High Air Concentrations Research Articles

Hydrochemical Assessment of Groundwater in Ludhiana and Amritsar Districts of Punjab and Identification of Fluoride Hotspots using GIS

High fluoride concentrations in soil, water, or air can pose serious environmental and health risks to plants, and animals. Along with other hydrochemical parameters, this study investigates fluoride concentrations in the groundwater in the Ludhiana and Amritsar districts of Punjab, India. A total of 222 water samples were uniformly collected at approximately five-kilometer intervals for hydrochemical analyses. Statistical methods such as inverse distance weighting (IDW) and correlation matrices were used to assess the fluoride distribution and its relationships with other parameters. According to WHO guidelines, most fluoride concentrations were below 0.6 ppm in Ludhiana (84.30%) and Amritsar (77.23%). Fluoride levels that were within the permissible range (0.6–1.5 ppm) were found in 15.70% of Ludhiana’s samples and 21.78% of Amritsar’s samples; only 1% of Amritsar’s samples exceeded the permissible limit (>1.5 ppm). The water quality index (WQI) analysis indicated that0.83% of the groundwater samples from the Ludhiana district and 4.95% from the Amritsar district were unfit for consumption. This study demonstrates the importance of standardized sample collection and the use of GIS technology for comprehensive hydrochemical assessments, raising awareness and reducing health risks.

Cyclic methylsiloxanes in wastewater treatment plants: Occurrence, emissions, environmental distributions, and occupational exposure

Cyclic methylsiloxanes (CMSs), widely found in wastewater treatment plants (WWTPs), are potentially hazardous to the environment and human health. In this study, the environmental behavior and human exposure risks of three CMSs (D4-D6) were evaluated in WWTPs located in Beijing and Kunming, Yunnan province. D5 had the highest concentrations in air, water, and sludge, with seasonal variation that consisted of a high concentration in summer and low concentration in winter. The CMS concentrations in air were 3–4-fold higher in the A2/O (Anaerobic-Anoxic-Oxic) treatment units than in the other units. CMS emissions to air, soil, and water from the Beijing WWTP were in the ranges of 3.4 × 104–5.0 × 104 kg·a−1, 4.5 × 102–7.5 × 102 kg·a−1, and 2.5 × 102–2.9 × 102 kg·a−1, constituting 98 %, 1.3 %, and 0.7 % of the total emissions, respectively. Total daily inhalation exposure doses of CMSs (ADDinh,CMSs) associated with four different jobs in WWTPs showed that wastewater treatment technicians had the highest ADDinh,CMSs (51 μg/kg/day), indicating that these people had the highest occupational exposure risk in WWTPs. Therefore, this study identified that atmospheric emission was the main environmental fate of CMSs in WWTPs, and provide a basis for the improvement of WWTP process and risk management decisions. Environmental implicationAssessing the environmental fate and occupational exposure risk of cyclic methylsiloxanes (CMSs) found in wastewater treatment plants (WWTPs) is crucial. This is the first study to identify that atmospheric emission was the main environmental fate of CMSs in WWTPs, especially D5; the inhalation exposure doses of CMSs were all significantly higher in the occupational population working in WWTPs. The results described in our study will help enhance the understanding of current knowledge base of environmental fate and exposure risk of CMSs in WWTPs, and provide a basis for the improvement of WWTP process and risk management decisions.

Allergen-specific immunotherapy for mold allergies

AbstractMolds are ubiquitous in our environment and are considered by the population to be the most important indoor pollutant problem [1]. The current 2023 update to the AWMF mold guideline [1] is intended to allay or channel fears and provide assistance for a sensible diagnosis and treatment decision.The detection of an IgE-mediated allergy implies for allergists Allergen immunotherapy (AIT) as an established treatment option. However, compared to the well-validated AIT with pollen and house dust mites, the decision to use AIT with mold extracts must be weighed more heavily between the benefits and risks.Spores of Alternaria alternata are found in high concentrations in the outdoor air. Due to the high allergenic potential and the small size of the spores, an Alternaria allergy often leads to bronchial asthma, especially in children. The effectiveness of AIT with Alternaria extracts has been tested in several studies; for other molds, especially those from the indoor environment, the efficacy and applicability is very limited.In terms of differential diagnosis, it must be borne in mind that molds can not only cause common allergic reactions but can also be responsible for allergic bronchopulmonary mycoses/aspergillosis (ABPA), Aspergillus bronchitis, exogenous allergic alveolitis (EAA), invasive aspergillosis, mycoses and rhinosinusitis. Very high concentrations, which can occur particularly in workplaces, can also result in toxic effects (“organic dust toxic syndrome”); molds are also held responsible for mucous membrane irritation, odor effects and mood disorders [1].

Trace Metals in Global Air: First Results from the GAPS and GAPS Megacities Networks.

Trace metals, as constituents of ambient air, can have impacts on human and environmental health. The Global Atmospheric Passive Sampling (GAPS) and GAPS Megacities (GAPS-MC) networks investigated trace metals in the air at 51 global locations by deploying polyurethane foam disk passive air samplers (PUF-PAS) for periods of 3-12 months. Aluminum and iron exhibited the highest concentrations in air (x̅ = 3400 and 4630 ng/m3, respectively), with notably elevated values at a rural site in Argentina thought to be impacted by resuspended soil. Urban sites had the highest levels of toxic Pb and Cd, with enrichment factors suggesting primarily anthropogenic influences. High levels of As at rural sites were also observed. Elevated trace metal concentrations in cities are associated with local emissions and higher PM2.5 and PM10 concentrations. Brake and tire wear-associated metals Sb, Cu, and Zn are significantly correlated and elevated at urban locations relative to those at background sites. These data demonstrate the versatility of PUF-PAS for measuring trace metals and other particle-associated pollutants in ambient air in a cost-effective and simple manner. The data presented here will serve as a global baseline for assessing future changes in ambient air associated with industrialization, urbanization, and population growth.

Interfacial heat transfer with non-condensable gas in ASTEC V2.2: Application to severe accidents study during PWR cold shutdown states

In a diphasic flow, the presence of non-condensable gas has an important impact on interfacial heat transfer, especially at low global pressure. In severe accidents studies, such flow can be commonly encountered. For example, in pressurised water reactors, high concentration of non-condensable gas can be found in the reactor coolant system in case of late core reflooding with a high oxidation rate (high hydrogen concentration) or in case of accidents happening during the cold shutdown of the reactor, when the reactor coolant system has been partly drained (high air concentration). Such flows with non-condensable gas are challenging to compute for severe accident system codes. A new model is implemented in ASTEC v2.2 to improve the interfacial heat transfer calculation in presence of non-condensable gas. The model gives a more accurate estimation of the heat transfer by assuming that it is mainly driven by vapour diffusion in the gas phase. The new model is applied to study cold shutdown states for 1300 MWe pressurized water reactors. A complete calculation of the cooling, depressurisation and draining of the reactor can be successfully performed. In order to show ASTEC new capabilities, a first accident scenario with loss of the residual heat removal system is also presented.

Condensation characteristics of air–water vapor mixture on the surface of vertical flat plate

The condensation heat transfer of air–water mixed vapor is an important heat transfer phenomenon in production life. An experimental system for condensation heat transfer of the air–water vapor mixed vapor is built in this paper. The condensation characteristics of the mixed vapor and the double boundary layer structure characteristics were investigated. The study mainly discussed the influence of flow velocity on the condensation performance of mixed vapor and summarized the experimental correlation equations considering flow velocity. Results indicate that the condensation performance decreases significantly as the air concentration increases. The mixed vapor flow velocity was increased from 1 to 3 m/s, and the condensation heat transfer coefficient was increased by 34.9–121.0%. The enhanced effect of flow velocity was also observed at high air concentration and low subcooling. The ratio of convective and condensation heat transfer coefficients increases with the rise in air concentration, reaching a maximum of 0.12. The proportion of convective heat transfer can be reduced by increasing the mixed vapor flow velocity. The gas film thickness is substantially higher than the liquid film thickness in mixed vapor condensation, and the gas/liquid film thermal resistance ratio can be more than 30 times. And increasing the flow velocity can significantly reduce the gas film/liquid film thermal resistance ratio. A new experimental correlation equation is fitted based on the experimental results, and this equation can be used as a reference for the design of related heat exchangers.

Technical and Managerial Measures to Reduce the Environmental Risks Generated by the Activities Carried out at Zăoaga Water Treatment Plant

Abstract Environmental risk can result from the interaction between human activity and the environment. Human activities can generate certain changes in the environmental components, thus inducing a potential danger for the health of people, flora, vegetation and fauna through the negative effects they have on water resources, air and soil quality, climate, microclimate, and so on. This paper presents the potable water treatment plant from Zănoaga, located in Petroșani Municipality, and highlights the potential risks related to the activity within this plant. Particular emphasis is placed on the risk to the environment and human health that may arise from improper storage and handling of liquid chlorine tanks, chlorine being a toxic gas if found in high concentrations in air, water or soil.

Atmospheric wet deposition of mercury in urban Jinan, eastern China: Speciation, scavenging process and potential sources

Understanding the speciation and related influence factors of Hg in wet deposition is important to predict the fate and transport of mercury in the atmosphere. In this study, event-based samples of rainwater were collected for one year in Jinan, a northern city in eastern China. The volume-weighted mean concentration of total mercury (THg) in rainwater was 34.8 ng L−1, comparable to levels in some inland cities in China and were significantly higher than those in North America, Korea and Japan. Most of the Hg in rainwater was associated with particulates, accounted for 15.2–92.9% of THg with a mean of 66.9%, which might be attributed to the scavenging effects of high particulate-bound mercury concentrations in ambient air in urban Jinan. Dissolved mercury (DHg) accounted for 33.1% of THg, in which Hg(OH)2, HgClOH, HgCl2 and Hg(NH3)22+ are the dominant species based on the chemical equilibrium modeling simulations. THg concentrations in rainwater decreased as the rainfall amount increased owing to the dilution effect and 5 mm rainfall might be a threshold for the full wash-out capability of atmospheric Hg. For a continuous rain event, the proportion of DHg in THg could increase from 7.1% to 84.8% with the rainfall processing, especially for the species of HgClOH and HgCl2 under the influence of rainwater pH. Positive matrix factorization (PMF) analysis suggested that the major sources of Hg in rainwater were combustion emissions, marine sources, industrial emissions, as well as complexation process, which contributed to 51.4%, 24.7%, 12.2%, and 11.7% of the THg, respectively. For the specific species, the main sources varied with different Hg species, in which combustion emissions contributed one third to one half of each species sum to particulate mercury (PHg), HgClOH, HgCl2, HgBrOH and HgBrCl followed by marine sources and industrial emissions. Cluster analysis of backward trajectories revealed that polluted air masses, transported from southeast Shandong, Anhui and Jiangsu Provinces, as well as Beijing-Tianjin-Hebei region, contributed to high Hg concentration in rainwater in Jinan.

Effects of modified atmosphere packaging nitrogen gas in storage Ross 308 broiler hatching eggs on eggshell conductance values and some hatchability traits

Modified atmosphere packaging (MAP) is considered as an effective and common method for packaging and storing fresh meat products, but few studies have examined the usage of MAP in egg. In this article, the effect of MAP storage on the functional eggshell conductance and Some Hatchability Traits. Egg storage beyond 7 d is associated with an increase in incubation duration and a decrease in hatchability. Negative effects of prolonged egg storage may be caused by changes in the embryo, by changes in egg characteristics, or by both. An adjustment in storage air composition may reduce negative effects of prolonged egg storage because it may prevent changes in the embryo and in egg characteristics.An experiment was conducted to investigate the effects of high N2 concentrations in the storage air on eggshell conductance and hatchability. 750 Eggs were stored period for 7, 14 and 21 day (250 eggs/ period) were in plastic bags in 3 different storage atmosphere compositions: control treatment Unpackaged, 100% Air treatment , 100% N2 treatment. The storage temperature was 14°C and a pressure of 10 mbar. Results showed The interaction between the Modified atmosphere packaging factor in favor of the treatment of nitrogen gas and a storage period of 14 and 21 days to a significant decrease in the measured conductance values G1, g2 and conductance constant (K).The Modified atmosphere packaging factor for nitrogen gas and air to a significant decrease in the measured conductance values (G1) and conductance constant (K). The factor of storage duration of broiler breeder hatching eggs and caused a significant decrease in the measured conductance values G1 and g2. The interaction between the Modified atmosphere packaging factor for the treatment of nitrogen gas with different storage periods (7-14-21 days) a significant increase in the percentage and hatching from fertilized eggs as a result of a significant decrease of early embryonic deaths. The use of the Modified atmosphere packaging factor to treat the of nitrogen gas in storing the hatching eggs to a significant increase in the hatching rate of fertilized eggs. The factor of storage duration of broiler breeder hatching eggs during the storage period of 7 days caused a significant increase in the percentage of early embryonic deaths, And it was found that there was no significant positive or negative correlation coefficient when studying the correlation coefficient between the conductance characteristics (conductance, conductance constant) and hatching traits (the percentage of hatching from fertilized eggs, early, medium and late embryonic mortality, live and dead click embryos)

Effects of Converging Sidewalls on Skimming Flow over Converging Stepped Spillway

A numerical study is conducted for converging stepped spillways with various spillway slopes, sidewall convergence and flow discharges to understand the influences of converging sidewalls on skimming flows. Compared with the traditional uniform-width stepped spillway, the converging sidewall changes the skimming flow features by generating standing waves on the free-surface, curving the mainstream streamlines and squeezing and distorting the bottom rotations. For free-surface, mainstream and bottom rotations, the width of disturbed regions by the converging sidewall varies, with that for bottom rotations being 1.5 times that for mainstream and 3 times that for free-surface. The variation rules of disturbed region widths along the spillway are obtained, and the maximum widths increase as the convergence angle and incoming flow discharge increase, and the spillway slope decreases. Three equations are established for predicting the maximum widths of disturbed regions for free-surface, mainstream and bottom rotations of skimming flow. Since the disturbed region of skimming flow generated by the converging sidewall is characterized by strong standing waves, high flow velocity and low air concentration, appropriate engineering measurements should be taken for the disturbed region to meet the challenges to overtopping, energy dissipation and cavitation control.

Occupational Exposure among Electronic Repair Workers in Ghana.

Electronic repair workers may be exposed to lead, mercury, cadmium and other elements including rare earth elements used in electronic equipment. In this study, repair work took place in small repair shops where, e.g., televisions, radios, video players, compact discs and computers were repaired. Personal full-shift air samples of particulate matter were collected among 64 electronic repair workers in Kumasi (Ghana) and analysed for 29 elements by inductively coupled plasma mass spectrometry. Results showed that air concentrations of all elements were low. The highest air concentration was measured for iron with a geometric mean concentration and geometric standard deviation of 6.3 ± 0.001 µg/m3. The corresponding concentration of Pb and Hg were 157 ± 3 ng/m3 and 0.2 ± 2.7 ng/m3, respectively. The cerium concentration of 5 ± 2 ng/m3 was the highest among the rare earth elements. Source apportionment with ranked principal component analysis indicated that 63% of the variance could be explained by the repair and soldering of electronic components such as batteries, magnets, displays and printed circuit boards. An association between concentrations of lead in the workroom air and lead in whole blood was found (Pearson’s correlation coefficient r = 0.42, p < 0.001). There was, however, no statistically significant difference between whole blood lead concentrations in the workers and references indicating that lead did not exclusively originate from occupational exposure.

High-efficiency removal of benzene vapor using activated carbon from Althaea officinalis L. biomass as a lignocellulosic precursor.

Benzene is a primary air pollutant commonly found widespread in the indoor environment. It has always been a research focus on the environment due to the causes of significant human health concerns. It has been widely utilized in the synthesis of solvent production, which can rarely be found in high concentrations in outdoor air or high amounts in indoor air, depending on its sources. It is aimed to remove different initial benzene concentrations (from 5 to 1500ppm) with the production of activated carbon as an excellent adsorbent with a high surface area to be used in these situations. Lignocellulosic wastes have great potential for activated carbon for their advantages (abundant, recycled, and low-cost materials, etc.). This study aimed to evaluate biowaste material for activated carbon production from Althaea officinalis L. biomass by chemical activation (H2SO4, LiOH, and ZnCl2) at temperatures between 500 and 900°C. Newly developed powdered activated carbons (Ao-ACs) are also tabulated as Ao-AC1-45 for easy reference. Benzene vapor was collected into Tenax TA® tubes by automatic thermal desorption in conjunction with a capillary gas chromatography-mass spectrometry (TD-GC/MS). The significant surface area and production yield of Ao-ACs were obtained at 1424 m2/g (Ao-AC43) and up to 40.32%, respectively. The maximum gas-phase benzene adsorption capacity was 140mg/g at 270min. This research has focused on adsorption gas-phase benzene removal onto Ao-ACs as a low-cost adsorbent from the Althaea officinalis L. biomass. Conspicuously, more study is needed to perform the enhanced adsorption of airborne pollutants capacity with inexpensive activated carbon from waste biomass materials.

Innovative method for CO2 fixation and storage

The concentration of CO2 in Earth’s atmosphere has been gradually increasing since the Industrial Revolution, primarily as a result of the use of fossil fuels as energy sources. Although coal and oil have been vital to the development of modern civilization, it is now recognized that atmospheric CO2 levels must be reduced to avoid the serious effects of climate change, including natural disasters. Consequently, there is currently significant interest in developing suitable methods for the fixation of CO2 in the air and in exhaust gases. The present work demonstrates a simple yet innovative approach to the chemical fixation of extremely low and very high CO2 concentrations in air, such as might result from industrial sources. This process is based on the use of aqueous solutions of the water-soluble compounds NaOH and CaCl2, which react with CO2 to produce the harmless solids CaCO3 (limestone) and NaCl (salt) via intermediates such as NaHCO3 and Na2CO3. The NaCl generated in this process can be converted back to NaOH via electrolysis, during which H2 (which can be used as a clean energy source) and Cl2 are produced simultaneously. Additionally, sea water contains both NaCl and CaCl2 and so could provide a ready supply of these two compounds. This system provides a safe, inexpensive approach to simultaneous CO2 fixation and storage.

Spatiotemporal Variations and Influent Factors of Tropospheric Ozone Concentration over China Based on OMI Data

Spatiotemporal distribution of atmospheric pollutants has been a hot topic in the field of environmental science in recent years. Rapid economic development, urbanization, and industrialization have resulted in a significant increase in ozone emissions, and China is facing the issue of air pollution with high ozone concentrations in the ambient air. The Aura ozone monitoring instrument (OMI), can provide long-term and large-scale dynamic monitoring of tropospheric column ozone (TCO). The TCO concentrations over China were extracted and analyzed from 2005 to 2019. The results showed that the spatiotemporal distribution of ozone concentration decreased from northeast to southeast in China. The seasonal variations of ozone concentration were spring’s concentration is greater than winter’s concentration, winter’s concentration is greater than summer’s concentration, summer’s concentration is greater than autumn’s concentration. The monthly variation showed a cyclical trend, with low values observed from June to November and high values from December to May. In addition, the spatiotemporal distribution of ozone concentration was affected by natural factors and anthropogenic factors. Regarding natural factors, TCO concentration was positively correlated with temperature, wind field, and vegetation coverage, but negatively with precipitation in southwest China. Regarding anthropogenic factors, TCO concentration showed a significant positive correlation with regional GDP, oxides of nitrogen (NOx), and volatile organic compounds (VOCs) in most areas of China. Clustering of backward air trajectories revealed that northwest and southeast airflows led to a higher TCO concentration in northeast China. These further indicate that the variation of TCO concentration was affected by many factors, but temperature, wind field, and the emissions of NOx and VOCs were the key factors.

Passive air sampler-derived concentrations and carcinogenic potential of PAHs in oil/gas production city (Macaé, Brazil)

Urban centers cause atmospheric pollution and suffer the most from their emissions. Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic substances (PTS) that can be air transported at urban sites and impact human health, causing skin allergies, respiratory diseases, and cancer. Macaé is a southeastern Brazilian coastal city that had an intense process of urbanization and population growth due to the installation of oil companies in the 1970s. The study aimed to evaluate Macaé's air quality regarding atmospheric PAH occurrence, measured using polyurethane foam passive air samplers (PUF-PAS). PUF disks were deployed along environmental gradients during the 2018–2019 spring/summer in Macaé city and its surroundings. In total, 22 individual PAHs were analyzed by gas chromatography coupled with mass spectrometry. Total PAH air concentrations ranged from 0.3 to 3.3 ng.m-3, pointing out three- to four-membered ring compounds as the most abundant (76%). Among them, phenanthrene, anthracene, and fluoranthene had the highest air concentrations, especially at sampling sites where fossil fuel combustion seemed more prominent. Compared to other cities worldwide, the lower PAH air levels reported in this study may be linked to the influence of marine air masses. As the most carcinogenic PAH compound is benzo[a]pyrene, the results are also given in benzo[a]pyrene-equivalent (BaPeq). BaPeq ranged from 0.02 to 0.10 ng.m-3. This study indicated an environmental trend along urban-industry-background spatial transects. Even though a prominent marine air mass might contribute to efficient air pollution dispersion, in urban/industrial areas, human exposure to carcinogenic chemicals is higher, probably due to local PAH sources inside the urban perimeter of Macaé.

Emerging and legacy flame retardants in indoor air and dust samples of Tarragona Province (Catalonia, Spain)

Flame retardants (FRs) are widely used in consumer products including furniture foam and electronic equipment such as computers, monitors and TVs. Over time, FRs can easily migrate into the surrounding environments. Since brominated FRs (BFRs) has been determined of high concern due to their environmental persistence, bioaccumulation and potential toxicity, novel FRs have emerged. The present study was aimed at identifying and quantifying the indoor levels of 41 legacy and novel FRs, which include 20 OPFRs and 21 HFRs (8 PBDEs, 3 HBCDDs, 5 NBFRs and 5 DECs) in Tarragona Province (Catalonia, Spain). The results have confirmed the presence of both legacy and novel FRs in air and dust of homes, schools and offices. To the best of our knowledge, this is the first European study measuring OPFRs at office environments and also confirming the presence of the following OPFRs: TEP, TCIPP, T2IPPP, TPPO, DCP, TMCP and B4IPPPP in indoor air, even some of them at high levels. OPFRs in general and TCIPP in particular showed high concentrations in air (94,599 pg/m3 and 72,281 pg/m3, respectively) and dust (32,084 ng/g and 13,496 ng/g, respectively) samples collected in indoor environments. HBCDDs were found at high levels in dust (32,185 ng/g), whereas the presence of PBDEs and DECs were low in both matrices (<160 pg/m3 in air and <832 ng/g in dust). NBFRs showed higher levels than the two legacy FRs groups, which is supported by the current restrictions of these FRs (640 pg/m3 in air and 1291 ng/g in dust). Samples of schools had significantly lower levels of NBFRs, but significantly higher concentrations of HFRs in air than in home samples, while dust levels of HFRs were significantly lower than those in samples of offices. Regarding human health risks, the current assessment suggests that those derived from exposure to FRs were lower -although close- to assumable risks, evidencing the potential of FRs for non-carcinogenic and carcinogenic risks, mainly due to the exposure to TCIPP, which was the main contributor together with ΣHBCDDs and also EHDPP.

Application of Chemical Sensors and Olfactometry Method in Ecological Audits of Degraded Areas.

Mineral excavation is a common process throughout the world. The open pits remaining after the closure of a mine require well-considered and meticulous reclamation activities aimed at restoring the environmental properties of a given area. The inspections carried out in Poland indicate numerous irregularities in implementing the reclamation process. The research in this study was conducted in six measurement series and includes both chemical and olfactometry determinations by devices: multisensor portable gas detector and field olfactometer. Statistical analysis of the results obtained show high concentrations in ambient air of both chemical compounds (NH3, VOCs, H2S, CH3SH) and odour, excluding the possibility of occurrence in the pit of only waste types contained in the administrative decision on reclamation. In addition to the unpleasant odour, the listed compounds can have dangerous effects on the health and life of living organisms. This paper presents a suitable method of control and detection of irregularities in the conducted processes. The main advantage is the relatively low cost of purchasing sensors and field olfactometers compared to other devices, and the possibility to test the polluted air in situ, without the risk of chemical processes occurring during transport of gas samples to the laboratory.

Protecting children from tobacco-related harm in private vehicles

Protecting children from tobacco-related harm in private vehicles

Insights into sources and occurrence of oxy- and nitro-PAHs in the alberta oil sands region using a network of passive air samplers

Mining-related activities in the Alberta Oil Sands Region (AOSR) are known to emit polycyclic aromatic hydrocarbons (PAHs) and related compounds to ambient air. This is a concern due to the toxicity of PAHs, including their transformation products such as nitrated (NPAHs) and oxygenated (OPAHs) PAHs. This is the first study that provided a more extensive outlook into the sources, occurrence in air, and spatial and seasonal patterns of NPAHs and OPAHs in the AOSR by using passive air sampling. A sampling campaign from 2013 to 2016 revealed concentrations of NPAHs that were much lower than those of OPAHs. The highest concentrations of NPAHs were concentrated in the region associated with extensive mining activities, with ∑NPAH concentrations ranging from 20 to 250 pg/m3. Within the oil sands (OS) mineable area, NPAHs associated with primary release appear more commonly, while NPAHs produced via oxidative transformation are predominant outside of this area. The concentrations of ∑OPAH ranged from 400 to 2400 pg/m3, with the highest air concentrations in the region located south of the main OS activity zone, with peak concentrations attributed to a 2016 forest fire event. Uptake of PAHs from ambient air and their subsequent conversion to generate OPAHs is believed to play an important role in wildfire emissions of OPAHs. The seasonal trend investigation was inconclusive, with NPAHs slightly higher during the winter, while OPAHs were slightly elevated during summer. A preliminary comparison of ambient concentrations of OPAHs and NPAHs in the AOSR to measurements in the Greater Toronto Area revealed a similar range of concentrations, but also a unique presence of certain NPAHs such as 4-nitrobiphenyl, 2-nitrodibenzothiophene, 2,8-dinitrodibenzothiophene and 6-nitrobenzo-(a)-pyrene. This indicates that AOSR might have its own NPAH profile – creating the need to better understand associated NPAH toxicity and propensity for long range transport.

Моделирование загрязнения тонкодисперсными взвешенными частицами атмосферного воздуха промышленного города

The paper deals with the quantification of fine particulate matter (PM10) dispersion in atmospheric air of an industrial city using the AERMOD model by an example of Zhlobin (the Gomel oblast, Belarus). Model input data and procedures for the emission inventory and obtaining spatially distributed estimates are described. Emissions and dispersion of PM10 from the main categories of sources are considered, including industrial facilities, road and off-road mobile sources, domestic sector, and agriculture. It is shown that the main contribution to high PM10 concentrations in atmospheric air is made by industrial enterprises, the domestic sector, and road transport. The spatial pattern of urban air pollution is described. The simulation results are compared with the results of PM10 measurements at the monitoring site, their satisfactory consistency is demonstrated.