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Perez-Anaya, Eduardo, David A. Elvira-Ortiz, Roque A. Osornio-Rios i Jose A. Antonino-Daviu. "Methodology for the Identification of Dust Accumulation Levels in Photovoltaic Panels Based in Heuristic-Statistical Techniques". Electronics 11, nr 21 (28.10.2022): 3503. http://dx.doi.org/10.3390/electronics11213503.
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The use of renewable energies is increasing around the world in order to deal with the environmental and economic problems related with conventional generation. In this sense, photovoltaic generation is one of the most promising technologies because of the high availability of sunlight, the easiness of maintenance, and the reduction in the costs of installation and production. However, photovoltaic panels are elements that must be located outside in order to receive the sun radiation and transform it into electricity. Therefore, they are exposed to the weather conditions and many environmental factors that can negatively affect the output delivered by the system. One of the most common issues related to the outside location is the dust accumulation in the surface of the panels. The dust particles obstruct the passage of the sunlight, reducing the efficiency of the generation process and making the system prone to experimental long-term faults. Thus, it is necessary to develop techniques that allow us to assess the level of dust accumulation in the panel surface in order to schedule a proper maintenance and avoid losses associated with the reduction of the delivered power and unexpected faults. In this work, we propose a methodology that uses a machine learning approach to estimate different levels of dust accumulation in photovoltaic panels. The developed method takes the voltage, current, temperature, and sun radiance as inputs to perform a statistical feature extraction that describes the behavior of the photovoltaic system under different dust conditions. In order to retain only the relevant information, a genetic algorithm works along with the principal component analysis technique to perform an optimal feature selection. Next, the linear discrimination analysis is carried out using the optimized dataset to reduce the problem dimensionality, and a multi-layer perceptron neural network is implemented as a classifier for discriminating among three different conditions: clean surface, slight dust accumulation, and severe dust accumulation. The proposed methodology is implemented using real signals from a photovoltaic installation, proving to be effective not only to determine if a dust accumulation condition is present but also when maintenance actions must be performed. Moreover, the results demonstrate that the accuracy of the proposed method is always above 94%.
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Shaaban, Mostafa F., Amal Alarif, Mohamed Mokhtar, Usman Tariq, Ahmed H. Osman i A. R. Al-Ali. "A New Data-Based Dust Estimation Unit for PV Panels". Energies 13, nr 14 (13.07.2020): 3601. http://dx.doi.org/10.3390/en13143601.
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Solar photovoltaic (PV) is playing a major role in the United Arab Emirates (UAE) smart grid infrastructure. However, one of the challenges facing PV-based energy systems is the dust accumulation on solar panels. Dust accumulation on solar panels results in a high degradation in the output power. The UAE has low intensity rainfall and wind velocity; therefore solar panels must be cleaned manually or using automated cleaning methods. Estimating dust accumulation on solar panels will increase the output power and reduce maintenance costs by initiating cleaning actions only when required. In this paper, the impact of natural dust accumulation on solar panels is investigated using field measurements and regression modeling. Experimental data were collected under various real weather conditions and controlled levels of dust. Moreover, this paper proposes a data-driven approach based on machine learning to estimate the accumulated dust level on solar panels. In this approach, a dust estimation unit based on a regression tree model has been developed to estimate the dust accumulation. This unit is trained using experimental records of solar irradiance, ambient temperature, and the output power generated from solar panels as well as the amount of dust at these conditions. The proposed unit is evaluated through different case studies with a random amount of dust applied to the solar panels to demonstrate the accurate performance of the proposed unit.
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Pan, Huiyun, Xinwei Lu i Kai Lei. "Contamination Identification of Trace Metals in Roadway Dust of a Typical Mountainous County in the Three Gorges Reservoir Region, China, and its Relationships with Socio-Economic Factors". Sustainability 12, nr 14 (13.07.2020): 5624. http://dx.doi.org/10.3390/su12145624.
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Trace metal contamination in urban road dust has attracted global concern due to its potential risk to the urban environment and human health. Compared to big cities, relative studies in counties and small towns have not been well quantified. This research identified the trace metal contamination characteristics and possible sources in the road dust of a typical mountainous county and a town in the Three Gorges Reservoir region, southwest China, and their associations with major regional socio-economic factors. The trace metal concentrations were determined, and the contamination levels were assessed. Concentrations of Zn, Pb, and Cu were relatively high in both locations, and a significant accumulation of them was confirmed by the geo-accumulation method. Multivariate analysis and geographic information system (GIS) mapping were combined to explore the sources of trace metals in the investigated area. Anthropogenic activities predominantly affected the contamination levels of Zn, Pb, Cu, and Co, and traffic emission, agricultural activities, and fossil fuel combustion were their main sources. The significant accumulation of Zn should attract special concern for its wide use in industrial and agricultural activities. Population and vehicle density were the main factors that controlled the trace metal contamination levels in the roadway dust. Rapid urbanizing promoted trace metal accumulation in counties and towns. Therefore, it is urgent to make appropriate strategies for trace metal pollution mitigation in the process of urbanization.
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Bezberdaya, Liliya, Natalia Kosheleva, Olga Chernitsova, Mikhail Lychagin i Nikolay Kasimov. "Pollution Level, Partition and Spatial Distribution of Benzo(a)pyrene in Urban Soils, Road Dust and Their PM10 Fraction of Health-Resorts (Alushta, Yalta) and Industrial (Sebastopol) Cities of Crimea". Water 14, nr 4 (12.02.2022): 561. http://dx.doi.org/10.3390/w14040561.
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Polycyclic aromatic hydrocarbons (PAHs), in particular benzo(a)pyrene (BaP), are priority organic pollutants coming from various anthropogenic sources. The levels of accumulation and the spatial distribution of BaP in urban soils, road dust and their PM10 particles (with a diameter of less than 10 microns) were for the first time determined for various land use zones and roads of different size in the cities of Crimea—Alushta, Yalta and Sebastopol. The average content of BaP in soils and road dust in Alushta is 60 and 97 ng/g, in Yalta—139 and 64 ng/g, in Sebastopol—260 and 89 ng/g, respectively, which considerably exceeds the background level (1 ng/g). The BaP concentrations in PM10 particles of soils and dust are up to 11 and four times higher, respectively, than the total contents; they concentrate 35–70% of amount of the pollutant. The accumulation of BaP in soils and dust depends on the type of land use and size of roads. The exceedance of BaP standards in soils and road dust indicates a hazardous environmental situation in three cities of Crimea. The most dangerous are PM10 particles, which form anomalies with extreme levels of BaP contamination.
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Brodny, Jarosław, i Magdalena Tutak. "Exposure to Harmful Dusts on Fully Powered Longwall Coal Mines in Poland". International Journal of Environmental Research and Public Health 15, nr 9 (27.08.2018): 1846. http://dx.doi.org/10.3390/ijerph15091846.
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The mining production process is exposed to a series of different hazards. One of them is the accumulation of dust which can pose a serious threat to the life and health of mine workers. The analysis of dust hazard in hard coal mining should include two aspects. One is the risk of coal dust explosions, which poses a direct risk of injury or even loss of life, the second is the risk of harmful dust, associated with the possibility of negative health effects as a result of long-term exposure to dust in the worker’s body. The technologies currently applied in underground mining produce large amounts of coal and stone dust. Long-term exposure to dust and crystalline silica may cause chronic respiratory disease. The article presents the results of tests on the dust levels in the area of a fully-powered longwall. The tests were conducted for five longwalls from different hard coal mines. In each of them, the average values of inhalable and respirable dust as well as the percentage content of free silica in the dust were determined in ten selected working positions. Additionally, for the longwall with the highest dust concentration, the levels of dust were determined for the basic activities related to the phases of the technological cycle. The comparative analysis conducted and the results obtained demonstrate large variations in the dust levels in the different areas. The permissible values were significantly exceeded in a number of cases. This poses a great threat to the health of Polish miners. The results obtained indicate that it is necessary to undertake more effective measures in order to improve the working environment of the crew in hard coal mines.
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Lin, Wenpeng, Xumiao Yu, Di Xu, Tengteng Sun i Yue Sun. "Effect of Dust Deposition on Chlorophyll Concentration Estimation in Urban Plants from Reflectance and Vegetation Indexes". Remote Sensing 13, nr 18 (8.09.2021): 3570. http://dx.doi.org/10.3390/rs13183570.
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Using reflectance spectroscopy to monitor vegetation pigments is a crucial method to know the nutritional status, environmental stress, and phenological phase of vegetation. Defining cities as targeted areas and common greening plants as research objects, the pigment concentrations and dust deposition amounts of the urban plants were classified to explore the spectral difference, respectively. Furthermore, according to different dust deposition levels, this study compared and discussed the prediction models of chlorophyll concentration by correlation analysis and linear regression analysis. The results showed: (1) Dust deposition had interference effects on pigment concentration, leaf reflectance, and their correlations. Dust was an essential factor that must be considered. (2) The influence of dust deposition on chlorophyll—a concentration estimation was related to the selected vegetation indexes. Different modeling indicators had different sensitivity to dust. The SR705 and CIrededge vegetation indexes based on the red edge band were more suitable for establishing chlorophyll-a prediction models. (3) The leaf chlorophyll concentration prediction can be achieved by using reflectance spectroscopy data. The effect of the chlorophyll estimation model under the levels of “Medium dust” and “Heavy dust” was worse than that of “Less dust”, which meant the accumulation of dust had interference to the estimation of chlorophyll concentration. The quantitative analysis of vegetation spectrum by reflectance spectroscopy shows excellent advantages in the research and application of vegetation remote sensing, which provides an important theoretical basis and technical support for the practical application of plant chlorophyll content prediction.
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Song, Yuhang, Chengzhi Xing, Cheng Liu, Jinan Lin, Hongyu Wu, Ting Liu, Hua Lin i in. "Evaluation of transport processes over North China Plain and Yangtze River Delta using MAX-DOAS observations". Atmospheric Chemistry and Physics 23, nr 3 (2.02.2023): 1803–24. http://dx.doi.org/10.5194/acp-23-1803-2023.
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Abstract. Pollutant transport has a substantial impact on the atmospheric environment in megacity clusters. However, owing to the lack of knowledge of vertical pollutant structure, quantification of transport processes and understanding of their impacts on the environment remain inadequate. In this study, we retrieved the vertical profiles of aerosols, nitrogen dioxide (NO2), and formaldehyde (HCHO) using multi-axis differential optical absorption spectroscopy (MAX-DOAS) and analyzed three typical transport phenomena over the North China Plain (NCP) and Yangtze River Delta (YRD). We found the following: (1) the main transport layers (MTL) of aerosols, NO2, and HCHO along the southwest–northeast transport pathway in the Jing-Jin-Ji region were approximately 400–800, 0–400, and 400–1200 m, respectively. The maximum transport flux of HCHO appeared in Wangdu (WD), and aerosol and NO2 transport fluxes were assumed to be high in Shijiazhuang (SJZ), both urban areas being significant sources feeding regional pollutant transport pathways. (2) The NCP was affected by severe dust transport on 15 March 2021. The airborne dust suppressed dissipation and boosted pollutant accumulation, decreasing the height of high-altitude pollutant peaks. Furthermore, the dust enhanced aerosol production and accumulation, weakening light intensity. For the NO2 levels, dust and aerosols had different effects. At the SJZ and Dongying (DY) stations, the decreased light intensity prevented NO2 photolysis and favored NO2 concentration increase. In contrast, dust and aerosols provided surfaces for heterogeneous reactions, resulting in reduced NO2 levels at the Nancheng (NC) and Xianghe (XH) stations. The reduced solar radiation favored local HCHO accumulation in SJZ owing to the dominant contribution of the primary HCHO. (3) Back-and-forth transboundary transport between the NCP and YRD was found. The YRD-to-NCP and NCP-to-YRD transport processes mainly occurred in the 500–1500 and 0–1000 m layers, respectively. This transport, accompanied by the dome effect of aerosols, produced a large-scale increase in PM2.5, further validating the haze-amplifying mechanism.
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Roumpakias, Elias, i Tassos Stamatelos. "Surface Dust and Aerosol Effects on the Performance of Grid-Connected Photovoltaic Systems". Sustainability 12, nr 2 (11.01.2020): 569. http://dx.doi.org/10.3390/su12020569.
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A large number of grid-connected Photovoltaic parks of different scales have been operating worldwide for more than two decades. Systems’ performance varies with time, and an important factor that influences PV performance is dust and ambient aerosols. Dust accumulation has significant effects depending the region, and—on the other hand—understanding the role of absorption or scattering in particular wavelengths from aerosols is a challenging task. This paper focuses on performance analysis of a grid-connected PV system in Central Greece, aiming to study these effects. The methodology of analysis follows three directions, namely, PR computations, use of mathematical model’s prediction as reference value, and normalized efficiency calculation. These metrics are correlated with the levels of dust accumulation on PV panels’ surfaces and the ambient aerosol mass concentration. The results show that only heavily soiled surfaces have significant impact on PV performance and, particularly, a decrease of 5.6%. On the other hand, light or medium soiling have negligible impact on PV performance. On the other hand, the impact of ambient aerosol concentration levels on PV efficiency is more complex and requires further study. Aerosol scattering of different wavelengths can possibly affect PV efficiency, however, this fact may be related to the specific spectral response of PV cells.
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Qusay Kamil Jasim. "Effect of The Different Types of Dust on The Performance of Photovoltaic Panels in Iraq". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 100, nr 3 (31.12.2022): 1–10. http://dx.doi.org/10.37934/arfmts.100.3.110.
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Iraq is characterized by an atmosphere that contains dust particles most of the time. In this study, a detailed investigation was conducted on the effect of dust particles of different types on the performance of the photovoltaic (PV) model. Data were collected for samples of four types of dust (chalk powder, brick powder, Sand, Cool powder) and different weights (30,60,90 and 120 g/m2) with the change in the energy loss of the PV module at four levels of solar radiation (500, 600, 700 and 800 W/m2). In this study the effect of environmental dust particles on energy loss as well as electrical efficiency was evaluated. The minimum and maximum power value of (43.58, 101.95W) respectively, was observed during dust accumulation on the photovoltaic unit. It was also noted that the efficiency and power were inversely proportional to the increase in weight and directly to the size of the dust particles.
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Choi, Soo-Min, i Hyo Choi. "Statistical Modeling for PM10, PM2.5 and PM1 at Gangneung Affected by Local Meteorological Variables and PM10 and PM2.5 at Beijing for Non- and Dust Periods". Applied Sciences 11, nr 24 (15.12.2021): 11958. http://dx.doi.org/10.3390/app112411958.
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Multiple statistical prediction modeling of PM10, PM2.5 and PM1 at Gangneung city, Korea, was performed in association with local meteorological parameters (air temperature, wind speed and relative humidity) and PM10 and PM2.5 concentrations of an upwind site in Beijing, China, in the transport route of Chinese yellow dusts which originated from the Gobi Desert and passed through Beijing to the city from 18 March to 27 March 2015. Before and after the dust periods, the PM10, PM2.5 and PM1 concentrations showed as being very high at 09:00 LST (the morning rush hour) by the increasing emitted pollutants from vehicles and flying dust from the road and their maxima occurred at 20:00 to 22:00 LST (the evening departure time) from the additional pollutants from resident heating boilers. During the dust period, these peak trends were not found due to the persistent accumulation of dust in the city from the Gobi Desert through Beijing, China, as shown in real-time COMS-AI satellite images. Multiple correlation coefficients among PM10, PM2.5 and PM1 at Gangneung were in the range of 0.916 to 0.998. Multiple statistical models were devised to predict each PM concentration, and the significant levels through multi-regression analyses were p < 0.001, showing all the coefficients to be significant. The observed and calculated PM concentrations were compared, and new linear regression models were sequentially suggested to reproduce the original observed PM values with improved correlation coefficients, to some extent.
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Opolot, Mark, Timothy Omara, Christopher Adaku i Emmanuel Ntambi. "Pollution Status, Source Apportionment, Ecological and Human Health Risks of Potentially (Eco)toxic Element-Laden Dusts from Urban Roads, Highways and Pedestrian Bridges in Uganda". Pollutants 3, nr 1 (20.01.2023): 74–88. http://dx.doi.org/10.3390/pollutants3010007.
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The occurrence of potentially (eco)toxic elements (PTEs) in street, indoor and roadside dusts have been associated with potential human health risks. For the first time, the pollution levels of PTEs—copper (Cu), nickel (Ni), manganese (Mn), zinc (Zn), lead (Pb), cadmium (Cd) and chromium (Cr)—were investigated in 24 dust samples from eight selected sampling sites on urban roads, highways and pedestrian bridges constructed over River Manafwa, a flood-prone river in Eastern Uganda. Concentration of PTEs in the sample digests were quantified by atomic absorption spectrometry. Multivariate geostatistical (Pearson’s Correlation, Principal Components and Hierarchical Cluster) analyses were used to apportion sources of the contaminants. Contamination, ecological and human health assessment indices and models were employed to establish any potential risks the elements could pose to the environment and humans. The study revealed that there is severe PTE pollution of dusts from roads, highways and pedestrian bridges in Eastern Uganda when compared with their crustal averages, except for Cu, Ni and Cr. The mean concentrations (mg kg−1) of Cu (11.4–23.2), Ni (0.20–23.20), Mn (465.0–2630.0), Zn (26.8–199.0), Pb (185.0–244.0), Cd (0.178–1.994) and Cr (5.40–56.60) were highest in samples obtained near high-traffic areas. Source apportionment studies suggested that Cu, Ni, Mn and Cr are from combustion processes and vehicular traffic, whereas Pb, Zn and Cd came from traffic and geogenic contributions. Assessment using the pollution load index indicated that only dust from Zikoye–Bushika road, the junction of Zikoye–Bushika and Bududa–Manafwa roads and Manafwa town were substantially polluted as the indices were greater than 1. Further assessment of pollution degree of the dust samples using index of geo-accumulation revealed that the dusts were practically uncontaminated to medium-to-strongly contaminated. Health risk assessment showed that there are non-carcinogenic health risks that could emanate from direct ingestion of PTEs in dusts by children. This study therefore opens the lead for investigation of the contamination levels and the health risks of PTEs in dusts from industrial areas as well as busy Ugandan cities such as Kampala, Jinja, Mbarara and Gulu.
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Roettig, Christopher-Bastian, György Varga, Daniela Sauer, Thomas Kolb, Daniel Wolf, Vera Makowski, José Manuel Recio Espejo, Ludwig Zöller i Dominik Faust. "Characteristics, nature, and formation of palaeosurfaces within dunes on Fuerteventura". Quaternary Research 91, nr 1 (31.10.2018): 4–23. http://dx.doi.org/10.1017/qua.2018.52.
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AbstractThe appearances of palaeosurfaces intercalated into palaeo-dune fields on Fuerteventura are multifaceted. Although reddened layers in these dune sediments might suggest that strong soil-formation processes have taken place, the combination of aridity and parent material, namely biogenic carbonate sand of shelf origin, reveals that strong soil formation seems unlikely. These sediments rather represent de- and recalcification processes only. Solely in the case of admixed material of volcanic origin and dust deposits further soil-forming processes seem to be possible. Hematite-rich Saharan dust contributes to reddish colouration of the palaeosurfaces. In addition, CaCO3-coated iron particles appear to be ingredients of dust being leached after deposition and transformed to hematite. Overall, we propose much weaker soil-forming processes during the Pleistocene than previously postulated. Our findings support the relevance of local environments. Carbonate sands of shelf origin hinder strong soil formation and the reddish layers separating dune generations are palaeosurfaces, which mainly consist of Saharan dust. After deposition of allochthonous material, these layers are overprinted by weak soil-forming processes. The formation of palaeosurfaces primarily depends on morphodynamically stable periods during limited sand supply. Our data suggest a cyclicity of processes in the following order: (1) sand accumulation, (2) dust accumulation and weak soil formation, and (3) water-induced erosion. For the Canary Islands, we support the assumption of glacial maxima being periods of increased levels of moisture. In combination with rising sea level, we propose that favorable conditions of surface stability occur immediately after glacial maxima during periods of starting transgression, whereas regression periods immediately after sea-level high stands seem to yield the highest sand supply for the study area.
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Ali Abed, Salwan, Safaa A Kadhum, Salam Hussein Ewaid i Nadhir Al-Ansari. "Bioaccumulation and health risk assessment of severe metal pollution of street dust from various urban regions in Baghdad, Iraq". E3S Web of Conferences 158 (2020): 05004. http://dx.doi.org/10.1051/e3sconf/202015805004.
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This study sought to define the metals bioaccumulation from street dust in Baghdad, Iraq for the first time. The samples were collected that research the levels, sources, and health hazard model Cd, Cr, Zn and Cu. The geo accumulation Index (Igeo) found that the contamination level for Cd was moderately to strongly polluted in Karada, Jihad and Kinidi streets. Hence, it is important to measure the level of cadmium in the local environment. The relative bioaccumulation of chromium was high in Jadriyah Street (87.2%). The PCA showed two major sources of these minerals in Baghdad road dust that Cd, Zn are likely to originate from tire wear, brake wear and vehicular emissions as well as the fact that Cr and Cu originate from metal-processing industries. Assessing hazard to human health utilized measure population show suggested both non-carcinogenic and carcinogenic hazards minerals Baghdad road dust harmless to human environment.
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Pinglot, J. F., M. Pourchet, B. Lefauconnier i M. Creseveur. "Equilibrium line and mean annual mass balance of Finsterwalderbreen, Spitsbergen, determined by in situ and laboratory gamma-ray measurements of nuclear test deposits". Annals of Glaciology 24 (1997): 54–59. http://dx.doi.org/10.3189/s0260305500011939.
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In order to determine the equilibrium line (EL) and the annual net mass balance over the accumulation area of Finsterwalderbreen, Spitsbergen, Svalbard (by detection of the 1962–63 radioactive peak from the 1961–62 atmospheric nuclear tests), we collected 14 ice cores, at elevations of 445–730 m, in the springs of 1994 and 1995. The corresponding samples were melted and filtered for laboratory gamma spectrometry. In the accumulation area, the 1962–63 radioactive layer is found well below the surface. The mean annual accumulation is not invariably related to altitude. The EL, averaged to 545 in a.s.l., leads to an accumulation area ratio of 0.3 and indicates a strong negative balance. The 584 Bq m−2 mean137 Cs deposition rate (1954–74 nuclear tests) for eight ice cores in the accumulation area is nearly twice the 340 Bq m−2 mean Svalbard value obtained from six other glaciers (at time of deposition).An in situ gamma-ray detector was lowered down each borehole, and137 Cs levels were recorded. The counting rate is proportional to the apparent deposition rate and the specific activity. The laboratory measurements perfectly match the in situ determinations. In the ablation area, a dust layer and the associated nuclear test deposits are concentrated close to the bare ice surface of the glacier, under the winter snow layer and present maximum 137 Cs and 210 Pb contents. The dust layer acts like a filter for radioactive materials removed from the glacier and its basin by melting and water flow. The original specific activities and deposition rates at a given location are enhanced by adsorption of additional radioactivity on the dust particles. A linear relationship exists between 137 Cs and 210 Pb deposition rates. This process is almost constant for all studied ice cores. The apparent 137 Cs deposition rate for seven ice cores in the ablation area is 465 Bq m−2 (at date of measurement: 1 July 1995).
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Pinglot, J. F., M. Pourchet, B. Lefauconnier i M. Creseveur. "Equilibrium line and mean annual mass balance of Finsterwalderbreen, Spitsbergen, determined by in situ and laboratory gamma-ray measurements of nuclear test deposits". Annals of Glaciology 24 (1997): 54–59. http://dx.doi.org/10.1017/s0260305500011939.
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In order to determine the equilibrium line (EL) and the annual net mass balance over the accumulation area of Finsterwalderbreen, Spitsbergen, Svalbard (by detection of the 1962–63 radioactive peak from the 1961–62 atmospheric nuclear tests), we collected 14 ice cores, at elevations of 445–730 m, in the springs of 1994 and 1995. The corresponding samples were melted and filtered for laboratory gamma spectrometry. In the accumulation area, the 1962–63 radioactive layer is found well below the surface. The mean annual accumulation is not invariably related to altitude. The EL, averaged to 545 in a.s.l., leads to an accumulation area ratio of 0.3 and indicates a strong negative balance. The 584 Bq m−2 mean137 Cs deposition rate (1954–74 nuclear tests) for eight ice cores in the accumulation area is nearly twice the 340 Bq m−2 mean Svalbard value obtained from six other glaciers (at time of deposition). An in situ gamma-ray detector was lowered down each borehole, and137 Cs levels were recorded. The counting rate is proportional to the apparent deposition rate and the specific activity. The laboratory measurements perfectly match the in situ determinations. In the ablation area, a dust layer and the associated nuclear test deposits are concentrated close to the bare ice surface of the glacier, under the winter snow layer and present maximum 137 Cs and 210 Pb contents. The dust layer acts like a filter for radioactive materials removed from the glacier and its basin by melting and water flow. The original specific activities and deposition rates at a given location are enhanced by adsorption of additional radioactivity on the dust particles. A linear relationship exists between 137 Cs and 210 Pb deposition rates. This process is almost constant for all studied ice cores. The apparent 137 Cs deposition rate for seven ice cores in the ablation area is 465 Bq m−2 (at date of measurement: 1 July 1995).
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Li, Jialu, Qiting Zuo, Hao Hu, Feng Feng, Hongtao Jia i Yingxin Ji. "A Comprehensive Exploration on Occurrence, Distribution and Risk Assessment of Potentially Toxic Elements in the Multi-Media Environment from Zhengzhou, China". Toxics 11, nr 2 (31.01.2023): 140. http://dx.doi.org/10.3390/toxics11020140.
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Road dust (RD), roadside soils (RS) and river surface sediments (sediments) are important materials for evaluating contaminant levels in urban areas. This study aims to investigate the contaminant characteristics, pollution levels and ecological risks of RD, RS and sediments of potentially toxic elements (PTEs), including Cr, Ni, Cu, Zn, As, Cd, Hg and Pb, in the central urban area of Zhengzhou. Results reveal that RD shows a higher concentration of PTEs when compared to the other two environments. The spatial distribution characteristics suggest that PTEs in RD, RS and sediments may come from different sources. The geo-accumulation index (Igeo) was used to describe that the RD was moderately to extremely contaminated with Cd and Hg, while both RS and sediments were significantly enriched with Cd and Hg. For RD, RS and sediments, the potential ecological risk (RI) demonstrates a high potential ecological risk from Cd and Hg. Overall, PTEs in Zhengzhou road dust present a moderate risk.
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Yousefi, Robabeh, Fang Wang, Quansheng Ge, Abdallah Shaheen i Dimitris G. Kaskaoutis. "Analysis of the Winter AOD Trends over Iran from 2000 to 2020 and Associated Meteorological Effects". Remote Sensing 15, nr 4 (6.02.2023): 905. http://dx.doi.org/10.3390/rs15040905.
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High aerosol levels pose severe air pollution and climate change challenges in Iran. Although regional aerosol optical depth (AOD) trends have been analyzed during the dusty season over Iran, the specific factors that are driving the spatio-temporal variations in winter AOD and the influence of meteorological dynamics on winter AOD trends remain unclear. This study analyzes the long-term AOD trends over Iran in winter during the period 2000–2020 using the updated Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) and the Moderate Resolution Imaging Spectroradiometer (MODIS) datasets. Our results showed that the winter AOD exhibited a significant upward trend during the period 2000–2010 followed by a significant decrease during the period 2010–2018. We found that the winter AOD trends are important over this arid region due to multiple meteorological mechanisms which also affect the following spring/summer dusty period. Ground-based observations from Aerosol Robotic Network data (AERONET) in the Middle East region display trends comparable to those of both MERRA-2 and MODIS and indicated that aeolian dust and the meteorological dynamics associated with it play a central role in winter AOD changes. Furthermore, this study indicated that a significant downward trend in winter sea level pressure (SLP) during the early period (2000–2010) induced hot and dry winds which originated in the desert regions in Iraq and Arabia and blew toward Iran, reducing relative humidity (RH) and raising the temperature and thus promoting soil drying and dust AOD accumulation. In contrast, a significant increase in winter SLP during the late period (2010–2018) induced cold and wet winds from northwestern regions which increased RH and lowered the temperature, thus reducing dust AOD. This suggests that the changes in AOD over Iran are highly influenced by seasonal meteorological variabilities. These results also highlight the importance of examining wintertime climatic variations and their effects on the dust aerosol changes over the Middle East.
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Vlasov, Dmitry, Omar Ramírez i Ashok Luhar. "Road Dust in Urban and Industrial Environments: Sources, Pollutants, Impacts, and Management". Atmosphere 13, nr 4 (10.04.2022): 607. http://dx.doi.org/10.3390/atmos13040607.
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Road dust (RD) is one of the most important sources of particles in the atmosphere, especially in industrial areas and cities. In this special issue, we collected 16 original articles that describe field, experimental, and modeling studies related to RD and its various size fractions as a key issue in understanding the relationships between several urban and industrial environments and in the identification of pollution sources. Articles in the special issue focus primarily on the following main topics: (1) study of the chemical composition and speciation of RD and its source attribution; (2) assessment of RD and aerosol pollution levels (including express technique), environmental hazards and public health risks; (3) distribution of stable and radioactive isotopes in RD; (4) determination of factors affecting the level of dust accumulation on roads and the intensity of its pollution; and (5) study of the effect of RD on the atmosphere and other environments. Based on the results presented in this special issue, but not limited to, some of the current challenges in studying RD are formulated, including the need for further geographically wider and analytically deeper work on various aspects of the formation, transport pathways, and accumulation of RD in urban, industrial and other areas.
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Sager, M., H. Chon i László Márton. "Spatial variation of contaminant elements in roadside dust of Budapest and Seoul". Agrokémia és Talajtan 63, nr 1 (1.06.2014): 59–68. http://dx.doi.org/10.1556/agrokem.63.2014.1.7.
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Roadside dusts were studied to explain the spatial variation, and present level of contaminant elements (including Pt, Pd and Ir) in Budapest and Seoul, the capitals of Hungary and Seoul. Road dust samples were obtained twice from traffic focal points in Budapest centre (four bridges, Margaret Island, two main railway stations, main roads) and the agglomeration (suburbs) of Budapest. Similarly, samples were collected from six sites having high traffic volumes in Seoul metropolitan city and from two control sites within the suburbs of Seoul, for comparison. The samples were analysed for contaminant elements by ICP-AES and for Pt, Pd and Ir by ICP-MS.The level of contaminant elements in road dusts were in the range of 67.6 g∙kg−1 and 0.6 μg∙kg−1 for Budapest; 50.2 g∙kg−1 and 0.5 μg∙kg−1 for Budapest suburbs; 43.5 g∙kg−1 and 3.3 μg∙kg−1 for Seoul samples. The Geo-Accumulation Indexes (GAI) of contaminant elements for Budapest, Budapest suburbs and Seoul ranged between 3.88 and −0.03; 2.74 and −0.13; 4.23 and 1.22; Pollution Indexes (PI) of the contaminant elements were in the range of 4.2 and 0.6; 0.9 and 0.4; 7.8 and 2.7; Contamination Indexes (CI) of the contaminant elements ranged from 27.1 to 3.3; 4.9 to 2.7; 21.8 to 10.2, respectively.Pt, Pd and Ir concentration levels (μg∙kg−1) were in the range of 133 and 1.9, 170 and 12.8, 4.5 and 0.4 for Budapest; 37 and 3.6, 39.4 and 11.3, 0.8 and 0.2 for Budapest suburbs; 98.5 and 25.6, 148 and 30.6, 5.6 and 2.1 for Seoul.Correlations between the Pollution Index (PI) and Contamination Index (CI) of the platinum metals in road dust samples were: −0.4090 (Ir), −0.3098 (Pd), −0.1994 (Pt) for Budapest centre; 0.8343 (Ir), −0.7652 (Pt), −0.7626 (Pd) for Budapest bridges; 0.5266 (Ir), −0.2863 (Pd), −0.0333 (Pt) for Budapest suburbs; and 0.3193 (Pd), 0.2874 (Ir), −0.0017 (Pt) for Seoul, respectively. The highest Pt, Pd and Ir levels in road dusts were found in samples originating from the major roads with high traffic volume. Significant differences in Pollution Index (PI) and Contamination Index (CI) between Seoul and Budapest were 4.0 and 5.9 for heavy traffic roads; 2.9 and 11.0 for roads with light traffic. Light traffic roads reflect that an important source of Pt, Pd and Ir in roadside environment is the automobile catalytic converter. Road dusts with high Pt, Pd and Ir levels were enriched with traffic-related contaminant elements as well.
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Maki, Teruya, Shogo Furumoto, Yuya Asahi, Kevin C. Lee, Koichi Watanabe, Kazuma Aoki, Masataka Murakami i in. "Long-range-transported bioaerosols captured in snow cover on Mount Tateyama, Japan: impacts of Asian-dust events on airborne bacterial dynamics relating to ice-nucleation activities". Atmospheric Chemistry and Physics 18, nr 11 (8.06.2018): 8155–71. http://dx.doi.org/10.5194/acp-18-8155-2018.
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Abstract. The westerly wind travelling at high altitudes over eastern Asia transports aerosols from the Asian deserts and urban areas to downwind areas such as Japan. These long-range-transported aerosols include not only mineral particles but also microbial particles (bioaerosols), that impact the ice-cloud formation processes as ice nuclei. However, the detailed relations of airborne bacterial dynamics to ice nucleation in high-elevation aerosols have not been investigated. Here, we used the aerosol particles captured in the snow cover at altitudes of 2450 m on Mt Tateyama to investigate sequential changes in the ice-nucleation activities and bacterial communities in aerosols and elucidate the relationships between the two processes. After stratification of the snow layers formed on the walls of a snow pit on Mt Tateyama, snow samples, including aerosol particles, were collected from 70 layers at the lower (winter accumulation) and upper (spring accumulation) parts of the snow wall. The aerosols recorded in the lower parts mainly came from Siberia (Russia), northern Asia and the Sea of Japan, whereas those in the upper parts showed an increase in Asian dust particles originating from the desert regions and industrial coasts of Asia. The snow samples exhibited high levels of ice nucleation corresponding to the increase in Asian dust particles. Amplicon sequencing analysis using 16S rRNA genes revealed that the bacterial communities in the snow samples predominately included plant associated and marine bacteria (phyla Proteobacteria) during winter, whereas during spring, when dust events arrived frequently, the majority were terrestrial bacteria of phyla Actinobacteria and Firmicutes. The relative abundances of Firmicutes (Bacilli) showed a significant positive relationship with the ice nucleation in snow samples. Presumably, Asian dust events change the airborne bacterial communities over Mt Tateyama and carry terrestrial bacterial populations, which possibly induce ice-nucleation activities, thereby indirectly impacting climate change.
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Wang, Lili, Gaofeng Wu, Tianyue Zhang, Wenkai Lei, Xinyu Wang, Mi Wang, Dongyang Zheng i Wenji Zhao. "Characterisation and Risk Assessment of Metal Contaminants in the Dust Fall in the Vicinity of a Construction Waste Dump in Beijing". International Journal of Environmental Research and Public Health 19, nr 20 (11.10.2022): 13019. http://dx.doi.org/10.3390/ijerph192013019.
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In this study, a large construction waste dump in Beijing, China, was used as the study area. Nineteen effective atmospheric dust samples were collected. The mass fractions of 14 metal elements (Ca, Fe, Al, Mg, Mn, Zn, Cr, Cu, V, Pb, Ni, As, Co, and Cd) were determined for the samples using ICP-MS. The pollutants and the potential ecological risk levels of 10 different heavy metals were evaluated using the enrichment factor, geo-accumulation index, and a potential ecological risk assessment method. The results showed that the Ca, Fe, Al, and Mg contents in the dust fall were considerably high and accounted for 98.81% of the total mass of the analysed metals. Cd and Zn were the main metal contaminants in the dust fall in the vicinity of the construction waste dump, followed by Cu and Mn. The Cd, Zn, Cu, and Mn contents in the construction waste had a significant impact on atmospheric pollution within 250 m of the dump. Moreover, Cd had the largest contribution to the comprehensive ecological risk posed by the heavy metals in the dust fall and was determined to be the primary ecological risk factor in the atmospheric environment in the vicinity of the construction waste dump.
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Delgado-Iniesta, María José, Pura Marín-Sanleandro, Elvira Díaz-Pereira, Francisco Bautista, Miriam Romero-Muñoz i Antonio Sánchez-Navarro. "Estimation of Ecological and Human Health Risks Posed by Heavy Metals in Street Dust of Madrid City (Spain)". International Journal of Environmental Research and Public Health 19, nr 9 (26.04.2022): 5263. http://dx.doi.org/10.3390/ijerph19095263.
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In this work, sampling was carried out in the urban area of Madrid to analyze the content of total heavy metals (Zn, Pb, Cu, Cr, Ni, and Cd) in the street dust. Contamination was evaluated using various indices, such as the Contamination Factor (CF), Enrichment Factor (EF), Geo-accumulation Index (Igeo), Potential Ecological Risk Index (RI), Pollution Load Index (PLI), the Human Health Index Hazard Index (HI), and Cancer Risk (CR). Pollution indices were related to traffic density and color. Traffic density was the factor that most influenced the values of the pollution indexes, but no significant differences were found with the color of street dust. The concentration of heavy metals in the urban dust of Madrid had the following sequence: Zn (895) > Cu (411) > Pb (290) > Cr (100) > Ni (42) > Cd (1.25 mg kg−1). The pollution levels were high or very high in Pb, Zn, and Cd regarding the environmental pollution indexes. Ingestion was the main route of exposure to heavy metals contained in street dust. The CR for adults and children is less than 1 × 10−6, which means that there is no risk for the population. However, the HI was 10 times higher in children than in adults.
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Delgado-Iniesta, María José, Pura Marín-Sanleandro, Elvira Díaz-Pereira, Francisco Bautista, Miriam Romero-Muñoz i Antonio Sánchez-Navarro. "Estimation of Ecological and Human Health Risks Posed by Heavy Metals in Street Dust of Madrid City (Spain)". International Journal of Environmental Research and Public Health 19, nr 9 (26.04.2022): 5263. http://dx.doi.org/10.3390/ijerph19095263.
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In this work, sampling was carried out in the urban area of Madrid to analyze the content of total heavy metals (Zn, Pb, Cu, Cr, Ni, and Cd) in the street dust. Contamination was evaluated using various indices, such as the Contamination Factor (CF), Enrichment Factor (EF), Geo-accumulation Index (Igeo), Potential Ecological Risk Index (RI), Pollution Load Index (PLI), the Human Health Index Hazard Index (HI), and Cancer Risk (CR). Pollution indices were related to traffic density and color. Traffic density was the factor that most influenced the values of the pollution indexes, but no significant differences were found with the color of street dust. The concentration of heavy metals in the urban dust of Madrid had the following sequence: Zn (895) > Cu (411) > Pb (290) > Cr (100) > Ni (42) > Cd (1.25 mg kg−1). The pollution levels were high or very high in Pb, Zn, and Cd regarding the environmental pollution indexes. Ingestion was the main route of exposure to heavy metals contained in street dust. The CR for adults and children is less than 1 × 10−6, which means that there is no risk for the population. However, the HI was 10 times higher in children than in adults.
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Gupta, Vidhu, Lalita Bisht, Ajay Kumar Arya, Ajay Pratap Singh i Sneha Gautam. "Spatially Resolved Distribution, Sources, Exposure Levels, and Health Risks of Heavy Metals in <63 μm Size-Fractionated Road Dust from Lucknow City, North India". International Journal of Environmental Research and Public Health 19, nr 19 (8.10.2022): 12898. http://dx.doi.org/10.3390/ijerph191912898.
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In the present study, a total of 64 road dust samples were collected from five different functional areas (residential, commercial, parks, high-traffic, and industrial) in urban Lucknow to assess the accumulation, distribution, and health risk of heavy metals (HMs) (i.e., Fe, Mn, Zn, Cu, Pb, Cd, As, Cr and Ni). Acid digestion methods were used to analyze HMs, followed by inductively coupled plasma-mass spectrometry (ICPMS). The ascending frequency of HMs was Cd < As < Ni < Cr < Pb < Cu < Zn < Mn < Fe for all different functional areas. Almost all HMs exceed the limits of Indian natural soil background values (INSB) across all functional areas. The pollution assessment results reveal that the urban road dust of Lucknow is highly enriched with Zn and Pb, causing deterioration of dust quality. The spatial distribution of HMs shows that road dust found in the central and southwestern zones of the Lucknow urban area are more contaminated than in other areas. The ecological risk assessment demonstrates that Cd was the highest risk contributor, followed by Pb, Zn and Cu. The result of the health risk assessment i.e., the cumulative hazard index (HI) and the cumulative lifetime cancer risk (LCR), reveal that children (mean HIchildren = 1.26, LCRchildren = 0.000187) are more vulnerable to HM exposure than adults (HIadults = 0.14, LCRadults = 0.0000804). For carcinogenic and non-carcinogenic risk, ingestion appears to be the major pathway of HM exposure in both age groups. It is alarming that all studied four carcinogenic HMs were found in concentrations higher than 1 × 10−6 (the permissible limit for humans). This indicates slight chances of developing cancer for both age groups in all functional areas.
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Kavsar, Nargiza, Mamattursun Eziz i Nazupar Sidikjan. "Pollution and Health Risk Assessment of Hazardous Elements in Surface Dust along an Urbanization Gradient". Sustainability 15, nr 15 (1.08.2023): 11842. http://dx.doi.org/10.3390/su151511842.
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The hazardous element (HE) pollution of urban surface dust is a serious environmental issue, due to its toxicity and potential hazardous effects. Surface dust samples were collected from core urban, urban, and suburban gradients in the city of Urumqi in arid northwestern China, and the concentrations of six HEs, such as arsenic (As), cadmium (Cd), nickel (Ni), lead (Pb), mercury (Hg), and chromium (Cr) were determined. The pollution load index (PLI) and the US EPA health risk assessment model were applied, to assess and compare the pollution levels and the potential health risk of HEs in the surface dust in different urbanization gradients. The results indicated that the average concentrations of Hg, Cd, and Ni in the surface dust decreased in the order of core urban > urban > suburban, whereas the average concentrations of As, Cr, and Pb decreased in the order of urban > core urban > suburban. The PLI of HEs in surface dust decreased in the order of core urban > urban > suburban. The concentrations of HEs in the core urban and urban gradients were relatively higher than those in the suburban gradient. Furthermore, the total non-carcinogenic and carcinogenic risk index of the investigated HEs in surface dust decreased in the order of urban > core urban > suburban, for both adults and children. In addition, the pollution of surface dust by HEs in all urbanization gradients was more harmful to children’s health than to adults’. Overall, the potential non-carcinogenic and carcinogenic health risk of the investigated HEs, instigated primarily via the oral ingestion of surface dust, was found to be within the acceptable range. However, urbanization has effected the accumulation of HEs in surface dust, and Cr was the main non-carcinogenic risk factor, whereas Cd was the main carcinogenic risk factor, among the analyzed HEs in surface dust in three urban gradients in the study area.
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Zhang, Yong, Jing Xia Chen, Jun Qiu Zhang i Ying Te Wang. "Spatial Distribution and Sources of Heavy Metal Pollution of Surface Dust in Taiyuan, China". Applied Mechanics and Materials 737 (marzec 2015): 503–7. http://dx.doi.org/10.4028/www.scientific.net/amm.737.503.
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The concentrations of heavy metals (Cr, Cu, Ni, Pb and Mn) were determined using flame atomic absorption spectrophotometer after digested with four acids. The samples were collected from seven kinds of different functional areas in Taiyuan, China. The concentration of the heavy metals were found in Taiyuan is higher than the soil background values in Shanxi Province, which appeared different levels of accumulation. High concentrations of Cr, Ni, Mn were found in the samples from industrial area and Cu was noted from economic development area. The correlational analysis and principle component analysis showed that the heavy metals of surface dust in Taiyuan were mainly influenced by industrial activities.
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Chen, Hong, Changlin Zhan, Shan Liu, Jiaquan Zhang, Hongxia Liu, Ziguo Liu, Ting Liu, Xianli Liu i Wensheng Xiao. "Pollution Characteristics and Human Health Risk Assessment of Heavy Metals in Street Dust from a Typical Industrial Zone in Wuhan City, Central China". International Journal of Environmental Research and Public Health 19, nr 17 (2.09.2022): 10970. http://dx.doi.org/10.3390/ijerph191710970.
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This study aimed to assess the pollution levels, sources, and human health risks of heavy metals in street dust from a typical industrial district in Wuhan City, Central China. In total, 47 street dust samples were collected from the major traffic arteries and streets around Wuhan Iron and Steel (Group) Company (WISC) in Qingshan District, Wuhan. The concentrations of heavy metals (Cr, Mn, Ni, Zn, Fe, Cu, and Cd) in street dust were determined by atomic absorption spectroscopy. Results indicated that the mean concentrations of Zn (249.71 mg/kg), Cu (51.15 mg/kg), and Cd (0.86 mg/kg) in street dust were higher than their corresponding soil background values in Hubei Province. Heavy metal enrichment is closely related to urban transportation and industrial production. The pollution level of heavy metals in street dust was assessed using the geo-accumulation method (Igeo) and potential ecological risk assessment (PERI). Based on the Igeo value, Cr, Mn, Fe, and Ni showed no pollution, Zn and Cu showed light to moderate contamination, and Cd showed moderate contamination. The PERI values of heavy metals in street dust ranged between 76.70 and 7027.28, which represents a medium to high potential ecological risk. Principal component analysis showed that the sources of heavy metals in street dust were mainly influenced by anthropogenic activities. Among the studied metals, Cu, Cr, Zn, Fe, and Mn mainly come from industrial processes, while Ni and Cd come from traffic exhaust. The non-carcinogenic risk indexes of heavy metals for children and adults are ranked as Cr > Cu > Ni > Cd > Zn. The health risks to children through the different exposure pathways are higher than those for adults. Hand-to-mouth intake is the riskiest exposure pathway for non-carcinogenic risk. In addition, Cr, Ni, and Cd do not pose a carcinogenic risk for the residents.
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Mugudamani, Innocent, Saheed A. Oke i Thandi Patricia Gumede. "Influence of Urban Informal Settlements on Trace Element Accumulation in Road Dust and Their Possible Health Implications in Ekurhuleni Metropolitan Municipality, South Africa". Toxics 10, nr 5 (17.05.2022): 253. http://dx.doi.org/10.3390/toxics10050253.
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The study was aimed at assessing the influence of urban informal settlement on trace element accumulation in road dust from the Ekurhuleni Metropolitan Municipality, South Africa, and their possible health implications. The concentration of major and trace elements was determined using the wavelength dispersive XRF method. The major elements in descending order were SiO2 (72.76%), Al2O3 (6.90%), Fe2O3 (3.88%), CaO (2.71%), K2O (1.56%), Na2O (0.99%), MgO (0.94%), MnO (0.57%), TiO2 (0.40%), and P2O5 (0.16%), with SiO2 and P2O5 at above-average shale values. The average mean concentrations of 17 trace elements in decreasing order were Cr (637.4), Ba (625.6), Zn (231.8), Zr (190.2), Sr (120.2), V (69), Rb (66), Cu (61), Ni (49), Pb (30.8), Co (17.4), Y (14.4), Nb (8.6), As (7.2), Sc (5.8), Th (4.58), and U (2.9) mg/kg. Trace elements such as Cr, Cu, Zn, Zr, Ba, and Pb surpassed their average shale values, and only Cr surpassed the South African soil screening values. The assessment of pollution through the geo-accumulation index (Igeo) revealed that road dust was moderately to heavily contaminated by Cr, whereas all other trace elements were categorized as being uncontaminated to moderately contaminated. The contamination factor (CF) exhibited road dust to be very highly contaminated by Cr, moderately contaminated by Zn, Pb, Cu, Zr, and Ba, and lowly contaminated by Co, U, Nb, Ni, As, Y, V, Rb, Sc, Sr, and Th. The pollution load index (PLI) also affirmed that the road dust in this study was very highly polluted by trace elements. Moreover, the results of the enrichment factor (EF) categorized Cr as having a significant degree of enrichment. Zn was elucidated as being minimally enriched, whereas all other trace elements were of natural origin. The results of the non-carcinogenic risk assessment revealed a possibility of non-carcinogenic risks to both children and adults. For the carcinogenic risk, the total CR values in children and adults were above the acceptable limit, signifying a likelihood of carcinogenic risk to the local inhabitants. From the findings of this study, it can be concluded that the levels of trace elements in the road dust of this informal settlement had the possibility to contribute to both non-carcinogenic and carcinogenic risks, and that children were at a higher risk than the adult population.
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Yu, Rui, Zhengwu Cui, Nana Luo i Yong Yu. "Detection and Assessments of Sources and Health Hazards Caused by Heavy Metals in the Dust of Urban Streets in Harbin, Northeast China". Sustainability 14, nr 18 (16.09.2022): 11657. http://dx.doi.org/10.3390/su141811657.
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To investigate heavy metals (HMs) in the dust of the urban streets and evaluate health hazards through dust pollution exposure, this research implements an analysis method called principal component analysis and a model called positive matrix factorization to investigate the associations between HMs and their plausible allocation of sources. A total number of 118 dust samples were collected from Harbin, China, which is one of the most eloquent industrial hubs and tourist destinations. The results suggest that the mean concentrations of Cd, Cr, Cu, Zn, Ni, Pb, and Mn are 1.79 ± 1.618, 67.23 ± 32.84, 57.76 ± 51.50, 328.52 ± 117.62, 27.11 ± 4.66, 83.03 ± 25.39, and 745.34 ± 153.22 mg kg−1, respectively. The erratic enrichment of Cu, Zn, Pb, and Cd is succeeded by a geo-accumulation index and the factors that are used for enrichment. Both the spatial distribution and correlation analysis imply that Cu, Zn, Pb, and Cd can be controlled by anthropogenic activities. On the contrary, Cr, Mn, and Ni can be ascribed to natural sources. The hazard quotients are less than 1, and the hazard indexes for seniors and kids are 0.129 and 0.852, respectively. So, kids had more non-carcinogenic hazards than the older individuals did. Both groups have carcinogenic risks of less than 1 × 10−6. The results indicated that street dust could not be potentially accepted as a health hazard for dwellers. Cu, Zn, Pb, Cr, Ni, and Cd existed in the street dust of the research region and have been influenced by the combination of industrial and traffic sources and domestic coal combustion, and the parent material that forms soil affects the levels of Mn. A model, called the PMF, is implemented in the study of street dust pollution sources, enhancing the reliability and accuracy of pollution source determination, and presenting some potential applications.
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Subhani, Marghoob, Irfan Mustafa, Ambreen Alamdar, Ioannis A. Katsoyiannis, Nadeem Ali, Qingyu Huang, Siyuan Peng, Heqing Shen i Syed Ali Musstjab Akber Shah Eqani. "Arsenic levels from different land-use settings in Pakistan: Bio-accumulation and estimation of potential human health risk via dust exposure". Ecotoxicology and Environmental Safety 115 (maj 2015): 187–94. http://dx.doi.org/10.1016/j.ecoenv.2015.02.019.
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Van Dingenen, R., J. P. Putaud, S. Martins-Dos Santos i F. Raes. "Physical aerosol properties and their relation to air mass origin at Monte Cimone (Italy) during the first MINATROC campaign". Atmospheric Chemistry and Physics Discussions 5, nr 1 (25.02.2005): 1067–114. http://dx.doi.org/10.5194/acpd-5-1067-2005.
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Abstract. Aerosol physical properties were measured at the Monte Cimone Observatory (Italy) from 1 June till 6 July 2000. The measurement site is located in the transition zone between continental boundary layer and the free troposphere (FT), at the border between the Mediterranean area and Central Europe, and is exposed to a variety of air masses. Sub-micrometer number size distributions, aerosol hygroscopicity at 90% RH, refractory size distribution at 270°C and black carbon mass were continuously measured. Number size distributions and hygroscopic properties indicate that the site is exposed to aged continental air masses, however during daytime it is also affected by upslope winds. The mixing of this transported polluted boundary layer air masses with relatively clean FT air leads to frequent nucleation events around local noon. Night-time size distributions including fine and coarse fractions for each air mass episode have been parameterized by a 3-modal lognormal distribution. Number and volume concentrations in the sub-micrometer modes are strongly affected by the air mass origin, with highest levels in NW-European air masses, versus very clean air in the ''Arctic'' episode. During the dust episode, the coarse mode is clearly enhanced. The observed hygroscopic behavior of the aerosol is consistent with the chemical composition described by Putaud et al. (2004a), but no closure could be made because the hygroscopic properties of the water-soluble organic matter is not known. The data suggest that WSOM is slightly-to-moderately hygroscopic, and that this property may well depend on the air mass origin and history. Although externally mixing is observed in all air masses, the occurrence of ''less'' hygroscopic particles has mostly such a low occurrence rate that the average growth factor distribution mostly appears as a single mode. This is not the case for the dust episode, where the external mixing between less hygroscopic and more hygroscopic particles is very prominent, and indicating clearly the occurrence of a dust accumulation mode, extending down to 50 nm particles, along with an anthropogenic pollution mode. The presented physical measurements finally allow us to provide a partitioning of the sub-µm aerosol in four non-overlapping fractions (soluble + volatile, non-soluble + volatile, refractory + non-BC, BC) which can be roughly associated with separate groups of chemical compounds (ions, organic matter, dust, BC). For what concerns the relative contributions of the fractions, all air masses except the free-tropospheric (FT) and Dust Episodes show a similar composition within the uncertainty of the data. The latter two have a significantly higher refractory fraction, which in the FT air mass is attributed to carbonaceous particles, and in the dust episode to a sub-µm accumulation mode of dust.
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Liu, Guangbo, Tian Chen, Jinli Cui, Yanping Zhao, Zhi Li, Weixin Liang, Jianteng Sun, Zhenghui Liu i Tangfu Xiao. "Trace Metal(loid) Migration from Road Dust to Local Vegetables and Tree Tissues and the Bioaccessibility-Based Health Risk: Impacts of Vehicle Operation-Associated Emissions". International Journal of Environmental Research and Public Health 20, nr 3 (31.01.2023): 2520. http://dx.doi.org/10.3390/ijerph20032520.
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Traffic activities release large amounts of trace metal(loid)s in urban environments. However, the impact of vehicle operation-associated emissions on trace metal(loid) enrichment in road dust and the potential migration of these trace metal(loid)s to the surrounding environment remain unclear. We evaluated the contamination, sequential fraction, and bioaccessibility of trace metal(loid)s in urban environments by assessing their presence in road dust, garden vegetables, and tree tissues, including bark and aerial roots, at a traffic-training venue impacted by vehicle operation emissions and, finally, calculated the bioaccessibility-based health risk. The results indicated a significant accumulation of trace metal(loid)s in road dust, with the highest lead (Pb), cadmium (Cd), and antimony (Sb) concentrations in the garage entrance area due to higher vehicle volumes, frequent vehicle starts and stops, and lower speeds. Aerial roots exposed to hill start conditions exhibited the highest Pb, Zn, and Sb levels, potentially caused by high road dust resuspension, confirming that this tree tissue is an appropriate bioindicator. Sequential extraction revealed high percentages of carbonate-, Fe/Mn oxide-, and organic/sulphide-associated fractions of Pb, copper (Cu), and zinc (Zn) in road dust, while most Cd, Cr, Ni, and Sb occurred as residual fractions. According to the potential mobilizable fractions in sequential extraction, the in vitro gastrointestinal method could be more suitable than the physiologically based extraction test to evaluate the bioaccessibility-related risk of traffic-impacted road dust. The bioaccessibility-based health risk assessment of the road dust or soil confirmed no concern about noncarcinogenic risk, while the major risk originated from Pb although leaded gasoline was prohibited before the venue establishment. Furthermore, the cancer risks (CRs) analysis showed the probable occurrence of carcinogenic health effects from Cd and Ni to adults and from Cd, Cr, and Ni to children. Furthermore, the Cd and Pb concentrations in the edible leaves of cabbage and radish growing in gardens were higher than the recommended maximum value. This study focused on the health risks of road dust directly impacted by vehicle emissions and provides accurate predictions of trace metal(loid) contamination sources in the urban environment.
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Awuah, Prince Baffour, Albert Amatey Adjaottor, Emmanuel Gikunoo, Emmanuel Kwesi Arthur, Frank Ofori Agyemang i Douglas Siaw Baah. "Dust Deposition and Associated Heavy Metal Contamination in the Neighborhood of a Cement Production Plant at Konongo, Ghana". Journal of Chemistry 2022 (15.10.2022): 1–12. http://dx.doi.org/10.1155/2022/6370679.
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The release of harmful particles from industries is one of the important sources of environmental pollution worldwide. The goal of this study was to determine the amounts of dust deposition and heavy metal pollution in the soils surrounding a cement mill in Konongo, Ghana. Topsoils (0-10 cm) were sampled at the four geographical axes of the factory within a radius of 400 m, while at the same time, about 500 g of cement was sampled with a hand trowel. A Frisbee dust sampler was used to examine the levels of dust depositions at the various geographical axes of the factory. The heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), and lead (Pb) were measured in a total of 20 soil samples using atomic absorption spectroscopy (AAS). The results obtained for climatic elements such as wind speed and direction, temperature, and relative humidity were 2.25, 25.7, and 49.5 m3/s, respectively. The average deposition of dust within the study period using the geographical axis indicated that the southern axis recorded the highest dust accumulation with a mean of 60.2 g/m2 per month. The mean concentrations of metals at the various axes were 1.04 mg/kg, 4.78 mg/kg, 8.95 mg/kg, 9.30 mg/kg, and 18.4 mg/kg for Cd, Cr, Cu, Zn, and Pb, respectively. The concentration of chemical components investigated in the soil was below the WHO/FAO standard, except for Cd. The spatial distribution pattern of the examined heavy metals showed that Cd, Cr, and Cu represent possible sources of soil contaminants. According to the conclusions of this research, this paper suggests an approach to investigate the areas contaminated with heavy metals to call out the attention of local authorities to take action.
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Sembiring, Kristin Stephanie, i Nelva Karmila Jusuf. "Cell Phone Acne: New Acne Clinical Features in the Coronavirus Disease-19 Era". Open Access Macedonian Journal of Medical Sciences 9, F (10.10.2021): 481–85. http://dx.doi.org/10.3889/oamjms.2021.6872.
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Technological developments in telecommunications, especially cell phone, enable us to keep communicate without meeting each other. Especially during the latest coronavirus outbreak, when people need to keep up social distance. Meanwhile, electronic devices such as smartphone, tablets, laptops, and light-emitting diode screens are the sources of visible lights that can emit high levels of short-wavelength visible light (blue region in the light spectrum). Prolonged exposure to high-energy blue light, heat dissipation from cell phone, friction, trapped sweat and oil, accumulation of dust, and increased bacterial growth can cause cell phone acne. Management of cell phone acne from prevention to combination therapy based on the results of the evaluation of the severity of acne is needed.
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Aguilera, Anahi, Dorian Bautista-Hernández, Francisco Bautista, Avto Goguitchaichvili i Rubén Cejudo. "Is the Urban Form a Driver of Heavy Metal Pollution in Road Dust? Evidence from Mexico City". Atmosphere 12, nr 2 (17.02.2021): 266. http://dx.doi.org/10.3390/atmos12020266.
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Environmental pollution is a negative externality of urbanization and is of great concern due to the fact that it poses serious problems to human health. Pollutants, such as heavy metals, have been found in urban road dust; however, it is unclear whether the urban form has a role in its accumulation, mainly in cases where there is no dominant unique source. We collected 482 samples of road dust, we determined the concentrations of five heavy metals (Cr, Cu, Pb, Zn, and Ni) using inductively coupled plasma optical emission spectrometry (ICP-OES), and then we derived the pollution load index (PLI). After estimating the mostly anthropogenic origin of these pollutants based on global levels of reference, there were two main aims of this study. Firstly, to analyze the spatial correlation of heavy metals, and secondly, to identify the main factors that influenced the heavy metal concentrations in the road dust of Mexico City. We did this by using a spatial autocorrelation indicator (Global Moran’s I) and applying ordinary least squares (OLS) and spatial regression models. The results indicated low levels of positive spatial autocorrelation for all heavy metals. Most variables failed to detect any relationship with heavy metals. The median strip area in the roads had a weak (significance level of 90%) but consistent positive relationship with Cr, Cu, Ni, Pb, and the PLI. The distance to the airport had a weak (significance level of 90%) and inverse relationship with Pb. Manufacturing units were associated with an increase in Cu (significance level of 95%), while the entropy index was associated with an increase in Ni (significance level of 95%).
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Gerasopoulos, E., E. Koulouri, N. Kalivitis, G. Kouvarakis, S. Saarikoski, T. Mäkelä, R. Hillamo i N. Mihalopoulos. "Size-segregated mass distributions of aerosols over Eastern Mediterranean: seasonal variability and comparison with AERONET columnar size-distributions". Atmospheric Chemistry and Physics 7, nr 10 (15.05.2007): 2551–61. http://dx.doi.org/10.5194/acp-7-2551-2007.
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Abstract. This work provides long-term (2004–2006) size segregated measurements of aerosol mass at a remote coastal station in the southern Europe, with the use of size-selective samplings (SDI impactor). Seven distinct modes were identified in the range 0–10 µm and the dominant were the "Accumulation 1" (0.25–0.55 µm) and the "Coarse 2" (3–7 µm) modes. The seasonal characteristics of each mode were thoroughly studied and different sources for submicron and supermicron particles were identified, the first being related to local/regional and transported pollution with maximum in summer and the latter to dust from deserted areas in Northern Africa maximizing in spring. On average, PM2.5 and PM1 accounted for 60% and 40% of PM10 mass, respectively.The representativity of the ground-based measurements for the total column was also investigated by comparing the measured aerosol mass distributions with the AERONET volume size distribution data. Similar seasonal patterns were revealed and AERONET was found adequate for the estimation of background levels of both fine and coarse particles near surface, with certain limitations in the case of pollution or dust abrupt episodes due to its low temporal coverage.
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Fedoniuk, Tetiana, Roman Fedoniuk, Tetiana Klymenko, Oleh Polishchuk i Andrii Pitsil. "Bioindication of Aerotechnogenic Pollution of Agricultural Landscapes Caused by the Activities of Industrial Hubs". Ekológia (Bratislava) 40, nr 2 (1.06.2021): 115–23. http://dx.doi.org/10.2478/eko-2021-0013.
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Abstract The article provides the assessment of the levels of aerotechnogenic pollution caused by the emissions from stationary pollution sources of industrial agglomerations in Zhytomyr, taking into account climatic conditions that affect the dispersion and accumulation of pollutants in soils and vegetation cover of surrounding agricultural landscapes. The examination of dust accumulated on the surface of leaves showed that it contains high concentrations of Mn, Cr, Pb, Ni, and Cu. The bioindication method with the use of white-tip radishes was applied to estimate the extent of aerotechnogenic pollution. The results of the investigation testified to the high informativeness of the offered test objects. The indexes of soil saturation with heavy metals indicated the presence of intensive processes of their accumulation. As a consequence, this territory became unsuitable for agricultural production. The inhibition of growth of radish roots identified the toxicity level of the investigated technogenic substrates as medium and higher than average. Also, there is inverse close correlation relationship between the distance from the emission source and the soil phytotoxicity indicators in all the investigated directions.
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Tawabini, Bassam, Mubarak Al-Enazi, Mansour A. Alghamdi, Ashraf Farahat, Ahsan M. Shemsi, Marwan Y. Al Sharif i Mamdouh I. Khoder. "Potentially Harmful Elements Associated with Dust of Mosques: Pollution Status, Sources, and Human Health Risks". International Journal of Environmental Research and Public Health 20, nr 3 (2.02.2023): 2687. http://dx.doi.org/10.3390/ijerph20032687.
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Potentially harmful elements (PHEs) associated with dust generated from anthropogenic sources can be transported into mosques and deposited on the filters of the air-conditioners (AC); thereby, children and adults are exposed to such PHEs while visiting mosques. Data dealing with the assessment of PHEs pollution and its human health risk in mosques dust in Saudi Arabia are scarce. Therefore, this work aims to examine the levels and pollution status of PHEs in AC filter dust (ACFD) of mosques and their associated human health risk in three Saudi cities: Jubail, Jeddah, and Dammam metropolitan. A similar concentration pattern of PHEs is observed in three cities’ mosques with noticeably higher concentrations than both global crustal and local background values for Zn, Cu, Pb, As, and Cd only. Except for Fe, Al, and Mn, the highest PHEs concentrations were found in Jeddah (1407 mg/kg), followed by Dammam (1239 mg/kg) and Jubail (1103 mg/kg). High PHEs’ concentrations were also recorded in mosques located near workshops and suburban areas compared to urban areas. Based on the spatial pattern, enrichment factor, geo-accumulation index, pollution load index, and ecological risk values, Jubail, Jeddah, and Dammam have shown moderate pollution levels of Cd, As, Pb, and Zn. On the other hand, Cu. Zn, Cu, Cr, Pb, Ni, As, and Cd had degrees of enrichment levels that varied from significantly enriched to extremely highly enriched in the ACFD of the three cities. Heavy pollution is found in Jubail, which posed a higher potential ecological risk than in Jeddah and Dammam. Cd presents the highest ecological risk factors (ER) in the three cities. Carcinogenic and non-carcinogenic risks for children and adults follow the order: Jeddah > Dammam > Jubail, and the ingestion pathway was the main route for exposure. Carcinogenic and con-carcinogenic risks in the mosques of the various studied cities were generally within the acceptable range.
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Liyanage, N. M., D. P. Nagahawatta, Thilina U. Jayawardena, H. H. A. C. K. Jayawardhana, Hyo-Geun Lee, Young-Sang Kim i You-Jin Jeon. "Clionasterol-Rich Fraction of Caulerpa racemosa against Particulate Matter-Induced Skin Damage via Inhibition of Oxidative Stress and Apoptosis-Related Signaling Pathway". Antioxidants 11, nr 10 (28.09.2022): 1941. http://dx.doi.org/10.3390/antiox11101941.
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The increasing airborne particulate matter (PM) consisting of environmental contaminants such as dust, aerosols, and fibers has become a global concern by causing oxidative stress that leads to apoptosis and skin damage. The current study evaluated the protective effect of Caulerpa racemosa (CR) against PM-induced skin damage using human keratinocytes and a zebrafish model. The clionasterol-rich hexane fraction (CRHF2) of CR exhibited superior protective activity through downregulating intracellular reactive oxygen species levels and mitochondrial ROS levels, as well as the PM-induced increase in apoptotic body formation and upregulation of apoptotic signaling pathway proteins, along with sub-G1 cell accumulation dose-dependently. Furthermore, in vivo results showed that CRHF2 potentially downregulates PM-induced cell death, ROS, and NO production in the zebrafish model. Hence, the results evidenced that the protective effect of CRHF2 is caused by inhibiting oxidative stress and mitochondrial-mediated apoptosis in cells. Therefore, C. racemosa has the potential to be used in the development of pharmaceuticals to attenuate PM-induced skin diseases.
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Cai, Kui, i Chang Li. "Street Dust Heavy Metal Pollution Source Apportionment and Sustainable Management in A Typical City—Shijiazhuang, China". International Journal of Environmental Research and Public Health 16, nr 14 (23.07.2019): 2625. http://dx.doi.org/10.3390/ijerph16142625.
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Street dust is repeatedly raised by the wind as a secondary suspension, helping heavy metals therein to enter the human body through the respiratory system, harming human health. A detailed investigation was conducted to determine levels and sources of Cd (cadmium), Cr (chromium), Cu (copper), Pb (lead), Zn (zinc), Ni (nick), and Hg (mercury) contamination in street dust from Shijiazhuang, China. The average concentrations of these metals were: Cd, 1.86 mg·kg−1; Cr, 131.7 mg·kg−1; Ni, 40.99 mg·kg−1; Cu, 91.06 mg·kg−1; Pb, 154.78 mg·kg−1, Hg, 0.29 mg·kg−1; and Zn, 496.17 mg·kg−1—all of which were greater than the local soil reference values. The concentrations of the heavy metals were mapped for the three Shijiazhuang ring roads, with the results showing significant differences between each ring. Application of enrichment factors and geoaccumulation indexes showed that there was significant enrichment and accumulation of Cd, Pb, Zn, and Hg. Multivariate statistical analyses showed that Cd, Pb, Zn, and Hg levels were mainly controlled by human activities, while Cr, Ni, and Cu levels were associated with natural sources. Absolute principal component scores with multiple linear regression (APCS-MLR) were applied to facilitate source apportionment. The results showed that the mixed (traffic and industry) group contributed 53.55%, 59.7%, and 62.25% of the Cd, Pb, and Zn concentration, respectively, while the natural sources group contributed 58.01%, 65.09%, and 66.91% of the Cu, Ni, and Cr concentration, respectively. The burning coal group was found to be responsible for 63.38% of the Hg present in the samples. These results provide a useful theoretical basis for Shijiazhuang authorities to address heavy metal pollution management.
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Van Dingenen, R., J. P. Putaud, S. Martins-Dos Santos i F. Raes. "Physical aerosol properties and their relation to air mass origin at Monte Cimone (Italy) during the first MINATROC campaign". Atmospheric Chemistry and Physics 5, nr 8 (19.08.2005): 2203–26. http://dx.doi.org/10.5194/acp-5-2203-2005.
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Abstract. Aerosol physical properties were measured at the Monte Cimone Observatory (Italy) from 1 June till 6 July 2000. The measurement site is located in the transition zone between the continental boundary layer and the free troposphere (FT), at the border between the Mediterranean area and Central Europe, and is exposed to a variety of air masses. Sub-μm number size distributions, aerosol hygroscopicity near 90% RH, refractory size distribution at 270°C and equivalent black carbon mass were continuously measured. Number size distributions and hygroscopic properties indicate that the site is exposed to aged continental air masses, however during daytime it is also affected by upslope winds. The mixing of this transported polluted boundary layer air masses with relatively clean FT air leads to frequent nucleation events around local noon. Night-time size distributions, including fine and coarse fractions for each air mass episode, have been parameterized by a 3-modal lognormal distribution. Number and volume concentrations in the sub-μm modes are strongly affected by the air mass origin, with highest levels in NW-European air masses, versus very clean, free tropospheric air coming from the N-European sector. During a brief but distinct dust episode, the coarse mode is clearly enhanced. The observed hygroscopic behavior of the aerosol is consistent with the chemical composition described by Putaud et al. (2004), but no closure between known chemical composition and measured hygroscopicity could be made because the hygroscopic properties of the water-soluble organic matter (WSOM) are not known. The data suggest that WSOM is slightly-to-moderately hygroscopic (hygroscopic growth factor GF at 90% relative humidity between 1.05 and 1.51), and that this property may well depend on the air mass origin and history. External mixing of aerosol particles is observed in all air masses through the occurrence of two hygroscopicity modes (average GF of 1.22 and 1.37, respectively). However, the presence of "less" hygroscopic particles has mostly such a low occurrence rate that the average growth factor distribution for each air mass sector actually appears as a single mode. This is not the case for the dust episode, where the external mixing between less hygroscopic and more hygroscopic particles is very prominent, and indicating clearly the occurrence of a dust accumulation mode, extending down to 50 nm particles, along with an anthropogenic pollution mode. The presented physical measurements finally allow us to provide a partitioning of the sub-μm aerosol in four non-overlapping fractions (soluble/volatile, non-soluble/volatile, refractory/non-black carbon, black carbon) which can be associated with separate groups of chemical compounds determined with chemical-analytical techniques (ions, non-water soluble organic matter, dust, elemental carbon). All air masses except the free-tropospheric N-European and Dust episodes show a similar composition within the uncertainty of the data (53%, 37%, 5% and 5% respectively for the four defined fractions). Compared to these sectors, the dust episode shows a clearly enhanced refractory-non-BC fraction (17%), attributed to dust in the accumulation mode, whereas for the very clean N-EUR sector, the total refractory fraction is 25%, of which 13% non-BC and 12% BC.
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Мажайский, Ю. А., i Т. М. Гусева. "ЭКОЛОГИЧЕСКИЕ ПРОБЛЕМЫ АГРОЛАНДШАФТОВ РЯЗАНСКОЙ ОБЛАСТИ". Biosfera 11, nr 3 (5.02.2020): 1. http://dx.doi.org/10.24855/biosfera.v11i3.510.
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The leading sources of anthropogenic pollutants in Ryazan Region are emissions from industrial enterprises. The main route of heavy metals deposition is via atmospheric precipitation. Dust precipitations are enriched in Zn, Pb, Cd, whereas aqueous precipitations, in Cu. The first maximum of the accumulation of metal, mainly Cu, Mn, Zn, Ni, Pb, Cd and Co, is observed in all types of soils of the Ryazan region. The second maximum (Zn, Cu, Pb, Co, and Ni) is featured by the illuvial horizons on the geochemical barrier. Sn and Mo are almost evenly distributed across the soil profile. Based on the soil survey in Ryazan Region, its landscapes were ranked according to the gross content of heavy metals. The resulting maps characterize the current and forecasted levels of soil pollution with heavy metals in Ryazan Region.
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Nguyen, Van-Truc, Nguyen Duy Dat, Thi-Dieu-Hien Vo, Duy-Hieu Nguyen, Thanh-Binh Nguyen, Ly-Sy Phu Nguyen, Xuan Cuong Nguyen i in. "Characteristics and Risk Assessment of 16 Metals in Street Dust Collected from a Highway in a Densely Populated Metropolitan Area of Vietnam". Atmosphere 12, nr 12 (24.11.2021): 1548. http://dx.doi.org/10.3390/atmos12121548.
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The present study focused on investigating the contamination and risk assessment for 16 metals in street dust from Ha Noi highway, Ho Chi Minh City. The results indicated that the concentrations of metals (mg/kg) were found, in decreasing order, to be Ti (676.3 ± 155.4) > Zn (519.2 ± 318.9) > Mn (426.6 ±113.1) > Cu (144.7 ± 61.5) > Cr (81.4 ± 22.6) > Pb (52.2 ± 22.9) > V (35.5 ± 5.6) > Ni (30.9 ± 9.5) > Co (8.3 ± 1.2) > As (8.3 ± 2.5) > Sn (7.0 ± 3.6) > B (5.7 ± 0.9) > Mo (4.1 ± 1.7) > Sb (0.8 ± 0.3) > Cd (0.6 ± 0.2) > Se (0.4 ± 0.1). The geo-accumulation index (Igeo) showed moderate contamination levels for Pb, Cd, Cu, Sn, Mo, and Zn. The enrichment factor (EF) values revealed moderate levels for Cd, Cu, Mo, and Sn but moderate–severe levels for Zn. The pollution load index of the heavy metals was moderate. The potential ecological risk (207.43) showed a high potential. Notably, 40.7% and 33.5% of the ecological risks were contributed by Zn and Mn, respectively. These findings are expected to provide useful information to decision-makers about environmental quality control strategies.
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Valta, Art, Mika Ruusunen i Kauko Leiviskä. "On-line moisture content estimation of saw dust via machine vision". Open Engineering 10, nr 1 (9.05.2020): 336–49. http://dx.doi.org/10.1515/eng-2020-0035.
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AbstractThe effect of moisture content and feasibility of its estimation in granular material was investigated via machine vision. The test scheme consisted of saw dust samples derived from Norway spruce with moisture content adjusted to three distinct levels. The effect of moisture when present as ice or liquid water was compared. The experimental procedure consisted of pouring the saw dust under video camera recording. The equipment setup consisted of a vibrator feeder and custom-built pouring frame. Still images were extracted with fixed sample time from the recording done during the pouring procedure. From the extracted frames the dynamic behavior of cone profile was investigated via statistical means. It was observed that 2nd standardized moment correlated with moisture content, phase of water and their interaction. Furthermore, 4th standardized moment correlated with moisture content and phase. The 3rd moment was inspected qualitatively from which it was observed that wet samples exhibited tendency to build mass accumulation sites with increasing moisture content. Samples where water was present as ice this was observed in a very small scale with all moisture content values. Corroborated by optical microscopy, these correlations were deduced to be due to liquid bridging in the bulk. Moisture content when present as ice was, however, observed to have a drastic effect on the overall cone shape. Based on these findings, a machine vision application could be feasible way to estimate moisture content on-line in thawed saw dust by using statistical parameters in classification decision making. This would enable cost-effective on-line monitoring of moisture content and a control circuit to be designed.
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Ferrini, Maria M., Zeina Jaffar i Kevan Roberts. "IL-33 and allergen exposure promote development of “memory-like” ILC2s in the Airways". Journal of Immunology 204, nr 1_Supplement (1.05.2020): 147.5. http://dx.doi.org/10.4049/jimmunol.204.supp.147.5.
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Abstract The alarmin, IL-33 plays a critical role in the inception of lung inflammation and the exacerbation of allergic airway disease. Inhalation of environmental allergens and particulates is known to promote IL-33 release, and the cells responsive to this cytokine include group 2 innate lymphoid cells (ILC2s), dendritic cells and natural killer (NK) cells. In this study, we evaluated the effect of IL-33 and house dust mite allergen inhalation on the properties of lung ILC2s. Instillation of IL-33 into the airways of mice resulted in a marked elevation in number of ILC2s and eosinophils. Importantly, a notable feature of the inflammatory response was an increase in CD103 expression by ILC2 (from 3% to 45%). These CD103+ ILC2s appeared to represent memory-like ILC2s since they were highly responsive to IL-25 and produced significant levels of IL-9 and IL-13. Critically, inhalation of house dust mite allergen also increased CD103 expression by ILC2s. Given that CD103 expression can be induced by TGF-β, we next determined whether active TGF-β1 is released following IL-33-driven lung inflammation. Remarkably, the levels of active TGF-β1 present in the airways were markedly raised following IL-33 instillation, and this was responsible for a reduction in IFN-γ-producing NK cells and raised CD226 (DNAM-1) expression. Collectively, these findings reveal that IL-33 and allergen promote the accumulation of CD103+ memory-like ILC2s in the airways. A role for TGF-β in promoting CD103 expression while suppressing NK cell-mediated regulation of the inflammatory process is proposed.
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Ma, Hongmei, Guitao Shi i Yongqian Cheng. "Accumulation Characteristics of Metals and Metalloids in Plants Collected from Ny-Ålesund, Arctic". Atmosphere 11, nr 10 (20.10.2020): 1129. http://dx.doi.org/10.3390/atmos11101129.
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Toxic elements can be transported to polar regions by long-range atmospheric transport from mid and low latitudes, leading to enrichment of elements in the polar environment, especially in the Arctic. The plants can be ideal bioindicators of element contamination in environments, but information on the element enrichment and sources of plants remains limited in polar regions. Here, concentrations of 15 metals and metalloids (Pb, Ni, Cr, Cu, Co, As, Cd, Sb, Hg, Se, Fe, Zn, Mn, Al, and Ti) in six species of plants, Deschampsia caespitosa (Tufted Hair Grass), Puccinellia phryganodes (Creeping Alkaligrass), Saxifraga aizoides (Yellow Mountain Saxifrage), Dicranum angustum (Dicranum Moss), Salix Polaris (Polar Willow), and Cerastium arcticum (Arctic Mouse-Ear Chickweed), collected from Ny-Ålesund, the Arctic, were determined, and enrichment and sources of elements were assessed. Results show that element concentrations vary in different plant species, and element levels in D. angustum and C. arcticum are generally higher. In spatial terms, elevated element concentrations were found near residential areas, while low element levels were present at the sites far from settlement points. Enrichment assessment shows that Cd, Hg, and Zn are the most enriched elements, with enrichment factors above 30, suggesting sources other than soil dust control their concentrations. Principal component analysis (PCA) showed that the extracted three components can explain 82% of the total variance in element concentrations. The elements Ni, Cr, As, Sb, Fe, Al, Ti, and to a lesser extent Co are highly loaded in PC1, possibly associated with continental crust particles. PC2 is closely correlated with Cd, Se, Mn, Cu, and Zn, while Hg and Pb have high loadings on PC3. The elements highly loaded on PC2 and PC3 are likely associated with pollutants from atmospheric transportation. Together with enrichment assessment, the investigated plants have a great potential for monitoring atmospheric Cd, Hg, and Zn pollution in Ny-Ålesund, and D. angustum and D. caespitosa are the more sensitive species. The results would be of significance for monitoring element contamination in the pristine Arctic environments using the bioindicator plants.
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Cravens, Scott E., i Ronald M. Barrett. "Infra-Through Ultrasonic Piezoelectric Acoustic Vector Sensor Particle Rejection System". Smart Materials Research 2012 (29.03.2012): 1–6. http://dx.doi.org/10.1155/2012/356190.
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Sensor elements which employ fine filaments are often vulnerable to particulate fouling when used in certain operational field conditions. Depending on the size, attraction level, thermal and electrical conduction, and charge accumulation properties of the particles, erroneous readings can be easily generated in such “dirty” environments. This paper describes the design, development, and testing of an ultrasonic system which dynamically rejects highly tenacious electrostatically charged particles of a wide variety of sizes and even water. The paper starts with a brief introduction to the field of acoustic vector sensing, outlining its outstanding characteristics and history. Operational challenges including a statistical analysis of typical Middle-Eastern wind-blown desert sand and charge density are laid out. Several representative subscale hot-wire filaments were fouled with calibrated dust representing desert sand. The fouled elements were then exposed to airflows of 13 ft/s (4 m/s) and showed highly erratic shifted conduction levels with respect to baseline (clean) levels. An ultrasonic cleaning system was designed specifically resonate the filament and cantilever so as to mechanically reject foulants. When operated at resonance, the ultrasonic cleaning system showed 98.6% particulate rejection levels and associated restoration of uncorrupted filament resistance levels to within 2% of baseline resistance measurements.
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Artana, I. Gusti Ngurah Bagus, I. Gusti Ayu Artini, I. Gusti Kamasan Nyoman Arijana, Ida Bagus Ngurah Rai i Agung Wiwiek Indrayani. "Exposure Time of Silica Dust and the Incidence of Oxidative Stress, Inflammation, and Fibrosis in Rat Lungs". Open Access Macedonian Journal of Medical Sciences 10, A (21.07.2022): 1378–82. http://dx.doi.org/10.3889/oamjms.2022.9381.
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BACKGROUND: Until now, exposure to silica dust is still a health problem worldwide. Silica exposure in the lungs will cause pulmonary fibrosis which is initiated by inflammation. However, the results of several studies regarding the duration of inflammation and fibrosis are still inconsistent. There was a role of oxidative stress in silicosis, but there were also inconsistencies in terms of when oxidative stress occurs in silica exposure. AIM: This study aimed to study the toxic effects of silica dust exposure by looking at the picture of inflammation and fibrosis and malondialdehyde (MDA) levels in lung tissue during the observation period of 7 days, 14 days, 21 days, and 28 days. METHODS: This study used a randomized post-test only control group design. The research sample was male Wistar rat (Rattus norvegicus), aged 6–10 weeks, body weight 150–200 g (divided into 5 groups: Control group, day 7 group, group day 14, group day 21, and group day 28). We administered silica suspension through intratracheal injection of 30 mg/rat on 0.5 mL of volume. Examination of MDA level was using the ELISA technique; histopathological examination of the liver used hematoxylin-eosin (HE) staining to determine inflammation and fibrosis. Statistical test using one-way ANOVA or Kruskal–Wallis followed by post hoc test. RESULTS: The results of our study found that intratracheal silica exposure increased MDA levels on the 7th day, increased the accumulation of collagen from the 14th day, and increased the pulmonary inflammation score on the 14th day (p < 0.05). CONCLUSIONS: It was concluded that silica exposure caused significant oxidative stress on day 7 as well as significant inflammation and pulmonary fibrosis on day 14.
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Barth, Aaron M., Peter U. Clark, Nicholas S. Bill, Feng He i Nicklas G. Pisias. "Climate evolution across the Mid-Brunhes Transition". Climate of the Past 14, nr 12 (21.12.2018): 2071–87. http://dx.doi.org/10.5194/cp-14-2071-2018.
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Abstract. The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in the amplitude of the 100 kyr climate cycles of the past 800 000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO2 levels after the MBT, and benthic oxygen isotope (δ18O) records, which suggest that post-MBT interglaciations had higher sea levels and warmer temperatures than pre-MBT interglaciations. It remains unclear, however, whether the MBT was a globally synchronous phenomenon that included other components of the climate system. Here, we further characterize changes in the climate system across the MBT through statistical analyses of ice-core and δ18O records as well as sea-surface temperature, benthic carbon isotope, and dust accumulation records. Our results demonstrate that the MBT was a global event with a significant increase in climate variance in most components of the climate system assessed here. However, our results indicate that the onset of high-amplitude variability in temperature, atmospheric CO2, and sea level at ∼430 ka was preceded by changes in the carbon cycle, ice sheets, and monsoon strength during Marine Isotope Stage (MIS) 14 and MIS 13.
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SURES, B., T. SCHEIBLE, A. R. BASHTAR i H. TARASCHEWSKI. "Lead concentrations in Hymenolepis diminuta adults and Taenia taeniaeformis larvae compared to their rat hosts (Rattus norvegicus) sampled from the city of Cairo, Egypt". Parasitology 127, nr 5 (17.10.2003): 483–87. http://dx.doi.org/10.1017/s0031182003003901.
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Concentrations of lead, determined by electrothermal atomic absorption spectrometry, were compared between the cestodes Hymenolepis diminuta and Taenia taeniaeformis and its host rat (Rattus norvegicus). Rats were sampled at 2 sites, which differed in respect to lead pollution as quantified from road dust, adjacent to the city of Cairo, Egypt. Comparing lead levels among host tissues and the parasites the significantly highest accumulation was found in H. diminuta, followed by rat kidney and larvae of T. taeniaeformis. Calculation of bioconcentration factors showed that H. diminuta contained 36-, 29-, 6- and 6-fold higher lead levels than intestinal wall, liver, kidney and larvae of T. taeniaeformis, at the more polluted site. At the less contaminated site lead bioconcentration factors for H. diminuta were found to be 87, 87 and 11 referred to intestine, liver and kidney of the host. Due to a high variability of the lead concentrations in H. diminuta it was not possible to indicate differences in metal pollution between both sampling sites. This variability may be influenced by different age structures of cestode infrapopulations. It is likely that younger worms contain lower metal levels than older worms due to a shorter exposure period. Thus, it is necessary to standardize the sampling of worms which should be used for indication purposes. Due to a lack of adequate sentinel species in terrestrial habitats more studies are required to validate and standardize the use of helminths as accumulation bioindicators in order to obtain mean values with low standard deviations. The host–parasite system rat–H. diminuta appears to be a useful and promising bioindication system at least for lead in urban ecosystems as rats as well as the tapeworm are globally distributed and easily accessible.