Total Suspended Particulate Concentrations Research Articles

Dry deposition fluxes and inhalation risks of toxic elements in total suspended particles in the Bohai Rim region: Long-term trends and potential sources

Long-term changes in dry deposition fluxes (DDF) and health risks for toxic elements (TE) in total suspended particles (TSP) in the Bohai Rim region are important for assessing control effects of pollution sources. Thus, we investigated the trends in DDF and concentrations for TSP and TE and health risks of TE in eight cities in the region from 2011–2020. TSP concentration and DDF showed general downward trends. Compared to the before Clear Air Action Plan (BCAAP, 2011–2012) period, concentration and DDF of TE over the Clear Air Action Plan (CAAP, 2013–2017) period substantially decreased, with the highest decrease rates in Zn, Cd, and Cr. During the study period, non-carcinogenic (HI) and total carcinogenic (TCR) risks for children and adults were 0.09 and 0.04, and 1.54 × 10−5 and 2.65 × 10−5, respectively, with Cr6+ and As being dominant contributors. Compared to the BCAAP period, HI and TCR over the CAAP period decreased by 36.8 % and 32.4 %, respectively. However, their risks increased over the Blue Sky Protection Campaign (BSPC, 2018–2020) period. Potential source contribution function suggested substantial changes in potential risk areas over different control periods, with the BSPC primarily being on land and the Yellow Sea.

Influence of irrigation water and soil on annual mercury dynamics in Sacramento Valley rice fields.

Methylmercury (MeHg) is a human and environmental toxin produced in flooded soils. Little is known about MeHg in rice (Oryza Sativa L.) fields in Sacramento Valley, California. The objectives of this study were to quantify mercury fractions in irrigation water and within rice fields and to determine their mercury pools in surface water, soil, and grain. Soil, grain, and surface water (dissolved and particulate) MeHg and total mercury (THg) were monitored in six commercial rice fields throughout a winter fallow season and subsequent growing season. Both dissolved and particulate mercury fractions were higher in fallow season rice field water. Total suspended solids and particulate mercury concentrations were positively correlated (r=0.99 and 0.98 for THg and MeHg, respectively), suggesting that soil MeHg was suspended in the water column and potentially exported. Dissolved THg and MeHg concentrations were positively correlated with absorbance at 254nm (r=0.47 and 0.58, respectively) in fallow season field water. In the growing season, fields with higher irrigation water MeHg concentrations (due to recycled water use) had elevated field-water MeHg (r=0.86) and grain MeHg concentrations (r=0.96). Based on a mass balance analysis, soil mercury pools were orders of magnitude larger than surface water or grain mercury pools; however, fallow season drainage and grain harvest were the primary pathways for MeHg export. Based on these findings, reducing (1) discharge when water is turbid, (2) straw inputs, and (3) use of recycled irrigation water could help reduce mercury exports in rice field drainage water.

Statistical analysis of air quality dataset of Kathmandu, Nepal, with a New Extended Kumaraswamy Exponential Distribution.

This paper aims to create a new probability distribution and conducts statistical analysis on air quality dataset from Kathmandu. Using this innovative distribution, we have studied the ground reality of air quality conditions of Kathmandu, Nepal. In our research, we have developed a new probability distribution known as the New Extended Kumaraswamy Exponential Distribution by introducing an additional shape parameter to the Extended Kumaraswamy Exponential (EKwE) Distribution. Statistical characteristics such as cumulative distribution function, probability density function, hazard function, reversed hazard function, skewness, kurtosis, survival function, and hazard rate function are studied. The suggested model is non-normal and positively skewed with increasing and inverted bathtub-shaped hazard rate curves. To assess the model's suitability, we utilized a real dataset comprising air quality data from Kathmandu, Nepal, during the year 2021. Study shows that the air quality data exhibit an increasing failure rate, but the P2.5, P10, and total suspended particle concentrations exhibited its lowest levels during the monsoon season and its highest levels during the winter season. Parameters of the model are estimated by using the least square estimation (LSE), maximum likelihood estimation (MLE), and Cramér-von Mises (CVM) approach for P10 at Ratnapark Station, Kathmandu. To assess the model's validity, P-P plots and Q-Q plots are employed. Model comparisons are carried out using Akaike Information Criterion (AIC), Corrected Akaike Information Criterion (CAIC), Bayesian Information Criterion (BIC), and Hannan-Quinn Information Criterion (HQIC). Furthermore, the goodness of fit of the proposed model is evaluated using test statistics such as Anderson-Darling (A2) test, Cramér-von Mises (CVM) test, and the Kolmogorov-Smirnov (KS) test along with their respective p-values. From the findings, we have found that the air quality status of Kathmandu, Nepal, was found to be poor. Proposed distribution provides a better fit with greater flexibility for forecasting air quality data and conducting reliability data analyses. Dataset is analyzed and visualized using R programming.

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.

Indoor air quality improvement with filtration and UV-C on mitigation of particulate matter and airborne bacteria: Monitoring and modeling

Indoor air, especially with suspended particulate matter (PM), can be a carrier of airborne infectious pathogens. Without sufficient ventilation, airborne infectious diseases can be transmitted from one person to another. Indoor air quality (IAQ) significantly impacts people's daily lives as people spend 90% of their time indoors. An industrial-grade air cleaner prototype (filtration + ultraviolet light) was previously upgraded to clean indoor air to improve IAQ on two metrics: particulate matter (PM) and viable airborne bacteria. Previous experiments were conducted to test its removal efficiency on PM and airborne bacteria between the inlet and treated air. However, the longer-term improvement on IAQ would be more informative. Therefore, this research focused on quantifying longer-term improvement in a testing environment (poultry facility) loaded with high and variable PM and airborne bacteria concentrations. A 25-day experiment was conducted to treat indoor air using an air cleaner prototype with intermittent ON and OFF days in which PM and viable airborne bacteria were measured to quantify the treatment effect. The results showed an average of 55% reduction of total suspended particulate (TSP) concentration between OFF days (110 μg/m3) and ON days (49 μg/m3). An average of 47% reduction of total airborne viable bacteria concentrations was achieved between OFF days (∼3200 CFU/m3) and ON days (∼2000 CFU/m3). A cross-validation (CV) model was established to predict PM concentrations with five input variables, including the status of the air cleaner, time (h), ambient temperature, indoor relative humidity, and day of the week to help simulate the air-cleaning effect of this prototype. The model can approximately predict the air quality trend, and future improvements may be made to improve its accuracy.

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.

Characteristic Variation of Particulate Matter-Bound Polycyclic Aromatic Hydrocarbons (PAHs) during Asian Dust Events, Based on Observations at a Japanese Background Site, Wajima, from 2010 to 2021

Asian dust (AD) events and total suspended particles (TSPs) were observed at the Kanazawa University Wajima Air Monitoring Station (KUWAMS), a Japanese background site, during the East Asian winter monsoon periods (from November to May of the following year) from 2010 to 2021. Nine kinds of polycyclic aromatic hydrocarbons (PAHs) were determined in each TSP sample. In this study, a total of 54 AD events were observed. According to the different pathways of long-range transportation, AD events were divided into AD-high events (transported at higher altitudes, approximately 4000 m) and AD-low events (transported at lower altitudes, approximately 2500 m). The TSP concentrations increased sharply in the AD events and were higher in the AD-high events (39.8 ± 19.5 μg/m3) than in the AD-low events (23.5 ± 10.5 μg/m3). AD did not have a significant effect on the ΣPAHs characteristic variation, as ΣPAHs (ΣPAHs = fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene, and indeno [1,2,3-cd]pyrene) concentrations in non-AD periods, AD-high events, and AD-low events were 543 ± 374, 404 ± 221, and 436 ± 265 pg/m3, respectively. The PAH compositions were also consistent. As a result, the TSP concentration was affected by the input air mass transported at higher altitudes from the desert region while the PAH concentration was impacted by the air mass at lower altitudes, which carried the PAHs emitted from fossil fuels and biomass combustion in northeastern China. Moreover, the health risks of PAHs were calculated with the inhalation lifetime cancer risk, which ranged from 10−6 to 10−5 ng/m3, indicating a potential carcinogenic risk at the KUWAMS during the East Asian winter monsoon periods.

Deriving particulate backscattering coefficient at 400 nm from small-scale optically shallow waters using Landsat-8 data: a case study at Luhuitou Peninsula, Sanya.

The particulate backscattering coefficient (bbp) plays an important role in the growth of coral reefs by influencing the light field conditions. Small-scale optically shallow waters are commonly found in coastal fringing reefs, making it challenging to monitor the spatial and temporal patterns accurately using Aqua satellites with a low spatial resolution. In this study, six existing optimization-based algorithms for deriving bbp at 400 nm (bbp(400)) were evaluated with three simulated Landsat-8 (spatial resolution = 30 m) data sets and in situ data from the Luhuitou Peninsula, Sanya. The comparison results indicated that the HOPE (hyperspectral optimization process exemplar) (Fix-H-error or Fix-H-error-free) algorithm which sets an input value of the water depth alone outperformed other algorithms. However, the estimated bbp(400) from all the algorithms tended to be either overestimated and underestimated due to the improper the spectral shape value of the backscattering coefficient. The HOPE (Fix-H-error) algorithm estimated-bbp(400) from in situ reflectance also had a good correlation with the in situ total suspended particle concentrations data derived-bbp(400), with a correlation coefficient of 0.83. Therefore, the HOPE (Fix-H-error) algorithm was selected to estimate the bbp(400) from satellite-based Landsat-8 data of the Luhuitou Peninsula, Sanya. Time-series (2014-2021) results from these Landsat-8 images reveal the seasonal variation of bbp(400). The bbp(400) was low from May to September every year. From October to December or January, bbp(400) had an increasing trend, and then it decreased until May. Spatial analysis indicated that bbp(400) decreased with increasing water depth. The spatial and temporal patterns of bbp(400) were consistent with in situ observations reported in the literature. This study preliminarily showed the efficiency of an optimization-based algorithm in deriving bbp(400) in small-scale optically shallow water region using Landsat-8 data.

Determination of Particulate Matters and Total Suspended Particles emitted from Incense Burning

Incense burning is an important ceremonial ritual in Buddhism. It is well recognized that incense smoke has negative health effects, which may be caused by the emission of submicron particles, including ultrafine and nanoparticles. Hence, in this study, the concentration of particulate matter (PM) and total suspended particles (TSP) emitted from incense burning were determined from 4 incense stick brands. The experiment was conducted in a room with a volume of approximately 146m3 using two instruments: an HV sampler and a Nano Sampler. The highest TSPs concentration from long sticks and short sticks were S1 (319.03 μg/m3) and N2 (439.75 μg/m3), respectively. High mass concentration was found in the ultrafine particle range for S2 (112.27 μg/m3) and N2 (117.30 μg/m3). In contrast, S1 and N1 exhibited high concentrations in the coarse particle mode at 79.28 μg/m3 and 86.75 μg/m3, respectively. Out of the 4 incense brands, N2 appeared to have the highest concentration in almost every particle range compared to the other 3 brands. Incense should be burned in a well-ventilated setting and try not to stay in the same place as the altar to reduce the risk of incense smoke exposure.

Atmospheric transport of particulate matter and particulate-bound agrochemicals from beef cattle feedlots: Human health implications for downwind agricultural communities

Beef cattle feedlot particulate matter (PM) is a complex mixture of dust, animal waste, agrochemicals, and bioaerosols. However, no empirical data exist quantifying downwind residential exposure to PM or PM-bound agrochemicals. In the current study, authors investigated transport of PM and co-occurring insecticides and anthelmintics downwind of three feedlots in the Southern Great Plains (SGP) of North America from May–August 2022. PM collected on total suspended particulate (TSP) filters was analyzed via UHPLC-MS/MS for six pyrethroids and five macrocyclic lactones (MLs). Downwind TSP concentrations rapidly declined from 0.01 to ≤1.6 km (Monte Carlo mean ± SEM; 5049 ± 96.1 μg/m3) and stabilized >1.6–12.4 km (1791 ± 9.9; μg/m3). Distance decay >1.6 km indicated downwind PM exceeded levels of safe human exposure during diurnal peak periods. Pyrethroids and MLs were detected >LOQ in 96.2 and 98.1 % of downwind samples. Screening-level cumulative residential exposure indicates elevated pyrethroid risk (LOC = 1; RI = 0.173) to rural children (1–2 yrs) living near cropland operations in the SGP, with disproportionate co-exposure to feedlot PM and legacy pollution in low-income, Hispanic and Latino communities. Frequent occurrence and sustained transport of pyrethroids downwind of feedlots facilitate residue accumulation in outdoor residential areas that must also be quantified to assess the magnitude of daily average and lifetime-adjusted oral and dermal exposure in surrounding communities. Results significantly expand the known distribution of feedlot-derived PM and agrochemicals and highlight human exposure pathways unrecognized in residential human health assessments supporting pesticide registration and feedlot risk evaluation.

Temporal evolution of PM2.5, PM10, and total suspended particles (TSP) in the Ciuc basin (Transylvania) with specific microclimate condition from 2010 to 2019

Modern societies are characterized by increased air pollution, and particulate matter (PM) is one of the most significant air pollutants and is a major environmental health problem. Therefore, long- and short-term exposure via inhalation, ingestion, and dermal absorption of particulate matter may cause series health issues, such as cardio pulmonary and lung cancer disease. Air pollutants accumulation is significantly higher in closed regions or basins characterized by strong thermal inversions, especially during the cold period such in case of the Ciuc basin. The aim of this study was to carry out the time series analysis of PM2.5, PM10 and TSP in the Ciuc basin for the period 2010–2019, in order to decipher the main characteristics of air pollution in this region.The data obtained were analyzed on a daily, monthly and annual basis by different statistical methods. The average monthly concentration of TSP (60.03 µg m−3), PM10 (19.21 µg m−3) and PM2.5 (14.73 µg m−3) particulate matter in the studied regions varied between 29.84–134.79 µg m−3, 4.38–63.51 µg m−3 and 4.01–54.41 µg m−3, respectively. Regarding the ratio of PM2.5 and PM10 in the total particulate matter (TPM) was 0.25 and 0.33. Due to meteorological factors and emission fluctuations, particulate matter exhibits high seasonal variations, therefore the highest concentrations were recorded during the cold period, while the lowest values were observed in summer. The percentage of PM10 exceedances (50 µg m−3) represents 24.8% in winter, meanwhile in autumn and spring a significantly lower exceedances percentage was observed, 2.6% and 1.7%, respectively. The correlation analysis revealed that the correlation level of the studied pollutants varied between 0.73–0.78.

Characterizing a Year-Round Particulate Matter Concentration and Variation under Different Environmental Controls in a Naturally Ventilated Dairy Barn

A mixing fan and spraying system is commonly used to control the indoor environment of naturally ventilated dairy barns worldwide. However, its impact on particulate matter (PM) concentration and variation is still unclear due to the lack of year-round field data. To systematically characterize the PM dynamics under different environmental controls (namely, EC1: No Fans and No Spraying; EC2: Fans; EC3: Fans and Spraying), a year-round continuous monitoring of PM less than 2.5 μm in aerodynamic diameter (PM2.5) and total suspended particle (TSP) concentrations, as well as indoor environmental factors, was carried out inside a naturally ventilated dairy barn using an IoT-based sensor monitoring network. Results showed that the hourly mean TSP and PM2.5 concentrations were 94.7 μg m−3 and 49.8 μg m−3, respectively. EC2 had a higher TSP content (116.6 μg m−3) than EC1 (98.0 μg m−3) and EC3 (81.9 μg m−3). EC1 had the greatest PM2.5 concentration (57.1 μg m−3), followed by EC2 (48.3 μg m−3) and EC3 (44.7 μg m−3). EC1 showed clear TSP and PM2.5 fluctuations during the daily operations at 07:00 to 08:00 and 18:00 to 19:00, while irregular peaks in EC2 and a relatively steady diurnal variation in EC3 were found. Daily Tsp concentrations in the three ECs did not exceed 300 μg m−3. However, 17.8%, 11.5%, and 4.8% of the observed days in EC1, EC2, and EC3 had daily mean PM2.5 concentrations above the healthy threshold (75 μg m−3), mostly from 07:00 to 08:00 and 22:00–07:00. In conclusion, the mixing fan and spraying system had significant effects on PM concentration and variation, and more protection procedures should be taken for farm workers to prevent long-term health risk exposure, to EC1 in particular.

Sources Causing Long-Term and Seasonal Changes in Combustion-Derived Particulate Matter in the Urban Air of Sapporo, Japan, from 1990 to 2002

Fifty-one samples were collected seasonally to estimate the amounts of total suspended particulate (TSP) in Sapporo, Japan, from 1990 to 2002. The atmospheric concentration of combustion-derived particulate (Pc) was calculated based on the NP method using 1-nitropyrene and pyrene. The atmospheric TSP and Pc concentration ranges were between 31–121 µg m−3 of air (Mean ± standard deviation (SD) = 58.2 ± 20.2 µg m−3) and 31–121 µg m−3 (Mean ± SD = 8.2 ± 6.0 µg m−3), respectively. First-order linear regression equations suggested that the Pc fraction decreased faster than TSP. The highest and lowest Pc concentrations were observed in winter and summer, respectively, whereas the highest and lowest TSP concentrations were observed in spring and winter, respectively. The largest and smallest Pc/TSP concentration ratios were observed in winter (0.324) and summer (0.075), respectively. The seasonal fractions of high-temperature combustion-derived particulate (Ph) in Pc ranged from 0.56 (winter) to 0.75 (summer), suggesting that the contribution of vehicle emissions to Pc was always larger than those of coal and biomass combustion. The sources of long-term and seasonal change in Pc were elucidated by analyzing organic source markers. Atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs), nitropolycyclic aromatic hydrocarbons (NPAHs) and hopanes showed long-term and seasonal changes similar to those of Pc, although biomarkers of biomass and coal combustion, such as levoglucosan, mannosan, and galactosan were not as strongly correlated. These results suggest that the change in the Pc concentration was mainly affected by vehicle emissions rather than by coal and biomass combustion or secondary pollutant formation. The decrease in the Pc over the study period was mainly a result of the Japanese particulate matter/NOx regulations on vehicle exhaust.

Insight into the relationships between total suspended particles and mercury in meltwater in a typical glacierized basin in the inland Tibetan Plateau

Mercury (Hg) released by melting glaciers is likely to bind to suspended particles in meltwater runoff, posing potential risks to downstream ecosystems. The rapidly receding glaciers on the Tibetan Plateau promote the export of total suspended particles (TSP), increasing the uncertainty of Hg export released by glacier melting. To investigate the relationships between TSP and Hg, a multimedia sampling campaign was conducted in July 2020 in the Kuoqionggangri glacier region of the Lhasa River Valley No. 1 glacierized basin located in the inland Tibetan Plateau. Samples from glacier snow/ice, supraglacial rivers, subglacial rivers, proglacial lakes, and meltwater runoff were obtained, and the relationships between TSP and Hg and their transport in glacier meltwater runoff in the context of glacier retreat were explored. The average TSP concentration of different environmental samples ranged from 9.51 mg/L to 399. 27 mg/L, showing significant differences. The average total Hg (THg) concentrations ranged from 0.52 ng/L to 58.81 ng/L and decreased in the order of snow/ice >runoff> subglacial river > proglacial lake > supraglacial river. Both TSP mass concentration and number concentration have an impact on the diurnal variation in meltwater runoff Hg, and the influence of TSP number concentration is stronger than that of concentration. Sites with high TSP concentrations and quantities tended to have higher Hg concentrations, while TSP particle size had no significant effect on Hg concentration or spatial distribution. Our study further divided the glacier recharge basin into the glacier cover zone, the periglacial zone, and the downstream zone and discussed the potential impact of TSP on Hg transport in each zone. Our analysis highlights that the periglacial zone will expand and activate the resuspension process of river sediments in the warming future, which may increase the export of TSP and Hg downstream.

Measurement of Airborne Particles and Volatile Organic Compounds Produced During the Heat Treatment Process in Manufacturing Welding Materials

BackgroundThere is little information about the airborne hazardous agents released during the heat treatment when manufacturing a welding material. This study aimed to evaluate the airborne hazardous agents generated at welding material manufacturing sites through area sampling. Methodsconcentration of airborne particles was measured using a scanning mobility particle sizer and optical particle sizer. Total suspended particles (TSP) and respirable dust samples were collected on polyvinyl chloride filters and weighed to measure the mass concentrations. Volatile organic compounds and heavy metals were analyzed using a gas chromatography mass spectrometer and inductively coupled plasma mass spectrometer, respectively. ResultsThe average mass concentration of TSP was 683.1 ± 677.4 μg/m3, with respirable dust accounting for 38.6% of the TSP. The average concentration of the airborne particles less than 10 μm in diameter was 11.2–22.8 × 104 particles/cm3, and the average number of the particles with a diameter of 10–100 nm was approximately 78–86% of the total measured particles (<10 μm). In the case of volatile organic compounds, the heat treatment process concentration was significantly higher (p < 0.05) during combustion than during cooling. The airborne heavy metal concentrations differed depending on the materials used for heat treatment. The content of heavy metals in the airborne particles was approximately 32.6%. ConclusionsNanoparticle exposure increased as the number of particles in the air around the heat treatment process increases, and the ratio of heavy metals in dust generated after the heat treatment process is high, which may adversely affect workers' health.

Uptake, accumulation, and translocation of organophosphate esters and brominated flame retardants in water hyacinth (Eichhornia crassipes): A field study

Mechanisms underlying the plant uptake, accumulation, and translocation of organophosphate esters (OPEs) and brominated flame retardants (BFRs) in field environments remain ambiguous. To better understand these processes, we selected a typically polluted river with steady flow and rampant water hyacinth (Eichhornia crassipes) and investigated 25 OPEs and 23 BFRs in 24 sets of matched water–plant samples. Both OPEs and BFRs showed high or ultra-high levels in field water hyacinths, statistically positive water–plant/root concentration correlations, and dominant distributions in the roots. Passive root uptake was the dominant route for OPEs and BFRs to enter the water hyacinth. Both OPEs and BFRs in water hyacinth exhibited acropetal translocation from the root and possible basipetal translocation from the leaf. The accumulation and translocation of OPEs in water hyacinth were significantly affected by their substituents and structures, including the chlorination degree, alkyl chain length, side chain, and methylation degree of aryl-substituted OPEs. The translocation of BFRs in water hyacinth also showed close association with their bromination degree, but their accumulation in roots showed anomaly, indicating possible transformations. Overall, the enrichment and behavior of OPEs and BFRs in water hyacinth seemed to be mainly controlled by physicochemical parameters. OPE/BFR concentrations in total suspended particulate (TSP), TSP-associated organic carbon content, TSP concentration, and plant biomass all showed significant effects on their root accumulation and translocations in water hyacinth. This study provides rare field evidences and novel insights into the basipetal translocation of OPEs and BFRs in plants.

The impact of heavy metals that released from vehicles exhausts on some biochemical parameters in Eucalyptus and Ziziphus plants in street intersections of Baghdad city

The air pollution by vehicles exhaust is consider the most risk environmental problems, especially when precipitate on soil surface and transport to the plants and entering the food chain. so that, the current study was carried out to determine the impacts of air pollution on the plants growth in traffic intersections, the study was carried out in Baghdad city, identified two regions for each of the both sides of the Rusafa and Karkh by two main sites for each region, as well as, the secondary stations in each site. the heavy metals and total suspended particles concentrations were determined in the filter paper that suffer the pollution air for 30 min. in specific sites using sniffer device. The concentrations decrease of some pollutants was noticed more than to the national and global permitted limits and the summer was the highest season in pollution during study period. Eucalyptus and Ziziphus spina Christi plants was chosen to evaluating the impacts of pollution on the plants because its being of the most common and the evergreen trees in the Baghdad s' streets. Primary metabolites content in plants was measured as total chlorophyll recorded a height concentration in August(98.631mg/gm) in Eucalyptus leaves ,while the total protein content reached to maximum concentration (26.101 mg/gm) in both plants, either total carbohydrate content reached to (88ppm) in Eucalyptus leaves and (74.62ppm) in Ziziphus leaves and noticed that , the increase in concentration of pollutants affected on the protein and carbohydrate content. Seven phenolic compounds was diagnosed being one of the main secondary compounds of metabolism , the increase in total phenolic content was recorded in the region that have a high concentration of carbon dioxide was reach to (6699.88ppm) in Al-Mansour(3) samples compared to the control samples was(2388.87ppm). the heavy metals concentrations in the leaves of eucalyptus and ziziphus arranged from more to less as steady regime throughout the study period in the following order: iron &gt; zinc &gt; copper &gt; lead .

Operational parameters impact on spatial and temporal distribution and multifractal characteristics of particulate matter concentration under the sink effect

The influences of different factors on spatial and temporal mass transfer mechanism and dynamic characteristics of particulate matter (PM) under the sink effect are not clear. The objective of this study was to quantitatively analyze the influences of operational parameters on spatial and temporal distribution and multifractal characteristics of indoor suspended PM concentration under the sink effect. Results showed that with the increase of the applied voltage of the purification device, the reverse increase processes of PM1 and PM2.5 concentrations were progressively attenuated, and PM10 and total suspended particulates (TSP) concentrations decreased clearly. The dynamic evolution processes of the PM concentration series all presented strong persistence and obeyed the scale-invariant power-law statistical distributions. The positive correlation of the PM concentration series between five distances increased with the increase of applied voltage. This study can provide a reference basis for further refining the PM purification theory system under the sink effect.