Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Applied Sciences applsci	2.5	5.3	2011	17.8 Days	CHF 2400
Atmosphere atmosphere	2.5	4.6	2010	15.8 Days	CHF 2400
Journal of Clinical Medicine jcm	3.0	5.7	2012	17.3 Days	CHF 2600
Pollutants pollutants	-	-	2021	28.9 Days	CHF 1000

17 pages, 5325 KiB

Open AccessArticle

Impact of COVID-19 Mobility Changes on Air Quality in Warsaw

by Artur Badyda, Andrzej Brzeziński, Tomasz Dybicz, Karolina Jesionkiewicz-Niedzińska, Piotr Olszewski, Beata Osińska, Piotr Szagała and Dominika Mucha

Appl. Sci. 2022, 12(15), 7372; https://doi.org/10.3390/app12157372 - 22 Jul 2022

Cited by 3 | Viewed by 1644

Abstract

During a pandemic, the mobility of people changes significantly from the normal situation (the number of trips made, the directions of travel and the modes of transport used). Changes in mobility depend on the scale of the pandemic threat and the scale of [...] Read more.

During a pandemic, the mobility of people changes significantly from the normal situation (the number of trips made, the directions of travel and the modes of transport used). Changes in mobility depend on the scale of the pandemic threat and the scale of the restrictions introduced and assessing the impact of these changes is not straightforward. This raises the question of the social cost of changes in mobility and their impact on the environment, including air quality. The article shows that it is possible to determine this impact using big data from mobile operators’-SIM card movements and data from air quality monitoring stations. Data on SIM card movements allows for reconstructing the state of the transport system before and during the different phases of a pandemic. The changes in mobility of people determined in this way can be related to the results of measurements of pollutant concentrations in the air. In this way, it is possible to identify links between mobility changes and air quality. The article presents the extent (in relation to the state without the pandemic) of changes in the mobility of the population during the pandemic and the related impact on air quality using the example of Warsaw. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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17 pages, 4127 KiB

Open AccessArticle

Effectiveness of the National Pollutant Release Inventory as a Policy Tool to Curb Atmospheric Industrial Emissions in Canada

by Tony R. Walker

Pollutants 2022, 2(3), 289-305; https://doi.org/10.3390/pollutants2030019 - 1 Jul 2022

Cited by 3 | Viewed by 2712

Abstract

To curb greenhouse gas emissions and reduce atmospheric pollutants in Canada, many pieces of environment legislation are targeted at reducing industrial emissions. Traditional regulation prescribes penalties through fines to discourage industries from polluting, but, in the past two decades, alternative forms of environmental [...] Read more.

To curb greenhouse gas emissions and reduce atmospheric pollutants in Canada, many pieces of environment legislation are targeted at reducing industrial emissions. Traditional regulation prescribes penalties through fines to discourage industries from polluting, but, in the past two decades, alternative forms of environmental regulation, such as the National Pollutant Release Inventory (NPRI), have been introduced. NPRI is an information management tool which requires industries to self-report emissions data based on a set of guidelines determined by Environment and Climate Change Canada, a federal agency. The tool works to inform the public regarding industry emissions and provides a database that can be analyzed by researchers and regulators to inform emissions trends in Canada. These tools have been successful in other jurisdictions (e.g., United States and Australia). However, research assessing the U.S. Toxic Release Inventory suggests there are fundamental weaknesses in the self-reported nature of the data and incidences of under-reporting. This preliminary study aimed to explore NPRI in Canada and test its effectiveness against the National Air Pollutant Surveillance Network (NAPS), an air quality monitoring program administered by the federal government. While instances of under-reporting were undetected, this study identified areas of weakness in the NPRI tool and instances of increasing emissions across various industrial sectors in Canada. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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11 pages, 3099 KiB

Open AccessArticle

Ambient Size-Segregated Particulate Matter Characterization from a Port in Upstate New York

by Omosehin D. Moyebi, Brian P. Frank, Shida Tang, Gil LaDuke, David O. Carpenter and Haider A. Khwaja

Atmosphere 2022, 13(6), 984; https://doi.org/10.3390/atmos13060984 - 18 Jun 2022

Cited by 2 | Viewed by 2251

Abstract

Air pollution impacts human health and the environment, especially in urban cities with substantial industrial activities and vehicular traffic emissions. Despite increasingly strict regulations put in place by regulatory agencies, air pollution is still a significant environmental problem in cities across the world. [...] Read more.

Air pollution impacts human health and the environment, especially in urban cities with substantial industrial activities and vehicular traffic emissions. Despite increasingly strict regulations put in place by regulatory agencies, air pollution is still a significant environmental problem in cities across the world. The objective of this study was to evaluate the environmental pollution from stationary and mobile sources using real-time monitoring and sampling techniques to characterize size-segregated particulate matter (PM), black carbon (BC), and ozone (O₃) at the Port of Albany, NY. Air pollution monitoring was carried out for 3 consecutive weeks under a 24-hour cycle in 2018 at the New York State Department of Environmental Conservation (NYSDEC) site within the Port. Sampling was done with an AEROCET 531, optical particle sizer (OPS), ozone monitor, and MicroAeth AE51. Higher mass and number concentrations of size-segregated particles were observed during the daytime. PM_2.5 and PM₁₀ concentrations ranged from 1 to 271 micrograms per cubic meter (µg/m³) and 1 to 344 µg/m³, respectively. While these values do not exceed the level of the USEPA 24-hour standards, frequent sharp peaks were observed at higher concentrations. Size-segregated PM at sizes 0.3 µm and 0.374 µm recorded maximum concentrations of 101,631 particle number per cubic centimeter (#/cm³) and 43,432 #/cm³, respectively. Wide variations were observed in the particle number concentrations for 0.3 µm, 0.374 µm, and 0.465 µm sizes, which ranged from 1521 to 101,631 #/cm³; 656 to 43,432 #/cm³; and 311 to 29,271 #/cm³, respectively. BC concentration increased during morning and evening rush hours with the maximum concentration of 11,971 ng/m³ recorded at 8:00 AM. This suggests that mobile sources are the primary contributor to anthropogenic sources of BC within the Port. Episodic elevations in the concentrations of size-segregated PM and BC confirmed the contribution of industrial and vehicular activities around the Port of Albany. This study underscores the importance of measuring particles on a size-segregated basis in order to more fully understand the contributions of the multiple sources present within and surrounding a port environment. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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17 pages, 8828 KiB

Open AccessArticle

A Case Analysis of Dust Weather and Prediction of PM₁₀ Concentration Based on Machine Learning at the Tibetan Plateau

by Changrong Tan, Qi Chen, Donglin Qi, Liang Xu and Jiayun Wang

Atmosphere 2022, 13(6), 897; https://doi.org/10.3390/atmos13060897 - 1 Jun 2022

Cited by 6 | Viewed by 2239

Abstract

Dust weather is common and disastrous at the Tibetan Plateau. This study selected a typical case of dust weather and analyzed its main development mechanism in the northeast of the Tibetan Plateau, then applied six machine learning methods and a time series regression [...] Read more.

Dust weather is common and disastrous at the Tibetan Plateau. This study selected a typical case of dust weather and analyzed its main development mechanism in the northeast of the Tibetan Plateau, then applied six machine learning methods and a time series regression model to predict PM₁₀ concentration in this area. The results showed that: (1) The 24-h pressure change was positive when the front intruded on the surface; convergence of vector winds with a sudden drop in temperature and humidity led by a trough on 700 hPa; a “two troughs and one ridge” weather situation appeared on 500 hPa while the cold advection behind the trough was strong and a cyclone vorticity was formed in the east of Inner Mongolia. (2) The trajectory of air mass from the Hexi Corridor was the main air mass path influencing Xining City, in this case, since a significant lag in the peak of PM₁₀ concentration appeared in Xining City when compared with Zhangye City. (3) The Multiple Linear Regression was not only timely and effective in predicting the PM₁₀ concentration but had great abilities for anticipating the transition period of particle concentration and the appearance date of maximum values in such dust weather. (4) The M_A and M_P in the clean period were much lower than that in the dust period; the PM₁₀ of Zhangye City as an eigenvalue played an important role in predicting the PM₁₀ of Xining City even in clean periods. Different from dust periods, the prediction effect of Random Forest Optimized by Bayesian hyperparameter was superior to Multiple Linear Regression in clean periods. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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17 pages, 7455 KiB

Open AccessArticle

Application of the Gaussian Model for Monitoring Scenarios and Estimation of SO₂ Atmospheric Emissions in the Salamanca Area, Bajío, Mexico

by Amanda Enrriqueta Violante Gavira, Wadi Elim Sosa González, Ramón de Jesús Pali Casanova, Marcial Alfredo Yam Cervantes, Manuel Aguilar Vega, Javier Chacha Coto, José del Carmen Zavala Loría, Luis Alonso Dzul López and Eduardo García Villena

Atmosphere 2022, 13(6), 874; https://doi.org/10.3390/atmos13060874 - 27 May 2022

Viewed by 2537

Abstract

Population and industrial growth in Mexico’s Bajío region demand greater electricity consumption. The production of electricity from fuel oil has severe implications on climate change and people’s health due to SO₂ emissions. This study describes the simulation of eight different scenarios for [...] Read more.

Population and industrial growth in Mexico’s Bajío region demand greater electricity consumption. The production of electricity from fuel oil has severe implications on climate change and people’s health due to SO₂ emissions. This study describes the simulation of eight different scenarios for SO₂ pollutant dispersion. It takes into account distance, geoenvironmental parameters, wind, terrain roughness, and Pasquill–Gifford–Turner atmospheric stability and categories of dispersion based on technical information about SO₂ concentration from stacks and from one of the atmospheric monitoring stations in Salamanca city. Its transverse character, its usefulness for modeling, and epidemiological, meteorological, and fluid dynamics studies, as suggested by the models approved by the Environmental Protection Agency (EPA), show a maximum average concentration of 399 µg/m³, at an average distance of 1800 m. The best result comparison in the scenarios was scenery 8. Maximum nocturnal dispersion was shown at a wind speed of 8.4 m/s, and an SO₂ concentration of 280 µg/m³ for stack 4, an atypical situation due to the geography of the city. From the validation process, a relative error of 14.7 % was obtained, which indicates the reliability of the applied Gaussian model. Regarding the mathematical solution of the model, this represents a reliable and low-cost tool that can help improve air quality management, the location or relocation of atmospheric monitoring stations, and migration from the use of fossil fuels to environmentally friendly fuels. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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18 pages, 5977 KiB

Open AccessArticle

Characterizing Air Pollution and Its Association with Emission Sources in Lahore: A Guide to Adaptation Action Plans to Control Pollution and Smog

by Mifrah Ali, Iffat Siddique and Sawaid Abbas

Appl. Sci. 2022, 12(10), 5102; https://doi.org/10.3390/app12105102 - 19 May 2022

Cited by 11 | Viewed by 6402

Abstract

Lahore, the home of 11 million people, is one of the most polluted cities in the world. Pollution causes deaths, birth defects, and years of life lost. This study’s real-time data analysis of the air quality index (AQI) showed that air pollution remained [...] Read more.

Lahore, the home of 11 million people, is one of the most polluted cities in the world. Pollution causes deaths, birth defects, and years of life lost. This study’s real-time data analysis of the air quality index (AQI) showed that air pollution remained “unhealthy for everyone” for 54% of the time, and “unhealthy for sensitive groups” for 88% of the time, during the last three years (June 2019–September 2021). The air quality index (AQI) value in Lahore reached 175 µg/m³ in 2021. This alarmingly hazardous air situation was analyzed by selecting fourteen sites based on the provenance of industrialization and tailpipe emissions. An analysis of remote sensing data for these sites was performed, in addition to field surveys, to identify the relationship between pollutant concentration and on-ground current practices. The key primary and secondary air pollutants selected for analysis were carbon monoxide (CO), nitrogen dioxide (NO₂), sulphur dioxide (SO₂), aerosol optical depth (AOD), methane (CH₄), and formaldehyde (HCHO). The assessment was carried out for the study period of July 2018 to April 2021. The real-time AQI was plotted against each pollutant’s monthly concentration, which showed a significant positive correlation of AQI with SO₂, NO₂, and CO. A plotting of the percentage contribution of each pollutant with its emission sources highlighted the main pollutant to take action to reduce, as a priority on those particular sites. The pollutant hotspot within each economic activity was also determined. Assessments showed that the AQI value was higher on weekends than on weekdays. These findings can help to develop smart adaptation action plans for immediate implementation, to dilute the current environmental risks in the city. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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11 pages, 3171 KiB

Open AccessArticle

Study on the Catalytic Decomposition Reaction of N₂O on MgO (100) in SO₂ and CO Environments

by Xiaoying Hu, Erbo Zhang, Wenjun Li, Lingnan Wu, Yiyou Zhou, Hao Zhang and Changqing Dong

Appl. Sci. 2022, 12(10), 5034; https://doi.org/10.3390/app12105034 - 16 May 2022

Cited by 1 | Viewed by 1630

Abstract

To study the role of MgO in the reduction of N₂O in circulating fluidized bed boilers, density functional theory was used to evaluate heterogeneous decomposition. The interference of SO₂ and CO on N₂O was considered. N₂O [...] Read more.

To study the role of MgO in the reduction of N₂O in circulating fluidized bed boilers, density functional theory was used to evaluate heterogeneous decomposition. The interference of SO₂ and CO on N₂O was considered. N₂O on MgO (100) is a two-step process that includes O transfer and surface recovery processes. The O transfer process is the rate-determining step with barrier energy of 1.601 eV, while for the Langmuir–Hinshelwood and Eley–Rideal surface recovery mechanisms, the barrier energies are 0.840 eV and 1.502 eV, respectively. SO₂ has a stronger interaction with the surface-active O site than that of N₂O. SO₂ will occupy the active site and hinder N₂O decomposition. CO cannot improve the catalysis of MgO (100) for N₂O because O transfer is the rate-determining step. Compared with homogeneous reduction by CO, MgO has a limited catalytic effect on N₂O, where the barrier energy decreases from 1.691 eV to 1.601 eV. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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15 pages, 3652 KiB

Open AccessReview

A Brief Review of Formaldehyde Removal through Activated Carbon Adsorption

by Yu-Jin Kang, Hyung-Kun Jo, Min-Hyeok Jang, Xiaoliang Ma, Yukwon Jeon, Kyeongseok Oh and Joo-Il Park

Appl. Sci. 2022, 12(10), 5025; https://doi.org/10.3390/app12105025 - 16 May 2022

Cited by 30 | Viewed by 12324

Abstract

Formaldehyde is a highly toxic indoor pollutant that can adversely impact human health. Various technologies have been intensively evaluated to remove formaldehyde from an indoor atmospheres. Activated carbon (AC) has been used to adsorb formaldehyde from the indoor atmosphere, which has been commercially [...] Read more.

Formaldehyde is a highly toxic indoor pollutant that can adversely impact human health. Various technologies have been intensively evaluated to remove formaldehyde from an indoor atmospheres. Activated carbon (AC) has been used to adsorb formaldehyde from the indoor atmosphere, which has been commercially viable owing to its low operational costs. AC has a high adsorption affinity due to its high surface area. In addition, applications of AC may be diversified by the surface modification. Among the different surface modifications for AC, amination treatments of AC have been reported and evaluated. Specifically, the amine functional groups of the amine-treated AC have been found to play an important role in the adsorption of formaldehyde. Surface modifications of AC by impregnating and/or grafting the amine functional groups onto the AC surface have been reported in the literature. The impregnation of the amine-containing species on AC is mainly achieved by physical interaction or H-bond of the amines to the AC surface. Meanwhile, the grafting of the amine functional groups is mainly conducted through chemical reactions occurring between the amines and the AC surface. Herein, the carboxyl group, as a representative functional group for grafting on the surface of AC, plays a key role in the amination reactions. A qualitative comparison of amination chemicals for the surface modification of AC has also been discussed. Thermodynamics and kinetics for adsorption of formaldehyde on AC are firstly reviewed in this paper, and then the major factors affecting the adsorptive removal of formaldehyde over AC are highlighted and discussed in terms of humidity and temperature. In addition, new strategies for amination, as well as the physical modification option for AC application, are proposed and discussed in terms of safety and processability. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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15 pages, 2295 KiB

Open AccessArticle

Source Apportionment and Toxic Potency of PM_2.5-Bound Polycyclic Aromatic Hydrocarbons (PAHs) at an Island in the Middle of Bohai Sea, China

by Lin Qu, Lin Yang, Yinghong Zhang, Xiaoping Wang, Rong Sun, Bo Li, Xiaoxue Lv, Yuehong Chen, Qin Wang, Chongguo Tian and Ling Ji

Atmosphere 2022, 13(5), 699; https://doi.org/10.3390/atmos13050699 - 28 Apr 2022

Cited by 3 | Viewed by 1938

Abstract

Polycyclic aromatic hydrocarbons (PAHs) have attracted more attention because of their high atmospheric concentration and toxicity in recent decades. In this study, a total of 60 PM_2.5 samples were collected from Beihuangcheng Island in Bohai Sea, China, from August 2017 to March [...] Read more.

Polycyclic aromatic hydrocarbons (PAHs) have attracted more attention because of their high atmospheric concentration and toxicity in recent decades. In this study, a total of 60 PM_2.5 samples were collected from Beihuangcheng Island in Bohai Sea, China, from August 2017 to March 2018 for analyzing 16 congeners of PAHs (Σ₁₆PAHs). Sources of PAHs were apportioned by a positive matrix factorization (PMF) model and the carcinogenic risk due to exposure to the PAHs was estimated by the toxicity equivalent of BaP (BaPeq). The results showed that the average concentration of Σ₁₆PAHs was 35.3 ± 41.8 ng/m³. The maximum concentration of Σ₁₆PAHs occurred in winter, followed by spring and autumn, and summer. The PMF modeling apportioned the PAHs into four sources, coal combustion, biomass burning, vehicle exhaust, and petroleum release, contributing 43.1%, 25.8%, 24.7%, and 6.39%, respectively. The average ΣBaPeq concentration was 2.32 ± 4.95 ng/m³ during the sampling period, and vehicle exhaust was the largest contributor. The finding indicates that more attention should be paid to reduce the emissions from coal combustion and vehicle exhaust because they were the largest contributors to the PAH concentration in PM_2.5 and ΣBaPeq concentration, respectively. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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14 pages, 4889 KiB

Open AccessArticle

Research on the Spatial Heterogeneity and Influencing Factors of Air Pollution: A Case Study in Shijiazhuang, China

by Yuan Sun, Jian Zeng and Aihemaiti Namaiti

Atmosphere 2022, 13(5), 670; https://doi.org/10.3390/atmos13050670 - 22 Apr 2022

Cited by 5 | Viewed by 2476

Abstract

Rapid urbanization causes serious air pollution and constrains the sustainable development of society. The influencing factors of urban air pollution are complex and diverse. Multiple factors act together to interact in influencing air pollution. However, most of the existing studies on the influencing [...] Read more.

Rapid urbanization causes serious air pollution and constrains the sustainable development of society. The influencing factors of urban air pollution are complex and diverse. Multiple factors act together to interact in influencing air pollution. However, most of the existing studies on the influencing factors of air pollution lack consideration of the interaction mechanisms between the factors. Using multisource data and geographical detectors, this study analyzed the spatial heterogeneity characteristics of air pollution in Shijiazhuang City, identified its main influencing factors, and analyzed the interaction effects among these factors. The results of spatial heterogeneity analysis indicate that the distribution of aerosol optical depth (AOD) has obvious agglomeration characteristics. High agglomeration areas are concentrated in the eastern plain areas, and low agglomeration areas are concentrated in the western mountainous areas. Forests (q = 0.620), slopes (q = 0.616), elevation (q = 0.579), grasslands (q = 0.534), and artificial surfaces (q = 0.506) are the main individual factors affecting AOD distribution. Among them, natural factors such as topography, ecological space, and wind speed are negatively correlated with AOD values, whereas the opposite is true for human factors such as roads, artificial surfaces, and population. Each factor can barely affect the air pollution status significantly alone, and the explanatory power of all influencing factors showed an improvement through the two-factor enhanced interaction. The associations of elevation ∩ artificial surface (q = 0.625), elevation ∩ NDVI (q = 0.622), and elevation ∩ grassland (q = 0.620) exhibited a high explanatory power on AOD value distribution, suggesting that the combination of multiple factors such as low altitude, high building density, and sparse vegetation can lead to higher AOD values. These results are conducive to the understanding of the air pollution status and its influencing factors, and in future, decision makers should adopt different strategies, as follows: (1) high-density built-up areas should be considered as the key areas of pollution control, and (2) a single-factor pollution control strategy should be avoided, and a multi-factor synergistic optimization strategy should be adopted to take full advantage of the interaction among the factors to address the air pollution problem more effectively. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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17 pages, 1184 KiB

Open AccessArticle

Can Environmental Regulation Reduce Urban Haze Concentration from the Perspective of China’s Five Urban Agglomerations?

by Xinfei Li, Yueming Li, Chang Xu, Jingyang Duan, Wenqi Zhao, Baodong Cheng and Yuan Tian

Atmosphere 2022, 13(5), 668; https://doi.org/10.3390/atmos13050668 - 22 Apr 2022

Cited by 2 | Viewed by 1527

Abstract

Based on the perspective of urban agglomerations, this paper explores the impact mechanism of environmental regulation on haze, and tries to find the most suitable environmental regulation intensity for haze control in urban agglomerations. This paper uses the fixed-effect model and panel threshold [...] Read more.

Based on the perspective of urban agglomerations, this paper explores the impact mechanism of environmental regulation on haze, and tries to find the most suitable environmental regulation intensity for haze control in urban agglomerations. This paper uses the fixed-effect model and panel threshold model to verify the effect of environmental regulations on haze concentration in 206 cities in China. A grouping test is also conducted to verify whether a regional heterogeneity arises due to different regional development levels for five urban agglomerations and non-five urban agglomerations, respectively. The results show that: (1) In the linear model, strengthening environmental regulation can reduce the haze concentration, but this effect is not significant. The effect of environmental regulation on haze control in the five major urban agglomerations is better than that in the non-five major urban agglomerations; (2) In the nonlinear model, the impact of environmental regulation on haze shows a “U” trend in the five major urban agglomerations and an inverted “U” trend in the non-five major urban agglomerations. Although the results are not significant, we can still conclude that the impact of environmental regulation on haze varies depending on the level of regional economic development. Therefore, the environmental regulation should be formulated according to local conditions; (3) In the threshold model, the impact of environmental regulation on the haze concentration in five major urban agglomerations has a threshold effect. In the five major urban agglomerations, although environmental regulation can effectively reduce haze concentration, the governance effect will weaken as the environmental regulation increases. This study plays a positive role in guiding local governments to adjust environmental regulation intensity according to local conditions and helping local environmental improvement. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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14 pages, 7093 KiB

Open AccessArticle

Atmospheric Hg Levels in Tree Barks Due to Artisanal Small-Scale Gold Mining Activity in Bunut Seberang Village in Indonesia

by Azhary Taufiq, Melya Riniarti, Endang Linirin Widiastuti, Hendra Prasetia, Slamet Budi Yuwono, Ceng Asmarahman and Tedy Rendra

Atmosphere 2022, 13(4), 633; https://doi.org/10.3390/atmos13040633 - 15 Apr 2022

Cited by 3 | Viewed by 2159

Abstract

Mercury (Hg) is a useful heavy metal; however, it is toxic to both humans and the environment. Tree bark is an excellent bioindicator, which has been proven to be effective in studying the level of atmospheric Hg contamination. This study aimed to determine [...] Read more.

Mercury (Hg) is a useful heavy metal; however, it is toxic to both humans and the environment. Tree bark is an excellent bioindicator, which has been proven to be effective in studying the level of atmospheric Hg contamination. This study aimed to determine the distribution of evaporated Hg using the total weight of Hg (THg) in tree barks in Indonesia at the artisanal and small-scale gold mining (ASGM) area of Bunut Seberang Village and Lampung University, respectively. Samples were taken using purposive sampling, based on the criteria of forestry trees at a height level of 1.3 m above ground as wide as 100 cm². The samples were analyzed by atomic absorption spectrometry and Scanning electron microscopy to determine the levels of THg and to investigate the bark structures. Results showed that the highest THg values were found in a Magnolia champaca sample (56.5 µg), followed by Swietenia mahagoni (45.8 µg) and Swietenia mahagoni (33.5 µg). All species studied showed THg levels in the tree barks at an elevation from 30 to 320 m above sea level. The Hg amounts found in the sampled barks indicated the dispersion of Hg throughout the ASGM area, which signified hazardous atmospheric conditions in the area. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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21 pages, 3854 KiB

Open AccessArticle

Characterization of Annual Air Emissions Reported by Pulp and Paper Mills in Atlantic Canada

by Gianina Giacosa, Codey Barnett, Daniel G. Rainham and Tony R. Walker

Pollutants 2022, 2(2), 135-155; https://doi.org/10.3390/pollutants2020011 - 8 Apr 2022

Cited by 9 | Viewed by 6908

Abstract

The pulp and paper industry is a major contributor to water and air pollution globally. Pulp and paper processing is an intensive energy consuming process that produces multiple contaminants that pollute water, air, and affect ecological and human health. In Canada, the National [...] Read more.

The pulp and paper industry is a major contributor to water and air pollution globally. Pulp and paper processing is an intensive energy consuming process that produces multiple contaminants that pollute water, air, and affect ecological and human health. In Canada, the National Pollutant Release Inventory (NPRI) is used to assess the release of air pollutants into the atmosphere from industrial facilities (including pulp and paper mills) and provides a repository of annual emissions reported by individual facilities. This study compared annual air emissions of carbon monoxide, nitrogen oxides, total particulate matter (TPM), PM_2.5, PM₁₀, sulphur dioxide, and volatile organic compounds from nine different pulp and/or paper mills in Atlantic Canada from three provinces (Nova Scotia, New Brunswick, and Newfoundland and Labrador) between 2002 and 2019. Results revealed that annual releases were several orders of magnitude higher than federal reporting thresholds suggested by Environment and Climate Change Canada. Pulp mills emit higher pollutant loads than those producing paper. The highest exceedance of a reporting threshold was for particulate matter (PM_2.5) at Northern Pulp in Nova Scotia. The emissions of PM_2.5 were on average (over a 17-year period) about 100,000% above the reporting threshold of 0.3 tonnes per year. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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21 pages, 7277 KiB

Open AccessArticle

Development of Vehicle Emission Model Based on Real-Road Test and Driving Conditions in Tianjin, China

by Yi Zhang, Ran Zhou, Shitao Peng, Hongjun Mao, Zhiwen Yang, Michel Andre and Xin Zhang

Atmosphere 2022, 13(4), 595; https://doi.org/10.3390/atmos13040595 - 7 Apr 2022

Cited by 6 | Viewed by 2568

Abstract

Based on the demand of vehicle emission research and control, this paper presents the development of a portable vehicle measurement system (PEMS) based on SEMTECH-DS and ELPI+, the vehicle emission tests carried out on actual roads, and the data obtained for the establishment [...] Read more.

Based on the demand of vehicle emission research and control, this paper presents the development of a portable vehicle measurement system (PEMS) based on SEMTECH-DS and ELPI+, the vehicle emission tests carried out on actual roads, and the data obtained for the establishment and validation of a vehicle emission model. Based on the results of the vehicle emission test, it was found that vehicle driving conditions (speed, acceleration, vehicle specific power (VSP), etc.) had a significant impact on the pollutant emission rate. In addition, local driving cycles were generated and the frequency distribution of VSP-bin under different cycles was analyzed. Then, through the establishment of an emission rate database, calculation of emission factors and validation of the emission model, a vehicle emission model based on actual road driving conditions was developed by taking VSP as the “surrogate variables”. It showed that the emission factor model established in this study could better reflect the vehicle transient emissions on the actual road with high accuracy and local adaptability. Through this study, it could be found that due to the great differences in traffic development modes and vehicle driving conditions in different cities in China, the emission model based on driving conditions was a better choice to carry out the research on vehicle emission in Chinese cities. Compared with directly applying international models or quoting the recommended values of relevant macroscopic guidelines, the emission factor model established in this study, using actual driving conditions, could better reflect the vehicle transient emissions on the actual road with high accuracy and local adaptability. In addition, due to the rapid development of China’s urban traffic and the rapid change of driving conditions, it was of great significance to regularly update China’s urban conditions to improve the accuracy of the model, no matter which model was chosen. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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13 pages, 2433 KiB

Open AccessArticle

Analysis of the Diurnal Changes in the Water-Soluble Ion Concentration in Wuhan between 2016 and 2019

by Yingying Sun, Jinhui Zhao, Chao He, Zhouxiang Zhang, Nan Chen, Jiaqi Hu, Huanhuan Liu and Xinlei Wang

Atmosphere 2022, 13(4), 582; https://doi.org/10.3390/atmos13040582 - 4 Apr 2022

Cited by 1 | Viewed by 1970

Abstract

This study uses online monitoring data from the Hubei Environmental Monitoring Center’s Atmospheric Compound Pollution Automatic Monitoring Station from 2016 to 2019 to analyze the diurnal changes in the concentration of water-soluble ions in particulate matter in Wuhan. During the study period, the [...] Read more.

This study uses online monitoring data from the Hubei Environmental Monitoring Center’s Atmospheric Compound Pollution Automatic Monitoring Station from 2016 to 2019 to analyze the diurnal changes in the concentration of water-soluble ions in particulate matter in Wuhan. During the study period, the concentrations of SO₂, NO₃⁻, and SO₄²⁻ changed significantly, while those of NH₄⁺, NH₃, and Ca²⁺ exhibited minimal differences. SO₂ and NO₃⁻ showed an annually increasing trend, while NH₄⁺ and SO₄²⁻ exhibited an annually decreasing trend. The ion concentration was generally higher in the winter and spring and lower in the summer and autumn. The concentration of water-soluble ions was generally higher during the day than at night. However, the “weekend effect” on the change in ion concentrations was substantial and higher during the day than at night. This effect was the strongest for NO₃⁻ and the weakest for NH₃. These changes in the weekend effect of water-soluble ions in particulate matter clearly revealed the impact of periodic human activities on atmospheric pollution. Taken together, the results of this novel study reveal the diurnal pollution characteristics and “weekend effect” of water-soluble ions with high concentrations in atmospheric aerosols in Wuhan over a four-year period, thus providing relevant insights for Wuhan’s atmospheric mitigation plan. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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17 pages, 9301 KiB

Open AccessArticle

Personal Exposure and Inhaled Dose Estimation of Air Pollutants during Travel between Albany, NY and Boston, MA

by Vineet Kumar Pal and Haider A. Khwaja

Atmosphere 2022, 13(3), 445; https://doi.org/10.3390/atmos13030445 - 9 Mar 2022

Cited by 2 | Viewed by 2347

Abstract

Out of eight deaths caused worldwide, one death is caused due to air pollution exposure, making it one of the top global killers. Personal exposure measurement for real-time monitoring has been used for inhaled dose estimation during various modes of workplace commuting. However, [...] Read more.

Out of eight deaths caused worldwide, one death is caused due to air pollution exposure, making it one of the top global killers. Personal exposure measurement for real-time monitoring has been used for inhaled dose estimation during various modes of workplace commuting. However, dose-exposure studies during long commutes are scarce and more information on inhaled doses is needed. This study focuses on personal exposures to size-fractionated particulate matter (PM₁, PM_2.5, PM₄, PM₇, PM₁₀, TSP) and black carbon (BC) inside a bus traveling more than 270 kms on a highway between Albany, NY and Boston, MA. Measurements were also made indoors, outdoors, and while walking in each city. Mean PM (PM₁, PM_2.5, PM₄, PM₇, PM₁₀, TSP) and mean BC concentrations were calculated to estimate the inhaled exposure dose. The highest average PM_2.5 and PM₁₀ exposures concentrations were 30 ± 12 and 111 ± 193 µg/m³, respectively, during Boston to Albany. Notably, personal exposure to BC on a bus from Albany to Boston (5483 ± 2099 ng/m³) was the highest measured during any commute. The average inhaled dose for PM_2.5 during commutes ranged from 0.018 µg/km to 0.371 µg/km. Exposure concentrations in indoor settings (average PM_2.5 = 37 ± 55 µg/m³, PM₁₀ = 78 ± 82 µg/m³, BC = 5695 ± 1774 ng/m³) were higher than those in outdoor environments. Carpeted flooring, cooking, and vacuuming all tended to increase the indoor particulate level. A high BC concentration (1583 ± 1004 ng/m³) was measured during walking. Typical concentration profiles in long-haul journeys are presented. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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10 pages, 3833 KiB

Open AccessArticle

Improvement of the Standard Chimney Electrostatic Precipitator by Dividing the Flue Gas Stream into a Larger Number of Pipes

by Juraj Trnka, Jozef Jandačka and Michal Holubčík

Appl. Sci. 2022, 12(5), 2659; https://doi.org/10.3390/app12052659 - 4 Mar 2022

Cited by 7 | Viewed by 2744

Abstract

Combustion of biomass-based solid fuels is becoming increasingly popular, especially in small heat sources. A major problem in the combustion of biomass is the increased production of emissions and especially the solid component of PM particles. Currently, the most used solution to this [...] Read more.

Combustion of biomass-based solid fuels is becoming increasingly popular, especially in small heat sources. A major problem in the combustion of biomass is the increased production of emissions and especially the solid component of PM particles. Currently, the most used solution to this problem is the application of electrostatic chimney separators, which innovations are discussed in our article. Two models of electrostatic precipitators were constructed in this work. The aim of this work was to compare the use of a standard single-pipe chimney electrostatic precipitator with a newer four-pipe variant. Eight measurements were performed on both devices with and without the use of an electrostatic precipitator, on the basis of which the separation efficiency was evaluated for both variants. The results of the measurements showed the initial value of the average PM production in the one-pipe variant decreased from 1012 to 416

mg . m^{- 3}

when using the separator, while in the use of the four-pipe variant it decreased from the starting value 342 to only 152

mg . m^{- 3}

. These results show that the improvement of the classic single-pipe separator by increasing the number of tubes significantly reduced the production of PM emissions and increased the separation efficiency from 66 to 85%. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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21 pages, 2937 KiB

Open AccessArticle

A Machine Learning-Based Ensemble Framework for Forecasting PM_2.5 Concentrations in Puli, Taiwan

by Peng-Yeng Yin, Alex Yaning Yen, Shou-En Chao, Rong-Fuh Day and Bir Bhanu

Appl. Sci. 2022, 12(5), 2484; https://doi.org/10.3390/app12052484 - 27 Feb 2022

Cited by 4 | Viewed by 2435

Abstract

Forecasting of PM_2.5 concentration is a global concern. Evidence has shown that the ambient PM_2.5 concentrations are harmful to human health, climate change, plant species mortality, etc. PM_2.5 concentrations are caused by natural and anthropogenic activities, and it is challenging [...] Read more.

Forecasting of PM_2.5 concentration is a global concern. Evidence has shown that the ambient PM_2.5 concentrations are harmful to human health, climate change, plant species mortality, etc. PM_2.5 concentrations are caused by natural and anthropogenic activities, and it is challenging to predict them due to many uncertain factors. Current research has focused on developing a new model while overlooking the fact that every single model for PM_2.5 prediction has its own strengths and weaknesses. This paper proposes an ensemble framework which combines four diverse learning models for PM_2.5 forecasting in Puli, Taiwan. It explores the synergy between parametric and non-parametric learning, and short-term and long-term learning. The feature set covers periodic, meteorological, and autoregression variables which are selected by a spiral validation process. The experimental dataset, spanning from 1 January 2008 to 31 December 2019, from Puli Township in central Taiwan, is used in this study. The experimental results show the proposed multi-model framework can synergize the advantages of the embedded models and obtain an improved forecasting result. Further, the benefit obtained by blending short-term learning with long-term learning is validated, in surpassing the performance obtained by using just single type of learning. Our multi-model framework compares favorably with deep-learning models on Puli dataset. It also shows high adaptivity, such that our multi-model framework is comparable to the leading methods for PM_2.5 forecasting in Delhi, India. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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20 pages, 1343 KiB

Open AccessReview

A Review of Air Pollution Mitigation Approach Using Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API)

by Ibironke Titilayo Enitan, Olatunde Samod Durowoju, Joshua Nosa Edokpayi and John Ogony Odiyo

Atmosphere 2022, 13(3), 374; https://doi.org/10.3390/atmos13030374 - 23 Feb 2022

Cited by 18 | Viewed by 5542

Abstract

Air pollution is a global environmental issue, and there is an urgent need for sustainable remediation techniques. Thus, phytoremediation has become a popular approach to air pollution remediation. This paper reviewed 28 eco-friendly indigenous plants based on both the air pollution tolerance index [...] Read more.

Air pollution is a global environmental issue, and there is an urgent need for sustainable remediation techniques. Thus, phytoremediation has become a popular approach to air pollution remediation. This paper reviewed 28 eco-friendly indigenous plants based on both the air pollution tolerance index (APTI) and anticipated performance index (API), using tolerance level and performance indices to evaluate the potential of most indigenous plant species for air pollution control. The estimated APTI ranged from 4.79 (Syzygium malaccense) to 31.75 (Psidium guajava) among the studied indigenous plants. One of the selected plants is tolerant, and seven (7) are intermediate to air pollution with their APTI in the following order: Psidium guajava (31.75) > Swietenia mahogany (28.08) > Mangifera indica L. (27.97) > Ficus infectoria L. (23.93) > Ficus religiosa L. (21.62) > Zizyphus Oenoplia Mill (20.06) > Azadirachta indica A. Juss. (19.01) > Ficus benghalensis L. (18.65). Additionally, the API value indicated that Mangifera indica L. ranges from best to good performer; Ficus religiosa L. and Azadirachta indica A. Juss. from excellent to moderate performers; and Cassia fistula L. from poor to very poor performer for air pollution remediation. The Pearson correlation shows that there is a positive correlation between API and APTI (R2 = 0.63), and this implies that an increase in APTI increases the API and vice versa. This paper shows that Mangifera indica L., Ficus religiosa L., and Azadirachta indica A. Juss. have good potential for sustainable reduction in air pollution for long-term management and green ecomanagement development. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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19 pages, 3610 KiB

Open AccessArticle

Effects of COVID-19-Epidemic-Related Changes in Human Behaviors on Air Quality and Human Health in Metropolitan Parks

by Wen-Pei Sung and Chun-Hao Liu

Atmosphere 2022, 13(2), 276; https://doi.org/10.3390/atmos13020276 - 7 Feb 2022

Cited by 2 | Viewed by 1572

Abstract

The outbreak of the new coronavirus pneumonia (Coronavirus disease 2019, COVID-19) created a serious impact on the lives of people around the world. Humans, affected by the COVID-19 virus, must reduce related activities to suppress the spread of this disease. However, the pandemic [...] Read more.

The outbreak of the new coronavirus pneumonia (Coronavirus disease 2019, COVID-19) created a serious impact on the lives of people around the world. Humans, affected by the COVID-19 virus, must reduce related activities to suppress the spread of this disease. However, the pandemic had a positive impact on the environment due to reduced outdoor activities. The correlation between reduced human outdoor activities and health effects was investigated in this study through two Metropolitan parks in Taichung, Taiwan. The developed low-cost air quality sensors were installed in these two parks to detect the variances in PM_2.5 concentrations during the epidemic outbreak. Experimental results indicated that PM_2.5 concentrations in these two parks were reduced from about 23.25 and 22.96 μg/m³ to 8.19 and 8.48 μg/m³, respectively, the median absolute deviations (MAD) decreased from 4.21 and 4.57 to 1.71 and 1.35, respectively after the epidemic outbreak, and the calculated standard deviation of all normal-to-normal interval (SDNN) and the ratio of low-frequency power to high-frequency (LF/HF) indicated that the drops of PM_2.5 concentrations caused the increased health-related benefits by 73.53% with the variances being low. These results showed that the PM_2.5 concentrations displayed high correlations with human activities, which also played important roles in human health effects. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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23 pages, 7718 KiB

Open AccessArticle

Poor Visibility in Winter Due to Synergistic Effect Related to Fine Particulate Matter and Relative Humidity in the Taipei Metropolis, Taiwan

by Li-Wei Lai

Atmosphere 2022, 13(2), 270; https://doi.org/10.3390/atmos13020270 - 5 Feb 2022

Cited by 6 | Viewed by 2170

Abstract

Visibility is important because it influences transportation safety. This study examined the relationships among sea–land breezes, relative humidity (RH), and the urban heat island (UHI) effect. The study also sought to understand how the synergistic effects of fine particulate matter (PM_2.5) [...] Read more.

Visibility is important because it influences transportation safety. This study examined the relationships among sea–land breezes, relative humidity (RH), and the urban heat island (UHI) effect. The study also sought to understand how the synergistic effects of fine particulate matter (PM_2.5) and RH influence visibility. Hourly meteorological, PM_2.5 concentration, and visibility data from 2016 to 2019 were obtained from government-owned stations. This study used quadratic equations, exponential functions, and multi-regression models, along with a comparison test, to analyse the relationships between these variables. While sea breezes alone cannot explain the presence of PM_2.5, UHI circulation coupled with sea breezes during winter can promote the accumulation of PM_2.5. The synergistic effects of RH, PM_2,5, and aerosol hygroscopicity exist in synoptic patterns type I and type III. PM_2.5 was negatively correlated with visibility in the winter, when the RH was 67–95% and the continental cold high-pressure (CCHP) system was over the Asian continent (type I), or when the RH was 49–89% and the CCHP had moved eastward, with its centre located beyond 125° E (type III). The synergistic predictor variable PM_2.5×RH was more important than PM_2.5 and RH individually in explaining the variation in visibility. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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18 pages, 4318 KiB

Open AccessArticle

Development and Characterization of a Time-Sequenced Cascade Impactor: Application to Transient PM_2.5 Pollution Events in Urbanized and Industrialized Environments

by Soulemane Halif Ngagine, Karine Deboudt, Pascal Flament, Marie Choël, Pierre Kulinski and Fabien Marteel

Atmosphere 2022, 13(2), 244; https://doi.org/10.3390/atmos13020244 - 31 Jan 2022

Cited by 2 | Viewed by 2804

Abstract

To set up a sampling and analysis strategy for particulate matter (PM) based on the time periods used in international standards is often inadequate for assessing the impact of day/night cycles or episodic emissions on urban air quality. To obtain a detailed physico–chemical [...] Read more.

To set up a sampling and analysis strategy for particulate matter (PM) based on the time periods used in international standards is often inadequate for assessing the impact of day/night cycles or episodic emissions on urban air quality. To obtain a detailed physico–chemical characterization of urban PM when concentrations exceed the regulatory thresholds, a new rotary cascade impactor named the Time-Resolved Atmospheric Particle Sampler (TRAPS) was designed and tested for coarse and fine particle sampling. The TRAPS implementation, coupled with Optical Particle Counter measurements, provides time-resolved samples that can be analyzed by a wide range of single-particle analysis techniques. The TRAPS theoretical design was verified experimentally. Experimental cut-off diameters of 1.32 and 0.13 µm, respectively, for coarse and fine stages, were found in good agreement with theoretical values. Additionally, good trace separation, preventing inter-sample contamination, was evidenced by Scanning Electron Microscopy (SEM). The homogeneous distribution of particles of different types over a trace was also verified. As a case study, automated SEM-EDX analysis of 2500 particles, collected during two pollution peaks of a transient PM_2.5 pollution event, revealed that individual particles’ chemical composition was influenced by local sources during the first pollution peak, and mainly transported during the second peak. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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11 pages, 257 KiB

Open AccessArticle

The Impact of Short-Term Outdoor Air Pollution on Clinical Status and Prognosis of Hospitalized Patients with Coronary Artery Disease Treated with Percutaneous Coronary Intervention

by Piotr Desperak, Aneta Desperak, Bożena Szyguła-Jurkiewicz, Piotr Rozentryt, Andrzej Lekston and Mariusz Gąsior

J. Clin. Med. 2022, 11(3), 484; https://doi.org/10.3390/jcm11030484 - 18 Jan 2022

Viewed by 1621

Abstract

Background: The aim of this study was to determine the influence of acute exposure to air pollutants on patients’ profile, short- and mid-term outcomes of hospitalized patients with coronary artery disease (CAD) treated with coronary angioplasty. Methods: Out of 19,582 patients of the [...] Read more.

Background: The aim of this study was to determine the influence of acute exposure to air pollutants on patients’ profile, short- and mid-term outcomes of hospitalized patients with coronary artery disease (CAD) treated with coronary angioplasty. Methods: Out of 19,582 patients of the TERCET Registry, 7521 patients living in the Upper Silesia and Zaglebie Metropolis were included. The study population was divided into two groups according to the diagnosis of chronic (CCS) or acute coronary syndromes (ACS). Data on 24-h average concentrations of particulate matter with aerodynamic diameter <10 μm (PM10), sulfur dioxide (SO₂), nitrogen monoxide (NO), nitrogen dioxide (NO₂), and ozone (O₃) were obtained from eight environmental monitoring stations. Results: No significant association between pollutants’ concentration with baseline characteristic and in-hospital outcomes was observed. In the ACS group at 30 days, exceeding the 3rd quartile of PM10 was associated with almost 2-fold increased risk of adverse events and more than 3-fold increased risk of death. Exceeding the 3rd quartile of SO₂ was connected with more than 8-fold increased risk of death at 30 days. In the CCS group, exceeding the 3rd quartile of SO₂ was linked to almost 2,5-fold increased risk of 12-month death. Conclusions: The acute increase in air pollutants’ concentrations affect short- and mid-term prognosis in patients with CAD. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

18 pages, 2673 KiB

Open AccessArticle

Characteristics of Volatile Organic Compounds in the Pearl River Delta Region, China: Chemical Reactivity, Source, and Emission Regions

by Weiqiang Yang, Qingqing Yu, Chenglei Pei, Chenghao Liao, Jianjun Liu, Jinpu Zhang, Yanli Zhang, Xiaonuan Qiu, Tao Zhang, Yongbo Zhang and Xinming Wang

Atmosphere 2022, 13(1), 9; https://doi.org/10.3390/atmos13010009 - 21 Dec 2021

Cited by 15 | Viewed by 4062

Abstract

Volatile organic compounds (VOCs) are important precursors of photochemical ozone and secondary organic aerosol (SOA). Here, hourly variations of ambient VOCs were monitored with an online system at an urban site (Panyu, PY) in the Pearl River Delta region during August–September of 2020 [...] Read more.

Volatile organic compounds (VOCs) are important precursors of photochemical ozone and secondary organic aerosol (SOA). Here, hourly variations of ambient VOCs were monitored with an online system at an urban site (Panyu, PY) in the Pearl River Delta region during August–September of 2020 in order to identify reactive VOC species and major sources of VOCs, OH loss rate (L_OH), SOA formation potential (SOAFP), and corresponding emission source regions. The average concentration of VOCs at PY was 31.80 ± 20.82 ppbv during the campaign. The C₂–C₅ alkanes, aromatics, and ≥C₆ alkanes contributed for the majority of VOC, alkenes and aromatics showed the highest contribution to L_OH and SOAFP. Further, m/p-xylene, propene, and toluene were found to be the top three most reactive anthropogenic VOC species, with respective contributions of 11.6%, 6.1%, and 5.8% to total L_OH. Toluene, m/p-xylene, and o-xylene constituted a large fraction of calculated SOAFP. Seven major sources were identified by using positive matrix factorization model. Vehicle exhaust made the most significant contribution to VOCs, followed by liquefied petroleum gas and combustion sources. However, industrial-related sources (including industrial solvent use and industrial process emission) had the largest contribution to L_OH and SOAFP. By combining source contribution with wind direction and wind speed, the regions of different sources were further identified. Based on high-resolution observation data during ozone pollution, this study clearly exhibits key reactive VOC species and the major emission regions of different VOC sources, and thus benefits the accurate emission control of VOCs in the near future. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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17 pages, 4083 KiB

Open AccessArticle

Study on the Law of Harmful Gas Release from Limnoperna fortunei (Dunker 1857) during Maintenance Period of Water Tunnel Based on K-Means Outlier Treatment

by Ruonan Wang, Xiaoling Wang, Songmin Li, Jupeng Shen, Jianping Wang, Changxin Liu, Yazhi Zheng, Yitian Chen and Chaoyuan Ding

Appl. Sci. 2021, 11(24), 11995; https://doi.org/10.3390/app112411995 - 16 Dec 2021

Cited by 2 | Viewed by 2431

Abstract

It is of great significance for air pollution control and personnel safety guarantee to master the release characteristics of harmful gases in the process of Limnoperna fortunei corruption. In view of the lack of research on the environmental pollution caused by the corruption [...] Read more.

It is of great significance for air pollution control and personnel safety guarantee to master the release characteristics of harmful gases in the process of Limnoperna fortunei corruption. In view of the lack of research on the environmental pollution caused by the corruption of Limnoperna fortunei, a model experiment was designed to study the three harmful gases of NH₃, H₂S, and CH₄ in the putrid process of Limnoperna fortunei by considering the density of Limnoperna fortunei and the time of leaving water. The results show that: (1) The recognition and processing of outliers based on wavelet decomposition and K-means algorithm can effectively reduce the standard deviation and coefficient of variation of the data set and improve the accuracy of the data set. (2) The variation of NH₃ and H₂S gas concentrations with the time of water separation satisfies polynomial linear regression (R² > 99%). (3) At a density of 0.5–7.0 × 10⁴ mussels/m², the highest concentration of NH₃ reached 47.9777–307.9454 mg/m³ with the increase in the density of Limnoperna fortunei and the extension of the time away from water, far exceeding the occupational exposure limit of NH₃ of 30 mg/m³, potentially threatening human health and safety. The highest detection value of H₂S concentration is 0.1909–5.0946 mg/m³, and the highest detection concentration of CH₄ is 0.02%, both of which can be ignored. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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31 pages, 9657 KiB

Open AccessArticle

Evaluating the Parameters of a Systematic Long-Term Measurement of the Concentration and Mobility of Air Ions in the Environment inside Císařská Cave

by Zdeněk Roubal, Eva Gescheidtová, Karel Bartušek, Zoltán Szabó, Miloslav Steinbauer, Jarmila Überhuberová and Ariana Lajčíková

Atmosphere 2021, 12(12), 1615; https://doi.org/10.3390/atmos12121615 - 3 Dec 2021

Cited by 4 | Viewed by 2265

Abstract

Determining the concentration and mobility of light air ions is an indispensable task to ensure the successful performance and progress of various operations within multiple fields and branches of human activity. This article discusses a novel methodology for measuring air ions in an [...] Read more.

Determining the concentration and mobility of light air ions is an indispensable task to ensure the successful performance and progress of various operations within multiple fields and branches of human activity. This article discusses a novel methodology for measuring air ions in an environment with high relative humidity, such as that of a cave. Compared to common techniques, the proposed method exhibits a lower standard deviation and analyses the causes of spurious oscillations in the measured patterns obtained from FEM-based numerical simulations on the one hand and a model with concentrated parameters on the other. The designed ion meter utilises a gerdien tube to facilitate long-term measurement in cold and very humid spaces, an operation that can be very problematic if executed with other devices. Importantly, the applied procedure for calculating the mobility spectra of air ions from the acquired saturation characteristics is insensitive to fluctuations and noises in the measured patterns, and it also enables us to confirm the presence of very mobile air ions generated by fragmenting water droplets. During the sensing cycles, the concentration of light negative ions was influenced by the active gerdien tube. For the investigated cave, we had designed a measuring sequence to cover not only the time dependence of the concentration of light negative ions but also their mobility; this approach then allowed monitoring the corresponding impact of the patients’ presence in the cave, an effect neither described nor resolved thus far. Such comprehensive research, especially due to its specific character, has not been frequently conducted or widely discussed in the literature; the efforts characterised herein have therefore expanded the relevant knowledge and methodology, thus contributing towards further advancement in the field. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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18 pages, 3037 KiB

Open AccessArticle

Has COVID-19 Lockdown Affected on Air Quality?—Different Time Scale Case Study in Wrocław, Poland

by Tomasz Turek, Ewa Diakowska and Joanna A. Kamińska

Atmosphere 2021, 12(12), 1549; https://doi.org/10.3390/atmos12121549 - 24 Nov 2021

Cited by 9 | Viewed by 2242

Abstract

Due to the COVID-19 pandemic, there are series of negative economic consequences, however, in limiting mobility and reducing the number of vehicles, positive effects can also be observed, i.e., improvement of air quality. The paper presents an analysis of air quality measured by [...] Read more.

Due to the COVID-19 pandemic, there are series of negative economic consequences, however, in limiting mobility and reducing the number of vehicles, positive effects can also be observed, i.e., improvement of air quality. The paper presents an analysis of air quality measured by concentrations of NO₂, NO_x and PM_2.5 during the most restrictive lockdown from 10 March to 31 May 2020 on the case of Wrocław. The results were compared with the reference period—2016–2019. A significant reduction in traffic volume was identified, on average by 26.3%. The greatest reduction in the concentration of NO₂ and NO_x was recorded at the station farthest from the city center, characterized by the lowest concentrations: 20.1% and 22.4%. Lower reduction in the average concentrations of NO₂ and NO_x was recorded at the municipal station (7.9% and 7.7%) and the communication station (6.7% and 10.2%). Concentrations of PMs in 2020 were on average 15% and 13.4% lower than in the reference period for the traffic station and the background station. The long-term impact of the lockdown on air quality was also examined. The analysis of the concentrations of the pollutants throughout 2020, and in the analyzed period of 2021, indicated that the reduction of concentrations and the improvement in air quality caused by the restrictions should be considered as a temporary anomaly, without affecting long-term changes and trends. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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19 pages, 3170 KiB

Open AccessArticle

Spatial-Temporal Variation of Air PM_2.5 and PM₁₀ within Different Types of Vegetation during Winter in an Urban Riparian Zone of Shanghai

by Jing Wang, Changkun Xie, Anze Liang, Ruiyuan Jiang, Zihao Man, Hao Wu and Shengquan Che

Atmosphere 2021, 12(11), 1428; https://doi.org/10.3390/atmos12111428 - 29 Oct 2021

Cited by 5 | Viewed by 2401

Abstract

Particulate matter (PM) in urban riparian green spaces are undesirable for human participation in outdoor activities, especially PM_2.5 and PM₁₀. The PM deposition, dispersion and modification are influenced by various factors including vegetation, water bodies and meteorological conditions. This study [...] Read more.

Particulate matter (PM) in urban riparian green spaces are undesirable for human participation in outdoor activities, especially PM_2.5 and PM₁₀. The PM deposition, dispersion and modification are influenced by various factors including vegetation, water bodies and meteorological conditions. This study aimed to investigate the impact of vegetation structures and the river’s presence on PM in riparian zones. The spatial-temporal variations of PM_2.5 and PM₁₀ concentrations in three riparian vegetation communities with different structures (open grassland (G), arbor-grass (AG) and arbor-shrub-grass (ASG) woodlands) were monitored under relatively stable environment. The removal percentages (RP) and ratios of PM_2.5 and PM₁₀ were calculated and compared to identify the removal effect of vegetation structures and the river’s presence. It is found that: (1) when the wind was static (hourly wind speed < 0.2 m/s), the RP was ranked as follows: G > AG > ASG. When the wind was mild (0.2 m/s < hourly wind speed < 2 m/s), the RP was ranked as follows: G > ASG > AG. Generally, the G had the best removal effect during the monitoring period; (2) the lowest RP occurred in the middle of the G (–3.4% for PM_2.5, 1.8% for PM₁₀) while the highest RP were found in middle of the AG and ASG, respectively (AG: 2.1% for PM_2.5, 6.7% for PM₁₀; ASG: 2.4% for PM_2.5, 6.3% for PM₁₀). Vegetation cover changed the way of natural deposition and dispersion; (3) compared with static periods, PM removal percentages were significantly reduced under mild wind conditions, and they were positively correlated with wind speed during the mild-wind period. Thus, a piecewise function was inferred between wind speed and PM removal percentage; (4) for all three communities, the 1 m-to-river PM_2.5/PM₁₀ ratio was significantly lower than that at 6 m and 11 m, even lower than that in the ambient atmosphere. The river likely promoted the hygroscopic growth of PM_2.5 and the generation of larger-sized particles by coagulation effect. Based on these findings, open grassland space is preferred alongside rivers and space for outdoor activities is suggested under canopies in the middle of woodlands. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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18 pages, 74100 KiB

Open AccessArticle

Modeling the Impacts of City-Scale “Ventilation Corridor” Plans on Human Exposure to Intra-Urban PM2.5 Concentrations

by Chao Liu, Qian Shu, Sen Huang and Jingwei Guo

Atmosphere 2021, 12(10), 1269; https://doi.org/10.3390/atmos12101269 - 29 Sep 2021

Cited by 6 | Viewed by 2301

Abstract

Increasingly, Chinese cities are proposing city-scale ventilation corridors (VCs) to strengthen wind velocities and decrease pollution concentrations, although their influences are ambiguous. To assess VC impacts, an effort has been made to predict the impact of VC solutions in the high density and [...] Read more.

Increasingly, Chinese cities are proposing city-scale ventilation corridors (VCs) to strengthen wind velocities and decrease pollution concentrations, although their influences are ambiguous. To assess VC impacts, an effort has been made to predict the impact of VC solutions in the high density and diverse land use of the coastal city of Shanghai, China, in this paper. One base scenario and three VC scenarios, with various VC widths, locations, and densities, were first created. Then, the combination of the Weather Research and Forecasting/Single-Layer Urban Canopy Model (WRFv.3.4/UCM) and Community Multiscale Air Quality (CMAQv.5.0.1) numerical simulation models were employed to comprehensively evaluate the impacts of urban spatial form and VC plans on PM2.5 concentrations. The modeling results indicated that concentrations increased within the VCs in both summer and winter, and the upwind concentration decreased in winter. These counter-intuitive results could be explained by decreased planetary boundary layer (PBL), roughness height, deposition rate, and wind speeds induced by land use and urban height modifications. PM2.5 deposition flux decreased by 15–20% in the VCs, which was attributed to the roughness height decrease for it weakens aerodynamic resistance (Ra). PBL heights within the VCs decreased 15–100 m, and the entire Shanghai’s PBL heights also decreased in general. The modeling results suggest that VCs may not be as functional as certain urban planners have presumed. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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14 pages, 2689 KiB

Open AccessArticle

Contributing towards Representative PM Data Coverage by Utilizing Artificial Neural Networks

by Chris G. Tzanis and Anastasios Alimissis

Appl. Sci. 2021, 11(18), 8431; https://doi.org/10.3390/app11188431 - 11 Sep 2021

Cited by 3 | Viewed by 1605

Abstract

Atmospheric aerosol particles have a significant impact on both the climatic conditions and human health, especially in densely populated urban areas, where the particle concentrations in several cases can be extremely threatening (increased anthropogenic emissions). Most large cities located in high-income countries have [...] Read more.

Atmospheric aerosol particles have a significant impact on both the climatic conditions and human health, especially in densely populated urban areas, where the particle concentrations in several cases can be extremely threatening (increased anthropogenic emissions). Most large cities located in high-income countries have stations responsible for measuring particulate matter and various other parameters, collectively forming an operating monitoring network, which is essential for the purposes of environmental control. In the city of Athens, which is characterized by high population density and accumulates a large number of economic activities, the currently operating monitoring network is responsible, among others, for PM₁₀ and PM_2.5 measurements. The need for satisfactory data availability though can be supported by using machine learning methods, such as artificial neural networks. The methodology presented in this study uses a neural network model to provide spatiotemporal estimations of PM₁₀ and PM_2.5 concentrations by utilizing the existing PM data in combination with other climatic parameters that affect them. The overall performance of the predictive neural network models’ scheme is enhanced when meteorological parameters (wind speed and temperature) are included in the training process, lowering the error values of the predicted versus the observed time series’ concentrations. Furthermore, this work includes the calculation of the contribution of each predictor, in order to provide a clearer understanding of the relationship between the model’s output and input. The results of this procedure showcase that all PM input stations’ concentrations have an important impact on the estimations. Considering the meteorological variables, the results for PM_2.5 seem to be affected more than those for PM₁₀, although when examining PM₁₀ and PM_2.5 individually, the wind speed and temperature contribution is on a similar level with the corresponding contribution of the available PM concentrations of the neighbouring stations. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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11 pages, 2501 KiB

Open AccessArticle

Characterization of PM-Bound Heavy Metal at Road Environment in Tianjin: Size Distribution and Source Identification

by Qijun Zhang, Hongjun Mao, Yanjie Zhang and Lin Wu

Atmosphere 2021, 12(9), 1130; https://doi.org/10.3390/atmos12091130 - 2 Sep 2021

Cited by 9 | Viewed by 2341

Abstract

To determine the size distribution and source identification of PM-bound heavy metals in roadside environments, four different particle size (<0.2 μm, 0.2–0.5 μm, 0.5–1.0 μm and 1.0–2.5 μm) samples were collected and analyzed from four different types of roads during the summer of [...] Read more.

To determine the size distribution and source identification of PM-bound heavy metals in roadside environments, four different particle size (<0.2 μm, 0.2–0.5 μm, 0.5–1.0 μm and 1.0–2.5 μm) samples were collected and analyzed from four different types of roads during the summer of 2015 in Tianjin. The results showed that the concentrations of PM-bound heavy metal from the roadside environment sampling sites were 597 ± 251 ng/m³ (BD), 546 ± 316 ng/m³ (FK), 518 ± 310 ng/m³ (JY) and 640 ± 237 ng/m³ (WH). There were differences in the concentrations of the heavy metal elements in the four different particle size fractions. The concentrations of Cu, Zn, Cd, Sn and Pb were the highest in the larger particle size fraction (0.5–2.5 μm). Cd, Cu, Zn and Pb were the elements that indicated emissions from tire wear and brake pad wear. The concentrations of Cr, Co and Ni were the highest in the smallest particle size fraction (<0.5 μm), indicating that motor vehicle exhaust was their main source. The correlation analysis results showed that there are differences in the concentration, distribution and correlation of different PM-bound heavy metals in different particle size fractions. The PCA results show that the accumulative interpretation variances of PM_0.2, PM_0.2–0.5, PM_0.5–1.0 and PM_1.0–2.5 reached 80.29%, 79.56%, 79.57% and 71.42%, respectively. Vehicle exhaust was the primary source of PM-bound heavy metal collected from the roadside sampling sites, while brake pad wear and tire wear were the second most common sources of the heavy metal. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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12 pages, 336 KiB

Open AccessReview

Ammonia Emission in Poultry Facilities: A Review for Tropical Climate Areas

by Matheus Dias Oliveira, Fernanda Campos Sousa, Jairo Osorio Saraz, Arele Arlindo Calderano, Ilda Fátima Ferreira Tinôco and Antônio Policarpo Souza Carneiro

Atmosphere 2021, 12(9), 1091; https://doi.org/10.3390/atmos12091091 - 25 Aug 2021

Cited by 15 | Viewed by 4609

Abstract

Brazil is the largest broiler meat exporter in the world. This important economic activity generates income in different branches of the production chain. However, the decomposition of residues incorporated in the poultry litter generates several gases, among them ammonia. When emitted from the [...] Read more.

Brazil is the largest broiler meat exporter in the world. This important economic activity generates income in different branches of the production chain. However, the decomposition of residues incorporated in the poultry litter generates several gases, among them ammonia. When emitted from the litter to the air, ammonia can cause several damages to animals and man, in addition to being able to convert into a greenhouse gas. Thus, the aim of this article was to carry out a review of the ammonia emission factors in the production of broilers, the methodologies for measuring, and the inventories of emissions already carried out in several countries. The main chemical processes for generating ammonia in poultry litter have been introduced and some practices that can contribute to the reduction of ammonia emissions have been provided. The PMU, Portable Monitoring Unit, and the SMDAE, Saraz Method for Determination of Ammonia Emissions, with the required adaptations, are methodologies that can be used to quantify the ammonia emissions in hybrid facilities with a natural and artificial ventilation system. An ammonia emission inventory can contribute to the control and monitoring of pollutant emissions and is an important step towards adopting emission reductions. However, quantifying the uncertainties about ammonia emission inventories is still a challenge to be overcome. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

14 pages, 4712 KiB

Open AccessArticle

Variation of Particle-Induced Oxidative Potential of PM_2.5 in Xinjiang, NW-China

by Juqin An, Dilnurt Talifu, Xiang Ding, Longyi Shao, Xinming Wang, Abulikemu Abulizi, Yalkunjan Tursun, Huibin Liu, Yuanyu Zhang and Turhun Aierken

Atmosphere 2021, 12(8), 1028; https://doi.org/10.3390/atmos12081028 - 11 Aug 2021

Cited by 1 | Viewed by 2149

Abstract

In order to evaluate the toxicity of PM_2.5 in the Dushanzi area, PM_2.5 samples were collected from December 2015 to July 2016, and a plasmid DNA damage assessment method was used to analyze the variation in the oxidative damage ability and [...] Read more.

In order to evaluate the toxicity of PM_2.5 in the Dushanzi area, PM_2.5 samples were collected from December 2015 to July 2016, and a plasmid DNA damage assessment method was used to analyze the variation in the oxidative damage ability and its relationship with sampling conditions and toxic components (polycyclic aromatic hydrocarbons, and heavy metals) loaded on the surface of PM_2.5. The results showed that the TD₃₀ values (toxic dosage of PM_2.5 causing 30% of plasmid DNA damage) of both the whole samples and the water-soluble fractions were lower during the heating period (369 μg/mL and 536 μg/mL, respectively), but higher in the dust period and non-heating period (681 μg/mL and 498 μg/mL, respectively; and 804 μg/mL and 847 μg/mL, respectively). Studies on the effect of meteorological parameters showed an increasing trend in TD₃₀ values for the whole samples and the water-soluble fractions as relative humidity, temperature and wind speed decrease. TD₃₀ values for the whole samples and the water-soluble fractions were negatively correlated with Flu (r = −0.690,r = −0.668; p < 0.05), Flt (r =−0.671, r = −0.760; p < 0.05), BaP (r = −0.672, r = −0.725; p < 0.05), IcdP (r = −0.694, r = −0.740; p < 0.05), Pyr (r = −0.727, r = −0.768; p < 0.01) and BghiP (r = −0.874, r = −0.845; p < 0.01) during the heating period, while As (r = 0.792, r = 0.749; p < 0.05) and Sr (r = 0.776, r = 0.754; p < 0.05) during the dust period showed significant positive correlation. In addition, the TD₃₀ values of PM_2.5 collected during sand blowing weather was the highest (1458 μg/mL and 1750 μg/mL), while the average TD₃₀ value of PM_2.5 collected on hazy days were the lowest (419.8 μg/mL and 488.6 μg/mL). Particles collected on the first day after snowfall showed a lower oxidizing capacity (676 μg/mL and 1330 μg/mL). The characteristic TD₃₀ values combined with back trajectory analysis indicated that hazy days were heavily influenced by air masses originating from the southern continent and local emissions, whereas the sand blowing weather came from the north of the Taklimakan Desert. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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10 pages, 1154 KiB

Open AccessTechnical Note

Evaluation of Using Satellite-Derived Aerosol Optical Depth in Land Use Regression Models for Fine Particulate Matter and Its Elemental Composition

by Chun-Sheng Huang, Ho-Tang Liao, Tang-Huang Lin, Jung-Chi Chang, Chien-Lin Lee, Eric Cheuk-Wai Yip, Yee-Lin Wu and Chang-Fu Wu

Atmosphere 2021, 12(8), 1018; https://doi.org/10.3390/atmos12081018 - 8 Aug 2021

Cited by 1 | Viewed by 3021

Abstract

This study introduced satellite-derived aerosol optical depth (AOD) in land use regression (LUR) modeling to predict ambient concentrations of fine particulate matter (PM_2.5) and its elemental composition. Twenty-four daily samples were collected from 17 air quality monitoring sites (N = 408) [...] Read more.

This study introduced satellite-derived aerosol optical depth (AOD) in land use regression (LUR) modeling to predict ambient concentrations of fine particulate matter (PM_2.5) and its elemental composition. Twenty-four daily samples were collected from 17 air quality monitoring sites (N = 408) in Taiwan in 2014. A total of 12 annual LUR models were developed for PM_2.5 and 11 elements, including aluminum, calcium, chromium, iron, potassium, manganese, sulfur, silicon, titanium, vanadium, and zinc. After applied AOD and a derived-predictor, AOD percentage, in modeling, the number of models with leave-one-out cross-validation R² > 0.40 significantly increased from 5 to 9, indicating the substantial benefits for the construction of spatial prediction models. Sensitivity analyses of using data stratified by PM_2.5 concentrations revealed that the model performances were further improved in the high pollution season. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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22 pages, 3415 KiB

Open AccessArticle

The Potential Ozone Impacts of Landfills

by Eduardo P. Olaguer

Atmosphere 2021, 12(7), 877; https://doi.org/10.3390/atmos12070877 - 7 Jul 2021

Cited by 6 | Viewed by 4224

Abstract

Landfill gas produces ozone precursors such as nitrogen oxides and formaldehyde when combusted in flares or stationary engines. Solid waste landfills are also the third largest anthropogenic source of methane in the United States. Methane is both a greenhouse gas and a tropospheric [...] Read more.

Landfill gas produces ozone precursors such as nitrogen oxides and formaldehyde when combusted in flares or stationary engines. Solid waste landfills are also the third largest anthropogenic source of methane in the United States. Methane is both a greenhouse gas and a tropospheric ozone precursor. Despite its low photochemical reactivity, methane may noticeably affect urban ozone if released in large quantities along with other organic compounds in landfill gas. A fine-scale 3D Eulerian chemical transport model was used to demonstrate that, under meteorological and background chemical conditions conducive to high ozone concentrations, typical emissions of ozone precursors from a single hypothetical landfill may result in persistent daytime additions to ozone of over 1 part per billion (ppb) by volume tens of kilometers downwind. Large leaks of landfill gas can enhance this ozone pollution by over a tenth of a ppb, and external sources of non-methane ozone precursors may further exacerbate this impact. In addition, landfill gas combustion may increase near-source exposure to toxic formaldehyde by well over half a ppb. In Southeast Michigan, the combined influence of several landfills upwind of key monitoring sites may contribute significantly to observed exceedances of the U.S. ozone standard. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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13 pages, 3650 KiB

Open AccessArticle

Real-World Vehicle Volatile Organic Compound Emissions and Their Source Profile in Chengdu Based on a Roadside and Tunnel Study

by Miao Feng, Xiang Hu, Li Zhou, Tianyue Zhang, Xiao Zhang, Qinwen Tan, Zihang Zhou, Ye Deng, Danlin Song and Chengmin Huang

Atmosphere 2021, 12(7), 861; https://doi.org/10.3390/atmos12070861 - 2 Jul 2021

Cited by 5 | Viewed by 2591

Abstract

With the continuous progress of air pollution prevention and control in China, the study of the emission characteristics of vehicles has become increasingly important. An in situ experiment was performed in the Tianfu tunnel in Chengdu to determine the vehicle emissions of volatile [...] Read more.

With the continuous progress of air pollution prevention and control in China, the study of the emission characteristics of vehicles has become increasingly important. An in situ experiment was performed in the Tianfu tunnel in Chengdu to determine the vehicle emissions of volatile organic compounds (VOCs). A total of 50 species of VOCs were quantified in the tunnel, with total concentrations in the range of 32.25–162.18 ppbv in the entrance and 52.90–233.92 ppbv in the exit, respectively. Alkanes were the most abundant group, followed by alkenes, aromatic hydrocarbons, oxygenated VOCs, alkynes and chlorocarbons. The general emission factors of the measured VOCs ranged from 141.71 mg veh⁻¹ km⁻¹ to 236.12 mg veh⁻¹ km⁻¹, and the average ± std was 177.31 ± 24.59 mg veh⁻¹ km⁻¹. The emission factors of diesel-fuelled vehicles, gasoline-fuelled vehicles and natural gas-fuelled vehicles were estimated based on linear regression analysis, with values of 272.39 ± 191.17 mg veh⁻¹ km⁻¹, 185.08 ± 12.85 mg veh⁻¹ km⁻¹ and 158.72 ± 3.21 mg veh⁻¹ km⁻¹, respectively. The results of roadside experiments indicate that the roadside ambience atmosphere contains many species characterized with vehicle emission features. Especially, there were fuel evaporation emission related substances, which were higher in content than tunnel samples. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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15 pages, 2526 KiB

Open AccessArticle

Improved Measurement Performance for the Sharp GP2Y1010 Dust Sensor: Reduction of Noise

by Jonathan E. Thompson

Atmosphere 2021, 12(6), 775; https://doi.org/10.3390/atmos12060775 - 16 Jun 2021

Cited by 1 | Viewed by 3368

Abstract

Sharp GP2Y1010 dust sensors are increasingly being used within distributed sensing networks and for personal monitoring of exposure to particulate matter (PM) pollution. These dust sensors offer an easy-to-use solution at an excellent price point; however, the sensors are known to offer limited [...] Read more.

Sharp GP2Y1010 dust sensors are increasingly being used within distributed sensing networks and for personal monitoring of exposure to particulate matter (PM) pollution. These dust sensors offer an easy-to-use solution at an excellent price point; however, the sensors are known to offer limited dynamic range and poor limits of detection (L.O.D.), often >15 μg m⁻³. The latter figure of merit precludes the use of this inexpensive line of dust sensors for monitoring PM_2.5 levels in environments within which particulate pollution levels are low. This manuscript presents a description of the fabrication and circuit used in the Sharp GP2Y1010 dust sensor and reports several effective strategies to minimize noise and maximize limits of detection for PM. It was found that measurement noise is primarily introduced within the photodiode detection circuitry, and that electromagnetic interference can influence dust sensor signals dramatically. Through optimization of the external capacitor and resistor used in the LED drive circuit—and the inter-pulse delay, electromagnetic shielding, and data acquisition strategy—noise was reduced approximately tenfold, leading to a projected noise equivalent limit of detection of 3.1 μg m⁻³. Strategies developed within this manuscript will allow improved limits of detection for these inexpensive sensors, and further enable research toward unraveling the spatial and temporal distribution of PM within buildings and urban centers—as well as an improved understanding of effect of PM on human health. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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14 pages, 1666 KiB

Open AccessArticle

Seasonality of the Airborne Ambient Soot Predominant Emission Sources Determined by Raman Microspectroscopy and Thermo-Optical Method

by Natalia Zioła, Kamila Banasik, Mariola Jabłońska, Janusz Janeczek, Barbara Błaszczak, Krzysztof Klejnowski and Barbara Mathews

Atmosphere 2021, 12(6), 768; https://doi.org/10.3390/atmos12060768 - 14 Jun 2021

Cited by 3 | Viewed by 2620

Abstract

Raman microspectroscopy and thermo-optical-transmittance (TOT) method were used to study airborne ambient soot collected at the suburban air monitoring station in southern Poland during the residential heating (January-February) and non-heating (June–July) seasons of 2017. Carbonaceous material constituted on average 47.2 wt.% of PM [...] Read more.

Raman microspectroscopy and thermo-optical-transmittance (TOT) method were used to study airborne ambient soot collected at the suburban air monitoring station in southern Poland during the residential heating (January-February) and non-heating (June–July) seasons of 2017. Carbonaceous material constituted on average 47.2 wt.% of PM_2.5 during the heating season and 26.9 wt.% in the non-heating season. Average concentrations of OC (37.5 ± 11.0 μg/m³) and EC (5.3 ± 1.1 μg/m³) during the heating season were significantly higher than those in the non-heating season (OC = 2.65 ± 0.78 μg/m³, and EC = 0.39 ± 0.18 μg/m³). OC was a chief contributor to the TC mass concentration regardless of the season. All Raman parameters indicated coal combustion and biomass burning were the predominant sources of soot in the heating season. Diesel soot, which is structurally less ordered than soot from other sources, was dominant during the non-heating season. The D1 and G bands area ratio (D1_A/G_A) was the most sensitive Raman parameter that discriminated between various soot sources, with D1_A/G_A > 1 for diesel soot, and less than 1 for soot from coal and wood burning. Due to high daily variability of both TOT and Raman spectroscopy data, single-day measurements can be inconclusive regarding the soot source apportionment. Long-time measurement campaigns are recommended. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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16 pages, 2768 KiB

Open AccessArticle

Source Apportionment and Health Risk Assessment of Metal Elements in PM_2.5 in Central Liaoning’s Urban Agglomeration

by Qingyuan Guo, Liming Li, Xueyan Zhao, Baohui Yin, Yingying Liu, Xiaoli Wang, Wen Yang, Chunmei Geng, Xinhua Wang and Zhipeng Bai

Atmosphere 2021, 12(6), 667; https://doi.org/10.3390/atmos12060667 - 24 May 2021

Cited by 14 | Viewed by 3029

Abstract

To better understand the source and health risk of metal elements in PM_2.5, a field study was conducted from May to December 2018 in the central region of the Liaoning province, China, including the cities of Shenyang, Anshan, Fushun, Benxi, Yingkou, [...] Read more.

To better understand the source and health risk of metal elements in PM_2.5, a field study was conducted from May to December 2018 in the central region of the Liaoning province, China, including the cities of Shenyang, Anshan, Fushun, Benxi, Yingkou, Liaoyang, and Tieling. 24 metal elements (Na, K, V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Sb, Pb, Bi, Al, Sr, Mg, Ti, Ca, Fe, Ba, and Si) in PM_2.5 were measured by ICP-MS and ICP-OES. They presented obvious seasonal variations, with the highest levels in winter and lowest in summer for all seven cities. The sum of 24 elements were ranged from to in these cities. The element mass concentration ratio was the highest in Yingkou in the spring (26.15%), and the lowest in Tieling in winter (3.63%). The highest values of elements in PM_2.5 were mostly found in Anshan and Fushun among the studied cities. Positive matrix factorization (PMF) modelling revealed that coal combustion, industry, traffic emission, soil dust, biomass burning, and road dust were the main sources of measured elements in all cities except for Yingkou. In Yingkou, the primary sources were identified as coal combustion, metal smelting, traffic emission, soil dust, and sea salt. Health risk assessment suggested that Mn had non-carcinogenic risks for both adults and children. As for Cr, As, and Cd, there was carcinogenic risks for adults and children in most cities. This study provides a clearer understanding of the regional pollution status of industrial urban agglomeration. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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14 pages, 1996 KiB

Open AccessArticle

Geochemical Characterization and Heavy Metal Sources in PM₁₀ in Arequipa, Peru

by Jianghanyang Li, Greg Michalski, Elizabeth Joy Olson, Lisa R. Welp, Adriana E. Larrea Valdivia, Juan Reyes Larico, Francisco Alejo Zapata and Lino Morales Paredes

Atmosphere 2021, 12(5), 641; https://doi.org/10.3390/atmos12050641 - 18 May 2021

Cited by 4 | Viewed by 3349

Abstract

Particulate matter smaller than 10 μm (PM₁₀) is an important air pollutant that adversely affects human health by increasing the risk of respiratory and cardiovascular diseases. Recent studies reported multiple extreme PM₁₀ levels at high altitude Peruvian cities, which resulted [...] Read more.

Particulate matter smaller than 10 μm (PM₁₀) is an important air pollutant that adversely affects human health by increasing the risk of respiratory and cardiovascular diseases. Recent studies reported multiple extreme PM₁₀ levels at high altitude Peruvian cities, which resulted from a combination of high emissions and limited atmospheric circulation at high altitude. However, the emission sources of the PM₁₀ still remain unclear. In this study, we collected PM₁₀ samples from four sites (one industrial site, one urban site, and two rural sites) at the city of Arequipa, Peru, during the period of February 2018 to December 2018. To identify the origins of PM₁₀ at each site and the spatial distribution of PM₁₀ emission sources, we analyzed major and trace element concentrations of the PM₁₀. Of the observed daily PM₁₀ concentrations at Arequipa during our sampling period, 91% exceeded the World Health Organization (WHO) 24-h mean PM₁₀ guideline value, suggesting the elevated PM₁₀ strongly affected the air quality at Arequipa. The concentrations of major elements, Na, K, Mg, Ca, Fe, and Al, were high and showed little variation, suggesting that mineral dust was a major component of the PM₁₀ at all the sites. Some trace elements, such as Mn and Mo, originated from the mineral dust, while other trace elements, including Pb, Sr, Cu, Ba, Ni, As and V, were from additional anthropogenic sources. The industrial activities at Rio Seco, the industrial site, contributed to significant Pb, Cu, and possibly Sr emissions. At two rural sites, Tingo Grande and Yarabamba, strong Cu emissions were observed, which were likely associated with mining activities. Ni, V, and As were attributed to fossil fuel combustion emissions, which were strongest at the Avenida Independencia urban site. Elevated Ba and Cu concentrations were also observed at the urban site, which were likely caused by heavy traffic in the city and vehicle brake wear emissions. Full article

(This article belongs to the Topic Air Pollution – An Interdisciplinary Approach to the Problem of Air Pollution and Improvement of Air Quality)

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