About

Suzanne Paulson is a Professor and the Director of the Center for Clean Air at the Department of Atmospheric and Oceanic Sciences at UCLA. She holds a Ph.D. in Environmental Engineering Science from the California Institute of Technology, obtained in 1991, and has earned two MS degrees—one in Environmental Engineering Science from Caltech and another in Plant Biology from the University of Illinois—as well as a BA in Chemistry from the University of Colorado. Her current research focuses on the chemistry occurring in cloud droplets and its impact on atmospheric aerosols, pollutant concentrations and their sources in urban environments at high spatial scales, and the application of quantum-enhanced technology to sensors for air pollution, climate, and public health. She is also engaged in understanding the health effects of particles, air pollution in Africa, and employs a variety of tools including field and laboratory measurements, modeling, bibliometrics, and machine learning techniques. Suzanne Paulson has received notable awards such as an NSF CAREER award and a Fulbright Specialist Award for her work in Senegal. She frequently collaborates with journalists on air quality topics, has given over 80 invited lectures, and is actively involved in public discussions on air quality and pollution.

Research topics

• Chemistry
• Environmental science
• Atmospheric sciences
• Environmental chemistry
• Physics
• Environmental health
• Geography
• Organic chemistry
• Meteorology
• Medicine
• Biochemistry
• Geology
• Environmental engineering
• Inorganic chemistry
• Mineralogy

Selected publications

• The John H. Seinfeld Festschrift

  ACS ES&T Air · 2026-04-10

  article
  PublisherDOI

• Short-lived reactive components substantially contribute to particulate matter oxidative potential

  Science Advances · 2025-03-19 · 13 citations

  articleOpen access

  Exposure to airborne particulate matter (PM) has been attributed to millions of deaths annually. However, the PM components responsible for observed health effects remain unclear. Oxidative potential (OP) has gained increasing attention as a key property that may explain PM toxicity. Using online measurement methods that impinge particles for OP quantification within seconds, we reveal that 60 to 99% of reactive oxygen species (ROS) and OP in secondary organic aerosol and combustion-generated PM have a lifetime of minutes to hours and that the ROS activity of ambient PM decays substantially before offline analysis. This implies that current offline measurement methods substantially underestimate the true OP of PM. We demonstrate that short-lived OP components activate different toxicity pathways upon direct deposition onto reconstituted human bronchial epithelia. Therefore, we suggest that future air pollution and health studies should include online OP quantification, allowing more accurate assessments of links between OP and health effects.

  PublisherDOI

• An interlaboratory comparison to quantify oxidative potential measurement in aerosol particles: challenges and recommendations for harmonisation

  Atmospheric measurement techniques · 2025-01-13 · 14 citations

  articleOpen access

  Abstract. This paper presents the findings from a collaborative interlaboratory comparison exercise designed to assess oxidative potential (OP) measurements conducted by 20 laboratories worldwide. This study represents an innovative effort as the first exercise specifically aimed at harmonising this type of OP assay, setting a new benchmark in the field. Over the last decade, there has been a noticeable increase in OP studies, with numerous research groups investigating the effects of exposure to air pollution particles through the evaluation of OP levels. However, the absence of standardised methods for OP measurements has resulted in variability in results across different groups, rendering meaningful comparisons challenging. To address this issue, this study engages in an international effort to compare OP measurements using a simplified method (with a dithiothreitol (DTT) assay). Here, we quantify the OP in liquid samples to focus on the protocol measurement itself, while future international OP interlaboratory comparisons (ILCs) should aim to assess the whole chain process, including the sample extraction. We analyse the similarities and discrepancies observed in the results, identifying the critical parameters (such as the instrument used, the use of a simplified protocol, the delivery and analysis time) that could influence OP measurements and provide recommendations for future studies and interlaboratory comparisons even if other crucial aspects, such as sampling PM methods, sample storage, extraction methods and conditions, and the evaluation of other OP assays, still need to be standardised. This collaborative approach enhances the robustness of the OP DTT assay and paves the way for future studies to build on a unified framework. This pioneering work concludes that interlaboratory comparisons provide essential insights into the OP metric and are crucial to move toward the harmonisation of OP measurements.

  PublisherOA PDFDOI

• Inhalation of electrophilic and redox active electronic cigarette aerosol increases oxidative potential in the lung in an acute manner

  Free Radical Biology and Medicine · 2025-08-28 · 1 citations

  article
  PublisherDOI

• Towards Realizing Schawlow-Townes Limited Dual-comb Spectroscopy with an Analog Feed-Forward Approach

  2025-01-01

  article

  Near Schawlow-Townes noise-limited dual-comb spectroscopy can be realized through analog feed-forward stabilization of carrier envelope phase. We present such a system, for applications in precision atmospheric sensing.

  PublisherDOI

• Cloud Water Chemistry and Aerosol Processing: Assessing the Hydroxyl Radical Burst in Newly Formed Cloud Droplets (Field Campaign Report)

  2024-05-01

  reportOpen access1st authorCorresponding

  Aerosol particles are tiny liquid or solid particles in the atmosphere, ranging in size from a few nanometers to several micrometers in diameter. Aerosol-cloud interactions are the most uncertain aspect of the climate system, and models routinely underpredict aerosol particle formation. Clouds are well known to alter aerosol size, chemical composition, and radiative properties, but the processes are poorly characterized. Organics and sulfates are the most abundant materials in particles, and for each of these there are significant gaps in the understanding of the role of clouds in their formation and/or aging. Many of the cloud processes are driven by aqueous chemistry that depends on hydroxyl (OH) radicals, the subject of this project.

  PublisherOA PDFDOI

• Coastal Cloud Chemistry during EPCAPE Field Campaign Report

  2024-12-01

  reportOpen accessSenior author

  For this campaign, Principal Investigator Markus Petters deployed a suite of instruments inside Lynn Russell’s container that was sited at Mt. Soledad during the Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) campaign. Funding for this activity was provided by National Science Foundation Award 2410536. The instrument rack (Figure 1) included a differential mobility analyzer, a condensation particle counter, a portable optical particle spectrometer, and a continuous flow diffusion cloud condensation nuclei counter (CCN). The instruments sampled from a counterflow virtual impactor (CVI) inlet and an isokinetic inlet. The measurements provided aerosol size distribution, size-resolved CCN activity, and denuded versus undenuded CCN activity of aerosols and cloud drop residuals.

  PublisherDOI

• Characterizing Hydroxyl Radical Formation from the Light-Driven Fe(II)–Peracetic Acid Reaction, a Key Process for Aerosol-Cloud Chemistry

  Environmental Science & Technology · 2024-04-15 · 12 citations

  articleOpen accessSenior authorCorresponding

  The reaction of peracetic acid (PAA) and Fe(II) has recently gained attention due to its utility in wastewater treatment and its role in cloud chemistry. Aerosol-cloud interactions, partly mediated by aqueous hydroxyl radical (OH) chemistry, represent one of the largest uncertainties in the climate system. Ambiguities remain regarding the sources of OH in the cloud droplets. Our research group recently proposed that the dark and light-driven reaction of Fe(II) with peracids may be a key contributor to OH formation, producing a large burst of OH when aerosol particles take up water as they grow to become cloud droplets, in which reactants are consumed within 2 min. In this work, we quantify the OH production from the reaction of Fe(II) and PAA across a range of physical and chemical conditions. We show a strong dependence of OH formation on ultraviolet (UV) wavelength, with maximum OH formation at λ = 304 ± 5 nm, and demonstrate that the OH burst phenomenon is unique to Fe(II) and peracids. Using kinetics modeling and density functional theory calculations, we suggest the reaction proceeds through the formation of an [Fe(II)–(PAA)2(H2O)2] complex, followed by the formation of a Fe(IV) complex, which can also be photoactivated to produce additional OH. Determining the characteristics of OH production from this reaction advances our knowledge of the sources of OH in cloudwater and provides a framework to optimize this reaction for OH output for wastewater treatment purposes.

  PublisherOA PDFDOI

• Association of ischemic placental disease in a Southern California Birth Cohort and PM_2.5 chemical species and oxidative potential markers

  Environmental Research Health · 2024-05-24 · 1 citations

  articleOpen access

  Abstract Road traffic is a significant source of particulate matter pollution, whose exposure is a significant risk factor in pregnancy-related health outcomes. The exact mechanisms behind the relationship between traffic-related air pollution (TRAP) exposure and adverse pregnancy outcomes remain unclear. We aim to assess the relationship between exposure to brake and tire wear-associated metals and oxidative potential and ischemic placental disease (IPD). Data were assembled from a final population of 178 women who sought specialized prenatal care at UCLA between 2016 and 2019 in Los Angeles, CA. Modeled first trimester exposures to chemical constituents and oxidative stress potential of PM 2.5 , black carbon, and PM 2.5 mass concentration. Speciated measurements included tracers of brake wear (barium), tire wear (zinc), and oxidative potential markers based on metal concentrations (KM-SUB-ELF ROS) or laboratory assays (DTT loss, OH radical formation). Exposures were modeled by integrating data from filter samples, a low-cost PM 2.5 sensor network, and land-use data. We used logistic regression to estimate the associations between air pollution exposures and IPD, adjusting for covariates assessed through medical records and interviews. Scaled to the interquartile range, odds ratios (95% CI) were as follows: barium OR: 1.7 (1.1, 2.7), zinc OR: 1.4 (.86, 2.4), and oxidative potential markers, both modeled as well as measured through DTT loss and OH formation assays (ORs ranging from 1.1-2.0). Point estimates of effect sizes for PM 2.5 and black carbon were lower than most measurements (ORs: 1.3-1.4). mass and black carbon. Our findings suggest two key points: (i) metals associated with brake and tire wear, currently unregulated, may play a role in the relationship between TRAP and adverse pregnancy outcomes, and (ii) reducing tailpipe emissions may not be sufficient to protect pregnant women from TRAP.

  PublisherOA PDFDOI

• Supplementary material to "An interlaboratory comparison to quantify oxidative potential measurement in aerosol particles: challenges and recommendations for harmonisation"

  2024-07-24

  preprintOpen access
  PublisherDOI

Recent grants

• Understanding the Burst of Hydroxyl Radicals (OH) in Newly Formed Cloud Droplets

  NSF · $514k · 2020–2025

• Production of Secondary Organic Aerosol: Formation of Acids, Peroxides and Multifunctional Oxidation Products

  NSF · $589k · 2001–2005

• Collaborative Research: Reactivity Associated with Ambient Particles: Hydrogen Peroxide, Quinones, Transition Metals and Hydroxyl Radical

  NSF · $630k · 2011–2017

Frequent coauthors

• Alam S. Hasson

  California State University, Fresno

  17 shared

• Arthur M. Winer

  16 shared

• Won‐Sik Choi

  Pukyong National University

  15 shared

• John H. Seinfeld

  California Institute of Technology

  14 shared

• Myeong Y. Chung

  California State University, Fresno

  13 shared

• Yifang Zhu

  China Automotive Technology and Research Center

  13 shared

• Richard C. Flagan

  California Institute of Technology

  12 shared

• Keith T. Kuwata

  Macalester College

  12 shared

Labs

• Paulson GroupPI

Education

• Ph.D., Environmental Engineering Science

  California Institute of Technology

  1991

Awards & honors

• NSF CAREER Award
• Fulbright Specialist Award