Total Suspended Particulate Samples Research Articles

Analysis of 78 trace liquid crystal monomers in air by gas chromatography coupled with triple quadrupole mass spectrometry

Liquid crystal monomers (LCMs) comprise a class of organic pollutants that have garnered considerable attention because of their dioxin-like toxicity (i.e., modulation of genes) and presence in various environments. However, limited information about the identities, occurrence, and distribution of LCMs has highlighted an urgent need for a high-throughput and sensitive analytical method. In this study, we developed and validated a rapid, simple, sensitive method that involves minimal solvent consumption. The method was applied for the simultaneous detection and identification of 78 LCMs in atmospheric total suspended particulate samples (dae < 100 μm) using gas chromatography coupled with triple quadrupole mass spectrometry. The results showed high degrees of linearity with correlation coefficients >0.995 in the concentration range of 5.0–500 ng/mL. The instrumental detection limits ranged from 0.7 to 5.3 pg, and the method detection limits ranged from 0.1 to 0.9 pg/m3. The accuracy of the method was between 70 % and 130 % for most analytes, and the relative standard deviations of six replicates were <15 % at three levels of spiking (10, 50, and 200 ng/mL). The developed analytical method was applied to analyze real air particulate samples from Beijing, China. Overall, 45 LCMs were present at 65.5 to 145.7 pg/m3, with a mean concentration of 92.5 pg/m3. Among them, (trans,trans)-4-propyl-4′-ethenyl-1,1′-bicyclohexane (PVB) was the most abundant, with an average concentration of 33.6 pg/m3. The total estimated daily intakes of LCMs for adults and children were 15.6 and 46.6 pg/kg bw/day, respectively. Accordingly, the method described herein is suitable for quantifying LCMs in atmospheric particulate samples. As such, it will be valuable for investigating LCM environmental occurrence, behaviors, and risk assessments.

Weak transport of atmospheric water-insoluble particulate carbon from South Asia to the inner Tibetan Plateau in the monsoon season

Carbonaceous particles play a crucial role in atmospheric radiative forcing. However, our understanding of the behavior and sources of carbonaceous particles in remote regions remains limited. The Tibetan Plateau (TP) is a typical remote region that receives long-range transport of carbonaceous particles from severely polluted areas such as South Asia. Based on carbon isotopic compositions (Δ14C/δ13C) of water-insoluble particulate carbon (IPC) in total suspended particle (TSP), PM2.5, and precipitation samples collected during 2020–22 at the Nam Co Station, a remote site in the inner TP, the following results were achieved: First, fossil fuel contributions (ffossil) to IPC in TSP samples (28.60 ± 9.52 %) were higher than that of precipitation samples (23.11 ± 8.60 %), and it is estimated that the scavenging ratio of IPC from non-fossil fuel sources was around 2 times that from fossil fuel combustion during the monsoon season. The ffossil of IPC in both TSP and PM2.5 samples peaked during the monsoon season. Because heavy precipitation during the monsoon season scavenges large amounts of long-range transported carbonaceous particles, the contribution of local emissions from the TP largely outweighs that from South Asia during this season. The results of the IPC source apportionment based on Δ14C and δ13C in PM2.5 samples showed that the highest contribution of liquid fossil fuel combustion also occurred in the monsoon season, reflecting increased human activities (e.g., tourism) on the TP during this period. The results of this study highlight the longer lifetime of fossil fuel-sourced IPC in the atmosphere than that of non-fossil fuel sources in the inner TP and the importance of local emissions from the TP during the monsoon season. The findings provide new knowledge for model improvement and mitigation of carbonaceous particles.

Tracing the Origins of Air Contaminants Near Environmental Protection Areas

This case study aimed to assess the impact of particulate matter (PM) emitted by highway works in an ecosystem belonging to one of the most important Atlantic Rainforest remnants in southeastern Brazil. The study was conducted during federal highway works, comprising a toll station construction and lane widening. To the best of our knowledge, this is the most comprehensive study on air pollution and its impacts on Environmental Protection Areas (EPAs) in Brazil. Total suspended particle (TSP) samples were obtained from 2014 to 2016, totaling 1823 samples. Some TSP samples were chosen for ionic and elemental quantification. Daily concentrations ranged from 8 to 345 µg m−3. The TSP concentrations exceeded Brazilian guidelines (240 µg m−3), mainly during the federal highway works. The main determined elements Fe (50–2100 ng m−3) and Mn (3–30 ng m−3) were associated with soil origin. Trace elements (Cu, Co, Ni, V, and Pb), detected from 2 × 10−7 to 54 ng m−3, and high NO3 − (2.4 − 8.3 µg m−3) and SO4 2− (2.6 − 6.8 µg m−3) concentrations were correlated with vehicular emissions. The findings of this study indicate that Cd and Cu represent environmental risks, as they may compromise biochemical plant processes.

Spatiotemporal variations in emission and particulate matter concentration outside a concentrated layer feeding operation

A year-round monitoring of Particulate Matter (PM) less than 2.5 μm in aerodynamic diameter (PM2.5) and Total Suspended Particulate (TSP) from a conventional cage laying hen house was conducted to reveal their spatiotemporal variations of concentrations downwind of tunnel fans. The PM Emission Rate (ER) and the correlations between PM with meteorological parameters and ventilation rate were studied. Ten self-developed Particle Concentration Monitoring Units were distributed to multiple horizontal (2, 25, and 50 m) and vertical (2 and 5 m) locations for PM examination. Four PM2.5 concentration categories were classified: good (0–35 μg m−3), moderate (35–75 μg m−3), unhealthy (75–150 μg m−3), and very unhealthy (150–350 μg m−3). Annual and monthly percentages of PM2.5 and TSP sampling hours for each category were calculated. Significant temporal variations in ER were observed, with monthly average ER ranging from 0.05 to 0.86 mg d−1 hen−1 for PM2.5 and 1.40–8.90 mg d−1 hen−1 for TSP. Approximately 10–40% of PM2.5 sampling hours exceeded 75 μg m−3, while no TSP concentration was higher than the recommended threshold. The monthly percentage for the “very unhealthy” PM2.5 category was higher in winter, whereas the highest monthly percentage for the 800–1,200 μg m−3 TSP category was found in summer. Higher PM2.5 concentrations were prone to be observed at further sampling points, while higher TSP concentrations were mostly detected near the fans or on both sides of the sampling area. PM2.5 and TSP were positively correlated with ambient temperature and ventilation rate, while negatively correlated with relative humidity.

Intrinsic and extrinsic techniques for quantification uncertainty of an interpretable GRU deep learning model used to predict atmospheric total suspended particulates (TSP) in Zabol, Iran during the dusty period of 120-days wind

Total suspended particulates (TSP), as a key pollutant, is a serious threat for air quality, climate, ecosystems and human health. Therefore, measurements, prediction and forecasting of TSP concentrations are necessary to mitigate their negative effects. This study applies the gated recurrent unit (GRU) deep learning model to predict TSP concentrations in Zabol, Iran, during the dust period of the 120-day wind (3 June - 4 October 2014). Three uncertainty quantification (UQ) techniques consisting of the blackbox metamodel, heteroscedastic regression and infinitesimal jackknife were applied to quantify the uncertainty associated with GRU model. Permutation feature importance measure (PFIM), based on the game theory, was employed for the interpretability of the predictive model's outputs. A total of 80 TSP samples were collected and were randomly divided as training (70%) and validation (30%) datasets, while eight variables were used in the TSP prediction model. Our findings showed that GRU performed very well for TSP prediction (with r and Nash Sutcliffe coefficient (NSC) values above 0.99 for both datasets, and RMSE of 57 μg m−3 and 73 μg m−3 for training and validation datasets, respectively). Among the three UQ techniques, the infinitesimal jackknife was the most accurate one, while all the observed and predicted TSP values fell within the continence limitation estimated by the model. PFIM plots showed that wind speed and air humidity were the most and least important variables, respectively, impacting the predictive model's outputs. This is the first attempt of using an interpretable DL model for TSP prediction modelling, recommending that future research should involve aspects of uncertainty and interpretability of the predictive models. Overall, UQ and interpretability techniques have a key role in reducing the impact of uncertainties during optimization and decision making, resulting in better understanding of sophisticated mechanisms related to the predictive model.

Analyzing Total Suspended Particulate at AP Pettarani Street in Makassar City

AP Pettarani Street is one of the main roads that is the center of activity in urban areas in Makassar City. The area on this road segment is almost entirely commercial and office area. This causes high motor vehicle traffic activity and frequent traffic jams. This activity can lead to decreased air quality as well as human health problems. One of the air pollutants is Total Suspended Particulate (TSP). This study was conducted to determine the concentration of TSP in ambient air and complaints of health problems felt by the people around AP Pettarani Street. There are six street points as TSP sampling sites and questionnaires. Measurements were carried out using the HVAS (High Volume Air Sampler) for TSP concentration and Google Form to distribute questionnaires to the community around the AP Pettarani Street Section. The results of the study showed that the concentration of TSP in the AP Pettarani Street of Makassar City ranged between 183.93 g/Nm3 - 301.64 g/Nm3. Furthermore, the health complaints perceived by the community around the AP Pettarani Street are still in a low scale – very low, but it is still recommended that the public continue to wear masks while outdoors to reduce the risk of health disturbances due to particulate dust.

Sulfate-associated liquid water amplifies the formation of oxalic acid at a semi-arid tropical location over peninsular India during winter

Aerosol liquid water (ALW) can serve as an aqueous-phase medium for numerous chemical reactions and consequently enhance the formation of secondary aerosols in a highly humid atmosphere. However, the aqueous-phase formation of secondary organic aerosols (SOAs) is not well understood in the Indian regions, particularly in tropical peninsular India. In this study, we collected total suspended particulate samples (n = 30) at a semiarid station (Ballari; 15.15°N, 76.93°E; 495 m asl) in tropical peninsular India during the winter of 2016. Homologous series of dicarboxylic acids (C2–C12), oxoacids (ωC2–ωC9), pyruvic acid (Pyr), and glyoxal (Gly) were determined by employing a water-extraction of aerosol and analyzed using capillary gas chromatography (GC). Results show that oxalic acid (C2) was the most abundant organic acid, followed by succinic (C4), malonic (C3), azelaic (C9), and glyoxylic (ωC2) or phthalic (Ph) acids. Total diacids-C accounted for 1.7–5.8 % of water-soluble organic carbon (WSOC) and 0.6–3.6 % of total carbon (TC). ALW, estimated from the ISORROPIA 2.1 model, showed a strong linear relationship with sulfate (SO42−), C2, C3, C4, ωC2, Pyr, and Gly. Based on molecular distribution, specific mass ratios (C2/C3, C2/C4, C2/Gly, and Ph/C9), linear relationships among the measured organic acids, ALW, organic (levoglucosan and oleic acid), and inorganic (SO42−) marker compounds, we emphasize that diacids and related organic compounds, especially C2, majorly form via aqueous-phase oxidation of precursor compounds including aromatic hydrocarbons (HCs) and unsaturated fatty acids (FAs) originated from biomass burning and combustion-related sources. The present study demonstrates that sulfate driven ALW largely enhances the formation of SOAs via the aqueous-phase reactions over tropical peninsular India during winter.

Characteristics of Real-World Non-Exhaust Particulates from Vehicles

The need to regulate the non-exhaust particulate matter (PM) emissions from vehicles has been discussed worldwide due to the bad environmental impact and the toxicity to the human body. In-depth studies have been precisely conducted on the analysis of the non-exhaust particulate matters, in particular, the amount of tire, brake and road wear particles and their proportion in the atmosphere. In this study, the influence of tire and road wear particles (TRWP) on PM in the atmosphere was investigated with tire and PM samples. The PM samples suspended in the atmosphere were collected with a high-volume sampler equipped with a quartz filter. Additionally, polycyclic aromatic hydrocarbons (PAHs) and metal components in tire rubber were analyzed as markers by pyrolysis–gas chromatography/mass spectrometry (pyrolysis–GC/MS), GC/MS, and inductively coupled plasma/mass spectrometry (ICP/MS). More vinylcyclohexene was detected than dipentene in the markers measured in the samples of tires equipped with vehicles driving on the road, while more dipentene was measured in total suspended particles (TSP) samples. Among the PAHs in tire samples, pyrene exhibited the highest concentration. Benzo(b)fluoranthene showed the highest concentration in the TSP samples. Among the metals, the highest concentration was zinc in all tire samples and calcium in TSP samples.

Relationships of the Hygroscopicity of HULIS With Their Degrees of Oxygenation and Sources in the Urban Atmosphere

AbstractHumic‐like substances (HULIS) are unresolved compounds isolated from organic matter in atmospheric aerosols. Understanding the chemical structures and sources that control the hygroscopicity of HULIS is important for predicting its environmental impacts and possibly useful for parameterization of the hygroscopicity of organic aerosol (OA). Here, the hygroscopic growth of HULIS from total suspended particles samples in Beijing was analyzed using a hygroscopicity tandem differential mobility analyzer. The hygroscopicity parameter of HULIS (κHULIS) was determined to be 0.06 ± 0.03, and was found to correlate positively with O:C and f44 from offline aerosol mass spectrometry. Additionally, κHULIS was correlated positively with oxygenated organic aerosol (OOA) and correlated negatively with cooking OA and biomass burning OA, for which the source‐related OA types were from mass‐spectral‐based positive matrix factorization analyses. Further analysis resolved substantial κ values of 0.09 and 0.22, respectively, for less‐oxidized and more‐oxidized OOA, in contrast to the low κ values for cooking OA and biomass burning OA. Extensions of O:C‐ and source‐based parameterizations reasonably estimated the hygroscopicity of total OA with a moderate contribution from HULIS. This result and the fact that the obtained OOA contributions to κ of OA were similar to those from different environments suggest the applicability of parameterizing the hygroscopicity for a wide range of OA in particular based on source‐related structural characteristics.

High Spatial Variability of Biomass Burning Emissions Observed at Three Tibetan Plateau Sites

AbstractAerosol from biomass burning (BB) can affect regional and global climate by changing radiation balance and cloud properties, especially over the high altitude environ‐vulnerable region. To investigate the contributions of BB on atmospheric particulate matter trans‐the Tibetan Plateau (TP), the total suspended particle samples were collected at three high altitude sites over the northeastern (Qinghai lake, 3,200 m a.s.l.), central (Beiluhe, 4,659 m a.s.l.), and southwestern TP (Ngari, 4,360 m a.s.l.), respectively. Highly spatial variations of BB tracers (including levoglucosan, mannosan, and galactosan) were obtained. Elevated BB tracer concentrations were observed in the northeastern and southwestern sites compared to the central TP site. The heighten concentrations of particulate matter from biomass burning and organic carbon from biomass burning were obtained at Ngari (with 5260.3 and 2257.7 ng m−3) and Qinghai lake (with 1508.8 and 647.6 ng m−3) compared with those at Beiluhe (with 18.8 and 8.1 ng m−3), respectively. The results indicated that the BB contributions to aerosol were significant on the margin of the TP. In addition to the long‐range transport of BB pollutant, the local emissions may be an important contributor in the northeastern and southwestern TP. The present study can improve the understanding of BB characteristics and effects in the TP.

Seasonal characteristics of biogenic secondary organic aerosol tracers in a deciduous broadleaf forest in northern Japan

We collected total suspended particulate (TSP) samples from January 2010 to December 2010 at Sapporo deciduous forest to understand the oxidation processes of biogenic volatile organic compounds (BVOCs). The gas chromatography-mass spectrometric technique was applied to determine biogenic secondary organic aerosols (BSOAs) in the TSP samples. We found the predominance of the isoprene SOA (iSOA) tracers (20.6 ng m−3) followed by α/β-pinene SOA (pSOA) tracers (8.25 ng m−3) and β-caryophyllene SOA (cSOA) tracer (1.53 ng m−3) in the forest aerosols. The results showed large isoprene fluxes and relatively high levels of oxidants in the forest atmosphere. The iSOA and pSOA tracers showed a clear seasonal trend with summer and autumn maxima and winter and spring minima. Their seasonal trends were mainly controlled by BVOCs emission from the local broadleaf deciduous forest. Additionally, the regional level of isoprene emissions from the oceanic sources may also be contributed during summertime aerosols. cSOA tracer showed high concentrations in the winter and spring, possibly due to an additional contribution of biomass burning (BB) aerosols from the local or regional BB activities. The biogenic secondary organic carbon (BSOC) was contributed mainly by the oxidation products of isoprene (136 ngC m−3) followed by β-caryophyllene (63.0 ngC m−3) and α/β-pinene (35.9 ngC m−3). The mass concentration ratio (0.92) of pinonic acid + pinic acid and 3-methyl-1,2,3-butanetricarboxylic acid ((PNA + PA)/3-MBTCA) indicates the photochemical transformation of first-generation oxidation products to the higher generation oxidation products. The average ratios of isoprene to α/β-pinene (1.64) and β-caryophyllene (18.6) oxidation products suggested a large difference in the emissions of isoprene and α/β-pinene compared to β-caryophyllene. The cSOA tracers in the forest aerosols are also contributed by BB during the winter and spring. Positive matrix factorization analyses of the BSOA tracers confirmed that organic aerosols of deciduous forests are mostly related to isoprene emissions. This study suggests that isoprene is a more significant precursor for the BSOA than α/β-pinene and β-caryophyllene in a broadleaf deciduous forest.

Impact of smelter re-development on spatial and temporal airborne Pb concentrations

Total suspended particulate (TSP) and PM10 filters collected from two ambient air monitoring stations in Port Pirie were analysed to determine the impact of a lead (Pb) smelter redevelopment on air quality parameters including total elemental concentration, Pb isotopic ratio, Pb bioaccessibility and Pb speciation. Filters from 2009 to 2020 were analysed with a focus on samples from 2017 (immediately prior to smelter redevelopment) and 2020 (post-smelter redevelopment). Lead concentration in 2009–2020 TSP was variable ranging up to 6.94 μg m−3 (mean = 0.57 μg m−3), however, no significant decrease in Pb concentration was observed at either Port Pirie West (p = 0.56, n = 34) or Oliver Street (p = 0.32, n = 28) monitoring stations when 2017 and 2020 TSP values were compared. Similarly, no significant difference (p = 0.42) in PM10 Pb concentration was observed in 2017 (mean = 0.80 μg m−3) and 2020 (0.60 μg m−3) Oliver Street filters. Although no change in percentage Pb bioaccessibility was observed when 2017 and 2020 Port Pirie West TSP samples were compared (mean of 88.7% versus 88.0%), Pb bioaccessibility was lower (p < 0.005) in both 2020 TSP (mean of 83.9% versus 62.9%) and PM10 (mean of 70.8% versus 58.3%) Oliver Street filters compared to 2017. While scanning electron microscopy, energy dispersive x-ray spectroscopy identified a number of Pb phases within filters (galena, anglesite, cerussite, conglomerates), differences in Pb speciation between 2017 and 2020 filters could not be identified although it was presumed that this influenced Pb bioaccessibility outcomes at Oliver Street. Data from this study suggests that recent smelter redevelopments have not significantly decreased the concentrations of airborne Pb in Port Pirie although re-entrainment of soil-Pb from historical impact may also be a contributing Pb source.

Importance of local non-fossil sources to carbonaceous aerosols at the eastern fringe of the Tibetan Plateau, China: Δ14C and δ13C evidences

Carbonaceous particles are an important radiative forcing agent in the atmosphere, with large temporal and spatial variations in their concentrations and compositions, especially in remote regions. This study reported the Δ14C and δ13C of total carbon (TC) and water-insoluble particulate carbon (IPC) of the total suspended particles (TSP) and PM2.5 at a remote site of the eastern Tibetan Plateau (TP), a region that is influenced by heavy air pollution from Southwest China. The average organic carbon and elemental carbon concentrations of TSP samples in this study were 3.20 ± 2.38 μg m−3 and 0.68 ± 0.67 μg m−3, respectively, with low and high values in summer and winter, respectively. The fossil fuel contributions of TC in TSP and PM2.5 samples were 18.91 ± 7.22% and 23.13 ± 12.52%, respectively, both of which were far lower than that in Southwest China, indicating the importance of non-fossil contributions from local sources. The δ13C of TC in TSP samples of the study site was −27.06 ± 0.96‰, which is between the values of long-range transported sources (e.g., Southwest China) and local biomass combustion emissions. Therefore, despite the contribution from the long-range transport of particles, aerosols emitted from local biomass combustion also have an important influence on carbonaceous particles at the study site. The findings of this work can be applied to other remote sites on the eastern TP and should be considered in related research in the future.

PARTICULATE MATTER LEVELS AND ELEMENTAL COMPOSITION IN THE SPRING AND TRANSITION PERIOD IN HANOI, VIETNAM

Particulate matter (PM) is a major environmental concern in Vietnam as well as in the world. Samples of PM2.5, PM10, and total suspended particle (TSP) were collected on the rooftop of a five-floor building inside Hanoi University of Science and Technology, Hanoi, from January to May 2015. The levels PM2,5, PM10, and the metal elements of TSP were determined. PM2,5 and PM10 had average concentrations of 73 ± 37 and 138 ± 67 μg\m3, respectively. The concentration of PM2,5 and PM10 in all samples were higher than the recommended level in the World Health Organization (WHO) guideline (2005) for 24h and annual concentrations of 25 and 50 μg\m3, respectively. Nineteen elements detected in TSP samples included the higher concentration group in order: Ca &gt; Fe &gt; Na &gt; Al &gt; Mg &gt; K &gt; Zn and in the lower concentration group: Pb &gt; Mn &gt; Ti &gt; Sr &gt; V &gt; Cr &gt; Cd. The potential sources revealed from element components were discussed.

Health risk assessment in atmosphere near a petrochemical industrial complex: Measuring oxidative potential and oxidative burden

Particulate matter (PM) contributes substantially to the hazards associated with air pollution. Oxidative potential (OP) and oxidative burden (OB) can be useful to assess health risk. The population living in the area surrounding an industrial complex in the Metropolitan Area of São Paulo (Brazil) has exhibited higher frequencies of health impacts, such as thyroid diseases, which highlighted the authors' attention. In the present study, total suspended particles (TSP) and fine PM (PM2.5) were collected between 2015 and 2018. Then, OP and OB related to PM exposure at this industrial complex neighborhood were determined, using methods which measure the oxidation of lung antioxidants, glutathione (GHS), and ascorbic acid (AA), and reactive oxygen species (ROS) production by dithiothreitol (DTT) assay. TSP samples (2015 mean = 49 ± 21 μg m−3) showed higher concentrations than PM2.5 (2018 mean = 32 ± 18 μg m−3). PM2.5 campaigns presented high OP and OB for ascorbate (AA), and glutathione (GSH), while OP and OB for dithiothreitol (DTT) was higher in TSP. There were associations between OPAA and PM, for both TSP and PM2.5. However, no positive associations were found between PM and OBGSH and OBDTT indicating that in this context PM concentration did not necessarily reflect the health risk of exposure. The air masses trajectories indicated influences from industrial, vehicular emissions over the years. In conclusion, OP results may reveal critical health risks better than PM mass at this industrial complex region.

Phytic acid functionalized magnetic adsorbents for facile enrichment of trace rare earth elements in environmental water, digested atmospheric particulates and the extracts followed by inductively coupled plasma mass spectrometry detection

Phytic acid (PA) functionalized magnetic adsorbents was synthesized through simple process. The functionalized sorbents are featured with core-shell structure, good magnetism, chemical stability, selectivity, and fast adsorption/desorption dynamics for the preconcentration of trace rare earth elements (REEs). With the aid of inductively coupled plasma mass spectrometry detection, the prepared Fe3O4@SiO2@PA sorbents were employed for the separation and enrichment of 15 REEs from environmental water and atmospheric particulates with different sizes. Under the optimal conditions, the method presented an enrichment factor of 300-fold and low detection limits (0.002–1.1 ng/L) for 15 REEs, with the relative standard deviations of 1.4–4.4%. Environmental water samples were analyzed by the proposed method, and 15 REEs of 0.08–5.80 ng/L were found in local rainwater and river water. The REEs concentration in locally collected fine particulate matter was 0.01–0.93 ng/m3, 0.03–1.70 ng/m3 and 0.03–2.47 ng/m3 of REEs were found in inhalable particulate matter and total suspended particulate samples, respectively. The bioaccessibility of REEs in PM2.5 was evaluated by using Gamble's solution extraction, which was calculated to be 0.73–5.46%.

Health risk assessment of exposure to polycyclic aromatic hydrocarbons in household indoor environments

Airborne particles are able to transport the potentially mutagenic and carcinogenic compounds adsorbed to their surfaces, such as polycyclic aromatic hydrocarbons (PAHs). As a result, they can affect human health and, consequently, the quality of life. In the present paper, we analyzed household airborne particles and estimated the human health risk due to PAH inhalation. Households from Cordoba city (Argentina) were selected for collecting weekly samples of total suspended particles, fine particles (> 2.5 µm) and submicron particles (< 1 µm) during a one-month period in both winter and summer. We found differences in the PAH composition among the three particle sizes, with the PAH levels being particularly high during summer for all three fractions, probably due to pollutants coming from outside or the persistence of pollutants inside homes. In addition, urban households had higher PAH levels than suburban houses. However, the calculated health risks due to the inhalation of particles never exceeded the levels recommended by the Environmental Protection Agency of the United States (< 1 in 10,000) for any age group. Our results, despite the relatively small number of houses included in the study, provide an indication of the likely exposure range of the population in urban environments of developing countries.

Air Pollution Associated with Total Suspended Particulate and Particulate Matter in Cement Grinding Plant in Vietnam

Air pollution associated with suspended particles has become a significant concern in Vietnam recently. The study aimed to (1) investigate dust sources; (2) measure concentration levels of Total Suspended Particulate (TSP), Particulate Matter (PM) fractions; (3) identify silica levels and the correlation with respirable particles at a cement grinding plant in Vietnam. A total of 312 samples (52 TSP, 160 PMs) at 13 processes were measured using the direct-reading dust meter. The silica composition was analyzed in a certified laboratory using the X-ray fluorescence (XRF) technique. SPSS version 26 for Window was used to analyze the data. The operations of the cement grinding plant created multiple dust sources from the jetty to the cement dispatch process. The TSP levels ranged 0.06–38.24 mg m−3, and 40.38% (n = 21) TSP samples exceeded the Permissible Exposure Limit (PEL) for an 8-h working shift. Besides that, there was a wide range and significant concentration levels of PMs in the cement processes. The levels of PMs were PM1 (0.00–0.06 mg m−3), PM2.5 (0.01–0.83 mg m−3), PM4 (0.02–4.59 mg m−3), PM7 (0.03–16.94 mg m−3), and PM10 (0.04–26.85 mg m−3). The highest mean levels of PMs factions were measured at the pre-grinding process. The inefficient operation of the dust collector contributed a significant factor to the dust dispersion in this process. The silica’s mean (SD) composition in respirable dust was 20.4% (0.86) and was not significantly different amongst the processes. There was a significant correlation between the levels of respirable dust and silica exposure in the cement grinding plant (r = 0.99). The improvement of indoor air quality is needed to prevent health effects on cement workers.

Source identification of exhaust and non-exhaust traffic emissions through the elemental carbon fractions and Positive Matrix Factorization method

Our study implies the importance of exhaust and non-exhaust emissions in a highway road tunnel, which is crucial to assess their impacts on air quality, human health, climate and developing functional methods for controlling. The total suspended particulates (TSP) and road dust (RD) samples were collected by PUF samplers and manually sweeping, respectively. Campaigns were performed in the summer and winter of 2014 in a highway road tunnel in Bolu, Turkey. Chemical analyses were presented to characterize the contents of organic carbon (OC) fractions (OC1,2,3,4), elemental carbon (EC) fractions (EC1,2,3,4,5,6), polycyclic aromatic hydrocarbons (PAHs) and metals (Al, Ba, Ca, Cu, Mg, Mn, Pb, Sr, Cr and Fe) in the collected TSP and RD samples. Positive matrix factorization (PMF) and orthogonal (Deming) regression analysis were applied to find out the exhaust and non-exhaust vehicle emissions of metal and carbonaceous species in the tunnel. The results showed that the identified source profiles included resuspended road dust (43%), non-exhaust emissions (37%), diesel exhaust emissions (13%), and gasoline exhaust emissions (7%). The relationship between emission markers of metal species and EC carbon fractions was supported by correlation studies. Among these EC fractions, EC4 and EC2 were the most abundant fractions in aerosol and RD samples, respectively and so they highly represented the diesel and non-exhaust emissions. Besides, the EC1 fraction was the indicator of gasoline-fueled emissions. Lower EC1 and higher soot-EC contribution obtained in tunnel aerosol (AS) samples showed the dominance of diesel-fueled vehicles in the tunnel. The data represented herein would help to identify the characteristic of vehicle emissions.

Geochemical characterization of dust from arsenic-bearing tailings, Giant Mine, Canada

Dust from uncovered mine tailings at Giant mine, an abandoned mine in northern Canada, has been a concern for nearby residents. We have utilized microanalytical mineralogical analysis combined with quantitative measurements of phase distribution and bulk concentration to fully characterize the dust currently generated from the Giant mine tailings. Surface tailings material was sampled from three tailings impoundments on site and sieved to <63 μm as a proxy for dust, and total suspended particulate (TSP) samples were collected continuously over two months to represent the airborne material that is generated from the tailings. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and -mass spectrometry (ICP-MS) show elevated concentrations of As, Sb, Zn, Pb, Cu and Ni in all samples; comparison of results for sieved and unsieved samples show that As is more concentrated in the <63 μm fraction of the tailings. The X-ray absorption near edge structure (XANES) results for the tailings indicate that the As in the samples is a mixture of As1−, As5+ and As3+. Scanning electron microscope-based mineral liberation analysis (SEM-MLA) results show that roaster-generated iron-oxides (i.e., maghemite), calcium-iron arsenate (i.e., yukonite), and arsenopyrite comprise the majority of the As-bearing particles in the surface tailings; of these three solid phases, calcium-iron arsenate poses the greatest risk to human health as it exhibits the highest relative bioaccessibility. A rare lead arsenate phase, which may be bioaccessible, was also detected in minor quantities in the surface tailings; this phase was identified as mimetite through μXRD analysis. Very little arsenic trioxide was found in the surface tailings samples, and no arsenic trioxide was found in the TSP samples; this is because the tailings that were exposed to arsenic trioxide-bearing roaster stack emissions during the 1950s and 1960s have been buried by more recent tailings. Soils near the Giant mine tailings have been found to contain arsenic trioxide from historic stack emissions, which indicates that the mine-impacted environmental media surrounding a tailings impoundment could in some cases pose a greater risk to environmental and human health than the tailings themselves.