Environmental science: atmospheres最新文献

{"title":"Ozone formation potential related to the release of volatile organic compounds (VOCs) and nitrogen oxide (NOX) from a typical industrial park in the Pearl River Delta†","authors":"Taicheng An, Jiajia Li, Qinhao Lin and Guiying Li","doi":"10.1039/D4EA00091A","DOIUrl":"https://doi.org/10.1039/D4EA00091A","url":null,"abstract":"<p >Ozone (O<small>₃</small>) pollution has been recognized as the major air pollution in the Pearl River Delta (PRD) region, South China. Understanding O<small>₃</small> formation sensitive to volatile organic compound (VOC)- and nitrogen oxide (NO<small>_X</small>)-limited regimes is a key step for alleviating O<small>₃</small> pollution. Herein, measurements of VOCs, NO<small>_X</small> and O<small>₃</small> were simultaneously performed at multi sampling sites in an industrial park of the PRD region during June, 2020. VOCs/NO<small>_X</small> ratios ranged from 0.5 to 5.7, suggesting that the O<small>₃</small> formation was in the VOC-limited regime in the industrial park. The estimated O<small>₃</small> formation potential (OFP) of VOCs showed that alkenes and aromatic hydrocarbons from motor vehicles and industrial sources contributed to 40% and 39% of the O<small>₃</small> formation, respectively, in the industrial park. However, a low O<small>₃</small> level (&lt;50 ppb) was observed in the region where high OFP values (&gt;194 ppb) were estimated. Further analysis found that the concentration of NOx (25 ± 10 ppb) in the high O<small>₃</small> region was lower than that (36 ± 6 ppb) in the low O<small>₃</small> region, mostly due to the titration reaction of NO and O<small>₃</small> to form NO<small>₂</small>, therefore leading to the consumption of O<small>₃</small>. This result implies that NO<small>_X</small> control was not conducive to the O<small>₃</small> pollution in the study region. Thus, O<small>₃</small> pollution control in the study region should be taken into consideration in terms of the effect of NO<small>_X</small> titration and control of VOC emissions.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 11","pages":" 1229-1238"},"PeriodicalIF":2.8,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00091a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of atmospheric water-soluble iron on α-pinene-derived SOA formation and transformation in the presence of aqueous droplets†","authors":"Sabine Lüchtrath, Sven Klemer, Clément Dubois, Christian George and Andreas Held","doi":"10.1039/D4EA00095A","DOIUrl":"https://doi.org/10.1039/D4EA00095A","url":null,"abstract":"<p >The impact of water-soluble atmospheric iron on formation, growth and aging of secondary organic aerosol (SOA) is a controversial subject in the literature. Iron chemistry drives Fenton reactions in the aqueous phase which is dependent on pH. Flow reactor experiments in the dark and under humid conditions were conducted to investigate systematically the influence of ferrous iron in the aqueous phase on α-pinene SOA by online physical analysis and offline high-resolution mass spectrometry. During the experiments increased SOA formation under conditions favorable for dark Fenton chemistry in the aqueous phase was observed. Furthermore, samples with an acidified and iron-containing aqueous phase showed a degradation of pinyl-diaterpenyl (C<small>₁₇</small>H<small>₂₆</small>O<small>₈</small>) ester which ages through oxidation <em>via</em> OH radicals and can thus be evidence for ongoing degradation processes of high molecular weight molecules by iron chemistry. Moreover, higher abundance of dimer MW338 (C<small>₁₉</small>H<small>₃₀</small>O<small>₅</small>) in the acidic sample affected by Fenton's chemistry was detected which is suggested to be formed <em>via</em> acid catalysis indicating competing acidity-driven reactions influencing SOA formation. Therefore, this study provides insight into the impact of aqueous phase iron on SOA formation and transformation under simulated natural conditions.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 11","pages":" 1218-1228"},"PeriodicalIF":2.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00095a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of atmospheric microplastics in Hangzhou, a megacity of the Yangtze river delta, China†","authors":"Liang Xu, Jiefeng Li, Shushen Yang, Zhenyang Li, Yan Liu, Yifan Zhao, Dantong Liu, Admir Créso Targino, Zhonghua Zheng, Mingzhou Yu, Peng Xu, Yele Sun and Weijun Li","doi":"10.1039/D4EA00069B","DOIUrl":"https://doi.org/10.1039/D4EA00069B","url":null,"abstract":"<p >Microplastics (MPs) have become a key environmental issue over the last few decades. However, while previous studies have mainly focused on aquatic MP pollution, research on atmospheric MPs remains limited. To expand our knowledge of atmospheric MPs, we collected atmospheric samples using active and dry deposition techniques during one year in an urban environment in the megacity of Hangzhou, China. MPs were identified in the samples using a range of analytical and optical techniques. The concentrations of MPs on the filters collected using active sampling ranged from 0.37–8.9 particles per m<small>³</small>, with an annual mean of 3.2 ± 0.5 particles per m<small>³</small>. The dry deposition rate of atmospheric MPs ranged from 441.18–3181.8 particles per m<small>²</small> per day, with an annual mean of 1387.8 ± 237.7 particles per m<small>²</small> per day. Fiber MPs were the most predominant type while a few film-type MPs were identified. Raman microspectrometer analysis identified that tires (27.0% of MPs) and polyethylene terephthalate (PET, 19.7% of MPs) were the dominant MP types. Finally, we estimated that the annual dry deposition rate of MPs in the Hangzhou urban area was 16.9 ± 2.9 tons. Exploring the abundance and deposition of MPs helps to evaluate their potential threat to human health or aquatic ecology, which finally contributes to development of MP control measures.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 10","pages":" 1161-1169"},"PeriodicalIF":2.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00069b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing the Earth's albedo: the Köhler equation at sea","authors":"J. I. Katz","doi":"10.1039/D4EA00073K","DOIUrl":"https://doi.org/10.1039/D4EA00073K","url":null,"abstract":"<p >Increasing marine haze and clouds has been considered as a possible means of increasing the Earth's albedo. This would reduce solar heating and global warming, counteracting the effects of the anthropogenic increase in greenhouse gases. One proposed method of doing so would inject small droplets of seawater or condensation nuclei into the marine boundary layer, creating artificial haze and cloud. The equilibrium size of such droplets is described by the Köhler equation that includes the vapor pressure reduction attributable to the solute according to Raoult's law and the vapor pressure increase of a small droplet as a result of surface tension according to Kelvin. Here we apply this classic result to small droplets in the marine boundary layer, where the partial pressure of water vapor is less than the equilibrium vapor pressure because it is in equilibrium with the saline ocean. We calculate the equilibrium size of a droplet containing dissolved ions and find that the radius of a droplet of seawater shrinks greatly before it achieves equilibrium.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 10","pages":" 1157-1160"},"PeriodicalIF":2.8,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00073k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the potential secondary contribution of photosensitized chemistry to OH production in aqueous aerosols†","authors":"Emma A. Petersen-Sonn, Marcello Brigante, Laurent Deguillaume, Jean-Luc Jaffrezo, Sébastien Perrier and Christian George","doi":"10.1039/D4EA00103F","DOIUrl":"https://doi.org/10.1039/D4EA00103F","url":null,"abstract":"<p >This study explores the potential contribution of secondary production of OH radicals in aerosols and cloud/fog conditions arising from brown carbon (BrC) triplet state chemistry. For this purpose, extracts of brown carbon from atmospheric aerosols from Grenoble, France, were analyzed for their ability to produce triplet states from the degradation of a common triplet state probe, 2,4,6-trimethylphenol (TMP). This ability of brown carbon to produce triplet states was compared to that of three photosensitizers, where it was found that vanillin (VL) showed a similar rate of degradation of the probe and was hence chosen as an alternative to BrC in aqueous aerosols to investigate OH formation from triplet states. The rates of OH formation from the triplet states were compared to those from nitrate anions (NO<small>₃</small><small>⁻</small>) and hydrogen peroxide (H<small>₂</small>O<small>₂</small>), which are well-known sources of OH radicals in the aqueous phase, and a species that is structurally similar to VL, 4-hydroxybenzaldehyde (4HB). VL and 4HB both showed a 1–2 orders of magnitude higher rate of secondary OH formation than NO<small>₃</small><small>⁻</small>, while it was similar or one order of magnitude smaller than H<small>₂</small>O<small>₂</small>. To evaluate the influence of the different OH radical sources in aqueous aerosols and cloud/fog conditions, the concentrations of the species were summarized from the literature. Considering the concentrations of HULISs in aerosols, the rates of secondary OH formation from BrC triplet states could potentially represent a significant source of OH in the atmospheric aqueous phase under some circumstances. This study shows the relevance of further investigations into the role of triplet states in impacting atmospheric oxidative capacity and studying other effects of triplet states in aerosols, a field that is, until now, still not fully understood.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 10","pages":" 1170-1182"},"PeriodicalIF":2.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00103f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of organic species and functional groups in pollen, fungi, algae, and bacteria bioaerosols†","authors":"Palina Bahdanovich, Kevin Axelrod, Andrey Y. Khlystov and Vera Samburova","doi":"10.1039/D4EA00083H","DOIUrl":"https://doi.org/10.1039/D4EA00083H","url":null,"abstract":"<p >Though the importance of bioaerosols is increasing with the changing climate, very little is known about the chemistry of bioaerosols, their atmospheric fate, and chemical composition. This paper is focused on the characterization of chemical functional groups of four atmospherically relevant bioaerosols: pollen (lodgepole pine and rabbitbrush), fungi (western gall rust), bacteria (<em>Pedobacter</em> and hay bacillus), and algae (spirulina). For this purpose, the proton nuclear magnetic resonance (<small>¹</small>H-NMR) technique was used on water-soluble extracts of the selected bioaerosols, while quantitative analysis of individual organic species (saccharides, amino acids, and fatty acids) was performed using gas chromatography mass spectrometry (GC-MS), ultra-high performance liquid chromatography (UPLC-MS), and UV-Vis-NIR (ultraviolet-visible-infrared) spectrophotometry. The obtained <small>¹</small>H-NMR results revealed major contributions from aliphatic protons in <em>Bacillus</em> (50.2%) and <em>Pedobacter</em> (57.0%) bacteria, western gall rust fungus (39.7%), spirulina algae (73.8%), and rabbitbrush pollen (31.3%). Protons from saccharides were dominant in lodgepole pine pollen (27.6%). The quantitative analysis shows that the saccharide glucose is common among the analyzed bioaerosols, as well as proline, leucine, isoleucine, alanine, and phenylalanine amino acids, and palmitic, oleic, linoleic, linolenic, and stearic fatty acids (except in <em>Bacillus</em> bacteria). Concentrations of analyzed saccharides ranged between 2.01 μg mg<small>⁻¹</small> of dry mass (in <em>Bacillus</em> bacteria) and 183.54 μg mg<small>⁻¹</small> (in lodgepole pine pollen), followed by amino acids (from 2.57 μg mg<small>⁻¹</small> in western gall rust fungus to 21.38 μg mg<small>⁻¹</small> in <em>Bacillus</em> bacteria), and fatty acids (from 0.05 μg mg<small>⁻¹</small> in <em>Bacillus</em> bacteria to 25.82 μg mg<small>⁻¹</small> in lodgepole pine pollen). Comparison of <small>¹</small>H-NMR and quantitative analyses showed a good correlation (<em>R</em><small>²</small> = 0.608) between the saccharide segment of <small>¹</small>H-NMR bioaerosol spectra and individual saccharide analysis.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 9","pages":" 1091-1104"},"PeriodicalIF":2.8,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00083h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method development and analysis of nanoparticle size fractions from tire-wear emissions†","authors":"Molly Haugen, Philipp Bühler, Stefan Schläfle, David O'Loughlin, Siriel Saladin, Chiara Giorio and Adam Boies","doi":"10.1039/D4EA00048J","DOIUrl":"https://doi.org/10.1039/D4EA00048J","url":null,"abstract":"<p >Herein, we examine the generation of nanoparticles from tire and road interactions, with a focus on two key aspects: replicating real-world conditions in a controlled environment for particle generation and analysing the collected particles through both online and offline techniques. In order to generate realistic wear patterns, third body particles were used in a standardized laboratory tire testing facility across dynamic and static speeds and load profiles. The findings indicated that milled stone dust as a third body particle significantly disrupted the nanoparticle size range, complicating the differentiation between tire-based and third-body-based nanoparticles. However, using sand as a third body particle, the interference showed comparatively lower background noise within the nanoparticle region. Here, steady-state cycles were employed to discern the relationships between force events and nanoparticle generation, which were compared to analyses conducted over an entire dynamic drive cycle. The steady-state cycles revealed that high lateral forces (&gt;2 kN) yielded the highest nanoparticle concentrations, surpassing background levels by over two orders of magnitude. Meanwhile, the drive cycle trials indicated that approximately 70% of the emitted nanoparticles throughout the entire drive cycle were semi-volatile emissions, likely originating from vaporization events. ICP-MS results confirmed the presence of tire-related elements in the nanoparticle region, but definitive attribution to the tire or road surface remains a challenge for the field. This study underscores the complexities inherent in generating, collecting, and assessing submicron tire wear particles, laying the groundwork for addressing uncertainties and refining non-exhaust tire emission methodologies.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 9","pages":" 1079-1090"},"PeriodicalIF":2.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00048j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unpaved road particulate matter emission rates and vehicle-induced transient plume characteristics†","authors":"James Kacer, Ralph Altmaier, David M. Cwiertny and Patrick T. O'Shaughnessy","doi":"10.1039/D4EA00055B","DOIUrl":"10.1039/D4EA00055B","url":null,"abstract":"<p >Particulate matter (PM) emitted from unpaved rural roads presents a potential inhalation hazard to people living and working near them. In the absence of site-specific exposure data, plume dispersion modeling can be used to predict ambient particulate concentrations in the vicinity of the unpaved roads. Hourly averaged PM<small>₁₀</small> concentrations were measured near a gravel road using an EPA reference method resulting in a geometric mean of 50 μg m<small>⁻³</small>. With these ambient concentrations, the AERMOD plume dispersion model was used to derive a PM emission factor of 444 g/VKT (grams per vehicle kilometer travelled). This result was lower than the emission factor calculated using the EPA's AP-42 guidance for unpaved roads (795 g/VKT). The transient nature of the plume of PM concentrations due to road traffic was also evaluated using a direct-reading instrument. Vehicle speed and wind speed were found to be significant determinants of PM concentration, average PM concentration, and total PM mass for each plume. Each vehicle produced an average concentration of 4096 μg m<small>⁻³</small> over the duration of the plume. Therefore, residents near the road are potentially exposed to substantially higher short-term concentrations from individual plumes than would be indicated by hourly averages.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 9","pages":" 1042-1050"},"PeriodicalIF":2.8,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11342916/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142057484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"O3 chemistry of 2,5-dimethylfuran: mechanism development†","authors":"Niklas Illmann and Vera Rösgen","doi":"10.1039/D4EA00045E","DOIUrl":"https://doi.org/10.1039/D4EA00045E","url":null,"abstract":"<p >Furans are emitted from biomass burning (BB) and contribute to the reactivity of BB plumes with a significant proportion. Consequently, the development of comprehensive furan oxidation schemes is one of the crucial elements towards a better understanding of BB plume chemistry. Nighttime oxidation is supposedly dominated by NO<small>₃</small> radicals and O<small>₃</small>. The present study has chosen 2,5-dimethylfuran (25DMF) as a model compound for the development of an O<small>₃</small> oxidation mechanism for furans. Experiments were performed in the QUAREC atmospheric simulation chamber (QUAREC ASC) at 299 ± 2 K and a pressure of 980 ± 20 mbar under dry conditions (relative humidity &lt; 0.1%) targeting the reaction kinetics, the OH formation and the oxidation mechanism. The reactions were monitored by long-path FTIR spectroscopy and a PTR-ToF-MS instrument. We determined a rate coefficient of (3.3 ± 1.0) × 10<small>⁻¹⁶</small> cm<small>³</small> molecule<small>⁻¹</small> s<small>⁻¹</small> for the target reaction using the relative-rate method. An OH yield of 25 ± 10% was obtained when using 1,3,5-trimethylbenzene as an OH tracer. Reaction products are formaldehyde, methyl glyoxal, ketene, glyoxal, methyl hydroperoxide, acetic anhydride, and acetic acid, respectively. The methyl glyoxal, glyoxal and formaldehyde yields were found to be sensitive to the overall peroxy radical level in the system. The PTR-MS data indicate further reaction products, which are tentatively assigned. A mechanism is postulated to account for the clearly identified reaction products. Overall, the obtained results indicate that O<small>₃</small> oxidation of furans might contribute to acidity in nighttime BB plumes.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 9","pages":" 1000-1011"},"PeriodicalIF":2.8,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00045e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142169803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Air pollution (PM2.5) and its meteorology predictors in Kampala and Jinja cities, in Uganda†","authors":"Aishat Jumoke Alaran, Natasha O'Sullivan, Lambed Tatah, Richard Sserunjogi and Gabriel Okello","doi":"10.1039/D4EA00074A","DOIUrl":"https://doi.org/10.1039/D4EA00074A","url":null,"abstract":"<p >Air pollution disproportionately affects African countries, including Uganda, but it is inadequately studied in these settings. The emergence of low-cost sensors offers an opportunity to improve routine air quality monitoring, assess interventions, and track progress. This study aimed to assess the spatiotemporal trends of PM<small>_2.5</small> in Kampala and Jinja cities in Uganda, whilst exploring the influence of meteorological parameters on PM<small>_2.5</small>. Calibrated PM<small>_2.5</small> values and meteorological parameters for three years (2020 to 2022) were obtained from 58 local low-cost sensors and 6 weather stations. Hourly averages for PM<small>_2.5</small> and meteorological data underwent necessary pre-processing, and various statistical analyses, including descriptive statistics, time series trends, spatial variation, Spearman rank correlation, and multivariate regression, were performed. The multivariate linear regression with a gamma-link function was selected as the model with the best fit. The average annual PM<small>_2.5</small> levels in Kampala and Jinja were 41.1 μg m<small>⁻³</small> (±18.91 μg m<small>⁻³</small>) and 25.6 μg m<small>⁻³</small> (±15.5 μg m<small>⁻³</small>), respectively, significantly exceeding the recommended World Health Organisation annual guideline values of 5 μg m<small>⁻³</small>. Meteorological parameters exhibited varying degrees of relationships with PM<small>_2.5</small> in both cities; multivariate regression indicated that meteorological factors could explain about 18% of the variation of PM<small>_2.5</small> in Kampala and 7% in Jinja. Both cities experienced a decrease in PM<small>_2.5</small> levels during the COVID-19 pandemic lockdown with Kampala experiencing a 31% reduction (average decrease of 11.2 μg m<small>⁻³</small>) and Jinja a 17% reduction (average decrease of 3.8 μg m<small>⁻³</small>). This study provides insights into the air quality challenges faced by a rapidly urbanising city in sub-Saharan Africa, the promise of locally made low-cost sensors, and how meteorology influences local air pollution and lays the foundation for informed decision-making to safeguard public health and promote a sustainable environment. The findings highlight the urgent need for targeted interventions and policy initiatives to address air pollution in Uganda.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 10","pages":" 1145-1156"},"PeriodicalIF":2.8,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ea/d4ea00074a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}