particulate matter in snow mainly consists of biogenic and lithogenic particles mixed with anthropogenic particles (ash and black carbon aggregates). The proportion of anthropogenic particles increases near cities and areas of active hydrocarbon production. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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32. Source–Receptor Relationships and Cluster Analysis of CO2, CH4, and CO Concentrations in West Africa: The Case of Lamto in Côte d'Ivoire.
- Author
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Tiemoko, Dro Touré, Yoroba, Fidèle, Paris, Jean-Daniel, Diawara, Adama, Berchet, Antoine, Pison, Isabelle, Riandet, Aurélie, and Ramonet, Michel
- Subjects
- *
CLUSTER analysis (Statistics) , *AIR masses - Abstract
The contribution in terms of long-range transport of CO2, CH4, and CO concentrations to measurements at Lamto (5°02′ W–6°13′ N) was analyzed for the 2014–2017 period using the FLEXPART model that calculates the retro-plumes of air masses arriving at the station. The identification of the source-receptor relationships was also studied with a clustering technique applied on those retro-plumes. This clustering technique enabled us to distinguish four categories of air mass transports arriving at Lamto site described as follows: oceanic and maritime origin (≈37% of the retro-plumes), continental origin (≈21%), and two hybrid clusters (≈42%). The results show that continental emission sources contribute significantly to the increases in concentrations of CO2, CH4, and CO and explain ≈40% of their variance. These emission sources are predominantly from north and north-east directions of the measurement point, and where densely populated and economically developed areas are located. In addition, the transport of air masses from these directions lead to the accumulation of CO2, CH4, and CO. Furthermore, the ratios ΔCO/ΔCH4 and ΔCO/ΔCO2 observed in the groups associated with Harmattan flows clearly show an influence of combustion processes on the continent. Thus, the grouping based on FLEXPART footprints shows an advantage compared to the use of simple trajectories for analyzing source–receptor relationships. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
33. Characterization of Aerosol Physical and Optical Properties at the Observatoire Pérenne de l'Environnement (OPE) Site.
- Author
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Farah, Antoine, Villani, Paolo, Rose, Clemence, Conil, Sebastien, Langrene, Laurent, Laj, Paolo, and Sellegri, Karine
- Subjects
- *
CARBONACEOUS aerosols , *OPTICAL properties , *AEROSOLS , *OPTICAL measurements , *BIOMASS burning , *AIR masses - Abstract
The Observatoire Pérenne de l'Environnement (OPE) station is a rural background site located in North-Eastern France. Besides emissions from agricultural activities, the site is located far from local emissions but at an even distance from the intense emission zones of Western Germany to the north-east and the Paris area to the south-west. In the paper, we report and analyze almost six years of measurements (1 May 2012 to 31 December 2018) of the optical and physical properties of aerosol particles. Based on aerosol optical and physical measurements combined with air mass back-trajectories, we investigate the dependence of these properties on air mass type. Two distinct equivalent black carbon (EBC) sources—origins-fossil fuel (FF) and biomass burning (BB)— were identified. FF was the dominant source of EBC (>70%) but showed a very marked seasonal variation. BB fraction is found higher during the cold seasons in the order of 35% (0.1 µg m−3) against 17% (0.05 µg m−3) during the warm seasons. The highest EBC and N0.54–1.15 (particles whose diameter ranged from 0.54 to 1.15 µm) median concentrations were observed during the night time and during the cold seasons compared to the warmer seasons, indicating primary sources trapped within a thin boundary layer (BL). A different behavior is found for N10–550 (particles whose diameter ranged from 10 to 550 nm) and coarse mode particles (N1.15–4.5, i.e., particles whose diameter ranged from 1.15 to 4.5 µm) median concentrations, which were observed during the warm seasons compared to the cold seasons, indicating rather biogenic secondary sources for the smaller particles, and potentially primary biogenic sources for the coarse mode particles. The scattering and absorption coefficients and single scattering albedo (SSA) show the same seasonal variations like the ones of N0.54–1.15 concentrations, indicating that particles larger than 500 nm seemed to contribute the most to the optical properties of the aerosol. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
34. Physico-Chemical Characterization of an Urban Rainwater (Zagreb, Croatia).
- Author
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Orlović-Leko, Palma, Vidović, Kristijan, Ciglenečki, Irena, Omanović, Dario, Sikirić, Mathieu Dutour, and Šimunić, Ivan
- Subjects
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TRACE elements , *RAINWATER , *TRAFFIC density , *ATMOSPHERIC deposition , *ENVIRONMENTAL quality , *INDUSTRIAL sites - Abstract
The characterization of organic matter (OM) and trace elements (TEs) was conducted in bulk precipitation samples collected in an urban area of Croatia (Zagreb center), from January 2009 to October 2011 (N = 31). Characterization of OM was performed by measurement of dissolved (DOC) and particulate forms of organic carbon (POC), as well as surface-active substances, copper complexing capacity and reduced sulfur species which were determined electrochemically. Concentrations of TEs (Al, Fe, Zn, Cr, Ba, Mn, Cu, Sr, Ti, Pb, V, Ni, Rb, Sb, As, Sn, Se, Co, Cd, Mo) were analyzed by HR ICP-MS. The most important outcome of this study is confirmed relatively low concentrations of DOC (0.69–4.86 mgC L−1) and TEs. Daily fluxes of Zn, Pb, Ni, As, and Cd were two to three times lower than that of those reported for an urban industrial site in Europe. Additionally, this study shows that the value and reactivity of rainwater DOC has not considerably changed if compared with the results from the 1998–1999 study (0.78–4.39 mgC L−1). High traffic density and thermal power plants are assumed to be the main local sources of pollutants in Zagreb. Using Al as a reference element, it was found that Cd, Sb, and Cu were associated with anthropogenic sources. The solubility of Sr, Zn, Cd, Ni, Cr, As, and Rb was higher than 70%. Another critical characteristic of precipitation composition is episodic variation in POC concentration because of Saharan dust transport. Obtained data can be valuable for environmental quality assessment, as well as for insight into atmospheric deposition processes. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
35. A Multiscale Tiered Approach to Quantify Contributions: A Case Study of PM2.5 in South Korea During 2010–2017.
- Author
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Bae, Minah, Kim, Byeong-Uk, Kim, Hyun Cheol, and Kim, Soontae
- Subjects
- *
MULTISCALE modeling , *PARTICULATE matter , *METEOROLOGICAL research , *WEATHER forecasting , *CASE studies , *AIR quality - Abstract
We estimated long-term foreign contributions to the particulate matter of 2.5 μm or less in diameter (PM2.5) concentrations in South Korea with a set of air quality simulations. The Weather Research and Forecasting (WRF)-Sparse Matrix Operator Kernel Emissions (SMOKE)-Community Multiscale Air Quality (CMAQ) modeling system was used to simulate the base and sensitivity case after a 50% reduction of foreign emissions. The effects of horizontal modeling grid resolutions (27- and 9-km) was also investigated. For this study, we chose PM2.5 in South Korea during 2010–2017 for the case study and emissions from China as a representative foreign source. The 9-km simulation results show that the 8-year average contribution of the Chinese emissions in 17 provinces ranged from 40–65%, which is ~4% lower than that from the 27-km simulation for the high-tier government segments (particularly prominent in coastal areas). However, for the same comparison for low-tier government segments (i.e., 250 prefectures), the 9-km simulation presented lowered the foreign contribution by up to 10% compared to that from the 27-km simulation. Based on our study results, we recommend using high-resolution modeling results for regional contribution analyses to develop an air quality action plan as the receptor coverage decreases. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
36. Study of Chemical and Optical Properties of Biomass Burning Aerosols during Long-Range Transport Events toward the Arctic in Summer 2017.
- Author
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Zielinski, Tymon, Bolzacchini, Ezio, Cataldi, Marco, Ferrero, Luca, Graßl, Sandra, Hansen, Georg, Mateos, David, Mazzola, Mauro, Neuber, Roland, Pakszys, Paulina, Posyniak, Michal, Ritter, Christoph, Severi, Mirko, Sobolewski, Piotr, Traversi, Rita, and Velasco-Merino, Christian
- Subjects
- *
BIOMASS burning , *CHEMICAL properties , *AEROSOLS , *OPTICAL properties , *ABSORPTION coefficients , *ATMOSPHERIC transport , *RADIOACTIVE aerosols - Abstract
Biomass burning related aerosol episodes are becoming a serious threat to the radiative balance of the Arctic region. Since early July 2017 intense wildfires were recorded between August and September in Canada and Greenland, covering an area up to 4674 km2 in size. This paper describes the impact of these biomass burning (BB) events measured over Svalbard, using an ensemble of ground-based, columnar, and vertically-resolved techniques. BB influenced the aerosol chemistry via nitrates and oxalates, which exhibited an increase in their concentrations in all of size fractions, indicating the BB origin of particles. The absorption coefficient data (530 nm) at ground reached values up to 0.6 Mm–1, highlighting the impact of these BB events when compared to average Arctic background values, which do not exceed 0.05 Mm–1. The absorption behavior is fundamental as implies a subsequent atmospheric heating. At the same time, the AERONET Aerosol Optical Depth (AOD) data showed high values at stations located close to or in Canada (AOD over 2.0). Similarly, increased values of AODs were then observed in Svalbard, e.g., in Hornsund (daily average AODs exceeded 0.14 and reached hourly values up to 0.5). Elevated values of AODs were then registered in Sodankylä and Andenes (daily average AODs exceeding 0.150) a few days after the Svalbard observation of the event highlighting the BB columnar magnitude, which is crucial for the radiative impact. All the reported data suggest to rank the summer 2017 plume of aerosols as one of the biggest atmosphere related environmental problems over Svalbard region in last 10 years. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
37. Long-Range Transport Influence on Key Chemical Components of PM2.5 in the Seoul Metropolitan Area, South Korea, during the Years 2012–2016.
- Author
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Bae, Changhan, Kim, Byeong-Uk, Kim, Hyun Cheol, Yoo, Chul, and Kim, Soontae
- Subjects
- *
METROPOLITAN areas , *PARTICULATE matter , *MULTISCALE modeling , *SEASONAL temperature variations - Abstract
This study identified the key chemical components based on an analysis of the seasonal variations of ground level PM2.5 concentrations and its major chemical constituents (sulfate, nitrate, ammonium, organic carbon, and elemental carbon) in the Seoul Metropolitan Area (SMA), over a period of five years, ranging from 2012 to 2016. It was found that the mean PM2.5 concentration in the SMA was 33.7 μg/m3, while inorganic ions accounted for 53% of the total mass concentration. The component ratio of inorganic ions increased by up to 61%–63% as the daily mean PM2.5 concentration increased. In spring, nitrate was the dominant component of PM2.5, accounting for 17%–32% of the monthly mean PM2.5 concentrations. In order to quantify the impact of long-range transport on the SMA PM2.5, a set of sensitivity simulations with the community multiscale air-quality model was performed. Results show that the annual averaged impact of Chinese emissions on SMA PM2.5 concentrations ranged from 41% to 44% during the five years. Chinese emissions' impact on SMA nitrate ranged from 50% (winter) to 67% (spring). This result exhibits that reductions in SO2 and NOX emissions are crucial to alleviate the PM2.5 concentration. It is expected that NOX emission reduction efforts in China will help decrease PM2.5 concentrations in the SMA. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
38. Comparative Analysis of PM 2.5 -Bound Polycyclic Aromatic Hydrocarbons (PAHs), Nitro-PAHs (NPAHs), and Water-Soluble Inorganic Ions (WSIIs) at Two Background Sites in Japan.
- Author
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Yang L, Zhang L, Zhang H, Zhou Q, Zhang X, Xing W, Takami A, Sato K, Shimizu A, Yoshino A, Kaneyasu N, Matsuki A, Hayakawa K, Toriba A, and Tang N
- Subjects
- China, Humans, Ions, Japan, Seasons, Water, Air Pollutants analysis, Environmental Monitoring, Particulate Matter analysis, Polycyclic Aromatic Hydrocarbons analysis
- Abstract
Daily PM
2.5 (particulate matter with aerodynamic diameter ≤2.5 μm) samples were simultaneously collected at two background sites (Wajima Air Monitoring Station (WAMS) and Fukue-Jima Atmosphere and Aerosol Monitoring Station (FAMS)) in Japan in the East Asian winter and summer monsoon periods of 2017 and 2019, to compare the characteristics of air pollutants among different regions and to determine the possible variation during the long-range transport process. Polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and water-soluble inorganic ions (WSIIs) were analyzed. Despite the PM2.5 concentrations at FAMS (8.90-78.5 µg/m3 ) being higher than those at WAMS (2.33-21.2 µg/m3 ) in the winter monsoon period, the average concentrations of ∑PAHs, ∑NPAHs, and ∑WSIIs were similar between the two sites. Diagnostic ratios indicated PAHs mainly originated from traffic emissions and mostly aged, whereas NPAHs were mostly secondarily formed during long-range transport. WSIIs at WAMS were mainly formed via the combustion process and secondary reactions, whereas those at FAMS mainly originated from sea salt and dust. Backward trajectories revealed the air masses could not only come from Asian continental coastal regions but also distant landlocked areas in the winter monsoon period, whereas most came from the ocean in the summer monsoon period. These findings can provide basic data for the establishment of prediction models of transboundary air pollutants in East Asia.- Published
- 2020
- Full Text
- View/download PDF
39. Characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) and Common Air Pollutants at Wajima, a Remote Background Site in Japan.
- Author
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Zhang X, Zhang L, Yang L, Zhou Q, Xing W, Toriba A, Hayakawa K, Wei Y, and Tang N
- Subjects
- Japan, Air Pollutants analysis, Environmental Monitoring, Polycyclic Aromatic Hydrocarbons analysis
- Abstract
Background : Background sites are mainly affected by long-range-transported air pollutants, resulting in potential adverse effects on local atmospheric environments. A 4-5 year observational study was conducted to illustrate the air pollution profile at the Kanazawa University Wajima air monitoring station (KUWAMS), an ideal remote background site in Japan. Methods : Nine polycyclic aromatic hydrocarbons (PAHs) in the particulate phase and various air pollutants were continuously monitored for 4-5 years. Diagnostic ratios of PAHs and back-trajectory analysis were applied to trace the possible sources of the air pollutants collected at the sampling site. Results : The atmospheric concentration of PAHs in the atmosphere at the site decreased from 2014 to 2019, benefit from the predominant air pollution control policy in China and Japan. Common air pollutants including sulfur dioxide (SO
2 ), nitrogen oxides (NOx ), ozone, methane (CH4 ), and non-methane hydrocarbon (NMHC) were detected in low concentrations from 2016 to 2019, while ozone (O3 ) and particulate matter (PM2.5 , PM with a diameter less than 2.5 μm) were present in high levels that exceeded the Japanese standards. Most air pollutants peaked in spring and showed evident diurnal variations in spring and summer. Conclusions : This is the first study to clarify the atmospheric behaviors of multiple air pollutants at a background site in Japan. Significant external air pollutant impact and unneglectable air pollution were demonstrated at KUWAMS, indicating the importance of studying atmospheric pollution at remote sites.- Published
- 2020
- Full Text
- View/download PDF
40. Cytotoxicity Assessment of PM 2.5 Collected from Specific Anthropogenic Activities in Taiwan.
- Author
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Ngo TH, Tsai PC, Ueng YF, and Chi KH
- Subjects
- Air Pollutants analysis, Air Pollutants chemistry, Air Pollution analysis, Environmental Monitoring, Humans, Lung cytology, Particle Size, Particulate Matter analysis, Particulate Matter chemistry, Taiwan, Toxicity Tests methods, Air Pollutants toxicity, Air Pollution adverse effects, Cell Survival drug effects, Particulate Matter toxicity
- Abstract
Fine particulate matter (PM
2.5 ) from different sources with different components have different health impact. In this research in Taiwan, composition and cytotoxicity of PM2.5 from long-range transport event (LRT), traffic activity, and outdoor cooking at night market were studied. The PM2.5 mass concentrations were 39.0 μg/m3 during LRT, 42.9 μg/m3 at traffic area, and 28.3 μg/m3 at the night market. Traffic area had highest concentrations of PCDD/Fs (46.9 fg I-TEQ/m3 ) when highest PAH concentrations of 3.57 BaPeq-ng/m3 were found at night market area. One quarter of PM2.5 mass at LRT and night market was constituted by water-soluble ion (26.02-28.93%). Road dust (represented by high concentration of Al and Ca) was the main contributor for metal element at traffic station whereas presence of natural salt (Na and Cl elements) was a marker of LRT and cooking activities. Cell viability reduced 9% after exposure to organic extracts of 0.316 μg of PM2.5 from LRT and night market samples. 150% elevation of ROS production was observed after exposure with organic compound of night market samples at the dose equivalent to 10.0 μg PM2.5 . Organic extracts from night market induced positive genotoxicity in umu test (at a dose of 20.0 μg PM2.5 ).- Published
- 2019
- Full Text
- View/download PDF
41. Seasonal Variation of Aerosol Size Distribution Data at the Puy de Dôme Station with Emphasis on the Boundary Layer/Free Troposphere Segregation.
- Author
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Farah, Antoine, Freney, Evelyn, Chauvigné, Aurélien, Baray, Jean-Luc, Rose, Clémence, Picard, David, Colomb, Aurélie, Hadad, Dani, Abboud, Maher, Farah, Wehbeh, and Sellegri, Karine
- Subjects
- *
ATMOSPHERIC aerosols , *ATMOSPHERIC boundary layer , *TROPOSPHERE , *SOLAR cycle , *PARTICULATE matter - Abstract
Aerosol particles are important due to their direct and indirect impacts on climate. Within the planetary boundary layer (BL), these particles have a relatively short lifetime due to their frequent removal process by wet deposition. When aerosols are transported into the free troposphere (FT), their atmospheric lifetime increases significantly, making them representative of large spatial areas. In this work, we use a combination of in situ measurements performed at the high altitude PUY (Puy de Dôme, 45°46′ N, 2°57′ E, 1465 m a.s.l) station, together with LIDAR profiles at Clermont-Ferrand for characterizing FT conditions, and further characterize the physical properties of aerosol in this poorly documented area of the atmosphere. First, a combination of four criteria was used to identify whether the PUY station lies within the FT or within the BL. Results show that the PUY station is located in BL with frequencies ranging from 50% during the winter, up to 97% during the summer. Then, the classification is applied to a year-long dataset (2015) of particle size distribution data to study the differences in particle physical characteristics (size distribution) and black carbon (BC) concentrations between the FT and the BL. Although BC, Aitken, and the accumulation mode particles concentrations were higher in the BL than in the FT in winter and autumn, they were measured to be higher in the FT compared to BL in spring. No significant difference between the BL and the FT concentrations was observed for the nucleation mode particles for all seasons, suggesting a continuous additional source of nucleation mode particles in the FT during winter and autumn. Coarse mode particle concentrations were found higher in the FT than in the BL for all seasons and especially during summer. This indicates an efficient long-range transport of large particles in the FT from distant sources (marine and desert) due to higher wind speeds in the FT compared to BL. For FT air masses, we used 204-h air mass back-trajectories combined with boundary layer height estimations from ECMWF ERA-Interim to assess the time they spent in the FT since their last contact with the BL and to evaluate the impact of this parameter on the aerosol properties. We observed that even after 75 h without any contact with the BL, FT aerosols preserve specific properties of their air mass type. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
42. The Influence of Climate Change on Atmospheric Deposition of Mercury in the Arctic—A Model Sensitivity Study.
- Author
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Hansen KM, Christensen JH, and Brandt J
- Subjects
- Arctic Regions, Humans, Air Pollutants analysis, Atmosphere chemistry, Climate Change, Environmental Monitoring methods, Mercury analysis, Models, Chemical
- Abstract
Mercury (Hg) is a global pollutant with adverse health effects on humans and wildlife. It is of special concern in the Arctic due to accumulation in the food web and exposure of the Arctic population through a rich marine diet. Climate change may alter the exposure of the Arctic population to Hg. We have investigated the effect of climate change on the atmospheric Hg transport to and deposition within the Arctic by making a sensitivity study of how the atmospheric chemistry-transport model Danish Eulerian Hemispheric Model (DEHM) reacts to climate change forcing. The total deposition of Hg to the Arctic is 18% lower in the 2090s compared to the 1990s under the applied Special Report on Emissions Scenarios (SRES-A1B) climate scenario. Asia is the major anthropogenic source area (25% of the deposition to the Arctic) followed by Europe (6%) and North America (5%), with the rest arising from the background concentration, and this is independent of the climate. DEHM predicts between a 6% increase (Status Quo scenario) and a 37% decrease (zero anthropogenic emissions scenario) in Hg deposition to the Arctic depending on the applied emission scenario, while the combined effect of future climate and emission changes results in up to 47% lower Hg deposition.
- Published
- 2015
- Full Text
- View/download PDF
43. Effects of Meteorological Conditions on PM2.5 Concentrations in Nagasaki, Japan.
- Author
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Wang J and Ogawa S
- Subjects
- Cities, Environmental Monitoring, Japan, Linear Models, Particle Size, Seasons, Statistics, Nonparametric, Air Pollutants analysis, Particulate Matter analysis, Weather
- Abstract
The fine particulate matter (PM2.5) problem has attracted much scientific and public attention, due to its effects on visibility, human health, and global climate. There are three factors that have important effect on PM2.5 mass concentration: domestic pollutant emission sources, external sources outside of the country, and the meteorological conditions. Nagasaki is a coastal prefecture located at the westernmost part of Japan, which is an ideal location to study pollutants from long range transport and correlation between PM2.5 and meteorological conditions. In this paper, PM2.5 concentration data and meteorological data were obtained during 1 January 2013~31 December 2013. The spatial distribution depicts that the western part of the study area has the most serious PM2.5 pollution. The correlation analysis results between PM2.5 concentration and meteorological data showed that temperature had a negative, and precipitation had a positive, correlation with PM2.5. There was a threshold in the correlations between humidity and wind speed and PM2.5. The correlation was positive or negative depending on the meteorological variable values, if these were lower or higher than the threshold. From the relationship with wind direction, it can be depicted that the west wind might bring the most pollutants to Nagasaki.
- Published
- 2015
- Full Text
- View/download PDF
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