Microdroplets: An Overlooked “Engine” of Chemistry in Air

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Learn More CiteCitationCitation and abstractCitation and referencesMore citation options ShareShare onFacebookXWeChatLinkedInRedditEmailBlueskyJump toExpandCollapse ViewpointMarch 25, 2025Microdroplets: An Overlooked "Engine" of Chemistry in AirClick to copy article linkArticle link copied!Deming Xia*Deming XiaKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China*[email protected]More by Deming XiaView Biographyhttps://orcid.org/0000-0003-4877-0058Hong-bin XieHong-bin XieKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, ChinaMore by Hong-bin XieView Biographyhttps://orcid.org/0000-0002-9119-9785Zhiqiang FuZhiqiang FuKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, ChinaMore by Zhiqiang Fuhttps://orcid.org/0000-0003-4199-7436Jingwen Chen*Jingwen ChenKey Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China*[email protected]More by Jingwen Chenhttps://orcid.org/0000-0002-5756-3336Open PDFEnvironmental Science & TechnologyCite this: Environ. Sci. Technol. 2025, XXXX, XXX, XXX-XXXClick to copy citationCitation copied!https://pubs.acs.org/doi/10.1021/acs.est.5c01041https://doi.org/10.1021/acs.est.5c01041Published March 25, 2025 Publication History Received 21 January 2025Published online 25 March 2025article-commentary© 2025 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissionsThis publication is licensed for personal use by The American Chemical Society. ACS Publications© 2025 American Chemical SocietySubjectswhat are subjects Article subjects are automatically applied from the ACS Subject Taxonomy and describe the scientific concepts and themes of the article. Atmospheric chemistry Charge transfer Chemical reactions Ions Liquids Microdroplets are everywhere, in both indoor and outdoor air, forming an immense air–water interface in the Earth's system. They appear as clouds, rain, dew, or fog outdoors and arise from cosmetic sprays, humidifiers, or shower heads indoors. At first glance, they look simple, composed primarily of water molecules (Figure 1), yet these tiny droplets host a range of chemical reactions so complex that they challenge long-held beliefs in environmental chemistry. For example, atmospheric nitrogen (N2), long considered inert due to its strong triple bond, can be unexpectedly activated at microdroplet surfaces and converted into nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting substance, through a reduction-then-oxidation pathway. (1) Similarly, per- and polyfluoroalkyl substances (PFASs), a family of compounds known as "forever chemicals", can undergo activation and even defluorination on these microdroplets, leading to mineralization reactions once deemed highly unlikely. (2) These surprising transformations underscore the previously unrecognized importance of microdroplets in atmospheric chemical cycles and prompt us to ask how these microdroplets achieve such magical power. (2)Figure 1Figure 1. Ubiquitous microdroplets in outdoor and indoor environments and plausible mechanisms by which they become highly reactive.High Resolution ImageDownload MS PowerPoint SlideHow Do the Microdroplets Become Highly Reactive?Click to copy section linkSection link copied!Although the exact chemical mechanisms driving the high reactivity of microdroplets remain somewhat unclear, some pioneers have given diverse interpretations from different perspectives. (3,4) These interpretations are centered around some important reactive species (RS), including hydroxyl radicals (•OH), hydrogen atoms (H•), water cation radicals (H2O•+), hydrated electrons (H2O•–), and hydrogen peroxide (H2O2). The formation of these RS is often linked to electrification at the surfaces of the microdroplets. Imagine rubbing your hands on a table quickly; the violent friction can make you feel a stinging sensation. In the upper troposphere, the friction between clouds and the air can be far more intense. This friction facilitates charge transfer between the air and microdroplets, resulting in the microdroplets acquiring a non-zero charge.This non-zero charge disrupts the initial ion distribution within the microdroplets, further amplifying the separation of positive and negative ions in the surface and subsurface of microdroplets. (3−5) As a result, a strong electric field perpendicular to the surface of the droplet is generated, even in the absence of a net charge. Such a strong electric field in the microdroplets substantially lowers the energy barrier for charge transfer between hydronium (H3O+) and hydroxide (OH–), two essential ions in water, producing strong oxidants (e.g., •OH) and reductants (e.g., H•) as described by eq 1: (3−5)H3O++OH−→H•+•OH+H2O(1)The charge transfer can also occur between two water molecules at the microdroplet surfaces (eq 2), generating reactive H2O•+ and H2O•–: (4)H2O+H2O→H2O•−+H2O•+(2)The strongly reducing H2O•– can even weaken the formidable N≡N bond to produce HN2 radicals, thus activating "stable" N2. (1) Meanwhile, H2O•+ quickly reacts with H2O to form an •OH–H3O+ pair, which rapidly dissociates into H3O+ and •OH. Once produced, those RS, especially •OH and H•, have opportunities to escape from the microdroplet surfaces, as these RS can usually form only one hydrogen bond with the interfacial water molecules and the interactions are not very strong. This makes the microdroplets behave like "engines" and continuously generate oxidants and reductants, driving atmospheric chemical reactions not only on their surfaces but also in the nearby gas phase.What Will We Do?Click to copy section linkSection link copied!As Newton once remarked "... whilst the great ocean of truth lay all undiscovered before me ..." in the 18th century, we, too, remain uncertain about the impacts of these tiny droplets, mainly composed of seemingly simple water just like the ocean, on the environment even in the 21st century. Clearly, we need to take some action as soon as possible.First, we need to establish a bridge between chemistry and environmental science. Pioneering chemical studies frequently utilized microdroplet systems analogous to those in electrospray ionization mass spectrometry. However, such approaches inherently introduce external energy perturbations that may decouple interfacial reactions from environmental processes. In contrast, water vapor adiabatic expansion and ultrasonic atomization better replicate the microdroplets observed in environmental systems, from outdoor clouds to indoor humidifier-generated droplets. Notably, the adiabatic expansion method circumvents debates over energy-driven artifacts via spontaneous nucleation of water vapor, where microdroplets originate from inherent thermodynamic driving forces rather than extrinsic energy manipulation. Consequently, these environmentally representative ways of generating microdroplets are useful for evaluating microdroplet reactions under different outdoor and indoor scenarios.Second, we should think about which substances, indoors or outdoors, could potentially undergo important chemical transformations on the microdroplet surfaces and whether the transformations can lead to impactful consequences (e.g., potential health risks from a humidifier). Compounds like surfactants, with both hydrophilic (e.g., −COOH, −OH, and −NH2) and hydrophobic (e.g., −CH2–, −CH3, and −CH═CH−) groups, are prime candidates due to their high potential to accumulate at the surfaces of the microdroplets. In addition, highly abundant atmospheric species, once thought to be inert (e.g., N2), also warrant re-examination.Finally, the importance of air–water interface chemistry may extend beyond the atmosphere to the ocean's surface microlayer (SML), where many pollutants such as PFASs (6) and organophosphate esters (7) exhibit significant enrichment. During wave-breaking events, hydrodynamic shear generates transient microbubbles and sea-spray aerosols simultaneously, potentially creating interfacial hot spots with intense electric fields and increased levels of reactive species. These unique physicochemical conditions may further drive contaminant transformation through mechanisms distinct from bulk-phase reactions. The SML's complex matrix (e.g., enriched inorganic ions and dissolved organic matter) may further modulate transformation pathways. Deciphering these interfacial processes is critical for evaluating pollutant fates in ocean ecosystems.Author InformationClick to copy section linkSection link copied!Corresponding AuthorsDeming Xia - Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; https://orcid.org/0000-0003-4877-0058; Email: [email protected]Jingwen Chen - Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; https://orcid.org/0000-0002-5756-3336; Email: [email protected]AuthorsHong-bin Xie - Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; https://orcid.org/0000-0002-9119-9785Zhiqiang Fu - Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), Dalian Key Laboratory on Chemicals Risk Control and Pollution Prevention Technology, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; https://orcid.org/0000-0003-4199-7436NotesThe authors declare no competing financial interest.BiographiesClick to copy section linkSection link copied!Deming XiaHigh Resolution ImageDownload MS PowerPoint SlideDr. Deming Xia received his doctoral degree from Dalian University of Technology under the supervision of Prof. Jingwen Chen in December 2021. After finishing his postdoctoral research at Dalian University of Technology (January 2022 to January 2024), he was promoted to be an associate professor at the university. His research focuses on heterogeneous chemistry on water droplet surfaces. He has published 28 peer-reviewed papers.Hong-bin XieHigh Resolution ImageDownload MS PowerPoint SlideDr. Jingwen Chen has been a professor at Dalian University of Technology since 2001. After earning his Ph.D. from Nanjing University in 1997, he performed postdoctoral studies at the German Research Center for Environmental Health as an Alexander von Humboldtian. His research interests cover environmental computational toxicology and ecological risk control technology for synthetic chemicals. He has published more than 360 peer-reviewed papers, reviews, and book chapters, as well as three books (two monographs and one textbook). He served as a member of Teaching Steering Committee on Environmental Science and Engineering of China Ministry of Education, a member of the Environmental Science and Engineering Discipline Evaluation Group of the Academic Degrees Committee of the State Council of China, an Executive Editor and Associated Editor of ACS Sustainable Chemistry & Engineering, and a member of editorial boards of several journals. He was a recipient of the Teaching and Research Award for Outstanding Young Teachers in Higher Education Institutions from the Ministry of Education of China in 2000, a winner (Second Class, second contributor) of the National Natural Science Award in 2011, and a winner (First Class, first contributor) of the Natural Science Award (2023) from the Ministry of Education of China. In 2013, he won the National Science Fund for Distinguished Young Scholars and was appointed as chair professor of the "Cheung Kong Scholars Program" by the China Ministry of Education.AcknowledgmentsClick to copy section linkSection link copied!This study was supported by the National Natural Science Foundation of China (22206019, 22136001, and 22276020), the National Key R&D Program of China (2022YFC3902100), the China National Postdoctoral Program for Innovative Talents (BX20220050), and the Fundamental Research Funds for the Central Universities (DUT24RC(3)047).ReferencesClick to copy section linkSection link copied! This article references 7 other publications. 1Jiang, Q.; Xia, D. M.; Li, X. F.; Zhang, H.; Yin, R. J.; Xie, H. J.; Xie, H.-b.; Jiang, J.; Chen, J. W.; Francisco, J. S. Rapid N2O Formation from N2 on Water Droplet Surfaces. Angew. Chem., Int. Ed. 2025, 64, e202421002 DOI: 10.1002/anie.202421002 Google ScholarThere is no corresponding record for this reference.2Xia, D. M.; Zhang, H.; Ju, Y.; Xie, H.-b.; Su, L.; Ma, F.; Jiang, J.; Chen, J. W.; Francisco, J. S. Spontaneous Degradation of the "Forever Chemicals" Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) on Water Droplet Surfaces. J. Am. Chem. Soc. 2024, 146 (16), 11266– 11271, DOI: 10.1021/jacs.4c00435 Google ScholarThere is no corresponding record for this reference.3Qiu, L.; Cooks, R. G. Simultaneous and Spontaneous Oxidation and Reduction in Microdroplets by the Water Radical Cation/Anion Pair. Angew. Chem., Int. Ed. 2022, 61, e202210765 DOI: 10.1002/anie.202210765 Google Scholar3Simultaneous and Spontaneous Oxidation and Reduction in Microdroplets by the Water Radical Cation/Anion PairQiu, Lingqi; Cooks, R. GrahamAngewandte Chemie, International Edition (2022), 61 (41), e202210765CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA) Microdroplets show unique chem., esp. in their intrinsic redox properties, and to this we here add a case of simultaneous and spontaneous oxidn. and redn. We report the concurrent conversions of several phosphonates to phosphonic acids by redn. (R-P → H-P) and to pentavalent phosphoric acids by oxidn. The exptl. results suggest that the active reagent is the water radical cation/anion pair. The water radical cation is obsd. directly as the ionized water dimer while the water radical anion is only seen indirectly though the spontaneous redn. of carbon dioxide to formate. The coexistence of oxidative and reductive species in turn supports the proposal of a double-layer structure at the microdroplet surface, where the water radical cation and radical anion are sepd. and accumulated. >> More from SciFinder ®https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitlGls7nK&md5=f7f3a5f19c80e62ffbc9ff853a552d5b4Heindel, J. P.; LaCour, R. A.; Head-Gordon, T. The Role of Charge in Microdroplet Redox Chemistry. Nat. Commun. 2024, 15, 3670, DOI: 10.1038/s41467-024-47879-0 Google ScholarThere is no corresponding record for this reference.5Cooks, R. G.; Holden, D. T. Breaking down microdroplet chemistry. Science 2024, 384, 958– 959, DOI: 10.1126/science.adp7627 Google ScholarThere is no corresponding record for this reference.6Casas, G.; Martínez-Varela, A.; Roscales, J. L.; Vila-Costa, M.; Dachs, J.; Jiménez, B. Enrichment of Perfluoroalkyl Substances in the Sea-Surface Microlayer and Sea-Spray Aerosols in the Southern Ocean. Environ. Pollut. 2020, 267, 115512, DOI: 10.1016/j.envpol.2020.115512 Google Scholar6Enrichment of perfluoroalkyl substances in the sea-surface microlayer and sea-spray aerosols in the Southern OceanCasas, Gemma; Martinez-Varela, Alicia; Roscales, Jose L.; Vila-Costa, Maria; Dachs, Jordi; Jimenez, BegonaEnvironmental Pollution (Oxford, United Kingdom) (2020), 267 (), 115512CODEN: ENPOEK; ISSN:0269-7491. (Elsevier Ltd.) Sea-spray (or sea-salt) aerosol (SSA) formation and their subsequent atm. transport and deposition have been suggested to play a prominent role in the occurrence of ionizable perfluoroalkyl substances (PFAS) in the maritime Antarctica and other remote regions. However, field studies on SSA's role as vector of transport of PFAS are lacking. Following a multiphase approach, seawater (SW), the sea-surface microlayer (SML) and SSA were sampled simultaneously at South Bay (Livingston Island, Antarctica). Av. PFAS concns. were 313 pg L-1, 447 pg L-1, and 0.67 pg m-3 in SW, the SML and SSA, resp. The enrichment factors of PFAS in the SML and SSA ranged between 1.2 and 5, and between 522 and 4690, resp. This amplification of concns. in the SML is consistent with the surfactant properties of PFAS, while the large enrichment of PFAS in atm. SSA may be facilitated by the large surface area of SSA and the sorption of PFAS to aerosol org. matter. This is the first field work assessing the simultaneous occurrence of PFAS in SW, the SML and SSA. The large measured amplification of concns. in marine aerosols supports the role of SSA as a relevant vector for long-range atm. transport of PFAS. >> More from SciFinder ®https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhvVeqs7rJ&md5=bc5c9e2a93a7cfc4a72bb6e2a29060d77Trilla-Prieto, N.; Iriarte, J.; Berrojalbiz, N.; Casas, G.; Sobrino, C.; Vila-Costa, M.; Jiménez, B.; Dachs, J. Enrichment of Organophosphate Esters in the Sea Surface Microlayer from the Atlantic and Southern Oceans. Environ. Sci. Technol. Lett. 2024, 11 (9), 1008– 1015, DOI: 10.1021/acs.estlett.4c00636 Google ScholarThere is no corresponding record for this reference.Cited By Click to copy section linkSection link copied!This article has not yet been cited by other publications.Download PDFFiguresReferences Get e-AlertsGet e-AlertsEnvironmental Science & TechnologyCite this: Environ. Sci. Technol. 2025, XXXX, XXX, XXX-XXXClick to copy citationCitation copied!https://doi.org/10.1021/acs.est.5c01041Published March 25, 2025 Publication History Received 21 January 2025Published online 25 March 2025© 2025 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissionsArticle Views-Altmetric-Citations-Learn about these metrics closeArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.Recommended Articles FiguresReferencesAbstractHigh Resolution ImageDownload MS PowerPoint SlideFigure 1Figure 1. Ubiquitous microdroplets in outdoor and indoor environments and plausible mechanisms by which they become highly reactive.High Resolution ImageDownload MS PowerPoint SlideDeming XiaHigh Resolution ImageDownload MS PowerPoint SlideDr. Deming Xia received his doctoral degree from Dalian University of Technology under the supervision of Prof. Jingwen Chen in December 2021. After finishing his postdoctoral research at Dalian University of Technology (January 2022 to January 2024), he was promoted to be an associate professor at the university. His research focuses on heterogeneous chemistry on water droplet surfaces. He has published 28 peer-reviewed papers.Hong-bin XieHigh Resolution ImageDownload MS PowerPoint SlideDr. Jingwen Chen has been a professor at Dalian University of Technology since 2001. After earning his Ph.D. from Nanjing University in 1997, he performed postdoctoral studies at the German Research Center for Environmental Health as an Alexander von Humboldtian. His research interests cover environmental computational toxicology and ecological risk control technology for synthetic chemicals. He has published more than 360 peer-reviewed papers, reviews, and book chapters, as well as three books (two monographs and one textbook). He served as a member of Teaching Steering Committee on Environmental Science and Engineering of China Ministry of Education, a member of the Environmental Science and Engineering Discipline Evaluation Group of the Academic Degrees Committee of the State Council of China, an Executive Editor and Associated Editor of ACS Sustainable Chemistry & Engineering, and a member of editorial boards of several journals. He was a recipient of the Teaching and Research Award for Outstanding Young Teachers in Higher Education Institutions from the Ministry of Education of China in 2000, a winner (Second Class, second contributor) of the National Natural Science Award in 2011, and a winner (First Class, first contributor) of the Natural Science Award (2023) from the Ministry of Education of China. In 2013, he won the National Science Fund for Distinguished Young Scholars and was appointed as chair professor of the "Cheung Kong Scholars Program" by the China Ministry of Education.References This article references 7 other publications. 1Jiang, Q.; Xia, D. M.; Li, X. F.; Zhang, H.; Yin, R. J.; Xie, H. J.; Xie, H.-b.; Jiang, J.; Chen, J. W.; Francisco, J. S. Rapid N2O Formation from N2 on Water Droplet Surfaces. Angew. Chem., Int. Ed. 2025, 64, e202421002 DOI: 10.1002/anie.202421002 There is no corresponding record for this reference.2Xia, D. M.; Zhang, H.; Ju, Y.; Xie, H.-b.; Su, L.; Ma, F.; Jiang, J.; Chen, J. W.; Francisco, J. S. Spontaneous Degradation of the "Forever Chemicals" Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) on Water Droplet Surfaces. J. Am. Chem. Soc. 2024, 146 (16), 11266– 11271, DOI: 10.1021/jacs.4c00435 There is no corresponding record for this reference.3Qiu, L.; Cooks, R. G. Simultaneous and Spontaneous Oxidation and Reduction in Microdroplets by the Water Radical Cation/Anion Pair. Angew. Chem., Int. Ed. 2022, 61, e202210765 DOI: 10.1002/anie.202210765 3Simultaneous and Spontaneous Oxidation and Reduction in Microdroplets by the Water Radical Cation/Anion PairQiu, Lingqi; Cooks, R. GrahamAngewandte Chemie, International Edition (2022), 61 (41), e202210765CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA) Microdroplets show unique chem., esp. in their intrinsic redox properties, and to this we here add a case of simultaneous and spontaneous oxidn. and redn. We report the concurrent conversions of several phosphonates to phosphonic acids by redn. (R-P → H-P) and to pentavalent phosphoric acids by oxidn. The exptl. results suggest that the active reagent is the water radical cation/anion pair. The water radical cation is obsd. directly as the ionized water dimer while the water radical anion is only seen indirectly though the spontaneous redn. of carbon dioxide to formate. The coexistence of oxidative and reductive species in turn supports the proposal of a double-layer structure at the microdroplet surface, where the water radical cation and radical anion are sepd. and accumulated. >> More from SciFinder ®https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB38XitlGls7nK&md5=f7f3a5f19c80e62ffbc9ff853a552d5b4Heindel, J. P.; LaCour, R. A.; Head-Gordon, T. The Role of Charge in Microdroplet Redox Chemistry. Nat. Commun. 2024, 15, 3670, DOI: 10.1038/s41467-024-47879-0 There is no corresponding record for this reference.5Cooks, R. G.; Holden, D. T. Breaking down microdroplet chemistry. Science 2024, 384, 958– 959, DOI: 10.1126/science.adp7627 There is no corresponding record for this reference.6Casas, G.; Martínez-Varela, A.; Roscales, J. L.; Vila-Costa, M.; Dachs, J.; Jiménez, B. Enrichment of Perfluoroalkyl Substances in the Sea-Surface Microlayer and Sea-Spray Aerosols in the Southern Ocean. Environ. Pollut. 2020, 267, 115512, DOI: 10.1016/j.envpol.2020.115512 6Enrichment of perfluoroalkyl substances in the sea-surface microlayer and sea-spray aerosols in the Southern OceanCasas, Gemma; Martinez-Varela, Alicia; Roscales, Jose L.; Vila-Costa, Maria; Dachs, Jordi; Jimenez, BegonaEnvironmental Pollution (Oxford, United Kingdom) (2020), 267 (), 115512CODEN: ENPOEK; ISSN:0269-7491. (Elsevier Ltd.) Sea-spray (or sea-salt) aerosol (SSA) formation and their subsequent atm. transport and deposition have been suggested to play a prominent role in the occurrence of ionizable perfluoroalkyl substances (PFAS) in the maritime Antarctica and other remote regions. However, field studies on SSA's role as vector of transport of PFAS are lacking. Following a multiphase approach, seawater (SW), the sea-surface microlayer (SML) and SSA were sampled simultaneously at South Bay (Livingston Island, Antarctica). Av. PFAS concns. were 313 pg L-1, 447 pg L-1, and 0.67 pg m-3 in SW, the SML and SSA, resp. The enrichment factors of PFAS in the SML and SSA ranged between 1.2 and 5, and between 522 and 4690, resp. This amplification of concns. in the SML is consistent with the surfactant properties of PFAS, while the large enrichment of PFAS in atm. SSA may be facilitated by the large surface area of SSA and the sorption of PFAS to aerosol org. matter. This is the first field work assessing the simultaneous occurrence of PFAS in SW, the SML and SSA. The large measured amplification of concns. in marine aerosols supports the role of SSA as a relevant vector for long-range atm. transport of PFAS. >> More from SciFinder ®https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXhvVeqs7rJ&md5=bc5c9e2a93a7cfc4a72bb6e2a29060d77Trilla-Prieto, N.; Iriarte, J.; Berrojalbiz, N.; Casas, G.; Sobrino, C.; Vila-Costa, M.; Jiménez, B.; Dachs, J. Enrichment of Organophosphate Esters in the Sea Surface Microlayer from the Atlantic and Southern Oceans. Environ. Sci. Technol. Lett. 2024, 11 (9), 1008– 1015, DOI: 10.1021/acs.estlett.4c00636 There is no corresponding record for this reference.