Total Suspended Particulate Concentrations Research Articles

Source identification of atmospheric particle-bound mercury in the Himalayan foothills through non-isotopic and isotope analyses

This study reports on the sources of atmospheric particle-bound mercury (HgP) in less studied regions of Nepal based on the analysis of stable mercury (Hg) isotopes in aerosol samples from two neighboring areas with high and low anthropogenic emissions (Kathmandu and Dhulikhel, respectively) during 2018. Although the Indian monsoon and westerlies are generally regarded as the primary carriers of pollutants to this region via the heavily industrialized Indo-Gangetic Plain, the concentrations of total suspended particles (TSP) and HgP in Kathmandu were higher than those in Dhulikhel, thus suggesting a substantial contribution from local sources. Both isotopic (δ200Hg and Δ199Hg) and non-isotopic evidence indicated that dust, waste burning, and industrial byproducts (without Hg amalgamation) were the major sources of Hg in Kathmandu during the study period. Mercury may have been transported via air masses from Kathmandu to Dhulikhel, as indicated by the similar organic carbon/elemental carbon ratios and seasonal trends of TSP and HgP in these two locations. Local anthropogenic sources were found to contribute significantly to atmospheric Hg pollution through dust resuspension. Therefore, dust resuspension should be considered when evaluating the long-range transport of air pollutants such as Hg, particularly in anthropogenically stressed areas.

Mitigation of particulate matters and integrated approach for carbon monoxide remediation in an urban environment

Air pollution is a serious threat throughout the world and may cause remarkable loss to human health and other living beings. A study was conducted to investigate the main sources of contaminants including CO, fine particle (PM2.5), coarse particle (PM10), and total suspended particulate (TSP) in the ambient air of a typical South Asian industrial city of Faisalabad, Pakistan. Twenty sites under five different city sectors (residential, health centers, commercial, industrial, and vehicular) were surveyed over one month. The average concentrations of TSP, PM10, PM2.5 and CO were 1037.62 ± 383.6 μg/m3, 434.62 ± 65 μg/m3, 35.88 ± 1.7 μg/m3, and 6.4 ± 1.95 μg/m3, respectively. The highest Air Quality Index (AQI) was recorded at the recorded commercial areas followed by the vicinities of health centers and industrial areas. The obtained results were compared against the acceptable limits of Pakistan (national) Environmental Quality Standards (NEQS) and the United States, Environmental Protection Agency (US-EPA). The results demonstrated that concentration of TSP, PM10,PM2.5, and CO in the ambient air of Faisalabad city exceeded the USEPA and NEQs air quality standards. Consequently, air pollution control should not only emphasize on regulatory particulate emissions but also involve the implementation of an integrated multi-pollutant control strategy.

Atmospheric pollutants sources, health risk assessment study at a commercial, urban and traffic site

Ambient air pollutants have detrimental effects on human health and ambient air quality in central Taiwan is worsening. The aims of this study are as follows: (1) Measure the ambient air concentrations and dry deposition fluxes of particulates at a mixed commercial, urban and traffic sampling site in Luliao. (2) Identify the metallic elements that are attached to the particulates at this mixed sampling site. (3) Discuss the effects of ambient air pollutants (metallic elements that are attached to the particulates) on the health of local people using contamination factors and degrees of contamination [Ghosh et al. (2018). Source and chemical species characterization of PM10 and human health risk assessment of semi-urban, urban and industrial areas of West Bengal, India. Chemosphere 207:626–636]. The mean total suspended particulate concentrations were highest in the winter and lowest in the summer. The deposition fluxes were highest in the autumn and lowest in the summer. ANOVA results revealed no significant seasonal variation in the concentrations or dry depositions of particulates and metallic elements (Al, Cd, Cr, Mn, Ni, Pb and Zn) at the sampling site. Cu was the only exception, as its concentration varied seasonally. Degrees of contamination and contamination factor values for metallic elements Cd, Cr, Cu, Mn, Ni, Pb and Zn were low. Most of the metallic elements – Zn, Cr, Ni, Cd, Pb and Al – were locally emitted. Local residents close to the site faced no immediate carcinogenic or other health-related risk. Taichung World Flora Exposition was held in Taichung city and lasted as long as six months, and traffic flow increased significantly during this period. Hence, high density traffic flow during the Taichung World Flora Exposition might have been responsible for the high concentration and seasonal variations concentrations of metallic elements Cu and Mn at this time.

Use of Black Poplar Leaves for the Biomonitoring of Air Pollution in an Urban Agglomeration.

Trees are considered to be an effective tool for metal pollution biomonitoring. In the present study, the concentration of metals (Cu, Pb, Zn, Cd, Co, Ni, Fe, Mn, and Al) in black poplar leaves (Populus nigra L.), together with the concentration of PM10, PM2.5, PM1, and total suspended particles (TSP), was used for the air pollution biomonitoring in 12 sites from various areas of Cluj-Napoca city, Romania. The concentration of PM10 in the air was high, but their metal content was low. However, Cu, Pb, and Zn were moderately enriched, while Cd was highly enriched in PM10 due to anthropogenic sources. The average metal concentration in leaves decreased in the order Zn>>Fe>Mn>Al>Pb>Ni>Cu>Co>Cd and increased with the increase of PM10 concentration, indicating that poplar leaves are sensitive to air pollution. The principal component analysis indicated that traffic, waste burning, road dust resuspension, and soil contamination are the main anthropogenic sources of metals in poplar leaves. The results indicated that black poplar leaves are a suitable biomonitoring tool for metal pollution, in urban environments.

Seasonal variation and affecting factors of organophosphate esters in particulate matter in air: a comparison between measured data and model predictions

Six organophosphate esters (OPEs) with different octanol-air partition coefficient (KOA) were measured from gas and particle samples collected from an urban area of Central China between June 2018 and May 2019. The highest concentration of total OPEs (∑6OPEs) in total suspended particle (TSP) were found in winter, followed by spring, autumn, and summer. ∑6OPEs showed significant positive correlation with TSP concentration (p < 0.01), significant negative correlation with temperature (p < 0.01), weak negative linear correlations with relative humility (p < 0.05), and no significant correlations with wind speed (p > 0.05). Although OPEs were not detected in polyurethane foams (PUFs), the poly-parameter linear free energy relationship model (pp-LFER) estimated particle fractions of OPEs (fpart pp-LFERg/p) were below 2.73% for Tris (2-chloroisopropyl) phosphate (TCIPP), Tris (chloroethyl) phosphate (TCEP), and Tributyl phosphate (TnBP); 67.8% for Triphenyl phosphate (TPhP); and above 99.6% for TBOEP and TCrP. The concentrations of particle-bound TPhP, TCrP, and TBOEP estimated by pp-LFER (Cpart pp-LFERg/p) were 0.19, 0.09, and 0.05 ng/m3, which were in good agreement with measurements. However, the estimated Cpart pp-LFERg/p of TCEP, TCIPP, and TnBP showed obvious differences with measured data. According to filter-air partitioning estimated by pp-LFER, the strong adsorption of gaseous OPEs to glass fiber filter (GFF) may be responsible to the underestimation. Besides, the weak adsorption of gaseous OPEs to PUF is likely to be another important reason for the discrepancy between measured and modeled results. Therefore, the risk assessment of gaseous OPEs should be of concern in the further research.

Dispersion and modeling discussion of aerosol air pollution caused during mining and processing of open-cast mines

Given the importance of mining as a source of Total Suspended Particles (TSP) and fine Particulate Matters (PM10), it is important to develop appropriate methods for estimating emissions for use in modeling forecasts and to be aware of regulatory decisions. Development of site-specific emission estimation and also dispersion radius in copper mines would be a practical guide for environmental regulatory bodies in developing countries with incomplete local data. To address these needs, this research is presented, at an open-cast copper mine in mountainous area, using both one-year measurement observational and AERMOD emission modeling software based on documented Environment Protection Agency emission factors. Results demonstrate TSP dispersion predictions were in better agreement with the measured concentrations than those for PM10. This research finds that PM10 and TSP concentration are lowest in autumn and winter, respectively, while both have the highest concentration in summer. The maximum observed concentration of both pollutants is about 300 μg/m3 which is beyond the standard level. The study further shows that generally, concentration of TSP is three times of PM10. The dispersion radius of aerosols was 14 km with wide dispersion for TSP compared with PM10; so, could potentially pose serious environmental and health threats to the surrounding environment and community. The TSP and PM10 emission are about 3.242 and 0.969 kg per any ton of copper produced. This research was applied to a mountainous copper mine in NW Iran, one of the biggest surface mines all across the world (~ 300Mt/y).

COMPARISON OF INORGANIC CHEMICAL COMPOSITIONS OF TOTAL SUSPENDED AND RESPIRABLE PARTICULATES IN DIFFERENT REGIONS OF CAIRO

The inorganic chemical composition of atmospheric Total Suspended Particulate (TSP) and Particulate Matter with an aerodynadic diameter less than 10 µm (PM10) in different regions of Cairo, in spring and autumn of 2018 was illustrated in this work. The results showed that the highest concentration of TSP and PM10 were close to industrial and heavy traffic areas “Tabbin, Helwan, Shobra Elkhimah and Fifth Settlement area”. The results showed that dust mass concentrations in Shobra Elkhimah were higher than all the other locations in both TSP and PM10. These results were pointed out in both spring and autumn. The results showed that the concentration of heavy metals in Helwan area was higher than all other locations. These concentrations suggest that heavy metals pollution in Helwan was more serious. Ration analysis of soluble ions showed that sodium and chloride were not from sea salt but sodium might be from the resuspension of soil dust, and chloride might be associated with the activities of burning. Potassium had diversity of sources other than burning of biomass. Sulfate and nitrate were mostly from fossil fuel origin. The 16NO3-> / 16SO4-> ratios in Tabbin were higher than in Helwan and Shobra Elkhimah for two types of particles during spring and autumn, indicating that the contribution of stationary emission to total particles in Tabbin were higher than in Helwan and Shobra Elkhimah.

Risk assessment of occupational and public exposures to airborne particulate matter arising from a subway construction site in Tehran, Iran

The objective of this study was to assess the health risk of occupational and public exposures to airborne particulate matter (PM) arising from a subway construction site in Tehran, Iran. The occupational exposure was determined by personal sampling in three occupational groups (drivers, workers, and engineers) and the environmental emission was estimated by sampling from five point exhausts. The PM was measured in terms of total suspended particles (TSP), particles with an aerodynamic diameter of less than 10 μm (PM10), and less than 2.5 μm (PM2.5). The ambient air concentrations of PM were modeled using AERMOD software and the health risk was estimated using AirQ+ software. The average (± standard deviation: SD) concentrations of TSP, PM10, and PM2.5 in the personal sampling were determined to be 3620 ± 250, 1690 ± 260, and 1350 ± 140 μg/m3 for drivers, 2190 ± 200, 1210 ± 310, and 960 ± 190 μg/m3 for workers, 690 ± 70, 410 ± 100, and 320 ± 60 μg/m3 for engineers, respectively. The average PM2.5/PM10 ratio in the workplace and exhausts was as high as 0.79. The average increases in ambient air PM2.5 concentrations in the surrounding areas were predicted to be in the range of 2.4–23.8 μg/m3. The all-cause death rates (per 100,000 persons) attributable to PM2.5 from the construction project for the drivers, workers, engineers, and general people were estimated to be as high as 225, 214.5, 193, and 18, respectively. The results indicated that the health effects of the PM emission in the subway construction site were remarkable; therefore, more control measures for the workplace exposure and environmental emission should be considered.

Monitoring and prediction of dust concentration in an open-pit mine using a deep-learning algorithm.

Dust pollution is currently one of the most serious environmental problems faced by open-pit mines. Compared with underground mining, open-pit mining has many dust sources, and a wide area of influence and complicated changes in meteorological conditions can result in great variations in dust concentration. Therefore, the prediction of dust concentrations in open-pit mines requires research and is of great significance for reducing environmental pollution and personal health hazards. This study is based on monitoring of the concentration of total suspended particulate (TSP) in the Anjialing open-pit coal mine in Pingshuo. This paper proposes a hybrid model based on a long short-term memory (LSTM) network and the attention mechanism (LSTM-Attention) and applies it to the prediction of TSP concentration. The LSTM model reflects the historical process of an input time series, and the attention mechanism extracts the inherent characteristics of the input parameters to assign weights based on the importance of the influencing factors. The autoregressive integrated moving average (ARIMA) and LSTM models are also used to predict the TSP concentration. Finally, several statistical measures of error are used to evaluate the accuracy of the model and perform a sensitivity analysis. It was found that, in general, the TSP concentration was highest in the period 08:00-09:00 and lowest in the period 15:00-16:00. In addition to the influence of meteorological parameters and normal operations, the reason for this trend is the presence of an inversion layer above the open-pit mine. The results show that, compared with the ARIMA and LSTM models, the LSTM-Attention model is more stable and has a prediction accuracy that is 5.6% and 3.0% greater, respectively. This model can be applied to the prediction of dust concentrations in open-pit mines and provide guidance on when to carry out dust-suppression work. It has expansibility and is potentially valuable for application in a wide range of areas.

Assessment of environmental impact of telecommunication base transceivers stations in residential areas

This paper assessed the environmental impact of a telecommunication base transceiver stations (BTS) located at Cardoso Close, Apapa, Lagos State, Nigeria with the coordinates 6°4392’N, 3°3126’E. The ambient air quality parameters: SO2, NO, CO, CH4 and total suspended particulates (TSP) were measured using the ITX Emission Analyzer at four sampling points within the base station. The concentrations of SO2, NO, CO and TSP atthe base station ranged between 0.3-0.5 ppm, 1.9-2.2 ppm, 5.5-7.5 ppm, 101-110 µg/m3 respectively for 24-hour averaging period. CH4 was not detected at any of the sampling points. A digital Realistic Sound Level Meter was used in measuring the noise level. The measured average noise levels in all the four sampling points at the BTS studied ranged between 83.1-88.7 dB (A). Samples of water were collected from boreholes around the base station and were subjected tophysico-chemical examinations using the ‘standard methods for water and waste water’ 14th edition prepared by American Public Health Association (APHA). The analyses of the water samples showed that all the parameters are within limits. To measure the electromagnetic radiation emitted from the station during the field study, the SPECTRAN HF-4049 RF, an in-situ dosimeter for radio frequency measurement was used. The results obtained showed that, the measured averageradiation levels in all the four sampling points within the BTS studied ranged between 0.051-0.054 µW/m2. All the measured parameters are within safety margins apart from SO2 and NO. SO2 was not traceable to the BTS while NO was only partly connected with the fossil-fuelled electricity generating sets. The parameters of the physico-chemical analysis of the borehole water were significantly below limits.

Short-Term Aerial Pollutant Concentrations in a Southwestern China Pig-Fattening House

Concentrations of critical aerial pollutants within animal farms are important to the health of animals and farm staff and can be reduced via manure management, ventilation control, and barn design. This study characterized measurements of ammonia (NH3), total suspended particle (TSP), and airborne microbial communities of a large-scale pig-fattening house, as well as their correlations with environmental variables in Southwestern China. Monitoring was conducted for 15 consecutive days during both August and January, at various locations inside the pig house. The concentrations of NH3 and TSP averaged 3.22 and 0.55 mg m−3, respectively, while the average number of airborne microbial colonies was 3.91 log cfu m−3. The aerial pollutant concentrations displayed significant seasonal differences (p &lt; 0.05). Specifically, concentrations in winter were significantly higher than those in summer (p &lt; 0.05), and the 07:00 measurements were the highest among the three measurement times. The concentrations were significantly correlated with indoor temperature and relative humidity. In summer, TSP concentration was negatively correlated with temperature (correlation coefficient = −0.732), while NH3 concentration was positively correlated with temperature (correlation coefficient = 0.58). In winter, TSP and NH3 concentrations were negatively correlated with relative humidity (correlation coefficients = −0.739 and −0.713, respectively), while the airborne microbial colonies were not correlated with either humidity or temperature in summer or winter. These findings confirm that the aerial pollutant concentrations in a Southwestern China pig-fattening house exhibited significant seasonal and diurnal variations. Air quality can be improved by more precise ventilation control as observed by the correlation of concentrations with ventilation control, indoor temperature, and humidity.

Metal(loid) bioaccessibility of atmospheric particulate matter from mine tailings at Zimapan, Mexico.

Metal(loid)s are contaminants of concern emitted as particulate matter (PM) from several pollution sources. The objective was to characterize potential exposure from local airborne metal(loid)s in a community in proximity to mine tailings. Air samples were collected weekly at five sites around the municipal mine tailings using two Hi-volume samplers for simultaneously collecting PM10 and PM2.5. Total suspended particulates (TSP), concentrations, speciation, and bioaccessibility of metal(loid)s were quantified. The size and form of particles were determined by scanning electron microscopy. The concentration of TSP (μgm-3) in the airborne samples ranged from 21.2 to 64.6 for PM2.5 and 23.6 to 80.1 for PM10. The profiles of analyzed quasi-total metal(loid) concentration from all sampling sites were similar between these aerosols PM sizes except at site 2 for Cd, at site 3 for Cu, and site 4 for Zn. The order of quasi-total metal(loid) concentration, in the airborne samples for both PM sizes, was As > Zn > Fe > Pb > Cu > Mn > Cd. As speciation included As-sulfite, As(III)-O, and As(V)-O with less concentration of As(III)-O in both PM sizes. Bioaccessible metal(loid) concentrations were very high and represented a great percentage from the quasi-total airborne concentrations, for instance, 10% and 37% for Pb and 8% and 6% for As in pulmonary and gastric bioaccessible concentrations, respectively. Knowing the toxic effects of these pollutants, there is an urgent need to establish environmental regulation of bioaccessible pollutant concentrations from PM dislodged from uncovered metal(loid) mine tailings affecting not only nearby human populations but also possible long-distance ecosystem transport.

Prediction of coal dust dispersion to total suspended particulate (TSP) concentration in ambient air quality, case study: PLTU Tanjung Jati B

According to the National Medium-Term Development Plan set a 35000 MW target in 2019, wherein 2016, coal still dominated the power plant’s fuel, which is 62%. The fastest rate of consumption is 4,7% per year since 2002; by the domination of coal-fired power plant in Indonesia in 2005 with 29.4 million tons of coal consumption, it is projected to be an increment in 2020 with 75 million tons of coal consumption. This condition could lead to generated coal dust, potentially impacting the ground concentration of TSP in the ambient air quality. The further impact may lead to environmental & social issues in the community residence of surrounding coal-fired power plants (PLTU). Considering the potential impact of coal dust emission from coal stockpile activities, then the prediction of coal dust dispersion generated from coal handling activities to determine the ground concentration of TSP is necessary to determine appropriate mitigating control to reduce the coal dust emission. Therefore, such a power plant will have mutual benefits with the surrounding area, especially the community. According to the model prediction result using AERMOD, it could be predicted that the emission contribution from the coal stockpiles is reached 100-200 μg/m3.

HVAC filtration of particles and trace metals: Airborne measurements and the evaluation of quantitative filter forensics.

Filters installed in the heating, ventilation, and air-conditioning (HVAC) systems can serve as air-cleaning and sampling devices for indoor particles. The purpose of this article is to evaluate these dual roles. An occupied home with a central HVAC system equipped with a Minimum Efficiency Reporting Value (MERV, from ASHRAE Standard 52.2) 11 filter was monitored for six weeks. Weekly airborne gravimetric and real-time sampling was performed to measure the particle size distribution and the concentration of total suspended particles (TSP), PM10, PM2.5, PM1, and 12 trace metals. The weekly system runtimes were intentionally changed to provide a wide range of weekly filtration volumes. The quantitative filter forensics (QFF) concentrations of particulate matter (PM) and trace metals were calculated using the analysis of the dust collected on the HVAC filter, the filtration volume, and filter in-situ efficiency. The results indicated that filtration was not influential to remove PM and trace metals as the concentrations during the weeks with continuous HVAC operation were not consistently lower than those during the other weeks. This suggests the dominance of other particle and trace metal source and loss mechanisms weakens the influence of filtration in this home. The QFF evaluation results indicated that the concentration of TSP and over half of the tested trace metals (e.g., Pb, Cd, Ni, V, Sb, K, and Sr) could be estimated by QFF within a factor of two when compared to airborne sampling results. PM10, PM2.5, and PM1 concentrations were significantly underestimated by QFF potentially due to the limitations of size distribution analysis by a laser diffraction particle sizer (LDPS) for the detection of <1μm particles. Overall, while QFF was promising for TSP and some trace metals, improvement in size distribution analysis could extend the application of QFF for airborne sampling.

Quantitative filter forensics: Size distribution and particulate matter concentrations in residential buildings.

We applied filter forensics, the analysis of dust from the heating, ventilation, and air-conditioning (HVAC) filters, to measure particle size distribution in 21 residences in Toronto, Canada over a year. Four filters with different nominal efficiencies (Minimum Efficiency Reporting Value (MERV) 8-14 from ASHRAE Standard 52.2) were deployed in each residence each for three months, while the effective filtration volumes (the product of flow rate, runtime, and in-situ filter efficiency) were characterized over each filter lifetime. Using extraction and laser diffraction, we found that approximately 90% of the volumetric distributions were >10µm and the volume median diameter (VMD) ranged from 23.4 to 75.1µm. Using quantitative filter forensics (QFF), total suspended particle (TSP) concentrations ranged from 2.9 to 823.7µg/m3 (median=89.8µg/m3 ) with a moderate correlation with the content of TSP on the filters (in terms of g) and with the TSP effective filtration volume (m3 ) indicating the importance of both filter forensics and HVAC metadata parameters to QFF concentration estimates. There was no strong correlation between PM10 or PM2.5 concentrations and hourly airborne particle number concentrations measured by low-cost sensors suggesting an evaluation of QFF is warranted, particularly for the exploration of smaller particles.

Inorganic pollutants in the indoor environment of the Moravian Library: assessment of Cd, Pb, Cu, and Zn in total suspended particles and dust using HR-CS GF-AAS.

In this study, the occurrence of lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) in the environment of the Moravian Library in Brno, the second largest library in Czechia, was in focus. The materials of interest were airborne particles, dust originating from books, and also book pages. Total suspended particles (TSP) were sampled in different areas of the library, including the reading room, the book depository, and an external book warehouse. Samples of dusts were obtained from the book-cleaning system, and, moreover, some pages taken from old books were also analyzed. Samples were microwave-digested and analyzed using graphite furnace high-resolution continuum source AAS (HR-CS GF-AAS). During the analysis, possibilities of the signal intensity modulation of the HR-CS technique were demonstrated and employed in order to determine Zn, an element which is rarely determined by GF-AAS. The median TSP concentrations (in ng/m3) were as follows: Pb, 4.4; Cd, 0.07; Cu, 2.6; and Zn, 20.9. Such concentrations are safely below allowed limits. Contents of Pb determined in dust samples and book pages were slightly higher (up to 707 and 38 mg/kg, respectively) than the usually reported values. However, none of these results indicate a potential risk to library staff or readers.

Potential consumer exposure to respirable particles and TiO2 due to the use of eyebrow powders.

BackgroundCosmetic powders contain numerous components, including titanium dioxide (TiO2), which is classified as possibly carcinogenic to humans (Group 2B). However, little is known about potential inhalation exposures to particles that are released during cosmetic powder applications.MethodsWe realistically simulated the application of five different eyebrow powders using a mannequin and then determined concentrations of total suspended particles (TSP), PM10, and PM4 fractions of particles that would be inhaled during powder application. We determined the size and shape of particles in the original powders and released particles, as well as their TiO2 concentrations and Ti content of individual particles.ResultsThe application of eyebrow powders resulted in the release and inhalation of airborne particles at concentrations ranging from 21.2 to 277.3 μg/m3, depending on the particle fraction and the powder. The concentrations of TiO2 in PM4 and PM10 samples reached 2.7 μg/m3 and 9.3 μg/m3, respectively. The concentration of TiO2 in airborne particle fractions was proportional to the presence of TiO2 in the bulk powder.ConclusionThe application of eyebrow powders results in user exposures to respirable PM4 and PM10 particles, including those containing TiO2. This information should be of interest to stakeholders concerned about inhalation exposure to TiO2.

Visibility Parameter in Sand/Dust Storms’ Radio Wave Attenuation Equations: An Approach for Reliable Visibility Estimation Based on Existing Empirical Equations to Minimize Potential Biases in Calculations

In efforts to structure an expression for wave attenuation under a sand/dust storm, most established calculations pronounce optical visibility as an essential parameter. Although visibility information can be retrieved from weather stations, other commonly encountered sources may present it differently, i.e., as total suspended particles (TSP). Consequently, several empirical equations linking visibility to TSP concentrations were evaluated to address offset tendencies in estimations. In addition to substantiating specific equations, the results revealed that averaging a pair of equations has a 46.09% chance of estimating visibilities with a probability of 37.27%, a relatively low error compared to that achieved by employing single equations, which were found to have a probability of 28.93% with a lesser chance (29.58%) of a low estimation error for the same set of data. The resulting enhancement was evaluated by considering a study on a wireless sensor network’s (WSN’s) signal performance under vaguely labelled meteorological conditions. The meteorological conditions were converted to visibility using the results’ suggestions and were found to be in good agreement with an observation standard set by the China Meteorological Administration (CMA) for sand/dust storm outbreak classifications.

A study of atmospheric pollutants (particulates, metallic elements) at an agricultural site

In this study, the total suspended particulate (TSP) concentrations and dry deposition of ambient air particulates are measured using a high-volume air sampler and a dry deposition plate at an agricultural sampling site in central Taiwan from March of 2019 to February of 2020. In addition, the concentrations of metallic elements attached to the particulates and dry deposits are analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Finally, the TSP and metallic elements concentrations in TSP at different sampling sites around the world are also compared and discussed. The results indicated that the average highest TSP concentrations and dry depositions values both occurred in autumn, and the agricultural sampling site had the average greatest ambient air particulates dry depositions velocities when compared with other previous characteristic-related studies in Taiwan. In addition, metallic element Al had the average highest concentrations and dry depositions and metallic element Cd had the average lowest concentrations and dry depositions values in this study. In addition, metallic elements Cr, Cu, Pb, and Zn had the average highest concentrations when compared with other typical sampling site studies (airport, suburban, downtown, residential, industrial, and wetlands) in central Taiwan. Furthermore, when compared with the other previous metallic elements concentrations found in related studies in other regions from 1978 to 2020, the results obtained in this study indicated that the average metallic element concentrations Cr, Cu, Pb, and Zn in Taiwan were only lower than those reported in India and China. Taiping District is the main fruits production area in central Taiwan. Therefore, continued monitoring of ambient air related pollutants and finding the possible pollution sources have become an important issue for this agricultural site. From the above analysis, we also conclude that ambient air particulates and all the metallic elements dry deposition values obtained in this study were higher than those from the other characteristic sampling sites where studies were previously conducted in Taiwan.

Distribution and gas-particle partitioning of polycyclic aromatic hydrocarbons over the East China Sea and Yellow Sea in spring: Role of atmospheric transport transition

To elucidate the variations in the East Asian monsoon system during seasonal changes and their impacts on continental outflow of polycyclic aromatic hydrocarbons (PAHs), sixteen integrated air samples were collected during a research cruise covering the Yellow Sea (YS) and East China Sea (ECS) in mid-spring of 2017. The concentrations of total suspended particle (TSP), aerosol-phase PAH fractions, ratios of organic to elemental carbon (OC/EC) and gas-particle partitioning of atmospheric PAHs exhibited clear regional differences associated with variations in the monsoon regime. The total concentrations of 16 USEPA priority PAHs (Σ16PAHs) varied from 3.11 to 13.4 ng/m3 throughout the cruise, with medium-to-high molecular weight (MW) PAHs more enriched over the YS and north ECS than the south ECS. Together with the relatively low gaseous PAH fraction over the YS and north ECS (78 ± 4%) relative to the south ECS (95 ± 13%), this result indicates the pattern of regional atmospheric transport. The ratio of organic to elemental carbon varied significantly between the south ECS (lower than 4) and the YS and north ECS (greater than 4), indicating contributions from vehicle emissions and coal combustion or biomass burning, respectively, following different atmospheric input pathways of carbonaceous aerosols, as supported by backward trajectory analysis. Considering the gas-particle partitioning of PAHs, soot adsorption was the main partitioning mechanism in the study region; while high-MW PAHs in the YS and north ECS were influenced by both absorption and adsorption. The Koa absorption model provided better predictions for high-MW PAHs when continental air masses prevailed, despite underestimating the partition coefficients (kp) of low-MW PAHs. Meanwhile, predicted kp for medium MW PAHs was better estimated over the YS and ECS when Ksa was included.