Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.6
2.9
Journals
Atmosphere
Special Issues
Urban Air Chemistry in Changing Times
share announcement

Urban Air Chemistry in Changing Times

A special issue of Atmosphere (ISSN 2073-4433). This special issue belongs to the section "Air Quality".

Deadline for manuscript submissions: closed (31 July 2022) | Viewed by 14346

Special Issue Editor

Dr. George M. Hidy

E-Mail Website
Guest Editor
Envair/Aerochem, Placitas, NM 87043, USA
Interests: tropospheric aerosol chemistry; environmental trends measurement; energy–environmental management policy

Special Issue Information

Dear Colleagues,

Adverse health effects and reduced visibility have motivated the study of chemical processes in urban air for more than a century. Post-World War II investigations focused on pollutant emissions leading to photochemical oxidant formation and fine particle production. In addition, the fact of the presence of toxins in urban air is widely known. Much of the knowledge on urban air chemistry stems from the influence of fuel combustion and industrial emissions combined with appreciation for multi-spatial scale influences. Major changes are taking place that are reducing emissions and affecting urban pollution in different ways. With reductions in fuel combustion and industrial processing, urban air chemistry will change in ways that are perhaps known but less predictable. These include the influence of a decline in carbon-based energy production and use, as well as the evolution of chemical industries superimposed on uncertain regional or global “background” processes. For oxidants, these include the shifting to nitrogen oxide sensitivity and ozone production efficiency. For fine particles, the shift away from secondary inorganic species to organic constituents. For toxins, what new species are emerging and what may be their reactivity? This Special Issue is devoted to exploring the features of atmospheric chemistry in response to contemporary urban changes in cities.

Dr. George M. Hidy
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Atmosphere is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Ozone chemistry
  • Aerosol chemistry
  • Airborne toxins
  • Emission changes

Published Papers (6 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Other

10 pages, 9125 KiB  
Article
US Clean Energy Futures—Air Quality Benefits of Zero Carbon Energy Policies
by Petros N. Vasilakos, Huizhong Shen, Qasim Mehdi, Peter Wilcoxen, Charles Driscoll, Kathy Fallon, Dallas Burtraw, Maya Domeshek and Armistead G. Russell
Atmosphere 2022, 13(9), 1401; https://doi.org/10.3390/atmos13091401 - 31 Aug 2022
Cited by 7 | Viewed by 2258
Abstract
In this work, we compare the air quality benefits of a variety of future policy scenarios geared towards controlling EGU (electricity generating units) emissions between the present-day conditions and 2050. While these policies are motivated by reducing CO2 emissions, they also yield [...] Read more.
In this work, we compare the air quality benefits of a variety of future policy scenarios geared towards controlling EGU (electricity generating units) emissions between the present-day conditions and 2050. While these policies are motivated by reducing CO2 emissions, they also yield significant co-benefits for criteria pollutants, such as ozone and PM2.5. An integrated set of clean energy policies were examined to assess the time-varying costs and benefits of a range of decarbonization strategies, including business as usual and the Affordable Clean Energy plan, with a primary focus on others that look to achieve very low, if not zero, CO2 emissions from the EGU sector by 2050. Benefits assessed include mitigation of greenhouse gas emissions as well as air quality co-benefits. In this introductory work, we describe the potential air quality changes from various clean air policies, to set the stage for upcoming work looking at health and monetized benefits. Emission changes for key pollutants are forecast using the Integrated Planning Model (IPM), which are then transformed into emission inputs for the Community Multiscale Air Quality Model (CMAQ). For all primary scenarios considered that achieve large greenhouse gas decreases, significant reductions in ozone and PM are realized, mainly in the eastern US, and all policies produce air quality benefits. Full article
(This article belongs to the Special Issue Urban Air Chemistry in Changing Times)
►▼ Show Figures

Figure 1

19 pages, 1312 KiB  
Article
Apportionment of Vehicle Fleet Emissions by Linear Regression, Positive Matrix Factorization, and Emission Modeling
by Xiaoliang Wang, L.-W. Antony Chen, Minggen Lu, Kin-Fai Ho, Shun-Cheng Lee, Steven Sai Hang Ho, Judith C. Chow and John G. Watson
Atmosphere 2022, 13(7), 1066; https://doi.org/10.3390/atmos13071066 - 6 Jul 2022
Cited by 7 | Viewed by 2122
Abstract
Real-world emission factors for different vehicle types and their contributions to roadside air pollution are needed for air-quality management. Tunnel measurements have been used to estimate emission factors for several vehicle types using linear regression or receptor-based source apportionment. However, the accuracy and [...] Read more.
Real-world emission factors for different vehicle types and their contributions to roadside air pollution are needed for air-quality management. Tunnel measurements have been used to estimate emission factors for several vehicle types using linear regression or receptor-based source apportionment. However, the accuracy and uncertainties of these methods have not been sufficiently discussed. This study applies four methods to derive emission factors for different vehicle types from tunnel measurements in Hong Kong, China: (1) simple linear regressions (SLR); (2) multiple linear regressions (MLR); (3) positive matrix factorization (PMF); and (4) EMission FACtors for Hong Kong (EMFAC-HK). Separable vehicle types include those fueled by liquefied petroleum gas (LPG), gasoline, and diesel. PMF was the most useful, as it simultaneously seeks source profiles and source contributions. Diesel-, gasoline-, and LPG-fueled vehicle emissions accounted for 52%, 10%, and 5% of PM2.5 mass, respectively, while ammonium sulfate (~20%), ammonium nitrate (6%), and road dust (7%) were also large contributors. MLR exhibited the highest relative uncertainties, typically over twice those determined by SLR. EMFAC-HK has the lowest relative uncertainties due to its assumption of a single average emission factor for each pollutant and each vehicle category under specific conditions. The relative uncertainties of SLR and PMF are comparable. Full article
(This article belongs to the Special Issue Urban Air Chemistry in Changing Times)
►▼ Show Figures

Graphical abstract

26 pages, 7344 KiB  
Article
Tropical Air Chemistry in Lagos, Nigeria
by Adebola Odu-Onikosi, Pierre Herckes, Matthew Fraser, Philip Hopke, John Ondov, Paul A. Solomon, Olalekan Popoola and George M. Hidy
Atmosphere 2022, 13(7), 1059; https://doi.org/10.3390/atmos13071059 - 3 Jul 2022
Cited by 2 | Viewed by 2311
Abstract
The Nigerian city of Lagos experiences severe air pollution as a result of emissions and subsequent atmospheric photochemistry and aerosol chemistry. A year-long study, between August 2020 and July 2021, included measurements of gas-phase and aerosol processes, with surface meteorology at six urban [...] Read more.
The Nigerian city of Lagos experiences severe air pollution as a result of emissions and subsequent atmospheric photochemistry and aerosol chemistry. A year-long study, between August 2020 and July 2021, included measurements of gas-phase and aerosol processes, with surface meteorology at six urban sites. The sites were selected to represent near seacoast conditions, urban sites, and inland locations near agricultural and grassland ecosystems. The observations included continuous concentrations for CO, SO2, NOx, O3, PM2.5, and PM10. Samples were collected and analyzed for speciated volatile organic compounds (VOCs) and particulate chemical composition including inorganic and organic chemical species. The average diel variations in concentrations indicated well-known local photochemistry resulting from the presence of combustion sources, including motor vehicles, petroleum production and use, and open burning. The annual diel characteristics were emission-dependent and were modulated by meteorological variability, including the sea breeze and the seasonal changes associated with monsoons and Harmattan winds. Gases and particulate matter varied daily, consistent with the onset of source activities during the day. Fine particles less than 2.5 μm in diameter (PM2.5) included both primary particles from emission sources and secondary particles produced in the atmosphere by photochemical reactions. Importantly, particle sources included a large component of dust and carbonaceous material. For the latter, there was evidence that particle concentrations were dominated by primary sources, with little secondary material formed in the atmosphere. From complementary measurements, there were occasions when regional chemical processes affected the local conditions, including transportation, industry, commercial activity, and open waste burning. Full article
(This article belongs to the Special Issue Urban Air Chemistry in Changing Times)
►▼ Show Figures

Figure 1

15 pages, 64692 KiB  
Article
Air Pollutants over Industrial and Non-Industrial Areas: Historical Concentration Estimates
by Jiri Michalik, Ondrej Machaczka, Vitezslav Jirik, Tomas Heryan and Vladimir Janout
Atmosphere 2022, 13(3), 455; https://doi.org/10.3390/atmos13030455 - 11 Mar 2022
Cited by 6 | Viewed by 2334
Abstract
Only a few researchers have addressed the issue of lifetime exposure related to air pollutant concentration. This study aims to develop a methodology to obtain the most reliable estimates of historical concentrations of air pollutants, which would be further applied to the long-term [...] Read more.
Only a few researchers have addressed the issue of lifetime exposure related to air pollutant concentration. This study aims to develop a methodology to obtain the most reliable estimates of historical concentrations of air pollutants, which would be further applied to the long-term exposure evaluation. In particular, PM10, PM2.5, NO2, SO2, benzene, and B(a)P concentrations have been obtained. Data of monitored concentrations, model calculations, and subsequent implementation of several corrections based on previous work on temporal and spatial correlations of these substances in the air have been deployed. This work makes an original contribution to the field of meteorology and epidemiology because of this innovative technique to estimate the most reliable historical concentrations of air pollutants. The novelty of our work lies in the additional implications of this study because historical concentration data serve as input data for the construction of epidemiological associations. The approach is based primarily on the availability of monitoring results of air pollutants. Full article
(This article belongs to the Special Issue Urban Air Chemistry in Changing Times)
►▼ Show Figures

Figure 1

18 pages, 6899 KiB  
Article
Changing Emissions Results in Changed PM2.5 Composition and Health Impacts
by Philip K. Hopke and George Hidy
Atmosphere 2022, 13(2), 193; https://doi.org/10.3390/atmos13020193 - 25 Jan 2022
Cited by 9 | Viewed by 2415
Abstract
In the period of 2005 to 2016, multiple air pollution control regulations have entered into effect in the United States at both the Federal and state level. In addition, economic changes have also occurred primarily in the electricity generation sector that substantially changed [...] Read more.
In the period of 2005 to 2016, multiple air pollution control regulations have entered into effect in the United States at both the Federal and state level. In addition, economic changes have also occurred primarily in the electricity generation sector that substantially changed the emissions from this sector. This combination of policy implementations and economics has led to substantial reductions in PM2.5, its major constituents, and source specific PM2.5 concentrations across the New York State, particularly those of sulfate, nitrate, and primary organic carbon. However, secondary organic carbon and spark-ignition vehicular emission contributions have increased. Related studies of changes in health outcomes, the excess rates of emergency department visits and hospitalizations for a variety of cardiovascular and respiratory diseases and respiratory infections have increased per unit mass of PM2.5. It appears that the increased toxicity per unit mass was due to the reduction in low toxicity constituents such that the remaining mass had greater impacts on public health. Full article
(This article belongs to the Special Issue Urban Air Chemistry in Changing Times)
►▼ Show Figures

Figure 1

Other

Jump to: Research

17 pages, 4084 KiB  
Commentary
Urban Air Chemistry in Changing Times
by George M. Hidy
Atmosphere 2022, 13(2), 327; https://doi.org/10.3390/atmos13020327 - 16 Feb 2022
Cited by 2 | Viewed by 1965
Abstract
Urban air chemistry is characterized by measurements of gas and aerosol composition. These measurements are interpreted from a long history for laboratory and theoretical studies integrating chemical processes with reactant (or emissions) sources, meteorology and air surface interaction. The knowledge of these latter [...] Read more.
Urban air chemistry is characterized by measurements of gas and aerosol composition. These measurements are interpreted from a long history for laboratory and theoretical studies integrating chemical processes with reactant (or emissions) sources, meteorology and air surface interaction. The knowledge of these latter elements and their changes have enabled chemists to quantitatively account for the averages and variability of chemical indicators. To date, the changes are consistent with dominating energy-related emissions for more than 50 years of gas phase photochemistry and associated reactions forming and evolving aerosols. Future changes are expected to continue focusing on energy resources and transportation in most cities. Extreme meteorological conditions combined with urban surface exchange are also likely to become increasingly important factors affecting atmospheric composition, accounting for the past leads to projecting future conditions. The potential evolution of urban air chemistry can be followed with three approaches using observations and chemical transport modeling. The first approach projects future changes using long term indicator data compared with the emission estimates. The second approach applies advanced measurement analysis of the ambient data. Examples include statistical modeling or evaluation derived from chemical mechanisms. The third method, verified with observations, employs a comparison of the deterministic models of chemistry, emission futures, urban meteorology and urban infrastructure changes for future insight. Full article
(This article belongs to the Special Issue Urban Air Chemistry in Changing Times)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-6
Back to TopTop