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Positive matrix factorization (PMF) was used to deduce the aerosol sources at a rural site on the Mediterranean coast of Turkey, using sample collected between February 1992 and December 1993. Approximately 600 daily aerosol sampl...
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Positive matrix factorization (PMF) was used to deduce the aerosol sources at a rural site on the Mediterranean coast of Turkey, using sample collected between February 1992 and December 1993. Approximately 600 daily aerosol samples were collected and 40 elements and compounds were analyzed by atomic absorption spectrometry, instrumental neutron activation analysis, ion chromatography and colorimetry. Seven factors were identified with PMF, namely local dust, Saharan dust, sea salt, long range transport, smelter, arsenic and fertilizer factors. The non-parametric bootstrapped potential source contribution function (PSCF) was then used to help identify likely locations of the regional sources of pollution. Besides, explained variance, enrichment factors, seasonal variation of G-score values and back trajectories were used to define the source regions of the factors. Results demonstrated that there are major potential source areas, for the pollution-derived component in aerosol mass, on the Aegean coast, Northwest Turkey, Balkan countries, Ukraine and regions located northern part of Ukraine. (c) 2007 Elsevier B.V. All rights reserved.
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Particulate matter (PM) specimens from a traffic site were sampled on Teflon filters using a low volume sampler. The sampling campaign ran over a one-year period with sampling frequency of twice a week for both PM2.5 and PM10. X-r...
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Particulate matter (PM) specimens from a traffic site were sampled on Teflon filters using a low volume sampler. The sampling campaign ran over a one-year period with sampling frequency of twice a week for both PM2.5 and PM10. X-ray diffraction (XRD) methods, which are not commonly used in PM analysis, have been utilized successfully to identify crystalline phases present, including secondary pollutants. XRD data confirmed results obtained by X-ray fluorescence, positive matrix factorization modeling, and scanning electron microscopy. PM2.5 consisted mainly of secondary sulfates, like Mascagnite [(NH4)(2)SO4], Koktaite [(NH4)(2)Ca(SO4)(2)center dot H2O], and Gypsum [CaSO4 center dot 2H(2)O]. For PM10, it was found that the major phases are mostly originating from natural sources, such as dust storms and sea salts, in addition to secondary compounds, such as sodium nitrate. The main phases identified were Calcite, Quartz, Gypsum, Halite, and Palygorskite. (C) The Author(s), 2020. Published by Cambridge University Press on behalf of International Centre for Diffraction Data.
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The most common construction material used in Taiwan is concrete, potentially contaminated by geologic heavy
metals (HMs). Younger children spend much time indoors, increasing HM exposure risks from household dust
owing to their...
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The most common construction material used in Taiwan is concrete, potentially contaminated by geologic heavy
metals (HMs). Younger children spend much time indoors, increasing HM exposure risks from household dust
owing to their behaviors. We evaluated arsenic (As), cadmium (Cd), and lead (Pb) concentrations in fingernails
among 280 preschoolers between 2017 and 2023. We also analyzed HM concentrations, including As, Cd, Pb,
chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn), in 90 household dust and 50
road dust samples from a residential area where children lived between 2019 and 2021 to deepen the understanding
of sources and health risks of exposure to HMs from household dust. The average As, Cd, and Pb
concentrations in fingernails were 0.12 ± 0.06, 0.05 ± 0.05, and 0.95 ± 0.77 μg/g, respectively. Soil parent
materials, indoor construction activities, vehicle emissions, and mixed indoor combustion were the pollution
sources of HMs in household dust. Higher Cr and Pb levels in household dust may pose non-carcinogenic risks to
preschoolers. Addressing indoor construction and soil parent materials sources is vital for children’s health. The
finding of the present survey can be used for indoor environmental management to reduce the risks of HM
exposure and avoid potential adverse health effects for younger children.
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A comparative study between Chemical Mass Balance (CMB) and multivariate receptor modeling techniques was conducted. The study involved common application of Robotic Chemical Mass Balance (RCMB) and 2 dimensional Positive Matrix F...
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A comparative study between Chemical Mass Balance (CMB) and multivariate receptor modeling techniques was conducted. The study involved common application of Robotic Chemical Mass Balance (RCMB) and 2 dimensional Positive Matrix Factorization (PMF). A two-fold methodology was developed for Source Apportionment (SA) of reactive species, in order to address previous limitations of CMB models. The developed methodology (a) uses a detailed set of theoretical source profiles, taking into account secondary reactions that were not considered in CMB modelling until now, and (b) implements a Least Squares (LS) fitting method that iteratively readjusts the values of independent variables in the CMB fit, providing (for the first time, to our knowledge) CMB source profiles as output data, in which secondary transformations may be reflected. A straight-forward computational procedure named Factor Mapping (FM) was developed as well, for intercomparison between RCMB and PMF. The distinctive feature of FM is that similarity measures are used not just to compare the results of the two models, as in previous intercomparison exercises, but, moreover, to actively assist in the physical interpretation of PMF factors, thus minimizing user interference. The intercomparison between RCMB and PMF also involved an independent evaluation of each model's performance in reproducing ambient concentrations of particulate matter (PM) and associated chemical constituents. Overall, it was shown that the employed series of computational steps substantially improve qualitative as well as quantitative agreement between the two models. (C) 2016 Elsevier B.V. All rights reserved.
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To date, few systematic studies have been conducted of the spatial distribution, formation mechanism, and health risks of high-fluoride (F~(−)) shallow groundwater in humid and semi-humid areas of the Xikuangshan antimony mine, H...
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To date, few systematic studies have been conducted of the spatial distribution, formation mechanism, and health risks of high-fluoride (F~(−)) shallow groundwater in humid and semi-humid areas of the Xikuangshan antimony mine, Hunan Province, China. In this study, during March and April 2022, a total of 39 shallow groundwater samples were collected and analyzed using factor analysis, principal component analysis, and health risk assessment. F~(−)concentrations in the shallow groundwater were found in the range of 0.08–15.00 mg/L (mean: 1.21 mg/L), with 25.64% of the samples having F~(−)concentrations higher than in the Chinese national standard for drinking water (1.00 mg/L). Principal component analysis revealed that the main source of F~(−)in the shallow groundwater samples is cation exchange, accounting for 73.40%, followed by the dissolution and precipitation of F-bearing minerals (15.10%) and human influence (11.50%). Among different age groups, children had the highest percentage of individuals (36.38%) with an F~(−)intake above the health risk quotient safety limit, followed by adult males (23.12%), teenagers (22.21%), and infants (21.22%). The findings of this study will contribute to devising strategies for the provision of safe drinking water and the management of the geological environment.
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Secondary organic aerosol, formed through atmospheric oxidation processes, plays an important role in affecting climate and human health. In this study, we conducted a comprehensive campaign in the megacity of Shanghai during the ...
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Secondary organic aerosol, formed through atmospheric oxidation processes, plays an important role in affecting climate and human health. In this study, we conducted a comprehensive campaign in the megacity of Shanghai during the 2019 International Import Expo (EXPO), with the first deployment of a chemical ionization- Orbitrap mass spectrometer for ambient measurements. With the ultrahigh mass resolving power of the Orbitrap mass analyzer (up to 140,000 Th/Th) and capability in dealing with massive spectral data sets by positive matrix factorization, we were able to identify the major gas-phase oxidation processes leading to the formation of oxygenated organic molecules (OOM) in Shanghai. Nine main factors from three independent sub-range analysis were identified. More than 90% of OOM are of anthropogenic origin and >60% are nitrogen-containing molecules, mainly dominated by the RO_2 + NO and/or NO_3 chemistry. The emission control during the EXPO showed that even though the restriction was effectual in significantly lowering the primary pollutants (20-70% decrease), the secondary oxidation products responded less effectively (14% decrease), or even increased (50 to >200%) due to the enhancement of ozone and the lowered condensation sink, indicating the importance of a stricter multi-pollutant coordinated strategy in primary and secondary pollution mitigation.
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Previously determined PCB concentrations in 10 dated sediment cores from Lakes Michigan, Huron, Erie, and Ontario are analyzed by positive matrix factorization in order to find characteristic congener patterns including signs of a...
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Previously determined PCB concentrations in 10 dated sediment cores from Lakes Michigan, Huron, Erie, and Ontario are analyzed by positive matrix factorization in order to find characteristic congener patterns including signs of anaerobic dechlorination. Three or four factors are sufficient to describe the PCB data for each lake. All four lakes are dominated by Aroclors 1248A, 1248G, 1254A, and 1254G. Aroclor 1260 is only a significant factor in Lake Michigan prior to 1975, reflecting in part a usage patterns of heavy chlorinated Aroclors early and less chlorinated Aroclors in the phase-out years in the 1970s. Dated records of factors or sources indicate clear PCB concentration maxima for Lakes Erie (1981) and Ontario(1968), while redistribution of PCBs in the less contaminated Lakes Michigan and Huron has occurred after 1980. Using a single data matrix for all four lakes provides a common basis and possibility to examine low degrees of dechlorination, while individual data matrices for each lake provide more accurate results and better separation of factors. Lakes Ontario, Michigan, and Huron undergo dechlorination via reactions such as 66(24-34) →25(24-3) and 18(25-2)→4(2-2) consistent with reactions H' + M, while Lake Erie appears to be dominated by 18(25-2)→4(2-2) and 53(25-26)→19(26-2) that are typical for processes M + Q.
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The seasonal and spatial variation characteristics of 19 elements (Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Sb, Se, Zn) in TSP/PM_(10)/PM_(2.5) samples were investigated, which were collected from April 2011 t...
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The seasonal and spatial variation characteristics of 19 elements (Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Sb, Se, Zn) in TSP/PM_(10)/PM_(2.5) samples were investigated, which were collected from April 2011 to January 2012 simultaneously at an urban downtown site, a traffic roadside site, a suburban site, and a rural site in Beijing. The elevated concentrations of several toxic trace elements (As, Cd, Mn, Ni, Pb, etc.) in particles revealed that the contamination of toxic elements in Beijing could not be neglected. Positive matrix factorization method (PMF) was applied for source apportionment of trace elements in PM, and three factors (crust related sources, combustion sources, and traffic and steel industrial related sources) were identified. Furthermore, the chemical speciation and bioavailability of various elements were identified by applying European Community Bureau of Reference (BCR) procedure. Our results showed that eight toxic elements (As, Cd, Cr, Cu, Ni, Pb, Sb and Zn) exhibited higher mobility in PM_(2.5) than in PM_(10). Notably, elements of As, Cd, Pb and Zn were presented with higher mobility than the other elements, and these elements were lightly to release into the environment and easily available to human body. Additionally, As, Cd, Pb and Zn also accounted for higher percentages in the bound to mobile fractions at the central urban areas of Beijing. Therefore, special concerns should be paid to these toxic trace elements which had relatively high mobility in fine particles, when planning and implementing the comprehensive air pollution mitigation policies in Beijing.
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Identifying and quantifying the major sources of atmospheric particulate matter (PM) is essential for the development of pollution mitigation strategies to protect public health. However, urban PM is affected by local primary emis...
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Identifying and quantifying the major sources of atmospheric particulate matter (PM) is essential for the development of pollution mitigation strategies to protect public health. However, urban PM is affected by local primary emissions, transport, and secondary formation; therefore, advanced methods are needed to elucidate the complex sources and transport patterns. Here, an improved source apportionment method was developed by incorporating the receptor model, Lagrangian simulation, and emissions inventories to quantify PM_(2.5) sources for an industrial city in China. PM_(2.5) data including ions, metals, organic carbon, and elemental carbon were obtained by analyzing 1 year of sampling results at urban and rural sites. This method identified coal combustion (30.64%), fugitive dust (13.25%), and vehicles (12.51%) as major primary sources. Secondary sources, including sulfate, nitrate, and secondary organic aerosols also contributed strongly (25.28%-30.76% in total) over urban and rural areas. Hebei Province was the major regional source contributor (43.05%-57.51%) except for fugitive dust, on which Inner Mongolia had a greater impact (43.51%). The megacities of Beijing and Tianjin exerted strong regional impacts on the secondary nitrate and secondary organic aerosols factors, contributing 11.32% and 15.65%, respectively. Pollution events were driven largely by secondary inorganic aerosols, highlighting the importance of reducing precursor emissions at the regional scale, particularly in the Beijing-Tianjin-Hebei region. Overall, our results demonstrate that this novel method offers good flexibility and efficiency for quantifying PM_(2.5) sources and regional contributions, and that it can be extended to other cities.
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In recent years, with the frequent occurrences of heavy metal (HM) pollution in agriculture, the problem of HM pollution in farmland soil, especially in the areas irrigation by the Yellow River, has been attracted increasing atten...
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In recent years, with the frequent occurrences of heavy metal (HM) pollution in agriculture, the problem of HM pollution in farmland soil, especially in the areas irrigation by the Yellow River, has been attracted increasing attention because of the complex sources of pollution. Qualitative identification of pollution sources and quantification of their contributions to HMs in soil are the key links in the prevention and control of HM pollution. The contents of 11 heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn, V, and Zn) in the rhizosphere soil of the Ningxia irrigation area were determined by inductively coupled plasma mass spectrometry (ICP-MS). Multiple methods were used for source identification, including positive matrix factorization (PMF) analysis combined with multiple other analyses (single factor index method (Pi), coefficient of variation(CV), correlation analysis(CA), enrichment factor(EF), and principal component analysis(PCA)). The results showed that (1) the over-standard rates of As, Cd, Cr, Mn, Pb, Sn, and Zn in the study area were 100%, of which Cd was seriously polluted, while As, Zn, and Sn were moderately polluted. (2) The HM contributions from irrigation and silt soil formed by the Yellow River sediment were the highest (42.45%), followed by the smelting industry and traffic pollution (16.06%). (3) The contribution of agricultural pollution to HMs in the region was 15.54%, in which As was mainly from pesticides and Cd was mainly from fertilizers.
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