Total Suspended Particulate Concentrations Research Articles

Carbon and Trace Element Compositions of Total Suspended Particles (TSP) and Nanoparticles (PM0.1) in Ambient Air of Southern Thailand and Characterization of Their Sources

The concentration of total suspended particles (TSP) and nanoparticles (PM0.1) over Hat Yai city, Songkhla province, southern Thailand was measured in 2019. Organic carbon (OC) and elemental carbon (EC) were evaluated by carbon aerosol analyzer (IMPROVE-TOR) method. Thirteen trace elements including Al, Ba, K, Cu, Cr, Fe, Mg, Mn, Na, Ni, Ti, Pb, and Zn were evaluated by ICP-OES. Annual average TSP and PM0.1 mass concentrations were determined to be 58.3 ± 7.8 and 10.4 ± 1.2 µg/m3, respectively. The highest levels of PM occurred in the wet season with the corresponding values for the dry seasons being lower. The averaged OC/EC ratio ranged from 3.8–4.2 (TSP) and 2.5–2.7 (PM0.1). The char to soot ratios were constantly less than 1.0 for both TSP and PM0.1, indicating that land transportation is the main emission source. A principal component analysis (PCA) revealed that road transportation, industry, and biomass burning are the key sources of these particles. However, PM arising from Indonesian peatland fires causes an increase in the carbon and trace element concentrations in southern Thailand. The findings make useful information for air quality management and strategies for controlling this problem, based on a source apportionment analysis.

On-Site Deployment of an Air-Liquid-Interphase Device to Assess Health Hazard Potency of Airborne Workplace Contaminants: The Case of 3-D Printers.

Biomonitoring of workers is an approach of evaluating workers’ exposure to chemicals and particulate matter by measuring biomarkers of parent chemicals, their metabolites, and reaction products in workers’ biospecimens. Prerequisites for biological monitoring in the workplace include permission to enter the workplace, approval of the study plan from the IRB (Institutional Review Board), and obtaining consent from workers. Because of the complex legal process involved in biomonitoring, few studies have been conducted so far on biomonitoring of workers’ exposures to nanoparticles and other hazards from emerging materials and advanced nanotechnologies. We have developed a cell-based biomonitoring device that can evaluate acute cytotoxicity and various other effect biomakers, such as inflammation, at realistic workplace exposure. This device is based on air–liquid interphase (ALI) and can be used to evaluate cell toxicity and early effect biomarkers along adverse outcome pathways. Following exposure of A549 lung epithelial cells in ALI to workplace air for 1–2 h, the cells were processed to assess the induction of inflammatory and cell damage biomarkers. Initially, we estimated the deposition rate of nanoparticles in the transwell by exposing the cell-free ALI device to silver nanoparticle aerosols (AgNP 20–30 nm) for 2 h in the laboratory. Then A549 lung epithelial cells cultured on the transwell in the ALI device were exposed to AgNP nanoaerosols for 2 h and evaluated for cytotoxicity and induction of mRNAs of pro-inflammatory cytokines IL-1b, IL-6, and TNF-α. Then the cells in the ALI device were exposed to 3-D printer emissions at the workplace and evaluated for the same matched endpoints. The mRNA levels for IL-1b, IL-6, and TNF-α increased significantly at the end of 2-h exposure of A549 cells to the positive control AgNP aerosols. These mRNAs, as well as LDH and microprotein concentrations, increased even more after 24-h post-exposure incubation (p < 0.05). Cytotoxicity evaluation of 3-D printer emissions at 810 and 957 μg/m3, which was more than 80 times higher than the airborne total suspended particulate concentrations in the workplace air (9–12.5 μg/m3), suggested no significant acute cytotoxicity at the end of 2-h exposure to 3-D-printing emission, as well as at 24-h post-exposure incubation. Hyperspectral microscopic observation showed that 3-D printers emitted particles to be attached to A549 cells after 2-h exposure, and many particles were internalized by A549 cells after 24 h of post-exposure incubation. The mRNA expression of pro-inflammatory cytokine IL-1b and IL-6 increased significantly after 2-h exposure to 3-D printer emissions and after 24-h incubation (only IL-6). In contrast, the expression of TNF-α mRNA decreased significantly after 2 h of exposure to 3-D printers and decreased even more after 24-h post-exposure incubation. These results support the use of cell-based ALI devices for direct assessment of airborne hazards in the workplace, for probing toxicological properties of airborne contaminants using adverse molecular pathways, and for guiding study design for workplace biomonitoring. ALI devices can bridge conventional exposure assessment with cellular toxicity testing platforms for hazard and risk assessment.

Applying principal component, health risk assessment, source identification for metallic elements of ambient air total suspended particulates at Taiwan Scientific Park.

This study collected ambient air total suspended particle (TSP) concentrations and dry depositions at Taichung Science Park sampling site. The metallic elements concentrations and dry depositions were analyzed. The possible pollutant sources are discussed in this study. In addition, this study used the principal component analysis method to find metallic element sources and their transportation pathway and distributions at Taichung Science Park (T.S.P). The results indicated that the average highest TSP concentrations and dry deposition fluxes occurred in the autumn and winter seasons. The highest average metallic element concentration and dry deposition was Fe, while the lowest average metallic element concentration and dry deposition was Hg(p). The study results further indicated that the lowest metallic element concentrations and dry depositions all occurred in the summer season. The pollutant parcels originated from the northern Taiwan counties and sea surface in the autumn, winter and spring seasons. Factor 1 was responsible for the local industrial emission results and traffic road dust. The metallic elements Hg(p) yield a value greater than 0.7 in Factor 2 which revealed that ambient air particulate pollutants were generated from Taichung Thermal Power Plant (T.T.P.P.) emissions and were transported from the coastal area of mainland China cities. The mean seasonal concentration differences existed for ambient air particulates, and there were no mean seasonal concentrations differences for all metallic elements. In addition, there were no significant mean concentrations differences for all metallic elements and meteorological factors such as temperature, humidity and wind speed. Therefore, the ambient air metallic element emissions were stable and considered primary emissions sources. The health risk value for metallic element Cr was higher than that for the acceptable health risk value suggested by the EPA. Metallic element Cr revealed that it was no mean seasonal concentrations differences. Thus, metallic element Cr was considered came from local emission source at this T.S.P. sampling site.

Marble Dust Effect on the Air Quality: An Environmental Assessment Approach

All over the world, increasing anthropogenic activities, industrialization, and urbanization have intensified the emissions of various pollutants that cause air pollution. Marble quarries in Pakistan are abundant and there is a plethora of small- and large-scale industries, including mining and marble-based industries. The air pollution caused by the dust generated in the process of crushing and extracting marble can cause serious problems to the general physiological functions of plants and it affects human life as well. Therefore, the objectives of this study were to assess the air quality of areas with marble factories and areas without marble factories, where the concentration of particulate matter in terms of total suspended particles (TSP) was determined. For this purpose, EPAM-5000 equipment was used to measure the particulate levels. Besides this, a spectrophotometer was used to analyze the presence of PM2.5 and PM10 in the chemical composition of marble dust. It was observed that the TSP concentrations in Darmangi and Malagori areas of Peshawar, Pakistan—having marble factories—were 626 µg/m3 and 5321 µg/m3 respectively. The (PM2.5, PM10) concentration in Darmangi was (189 µg/m3, 520 µg/m3) and in Malagori, it was recorded as (195 µg/m3, 631 µg/m3), which was significantly higher than the non-marble dust areas and also exceeded WHO recommended standards. It was concluded that the areas with the marble factories were more susceptible to air pollution as the concentration of TSP was significantly higher than the recommended TSP levels. It is recommended that marble factories should be shifted away from residential areas along with strict enforcement. People should be instructed to use protective equipment and waste management should be ensured along with control mechanisms to monitor particulate levels.

Organic aerosol compositions and source estimation by molecular tracers in Dushanbe, Tajikistan

To elucidate the molecular composition and sources of organic aerosols in Central Asia, carbonaceous compounds, major ions, and 15 organic molecular tracers of total suspended particulates (TSP) were analyzed from September 2018 to August 2019 in Dushanbe, Tajikistan. Extremely high TSP concentrations (annual mean ± std: 211 ± 131 μg m−3) were observed, particularly during summer (seasonal mean ± std: 333 ± 183 μg m−3). Organic carbon (OC: 11.9 ± 7.0 μg m−3) and elemental carbon (EC: 5.1 ± 2.2 μg m−3) exhibited distinct seasonal variations from TSP, with the highest values occurring in winter. A high concentration of Ca2+ was observed (11.9 ± 9.2 μg m−3), accounting for 50.8% of the total ions and reflecting the considerable influence of dust on aerosols. Among the measured organic molecular tracers, levoglucosan was the predominant compound (632 ± 770 ng m−3), and its concentration correlated significantly with OC and EC during the study period. These findings highlight biomass burning (BB) as an important contributor to the particulate air pollution in Dushanbe. High ratios of levoglucosan to mannosan, and syringic acid to vanillic acid suggest that mixed hardwood and herbaceous plants were the main burning materials in the area, with softwood being a minor one. According to the diagnostic tracer ratio, OC derived from BB constituted a large fraction of the primary OC (POC) in ambient aerosols, accounting for an annual mean of nearly 30% and reaching 63% in winter. The annual contribution of fungal spores to POC was 10%, with a maximum of 16% in spring. Measurements of plant debris, accounting for 3% of POC, divulged that these have the same variation as fungal spores.

Quantifying Farmers’ Exposure to Corn and Soybean Dust in On-Farm Grain Storage Bins

HighlightsOn-farm samples were used to analyze farmers’ exposure to dust while cleaning and unloading their grain bins.Over 18% of samples exceeded the 8-hour time-weighted average (TWA) concentration recommended by ACGIH for respirable dust, and over 27% of samples exceeded the ACGIH recommendation for total suspended particles.The results strengthen the need for relevant agricultural safety education programs to help farm workers understand the health hazards associated with grain dust.Abstract. Grain dust consists of grain particles, insect parts, silica, bacteria, fungi, and mycotoxins. The size of these airborne particulates is a concern because they can become deeply lodged in the respiratory tract. Exposure to grain dust can diminish overall lung function and lead to respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), organic dust toxic syndrome (ODTS), chronic bronchitis, and hypersensitivity pneumonitis (farmer’s lung). Grain storage and handling facilities are primary work locations with high levels of grain dust concentrations. The objective of this study was to understand farmers’ exposure to grain dust while cleaning and unloading their grain bins. During on-farm dust sampling, researchers visited farms to collect dust samples for analysis. Two types of samples were taken. Integrated samples provided average concentrations of total dust and respirable dust while farmers performed their normal tasks in the grain bin. Real-time samples provided instantaneous concentrations of respirable dust (RESP) and total suspended particles (TSP) and how the variations changed during the farmers’ working periods. From the data collected in corn storage bins, RESP concentrations ranged from 4.1 to 6.6 mg m-3, and TSP concentrations ranged from 33 to 70.7 mg m-3. From the data collected in soybean storage bins, RESP concentrations ranged from 1.6 to 82.3 mg m-3, and TSP concentrations ranged from 8.9 to 146.8 mg m-3. Based on the calculated 8-hour time-weighted average (TWA) concentration of all samples, 18.2% of the 8-hour TWA RESP concentrations exceeded the ACGIH-recommended respirable dust concentration of 3 mg m-3, and 27.3% of the 8-hour TWA TSP concentrations exceeded the ACGIH-recommended total dust concentration of 610 mg m-3. The results strengthen the need for relevant agricultural safety education programs to help farm workers understand the health hazards associated with grain dust. Keywords: Grain dust concentrations, Occupational health, On-farm grain storage bins.

Impact of COVID-19 lockdown

To prevent the spread of SARS-CoV-2 infection on March 16, 2020, Government of Kazakhstan has announced a nationwide emergency and imposed unprecedented lockdown restriction measures. The objective of this study is to evaluate the changes in air quality during the lockdown period in the four cities of Kazakhstan: Aktau, Atyrau, Karagandy, and Shymkent. The data on concentrations of Total Suspended Particles (TSP), NO2, SO2, and CO were collected for 56 days during the lockdown (16 March – 11 May 2020), during 56 days before lockdown (20 January – 15 March), and the same periods of the previous years (2018 – 2019). During the lockdown period (spring 2020), concentrations of TSP, NO2, SO2, and CO (on average for 4 cities) declined by 19, 8, 17, and 25% respectively, compared to the same period in 2018 – 2019, with significant variations between cities. In the pre-lockdown period (winter 2020), concentrations of TSP, NO2, SO2, and CO (on average for 4 cities) also declined, by 16, 13, 7, and 9%, respectively, compared to the same period in 2018 – 2019. Thus, reductions in the concentration of pollutants during 16 March – 11 May 2020, compared to the same period in the previous years could be only partially attributed to lockdown restriction measures and may be also affected by annual changes. In addition, despite some improvement in air quality during the lockdown period, in three out of four cities, the levels of air quality were still high and not safe.

Improving the Indoor Air Quality in Nursery Buildings in United Arab Emirates.

Children inhale indoor air at 400 mL/min∙kg per body weight, 2.76 times more than adults. They have weaker immunity than adults and are more exposed to asthma, allergies, and atopic diseases. The objective of this paper is to suggest effective management and improvement measures for indoor air quality for nurseries. As a methodology, 16 nurseries (total of 35 classrooms) were selected to measure the indoor air quality compared with WHO IAQ Standard, and identify the daily concentration change of the pollutants. Based on the measurements, IAQ improvements for selected facilities are carried out to compare the results before and after improvement. The result has shown that the concentration of Carbon Dioxide (CO2), Total Volatile Organic Compounds (TVOC), Total Suspended Particles (TSP) and formaldehyde (CH2O) exceeds WHO IAQ standards. The concentration of CO2 and TSP is changed mainly by physical activity of children and that of CH2O and TVOC is changed mainly by ventilation after school start. TVOC decreased by 46.4% and the TSP decreased by 21.7% after air purifier, but CH2O and TVOC increased 1.8–3.8 times after interior renovation with low-emission finishing materials. After new ventilation installation, the CH2O and TVOC reduced half and the TSP reduced one third. It is proven that the most effective way to reduce the concentration of air pollutants in nurseries is the installation of a new ventilation system, followed by an air purifier. The renovation with low-emission finishing materials cannot improve IAQ in a short period of time.

Approach to Predicting the Size-Dependent Inhalation Intake of Particulate Novel Brominated Flame Retardants.

The risk of human exposure to particulate novel brominated flame retardants (NBFRs) in the atmosphere has received increasing attention from scientists and the public, but currently, there is no reliable approach to predict the intake of these compounds on the basis of their size distribution. Here, we develop a reliable approach to predict the size-dependent inhalation intake of particulate NBFRs, based on the gas/particle (G/P) partitioning behavior of the NBFRs. We analyzed the concentrations of eight NBFRs in 363 size-segregated particulate samples and 99 paired samples of gaseous and bulk particles. Using these data, we developed an equation to predict the G/P partitioning quotients of NBFRs in particles in different size ranges (KPi) based on particle size. This equation was then successfully applied to predict the size-dependent inhalation intake of particulate NBFRs in combination with an inhalation exposure model. This new approach provides the first demonstration of the effects of the temperature-dependent octanol-air partitioning coefficient (KOA) and total suspended particle concentration (TSP) on the intake of particulate NBFRs by inhalation. In an illustrative case where TSP = 100 μg m-3, inhalation intake of particulate NBFRs exceeded the intake of gaseous NBFRs when log KOA > 11.4.

Potential implications of new information concerning manganese Ohio community health effects studies

Several epidemiology studies have been conducted in Ohio communities where industrial facilities with manganese emissions are located. New information not addressed in the published papers for this research has been disclosed by U.S. federal agencies pursuant to the Freedom of Information Act. This paper describes the newly available information, presents statistical analyses of the new summary data, and explores how this information potentially impacts the conclusions of the published research. Based on a statistical analysis of the newly available data, we found very few, and no consistent, statistical differences for various illnesses, self-reported symptoms, and neuropsychological/neuromotor test results between one community with a manganese emission source and a control town that were part of the initial research. Further, we determined that the distribution of total suspended particulate manganese air concentrations did not correlate with the distribution of the more biologically relevant respirable manganese concentrations when data from two communities with potential manganese emissions were combined. These results are important, particularly in determining whether the studies should influence regulatory reference values related to manganese. We recommend that the full health effects data set associated with the published research be made available and re-evaluated to address the issues identified in this paper.

Elevated particulate methanesulfonate, oxalate and iron over Sydney Harbour in the austral summer of 2019-20 during unprecedented bushfire activity

In the austral summer period, Dec 7, 2019 to Mar 1, 2020, which included unprecedented bushfire activity, total suspended particulate concentrations of methanesulfonate (MSA), oxalate, labile iron, SO42−, Cl−, Na+, K+, NH4+, water soluble solids (WSS) and water soluble organic carbon (WSOC) were measured from weekly filter samples at Seaforth on the northern edge of Sydney Harbour. Particle number concentrations (PNC) and meteorological conditions were also measured at hourly intervals. These entities were previously measured in the spring-summer period, Sep 30, 2018 to Feb 24, 2019. Data analysis is focussed on inter-comparison between the summer of 2018–19 (S1) and 2019–20 (S2) spanning the period 7 Dec to 24 Feb. During S2 seasonally averaged MSA, oxalate, labile iron, K+, PNC (0.5–2.5 μm), and WSOC were elevated by 102%, 57%, 64%, 72%, 108%, and 1907%, respectively, by comparison to S1. Aqueous phase secondary formation of oxalate and a marine source of MSA were evident during S1; however, during S2 it was indicated that the bushfires created conditions where oxalate formation was shifted away from aqueous phase processing and MSA became associated with bushfire generated WSOC aerosol. Correlation changes at the a = 0.05 significance level between S1 and S2 for MSA, and for oxalate, are examined and discussed in relation to effects apparently caused by the bushfires. It is indicated that the biogeochemical cycling of sulfur and carbon, and particulate deposition of iron micronutrient to the South Pacific Ocean, may be altered by bushfires in Australia.

Chemical Composition and Source Apportionment of Total Suspended Particulate in the Central Himalayan Region

The present study analyzes data from total suspended particulate (TSP) samples collected during 3 years (2005–2008) at Nainital, central Himalayas, India and analyzed for carbonaceous aerosols (organic carbon (OC) and elemental carbon (EC)) and inorganic species, focusing on the assessment of primary and secondary organic carbon contributions (POC, SOC, respectively) and on source apportionment by positive matrix factorization (PMF). An average TSP concentration of 69.6 ± 51.8 µg m−3 was found, exhibiting a pre-monsoon (March–May) maximum (92.9 ± 48.5 µg m−3) due to dust transport and forest fires and a monsoon (June–August) minimum due to atmospheric washout, while carbonaceous aerosols and inorganic species expressed a similar seasonality. The mean OC/EC ratio (8.0 ± 3.3) and the good correlations between OC, EC, and nss-K+ suggested that biomass burning (BB) was one of the major contributing factors to aerosols in Nainital. Using the EC tracer method, along with several approaches for the determination of the (OC/EC)pri ratio, the estimated SOC component accounted for ~25% (19.3–29.7%). Furthermore, TSP source apportionment via PMF allowed for a better understanding of the aerosol sources in the Central Himalayan region. The key aerosol sources over Nainital were BB (27%), secondary sulfate (20%), secondary nitrate (9%), mineral dust (34%), and long-range transported mixed marine aerosol (10%). The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) analyses were also used to identify the probable regional source areas of resolved aerosol sources. The main source regions for aerosols in Nainital were the plains in northwest India and Pakistan, polluted cities like Delhi, the Thar Desert, and the Arabian Sea area. The outcomes of the present study are expected to elucidate the atmospheric chemistry, emission source origins, and transport pathways of aerosols over the central Himalayan region.

Source apportionment and health risk due to PM10 and TSP at the surface workings of an underground coal mine in the arid desert region of northwestern China

The surface operations area of an underground coal mine near Lingwu in Ningxia Hui Autonomous Region was selected for this study. Particulate matter (PM) was sampled in the coal screening plant during the day and night in Spring and Winter, 2019. Twelve trace metals and eight water-soluble ions in particulate matter up to 10 μm in diameter (PM10) and total suspended particles (TSP) were analyzed using ICP-OES and ion chromatography, respectively. The enrichment factor (EF) and positive matrix fraction (PMF) were used to identify potential sources of particulate metals. The forward trajectory model was used to analyze the main migration pathways of particles. Results showed that higher concentrations of PM10 and TSP were found in Spring than in Winter; the concentration of PM at night was lower than during the day. Most of the trace metals in TSP were greater than in PM10, while the content of most water-soluble ions in TSP was lower than in PM10. The EF analysis confirmed that particulate metals were attributable to anthropogenic emission. PMF model results further demonstrated that the main sources of PM in both seasons were regional suspended dust, traffic emission, industrial emission and coal burning. Air mass dispersion analysis showed that PM generated by these operations may spread to eastern and southeastern China within 72 h in Spring, while mainly to southeastern and southern China in Winter. These suggest a need for greater focus on strengthening the monitoring and early warning of the presence of atmospheric PM in southern Shanxi, China. Because of the risks that particulate metals pose to human health, the protection of children should be strengthened around the surface operation area of an underground coal mine. Moreover, monitoring of the concentrations of Cr in PM10 and Mn in TSP in Spring should be strengthened, and the opposite procedure should be adopted in Winter. These findings are useful for providing a theoretical basis for the prevention and control of pollutants in underground mining areas and the construction of cleaner production lines.

Overview and Seasonality of PM10 and PM2.5 in Guayaquil, Ecuador

The focus of this study is the assessment of total suspended particles (TSP) and particulate matter (PM) with various aerodynamic diameters in ambient air in Guayaquil, a city in Ecuador that features a tropical climate. The urban annual mean concentrations of TSP (Total Suspended Particles), and particle matter (PM) with various aerodynamic diameters such as: PM10, PM2.5 and PM1 are 31 ± 14 µg m−3, 21 ± 9 µg m−3, 7 ± 2 µg m−3 and 1 ± 1 µg m−3, respectively. Air mass studies reveal that the city receives a clean Southern Ocean breeze. Backward trajectory analysis show differences between wet and dry seasons. During the dry season, most winds come from the south and southwest, while air masses from the peri urban may contribute as pollutant sources during the wet season. Although mean values of PM10 and PM2.5 were below dangerous levels, our year-round continuous monitoring study reveals that maximum values often surpassed those permissible limits allowed by the Ecuadorian norms. A cluster analysis shows four main paths in which west and southwest clusters account for more than 93% of the pollution. Total vertical column of NO2 shows the pollution footprint is strongest during the dry season, as opposed to the wet season. A microscopic morphological characterization of ambient particles within the city during the wet and the dry season reveals coarse mode particles with irregular and rounded shapes. Particle analysis reveals that samples are composed of urban dust, anthropogenic and organic debris during the dry season while mainly urban dust during the wet season.

Atmospheric aerosols analysis and identification of polluting sources in the industrial city of Arak, Iran

Total suspended particulates (TSP) were collected in the industrial city of Arak, Iran, during the windy and cold seasons of 2018–2019 to investigate the air pollution sources. The associated elements were analyzed by particle‐induced X‐ray emission technique. The major elements detected in the samples were Mg, Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Co, Cu, and Zn. In this investigation, the time trend, monthly and seasonal variations, the correlation between the elemental concentrations, and the sources of air pollution were evaluated. An increase in the concentrations of Zn, Ti, and Fe was seen in winter due to temperature inversions. The highest correlation coefficients were found between soil dust key elements, Fe–Si, Ca–S, Ca–Fe, Ca–Si, and Al–Si. From the aerosols time trend concentration and the wind map direction, it was identified that there are northwesterly winds bringing desert dusts to the sampling site. The statistical positive matrix factorization model in combination with correlation coefficient and enrichment factor values were used to identify the sources of air pollution. It was deduced that the soil dusts, machining and assembling activities, industrial salts, vehicle, aluminum metallurgy, and petrochemical productions were the main contribution to the detected TSP concentration.

A study to quantify surgical plume and survey the efficiency of different local exhaust ventilations

This study aimed to compare the concentration of surgical smoke produced by different tissues and electric diathermy modes and to measure the effectiveness of various local exhaust ventilations. We compared the surgical plume concentration from different tissues and settings with a porcine tissue model. We also compared the efficiency of three local exhaust ventilations: (1) a desktop unit (Medtronic Rapid Vac), (2) a central evacuation system with ENT suction, and (3) a central evacuation system with a urethral catheter (PAHSCO Urethral Catheter). In the cutting setting, the skin tissue had a higher concentration of total suspended particulates (TPS), which were 1990 ± 2000 (mean ± SD, μg/m3), 6440 ± 3000 and 9800 ± 2300 at 15, 30 and 45 s, respectively (p < 0.05). In the coagulation setting, the adipose tissue had a higher concentration of TPS, which were 3330 ± 2600, 11,200 ± 5500 and 15,800 ± 7300, respectively (p < 0.05). We found that all three smoke extractors had more than 96% efficiency in clearing surgical smoke. With electric diathermy, skin tissue in the cutting model and adipose tissue in the coagulation mode will produce higher concentration of particles within surgical plumes. An electric surgical scalpel adapted with a urethral catheter is a simple and effective way to exhaust smoke in surgical operations.

Spatio-Temporal Distribution and Health Risk Levels of TSP and PM10 in the Mining Town of Tarkwa, Ghana

Particulate matter (PM) varies significantly in space and time. Effective PM risk analysis requires adequate knowledge of the spatial and temporal distribution of PM. In order to understand TSP/PM10 variability within the microclimate of Tarkwa and their potential impact. The Spatio-temporal distribution of Total Suspended Particulates (TSP) and PM10 in Tarkwa was studied. Five years TSP and PM10 monthly concentration data from fifteen (15) monitoring stations were collected and analysed for Spatio-temporal characteristics within the suburbs around three mining companies in Tarkwa. Autocorrelation between neighbouring suburbs, attainment rate, particle size distribution and risk levels were evaluated. The results revealed that all the monitoring stations except two (stations NV and TN) recorded TSP and PM10 concentrations below the national guideline for all years of study. Geo-spatially, highest TSP and PM10 risk level were recorded East of Tarkwa. Inhalable particles constitute about 44.09-72.90% of TSP. Attainment values between 44.09%-100% and 30%-100% were recorded for TSP and PM10, respectively. Estimated AQI values ranged between good and unhealthy for sensitive groups. Future studies directed at the chemical composition of PM was recommended to enhance further understanding of the risk levels.&#x0D; &#x0D; Keywords: Particulate Matter, Attainment Rate, Air Pollution, Trends, Particle Size Distribution

Seasonal effects of street trees on particulate matter concentration in an urban street canyon

The net influence of trees on local air quality in urban street canyons, negative or positive, has rarely been evaluated by field investigations. To quantify the influence of street trees on particulate matter (PM) and total suspended particle (TSP) concentration near ground level, a seasonal field investigation was carried out in a street canyon with an aspect ratio of 0.52 in Shenyang, China. The greening tree species in this street were Sophora japonica and Ulmus pumila. We monitored PM1, PM2.5, PM4, PM10, TSP concentration and the microclimatic conditions at locations with or without trees from before the leaf expansion season until the end of the defoliation season. Concentration of PM2.5 was higher at the tree-stand location, whereas concentration of PM10 and TSP were higher at the tree-free location during the leaf-on season. Street trees were beneficial to coarse particle removal during the leaf-off and leaf-expansion season, but PM pollution increased during defoliation. Wind direction was more uniform at the tree-stand location. Street trees weakened the impact of the wind on PM dispersion near ground. This indicates that street trees might pose a health threat to pedestrians because fine PM can enter the human respiratory system more easily than coarse PM.

Community Health Risk Assessment of Total Suspended Particulates near a Cement Plant in Maros Regency, Indonesia.

Background.Cement plants generate particulate matter (PM) across processes from raw material preparation to packaging. The presence of total suspended particulates (TSP) coming out of the stack causes a high accumulation of dust in residential areas. Human exposure to TSP could affect human health and wellbeing.Objectives.The present study aims to evaluate concentrations of TSP and to estimate the health risks of TSP exposure through the inhalation pathway in communities surrounding a private cement industry in Maros regency, Indonesia.Methods.Total suspended particulates were collected using a high-volume air sampler (HVAS) at five locations. Samples were taken by grab sampling for 24 hours. The SCREEN3 program was used to view the maximum range and distribution of pollutants based on the geographical, stack profiles and meteorological factors in the study area. Hazard quotient (HQ) was used to estimate non-carcinogenic risks of TSP in surrounding communities.Results.Total suspended particulate concentrations were measured with a maximum value of 133.24 μg/m3 and a minimum value of 18.48 μg/m3. This maximum value exceeds the minimum acceptable level from Canadian National Ambient Air Quality Objectives (C-NAAQOs). The non-carcinogenic risks from the inhalation pathway were low except for location 3 (HQ>1) across all locations.Conclusions.The cement plant may significantly contribute to total TSP concentrations in air and may potentially have adverse effects on human health. Communities near the cement plant are vulnerable to TSP exposure and measures are needed to reduce TSP in Maros regency, Indonesia.Participant Consent.ObtainedEthics Approval.This study was approved by the Health Research Ethics Committee of Hasanuddin University with protocol number 28920093022.Competing Interests.The authors declare no competing financial interests.

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.