Sources Of PM2 Research Articles

Investigation of Organic Carbon Profiles and Sources of Coarse Pm in Los Angeles

Investigation of Organic Carbon Profiles and Sources of Coarse Pm in Los Angeles

PM10 Source Identification: A Case of a Coastal City in Colombia

This paper assesses the spatial variation of EC, OC, major, and trace elements in an industrialized coastal city, allowing identification and tracers of PM10 emission sources. 83 samples (24h average) were collected on quartz filters during the dry season using high-volume samplers. Major and trace elements were analyzed using ICP-AES and ICP-MS, whereas a thermal/optical carbon analyzer was used to determine OC and EC. Chemical characterization of major elements, SiO2, SO42-, MgO, and CaO, showed high spatial variation between sites. The abundance of these major elements and OC confirmed the effect of exposed land resuspension and road dust; mutually with the production of secondary organic aerosol (SOA). Trace elements showed high values of Cu, Pb, Mn, and V, indicating the influence of road traffic and some industries (Cu) and oil burning (V and Mn). Enrichment Factor analysis revealed that Mg, P, S, Cu, and Pb were highly/moderately enriched indicating the substantial contribution of anthropogenic sources. Results of diagnostic ratios and PMF receptor model of the spatially obtained data suggested major sources of PM10 as traffic-related emissions, heavy fuel oil combustion, biomass burning, and industrial processes. Back trajectory analysis (HYSPLIT) indicated air masses were coming from the North-East region of the Atlantic Ocean as the principal origin.

Evaluation of Modelled Lotos-Euros with Observational Based Pm10 Source Attribution

Evaluation of Modelled Lotos-Euros with Observational Based Pm10 Source Attribution

Demarcation of Pollution-Prone Areas around the Manyoni Uranium Project, Tanzania

This study employed PM10 source parameters and pre-processed topographical and meteorological data as input into the AERMOD atmospheric dispersion model to demarcate pollution-prone areas around the Manyoni Uranium Project. Knowing these areas before mining is an important step toward establishing efficient and effective environmental baseline data. This is because resources for collecting the data will be concentrated in areas with higher contamination potential. In this regard, AERMOD predicted that the regions suitable for pollution demarcation would be 25.55 km2, 25.85 km2, and 27.96 km2 if the prospective mine at Playa C1 operated for 5, 7, and 10 years, respectively. Within the demarcated areas, AERMOD predicted that the maximum annual ground level concentration of PM10 averaged over 5, 7, and 10 years would be 22.2 µg m-3, 22.8 µg m-3, and 25.7 µg m-3, respectively. These values are 11%, 14%, and 28.5% higher than the WHO annual limit of 20 µg m-3 for PM10. This information can help mine owners and government agencies figure out ways to protect people and the environment from the expected pollution.

PM2.5 induces the distant metastasis of lung adenocarcinoma via promoting the stem cell properties of cancer cells

Lung cancer is the most common cancer in China and second worldwide, of which the incidence of lung adenocarcinoma is rising. As an independent factor, air pollution has drawn the attention of the public. An increasing body of studies has focused on the effect of PM2.5 on lung adenocarcinoma; however, the mechanism remains unclear. We collected the PM2.5 in two megacities, Beijing (BPM) and Shijiazhuang (SPM), located in the capital of China, and compared the different components and sources of PM2.5 in the two cities. Vehicle emissions are the primary sources of BPM, whereas SPM is industrial emissions. We found that chronic exposure to PM2.5 promotes the tumorigenesis and metastasis of lung adenocarcinoma in patient-derived xenograft (PDX) models, as well as the migration and invasion of lung adenocarcinoma cell lines. SPM has more severe effects in vivo and in vitro. The underlying mechanisms are related to the stem cell properties of cancer cells, the epithelial-mesenchymal transition (EMT) process, and the corresponding miRNAs. It is hopeful to provide a theoretical basis for improving air pollution in China, especially in the capital area, and is of the significance of long-term survival of lung cancer patients.

Effects of COVID-19 lockdown on PM10 composition and sources in the Rome Area (Italy) by elements' chemical fractionation-based source apportionment

During the national lockdown imposed by the Government of Italy (from March 9th to May 18th 2020) to counter the Covid-19 pandemic, 24-h PM10 samples were collected at three sites in the Rome area (Central Italy), two urban (Sapienza and Via Saredo, highly impacted by vehicular traffic) and one peri-urban (Montelibretti, more impacted by biomass domestic heating). Further, at Sapienza and Montelibretti PM10 daily sampling had been carried out in the period immediately before lockdown, and at Via Saredo samples were additionally collected also after the end of lockdown. PM10 was chemically speciated for main components (major elements, inorganic ions, EC, OC, levoglucosan), and trace elements. The latter were chemically fractionated and considered for their water-soluble and insoluble fractions, which proved to be more source-selective than total element. Three datasets were thus built and analyzed by Positive Matrix Factorization (PMF), with the aim of identifying and apportioning mass contributions of sources acting in the periods before, during and after lockdown, in the Rome area. Identified emission sources were mostly from long-range advection (two different contributions of mineral dust, fresh sea spray, heavy oil combustion), while local sources (vehicular traffic and biomass burning) were strongly abated during lockdown, with respect to previous sampling period, and inorganic secondary aerosol showed a progressive increment of sulfates, driven by seasonal evolution from winter to spring. Since the lockdown interrupted all non-essential productive and work activities, thus reducing the chemical fingerprinting of local sources, this occurrence allowed to clearly describe both profiles and source contribution estimates of long-range transported PM10 components. Moreover, it allowed assessing the reduction of the impact of anthropogenic sources (such as vehicular traffic) and the efficiency of mitigation measures generally taken to control PM10 mass concentration. Acidic sulfates (bisulfate and letovicite) resulted associated to mineral dust transport events, and the role of chemically fractionated elements as source-specific tracers was further confirmed.

Characteristics, sources, and health risks of ambient nanoparticles (PM0.1) bound metal in Bangkok, Thailand

The objective of this study was to characterize ambient nanoparticles (PM 0.1 )-bound metals in Bangkok, Thailand and assess the health risks of these materials to human. A year-long sampling campaign was conducted between November 2014 and October 2015. The PM 0.1 mass concentration ranged from 10 to 27 μg/m 3 , and the average PM 0.1 mass concentration was 15 ± 2 μg/m 3 . The total concentration of the thirteen elements was 345 ± 31 ng/m 3 , with Fe, K, Na, Al, Cu, Mg, and Zn (>10 ng/m 3 ) being the dominant species. The highest total element concentration occurred in the cold dry season followed by the hot dry and wet seasons. A principal component analysis (PCA) indicated that the primary sources of PM 0.1 were derived from road traffic, the industrial sector, and biomass burning. The high concentrations of metals found in the cold dry season suggest that PM 0.1 -bound metal derived from road traffic and biomass burning from neighboring areas were transported to Bangkok. High level of K indicates that biomass burning was a major source during cold dry season. Total cancer risk from all the carcinogenic elements was 5.84 × 10 −6 in adults, which does not exceed the upper limit of the acceptable risk assessment range. The findings of this study provide further clarification of the emission source profile and the pattern of PM 0.1 particles and should be of value for emission control and mitigation of PM emission in an urban area. • The PM 0.1 fraction as a function of the season in Thailand examined in detail. • Sources of PM 0.1 were traffic, industry, and biomass fires. • The level of PM 0.1 during haze pollution is increased substantially. • Carcinogenic risk is assessed to be tolerable.

Uncovering the characteristics of air pollutants emission in industrial parks and analyzing emission reduction potential: case studies in Henan, China

Industrial parks contribute greatly to China’s economic development while emitting huge air pollutants. It is necessary to study the characteristics of air pollutant emissions in industrial parks. In this study, emission inventories for 11 industrial parks were established. Meanwhile, the source emission and spatial distribution characteristics of the industrial park were analyzed. The cluster analysis was used to classify these parks into “4Hs”, “Mixed” and “4Ls” parks. “4Hs”, “Mixed” and “4Ls” represent that the levels of energy intensity, economic proportion of energy-intensive industries, coal proportion and pollution performance value are high, medium and low in turn. Then three emission reduction measures were set up to estimate the emission reduction potential and environmental impacts. The results show that: (1) the emissions of SO2, NOx, CO, PM10, PM2.5, VOCs and NH3 of 11 industrial parks in 2017 were 11.2, 23.1, 30.8, 8.3, 3.5, 5.1, and 1.1 kt, respectively. (2) Power plants were the largest source of SO2 and NOx emissions, and industrial processes were the largest emission source of CO, PM10, PM2.5, VOCs and NH3. (3) “4Hs” parks with traditional energy-intensive industries as the leading industries should be the emphasis of air pollutant emission reduction. (4) Through the optimal emission reduction measures, SO2, NOx, PM10, PM2.5 and VOCs were reduced by 81, 46, 51, 46 and 77%, respectively. Environmental impact reductions include 1.6 kt SO2eq acidified gas emissions, 1.4 kt PO43−eq eutrophication substances, 4.2 kt PM10eq atmospheric particulate emissions, 7.0 kt 1,4-DCEeq human toxic substances, and 5.2 kt PM2.5 eq breathing Inorganic. This study is helpful to understand the characteristics of air pollutants emissions in industrial parks and promotes the proposal and implementation of air pollutant emissions reduction strategies.

Persistent pollution episodes, transport pathways, and potential sources of air pollution during the heating season of 2016-2017 in Lanzhou, China.

As one of the most important industrial cities in Northwest China, Lanzhou currently suffers from serious air pollution. This study analyzed the formation mechanism and potential source areas of persistent air pollution in Lanzhou during the heating period from November 1, 2016 to March 31, 2017 based on the air pollutant concentrations and relevant meteorological data. Our findings indicate that particulate pollution was extremely severe during the study period. The daily PM2.5 and PM10 concentrations had significantly negative correlations with daily temperature, wind speed, maximum daily boundary layer height, while the daily PM2.5 and PM10 concentrations showed significantly positive correlations with daily relative humidity. Five persistent pollution episodes were identified and classified as either stagnant accumulation or explosive growth types according to the mechanism of pollution formation and evolution. The PM2.5 and PM10 concentrations and PM2.5/PM10 ratio followed a growing "saw-tooth cycle" pattern during the stagnant accumulation type event. Dust storms caused abrupt peaks in PM10 and a sharp decrease in the PM2.5/PM10 ratio in explosive growth type events. The potential sources of PM10 were mainly distributed in the Kumtag Desert in Xinjiang Uygur Autonomous Region, the Qaidam Basin and Hehuang Valley in Qinghai Province, and the western and eastern Hexi Corridor in Gansu Province. The contributions to PM10 were more than 120μg/m3. The important potential sources of PM2.5 were located in Hehuang Valley in Qinghai and Linxia Hui Autonomous Prefecture in Gansu; the concentrations of PM2.5 were more than 60μg/m3.

Linking PM2.5 organic constituents, relative toxicity and health effects in Puerto Rico

This research investigates ambient air samples, the chemical compositions, and the potential toxicity of inhalable particulate matter PM2.5 from the municipalities on the south, north, and east coast of Puerto Rico. Ambient air samples from Guayama, Ponce, Guayanilla, Bayamón and Humacao were studied, during the year 2013. The various sources of PM2.5 affecting the air quality of Puerto Rico come from industrial activities, wildfire, anthropogenic inputs, and African dust storms, and volcanic eruptions. Data shows organic compounds, including n-alkanes, esters, phthalates, siloxanes, and others. A large number of organic compounds with irritating properties and potential toxic risks were identified. The plasticizers were the most crucial group due to their known adverse health effects. This research identified DEHP and DBP as the most abundant phthalates in PM2.5 extracts. In vitro testing to assess PM2.5 toxicity was performed on BEAS-2B human lung epithelial cells. The evidence of variable and relative abundance of organic compounds in ambient PM2.5 identified Guayama as the most concerned site. The most significant difference between the sites studied was having one of the highest relative toxicity due to its organic constituents.

Research On Enhanced Harmonic Effect of a Dual-PM-Excited Flux-Modulated Motor

In this paper, an improved design for a dual-permanent-magnet-excited (DPME) motor is proposed, where the harmonic characteristics are newly introduced into the design process to enhance the harmonic effect. Based on the role that harmonics play in the torque generation process, not only the amplitude characteristics of harmonics are considered, but also the phase characteristics of harmonics are introduced, which is the key to improve PM utilization. In addition, the harmonics excited by stator PM (SPM) source or rotor PM (RPM) source are considered separately due to the unique dual-PM source characteristic of the DPME motor, which can further enhance the amplitude and phase characteristics of harmonics and then improve the PM utilization. Firstly, the dominant harmonics excited by SPM or RPM are picked out with the analysis of amplitude characteristics. Then, by taking into account the phase characteristics, the effective harmonics excited by SPM or RPM are selected within the dominant harmonics and serve as design objectives. After that, a collaborative design can be realized with the parameters and the two harmonic characteristics of effective harmonics. Finally, the electromagnetic performances are investigated by the Finite Element Analysis (FEA), and the results verify the effectiveness of the design considering harmonic characteristics of dual-PM sources.

Possible sources of ambient PM10 inside Jadavpur University Campus, Kolkata.

High concentration of particulates in the university and research institutional campus can affect cognitive performance of students and researchers. However, studies on ambient particulate concentration in the campus of universities or research institutes are scarce. The ambient concentration of PM10 was measured in the campus of Jadavpur University, Kolkata, during two different seasons (S1: Post-monsoon; S2: Winter) to identify major sources of pollutant here. Significant seasonal variation of ambient PM10 was recorded in the campus. The average ambient PM10 concentration was recorded higher in S2 compared to S1 of the study period. Morphological characteristics of PM10 during the study period suggest that the roundness of particles was in the range of 0.66 to 0.68, whilst the mean spherical diameter suggests most of the PM10 particles were < 2.5 μ diameter. Based on factorial analysis, three factors were generated which includes factor 1: soil, building material and coal burning particles (53.76% of the variance); factor 2: particles from coal combustion (29.89% of the variance) and factor 3: particles from transport emission (16.33% of the variance). The study suggests that it is important to stop burning coal, reduce vehicular emission and reduce road dust resuspension around the campus to maintain the ambient PM10 concentration within the university campus during the post-monsoon and winter months.

Estimating the health and economic burden of shipping related air pollution in the Iberian Peninsula.

Air pollution is the leading cause of the global burden of disease from the environment, entailing substantial economic consequences. International shipping is a significant source of NOx, SO2, CO and PM, which can cause known negative health impacts. Thus, this study aimed to estimate the health impacts and the associated external costs of ship-related air pollution in the Iberian Peninsula for 2015. Moreover, the impact of CAP2020 regulations on 2015 emissions was studied. Log-linear functions based on WHO-HRAPIE relative risks for PM2.5 and NO2 all-cause mortality and morbidity health end-points, and integrated exposure-response functions for PM2.5 cause-specific mortality, were used to calculate the excess burden of disease. The number of deaths and years of life lost (YLL) due to NO2 ship-related emissions was similar to those of PM2.5 ship-related emissions. Estimated all-cause premature deaths attributable to PM2.5 ship-related emissions represented an average increase of 7.7% for the Iberian Peninsula when compared to the scenario without shipping contribution. Costs of around 9 100 million € yr-1 (for value of statistical life approach - VSL) and 1 825 million € yr-1 (for value of life year approach - VOLY) were estimated for PM and NO2 all-cause burden of disease. For PM2.5 cause-specific mortality, a cost of around 3 475 million € yr-1 (for VSL approach) and 851 million € yr-1 (for VOLY approach) were estimated. Costs due to PM and NO2 all-cause burden represented around 0.72% and 0.15% of the Iberian Peninsula gross domestic product in 2015, respectively for VSL and VOLY approaches. For PM2.5 cause-specific mortality, costs represented around 0.28% and 0.06%, respectively, for VSL and VOLY approaches. If CAP2020 regulations had been applied in 2015, around 50% and 30% respectively of PM2.5 and NO2 ship-related mortality would been avoided. These results show that air pollution from ships has a considerable impact on health and associated costs affecting the Iberian Peninsula.

Fine particulate matter constituents and infant mortality in Africa: A multicountry study

Few studies have investigated the association between exposure to fine particulate matter (PM2.5) and infant mortality in developing countries, especially for the health effects of specific PM2.5 constituents. We aimed to examine the association of long-term exposure to specific PM2.5 constituents with infant mortality in 15 African countries from 2005 to 2015. Based on the Demographic and Health Surveys (DHS) dataset, we included birth history records from 15 countries in Africa and conducted a multicountry cross-sectional study to examine the associations between specific PM2.5 constituents and infant mortality. We estimated annual residential exposure using satellite-derived PM2.5 for mass and a chemical transport model (GEOS-Chem) for its six constituents, including organic matter (OM), black carbon (BC), sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and soil dust (DUST). Multivariable logistic regression analysis was employed by fitting single-constituent models, the constituent-PM2.5 models, and the constituent-residual models. We also conducted stratified analyses by potential effect modifiers and examined the specific associations for each country. We found positive and significant associations between PM2.5 total mass and most of its constituents with infant mortality. In the single-constituent model, for an IQR increase in pollutant concentrations, the odds ratio (OR) of infant mortality was 1.03 (95%CI; 1.01, 1.06) for PM2.5 total mass, and was 1.04 (95%CI: 1.02, 1.06), 1.04 (95%CI: 1.02, 1.05), 1.02 (95%CI: 1.00, 1.03), 1.04 (1.01, 1.06) for BC, OM, SO42-, and DUST, respectively. The associations of BC, OM, and SO42- remained significant in the other two models. We observed larger estimates in subgroups with older maternal age, living in urban areas, using unclean cooking energy, and with access to piped water. The associations varied among countries, and by different constituents. The carbonaceous fractions and sulfate play a major important role among PM2.5 constituents on infant mortality. Our findings have certain policy implications for implementing effective measures for targeted reduction in specific sources (fossil fuel combustion and biomass burning) of PM2.5 constituents against the risk of infant mortality.

Cardiopulmonary Mortality and Fine Particulate Air Pollution by Species and Source in a National U.S. Cohort.

The purpose of this study was to estimate cardiopulmonary mortality associations for long-term exposure to PM2.5 species and sources (i.e., components) within the U.S. National Health Interview Survey cohort. Exposures were estimated through a chemical transport model for six species (i.e., elemental carbon (EC), primary organic aerosols (POA), secondary organic aerosols (SOA), sulfate (SO4), ammonium (NH4), nitrate (NO3)) and five sources of PM2.5 (i.e., vehicles, electricity-generating units (EGU), non-EGU industrial sources, biogenic sources (bio), "other" sources). In single-pollutant models, we found positive, significant (p < 0.05) mortality associations for all components, except POA. After adjusting for remaining PM2.5 (total PM2.5 minus component), we found significant mortality associations for EC (hazard ratio (HR) = 1.36; 95% CI [1.12, 1.64]), SOA (HR = 1.11; 95% CI [1.05, 1.17]), and vehicle sources (HR = 1.06; 95% CI [1.03, 1.10]). HRs for EC, SOA, and vehicle sources were significantly larger in comparison to those for remaining PM2.5 (per unit μg/m3). Our findings suggest that cardiopulmonary mortality associations vary by species and source, with evidence that EC, SOA, and vehicle sources are important contributors to the PM2.5 mortality relationship. With further validation, these findings could facilitate targeted pollution regulations that more efficiently reduce air pollution mortality.

Comparison of PM10 Sources at Traffic and Urban Background Sites Based on Elemental, Chemical and Isotopic Composition: Case Study from Krakow, Southern Poland

In large urban agglomerations, car traffic is one of the main sources of particulate matter. It consists of particulate matter directly generated in the process of incomplete liquid fuel burning in vehicle engine, secondary aerosols formed from exhaust gaseous pollutants (NOx, SO2) as well as products of tires, brake pads and pavement abrasion. Krakow is one of the cities in Europe with the highest concentrations of particulate matter. The article presents the results of combined elemental, chemical and isotopic analyses of particulate matter PM10 at two contrasting urban environments during winter and summer seasons. Daily PM10 samples were collected during the summer and winter seasons of 2018/2019 at two stations belonging to the network monitoring air quality in the city. Mean PM10 concentrations at traffic-dominated stations were equal to 35 ± 7 µg/m3 and 76 ± 28 µg/m3 in summer and winter, respectively, to be compared with 25.6 ± 5.7 µg/m3 and 51 ± 25 µg/m3 in summer and winter, respectively, recorded at the urban background station. The source attribution of analyzed PM10 samples was carried out using two modeling approaches: (i) The Positive Matrix Factorization (PMF) method for elemental and chemical composition (concentrations of elements, ions, as well as organic and elemental carbon in daily PM10 samples), and (ii) Isotope Mass Balance (IMB) for 13C and 14C carbon isotope composition of carbonaceous fraction of PM10. For PMF application, five sources of particulate matter were identified for each station: fossil fuel combustion, secondary inorganic aerosols, traffic exhaust, soil, and the fifth source which included road dust, industry, construction work. The IMB method allowed the partitioning of the total carbon reservoir of PM10 into carbon originating from coal combustion, from biogenic sources (natural emissions and biomass burning) and from traffic. Both apportionment methods were applied together for the first time in the Krakow agglomeration and they gave consistent results.

Seasonal Variation, Chemical Composition, and PMF-Derived Sources Identification of Traffic-Related PM1, PM2.5, and PM2.5-10 in the Air Quality Management Region of Žilina, Slovakia.

Particulate matter (PM) air pollution in the urban environment is mainly related to the presence of potential sources throughout the year. Road transport is one of the most important sources of PM in the urban environment, because it directly affects pedestrians. PM measurements were performed in the city of Žilina, Slovakia, at various road-traffic-related measurement stations over the course of several years. This paper evaluates changes in the concentration of the fine fraction (PM2.5), the ultrafine fraction (PM1), and the coarse fraction (PM2.5–10) over time. PM concentrations were measured by reference gravimetric method. Significant changes in PM concentrations over time due to the diversification of pollution sources and other, secondary factors can be observed from the analysis of the measured data. PM samples were subjected to chemical analysis inductively coupled plasma mass spectrometry (ICP-MS) to determine the concentrations of elements (Mg, Al, Ca, Cr, Cu, Fe, Cd, Sb, Ba, Pb, Ni, and Zn). The seasonal variation of elements was evaluated, and the sources of PM2.5, PM1, and PM2.5–10 were estimated using principal component analysis (PCA) and positive matrix factorization (PMF). PM2.5 (maximum concentration of 148.95 µg/m3 over 24 h) and PM1 (maximum concentration of 110.51 µg/m3 over 24 h) showed the highest concentrations during the heating season, together with the elements Cd, Pb, and Zn, which showed a significant presence in these fractions. On the other hand, PM2.5–10 (maximum concentration of 38.17 µg/m3 over 24 h) was significantly related to the elements Cu, Sb, Ba, Ca, Cr, Fe, Mg, and Al. High correlation coefficients (r ≥ 0.8) were found for the elements Mg, Ca, Fe, Al, Cd, Pb, and Zn in the PM1 fraction, Cd, Pb, and Zn in PM2.5, and Ba, Sb, Fe, Cu, Cr, Mg, Al, and Ca in PM2.5–10. Using PMF analysis, three major sources of PM (abrasion from tires and brakes, road dust resuspension/winter salting, and combustion processes) were identified for the PM2.5 and PM1 fractions, as well as for the coarse PM2.5–10 fraction. This study reveals the importance of non-exhaust PM emissions in the urban environment.

Chemical composition characteristics and source analysis of PM2.5 in Jiaxing, China: insights into the effect of COVID-19 outbreak

ABSTRACT Jiaxing is a medium-sized city in the Yangtze River Delta (YRD), which showed complex local and surrounding pollution sources. To study the COVID-19 impact on the ambient PM2.5 in Jiaxing, we collected the PM2.5 samples from 2 January to 25 April 2020 and analysed their chemical compositions (including carbon components, water-soluble ions (WSIs), and inorganic elements). The concentration of PM2.5 was 83.13 ± 30.93 μg/m3 before COVID-19 pandemic and then remarkably decreased with COVID-19 outbreak due to the suspension of mobility and industrial activities. Meanwhile, the concentrations of main chemical species (carbon components, water-soluble ions and inorganic elements) of PM2.5 all decreased from period A (2–20 January 2020) to period B (23 January to 10 February 2020). Moreover, Trajectory clustering analysis showed that close-range transport was one of the dominant factors throughout all the periods, except for period D (1–25 April 2020). In addition, the PSCF model indicated that the COVID-19 outbreak resulted in a significant decrease of WPSCF value. This study highlighted the differences in chemical compositions and sources of PM2.5 since COVID-19 pandemic was reported and provided a better understanding of its outbreak on PM2.5.

Real-Time Low-Cost Personal Monitoring for Exposure to PM2.5 among Asthmatic Children: Opportunities and Challenges

This study aims to evaluate the accuracy and effectiveness of real-time personal monitoring of exposure to PM concentrations using low-cost sensors, in comparison to conventional data collection method based on fixed stations. PM2.5 data were measured every 5 min using a low-cost sensor attached to a bag carried by 47 asthmatic children living in the Seoul Metropolitan area between November 2019 and March 2020, along with the real-time GPS location, temperature, and humidity. The mobile sensor data were then matched with station-based hourly PM2.5 data using the time and location. Despite some uncertainty and inaccuracy of the sensor data, similar temporal patterns were found between the two sources of PM2.5 data on an aggregate level. However, average PM2.5 concentrations via personal monitoring tended to be lower than those from the fixed stations, particularly when the subjects were indoors, during nighttime, and located farther from the fixed station. On an individual level, a substantial discrepancy is observed between the two PM2.5 data sources while staying indoors. This study provides guidance to policymakers and researchers on improving the feasibility of personal monitoring via low-cost mobile sensors as an alternative or supplement to the conventional station-based monitoring.

Chemical Fractionation of Trace Elements in Arctic PM10 Samples

In this study, the information potential of a two-step sequential extraction procedure was evaluated. For this purpose, first of all the elemental composition of Arctic PM10 samples collected in Ny-Ålesund (Svalbard Islands) from 28 February 2015 to 21 October 2015 was investigated. Enrichment Factors, Principal Component Analysis and Hierarchical Cluster Analysis were performed to identify PM10 sources and to understand the effects of short- and long-range transport processes. The investigation of the potential source areas was also aided by taking into account back-trajectories. Then, the sequential extraction procedure was applied to some of the samples in order to obtain more information on these sources. This approach allowed us to establish that most of the elements prevalently having an anthropogenic origin not only were present in higher concentrations, but they were also more easily extractable in late winter and early spring. This confirms the common statement that the anthropogenic portion of the elements present in a sample is generally loosely bound to the particulate matter structure, and so it is more easily extractable and releasable on the Arctic snowpack. Moreover, in the samples collected in late winter and early spring, even the elements prevalently having a crustal origin were more easily extractable, probably due to the particle size selection occurred during the long-range transport.