About

Sally Pusede is an Associate Professor in the Department of Environmental Sciences at the University of Virginia. She holds a Ph.D. from the University of California Berkeley, earned in 2014. Her research as an atmospheric chemist focuses on air quality and climate change, with broad interests that include reactive nitrogen, its role in chemical oxidation, neighborhood-level variability, and emissions of the greenhouse gas nitrous oxide. She leads an atmospheric chemistry research group that makes and utilizes measurements at the Earth’s surface, from aircraft, and from space in polluted cities, agricultural areas, and forest canopies. Her work aims to derive mechanistic insights into atmospheric processes within human-influenced environments and to find solutions to atmospheric problems that adversely affect human health and ecosystems. Pusede is also Co-Director of the Repair Lab, an interdisciplinary environmental justice lab at UVA. Her contributions to the field have been recognized through several awards, including the Presidential Early Career Award for Scientists and Engineers (PECASE) in 2024, the Turco Lectureship from the American Geophysical Union in 2022, and the NSF CAREER Award in 2021.

Research topics

• Atmospheric sciences
• Meteorology
• Environmental science
• Geography
• Chemistry
• Geology
• Physics
• Climatology
• Demography
• Geomorphology
• Mathematics
• Environmental chemistry
• Engineering
• Remote sensing

Selected publications

• Inequality in Hazardous Air Pollutant Emissions and Concentrations Measured Over Los Angeles

  Environmental Science & Technology · 2025-04-12 · 2 citations

  articleOpen access

  In Los Angeles, air pollution disproportionately impacts communities of color and low-income residents. Routine city-wide measurements of hazardous air pollutants (HAPs), of concern for health and contributing to urban air pollution, are notably lacking. In this study, we use the highest spatially resolved (∼2 km) measurements of emissions and concentrations ever reported of HAPs while covering a whole megacity and combine observations with US Census information. We observe higher concentrations and emissions of 17 measured HAPs, such as benzene, naphthalene, and p-chlorobenzotrifluoride (PCBTF), in California-designated Disadvantaged Communities (DACs) and census tracts with low-income Hispanics and Asians. These groups share an unequal burden from traffic-related emissions, with benzene, nitrogen oxides (NOx), and carbon monoxide (CO) concentrations up to 60% higher. However, in DACs and census tracts with large Hispanic populations (>50%), we observe toluene-to-benzene emission ratios above 3, pointing to inequalities in other HAPs primarily caused by non-traffic emission sources such as industry and solvents. In these communities, regulatory inventories also significantly underestimate emissions. We find that efforts to address HAP inequalities and environmental justice concerns in Los Angeles will need to consider contributions from volatile chemical products, which represent a growing source of emissions driving inequalities in impacted communities.

  PublisherDOI

• Satellite Observations of Atmospheric Ammonia Inequalities Associated with Industrialized Swine Facilities in Eastern North Carolina

  Environmental Science & Technology · 2025-01-29 · 6 citations

  articleOpen accessSenior authorCorresponding

  Industrialized swine facilities adversely affect the health and well-being of Eastern North Carolina residents in the U.S. and are an issue of environmental racism. Concentrated animal feeding operations (CAFOs) emit various harmful and noxious air pollutants, including ammonia (NH3). There are limited measurements of CAFO-related air quality, contributing to disputes around its severity. We use NH3 vertical column densities from the space-based Infrared Atmospheric Sounding Interferometer (IASI) to report systematic, distributive inequalities in NH3 column enhancements (ΔNH3 columns), equal to NH3 columns less an observationally determined tropospheric background. Population-weighted block group-scale ΔNH3 columns are higher by 27 ± 3% for Black and African Americans, 35 ± 3% for Hispanics and Latinos, and 49 ± 3% for American Indians compared to non-Hispanic/Latino whites in Eastern North Carolina (April–August 2016–2021). Surface winds and air temperature influence block group-scale NH3 distributions, with higher absolute NH3 inequalities for all groups on calm days and for Black and African Americans and Hispanics and Latinos on hot days, consistent with effects from NH3 volatization downfield of facilities from, e.g., manure-covered fields, particles, and other surfaces. ΔNH3 columns correspond spatially with permitted swine facilities, with residents living multiple kilometers from swine CAFOs chronically exposed to elevated NH3. Trends in NH3 columns over 2008–2023 are driven by regional-scale atmospheric processes rather than localized NH3 changes in CAFO emissions. Results are discussed in local decision-making contexts that have broad relevance for air quality issues without protective federal regulatory standards.

  PublisherDOI

• Inequality in hazardous volatile organic compound (VOC) emissions and concentrations measured over Los Angeles

  2025-03-14

  preprintOpen access

  In the United States, PM2.5 and NOx pollution disproportionately burden communities of color and of lower income. However, such information is lacking when it comes to hazardous air pollutants (HAPs) like toxic volatile organic compounds, for which city-wide measurements are more challenging and thus are not available in routine observations.In this study, we use the highest spatially resolved (~2 km) airborne measurements of emissions and concentrations ever reported of HAPs while covering a whole megacity, and combine these observations with US Census information. We observe higher concentrations and emissions of 17 measured HAPs – such as benzene, naphthalene, and p-chlorobenzotrifluoride (PCBTF) – in California-designated Disadvantaged Communities and census tracts with low-income Hispanics and Asians. While concentrations were on average 32 ± 5% higher for low-income Hispanics compared to high-income non-Hispanic whites, emissions were even 107 ± 21% higher - indicating the proximity of low-income Hispanics to localized emission sources. Low-income Hispanics and Asians share an unequal burden from traffic-related emissions, with benzene, nitrogen oxides (NOx ), and carbon monoxide (CO) concentrations up to 60% higher. However, in Disadvantaged Communities and census tracts with large Hispanic populations (>50%), we observe toluene-to-benzene emission ratios above 3, pointing to inequalities in other HAPs primarily caused by non-traffic emission sources such as industry and solvents. In these communities, regulatory inventories also significantly underestimate the observed emissions. We find that efforts to address HAP inequalities and environmental justice concerns in Los Angeles will need to consider contributions from volatile chemical products, which represent a growing source of emissions driving inequalities in impacted communities.

  PublisherDOI

• Practicing Repair: Advancing Community-Based Solutions on Coal Dust Pollution in Hampton Roads, Virginia, Through a Practitioner-in-Residence Program

  Environmental Justice · 2024-12-09

  articleSenior author

  Communities with environmental justice concerns are best positioned to drive effective local decision making. The Repair Lab Practitioner-in-Residence (PIR) program supports grassroots activists as they identify and implement policy solutions to environmental justice issues affecting their communities. Here, we describe the Repair Lab PIR program through a case study, the residency of two local grassroots environmental justice activists, who are advancing policy solutions for toxic coal dust mitigation from coal export terminals in the Southeast Community of Newport News and Lambert’s Point, Norfolk in Hampton Roads, Virginia. We summarize the history and context of the coal dust issue, ongoing activism and community preferences in both communities, and obstruction and inaction by the state of Virginia. We present the approach of the Repair Lab PIR program, which prioritizes action over research and foregrounds community expertise in decision making. Coal dust mitigation is political, technical, and emotional, and we discuss the available solutions and production of media that both document and affect change. In the Southeast Community, we are pursuing a new nuisance ordinance through the Newport News City Council, and, in Lambert’s Point, we are supporting ongoing advocacy and legal efforts, with the two approaches based on differences in local organizing and priorities and navigating the limitations on the powers of local governance in Virginia. Finally, we share challenges encountered to implement and sustain the Repair Lab PIR program within a university.

  PublisherDOI

• Constraining light dependency in modeled emissions through comparison to observed biogenic volatile organic compound (BVOC) concentrations in a southeastern US forest

  Atmospheric chemistry and physics · 2024-11-12 · 1 citations

  articleOpen access

  Abstract. Climate change will bring about changes in meteorological and ecological factors that are currently used in global-scale models to calculate biogenic emissions. By comparing long-term datasets of biogenic compounds to modeled emissions, this work seeks to improve understanding of these models and their driving factors. We compare speciated biogenic volatile organic compound (BVOC) measurements at the Virginia Forest Research Laboratory located in Fluvanna County, VA, USA, for the year 2020 with emissions estimated by the Model of Emissions of Gases and Aerosols from Nature version 3.2 (MEGANv3.2). The emissions were subjected to oxidation in a 0-D box model (F0AM v4.3) to generate time series of modeled concentrations. We find that default light-dependent fractions (LDFs) in the emissions model do not accurately represent observed temporal variability in regional observations. Some monoterpenes with a default light dependence are better represented using light-independent emissions throughout the year (LDFα-pinene=0, as opposed to 0.6), while others are best represented using a seasonally or temporally dependent light dependence. For example, limonene has the highest correlation between modeled and measured concentrations using an LDF =0 for January through April and roughly 0.74–0.97 in the summer months, in contrast to the default value of 0.4. The monoterpenes β-thujene, sabinene, and γ-terpinene similarly have an LDF that varies throughout the year, with light-dependent behavior in summer, while camphene and α-fenchene follow light-independent behavior throughout the year. Simulations of most compounds are consistently underpredicted in the winter months compared to observed concentrations. In contrast, day-to-day variability in the concentrations during summer months are relatively well captured using the coupled emissions–chemistry model constrained by regional concentrations of NOX and O3.

  PublisherOA PDFDOI

• Neighborhood-Level Nitrogen Dioxide Inequalities Contribute to Surface Ozone Variability in Houston, Texas

  ACS ES&T Air · 2024-07-30 · 2 citations

  articleOpen accessSenior authorCorresponding

  In Houston, Texas, nitrogen dioxide (NO2) air pollution disproportionately affects Black, Latinx, and Asian communities, and high ozone (O3) days are frequent. There is limited knowledge of how NO2 inequalities vary in urban air quality contexts, in part from the lack of time-varying neighborhood-level NO2 measurements. First, we demonstrate that daily TROPOspheric Monitoring Instrument (TROPOMI) NO2 tropospheric vertical column densities (TVCDs) resolve a major portion of census tract-scale NO2 inequalities in Houston, comparing NO2 inequalities based on TROPOMI TVCDs and spatiotemporally coincident airborne remote sensing (250 m × 560 m) from the NASA TRacking Aerosol Convection ExpeRiment–Air Quality (TRACER-AQ). We further evaluate the application of daily TROPOMI TVCDs to census tract-scale NO2 inequalities (May 2018–November 2022). This includes explaining differences between mean daily NO2 inequalities and those based on TVCDs oversampled to 0.01° × 0.01° and showing daily NO2 column-surface relationships weaken as a function of observation separation distance. Second, census tract-scale NO2 inequalities, city-wide high O3, and mesoscale airflows are found to covary using principal component and cluster analysis. A generalized additive model of O3 mixing ratios versus NO2 inequalities reproduces established nonlinear relationships between O3 production and NO2 concentrations, providing observational evidence that neighborhood-level NO2 inequalities and O3 are coupled. Consequently, emissions controls specifically in Black, Latinx, and Asian communities will have co-benefits, reducing both NO2 disparities and high O3 days city wide.

  PublisherOA PDFDOI

• Constraining Light Dependency in Modeled Emissions Through Comparison to Observed BVOC Concentrations in a Southeastern US Forest

  2024-06-18

  preprintOpen accessCorresponding

  Abstract. Climate change will bring about changes in meteorological and ecological factors that are currently used in global-scale models to calculate biogenic emissions. By comparing long-term datasets of biogenic compounds to modeled emissions, this work seeks to improve understanding of these models and their driving factors. We compare speciated BVOC measurements at the Virginia Forest Research Laboratory located in Fluvanna County, VA, USA for the 2020 year with emissions estimated by MEGANv3.2. The emissions were subjected to oxidation in a 0-D box-model (F0AM v4.3) to generate timeseries of modeled concentrations. We find that default light-dependent fractions (LDFs) in the emissions model do not accurately represent observed temporal variability of regional observations. Some monoterpenes with a default light dependence are better represented using light-independent emissions throughout the year (LDFα-pinene=0, as opposed to 0.6), while others are best represented using a seasonally or temporally dependent light dependence. For example, limonene has the highest correlation between modeled and measured concentrations using LDF=0 for January through April and roughly 0.74–0.97 in the summer months, in contrast to the default value of 0.4. The monoterpenes β-thujene, sabinene, and γ-terpinene similarly have an LDF that varies throughout the year, with light-dependent behavior in summer, while camphene and α-fenchene follow light-independent behavior throughout the year. Simulations of most compounds are consistently underpredicted in the winter months compared to observed concentrations. In contrast, day-to-day variability in the concentrations during summer months are relatively well captured using the coupled emissions-chemistry model constrained by regional concentrations of NOx and O3.

  PublisherDOI

• Response to “Comment on ‘State-of-the-Science Data and Methods Need to Guide Place-Based Efforts to Reduce Air Pollution Inequity’”

  Environmental Health Perspectives · 2024-03-01

  articleOpen access
  PublisherDOI

• Supplementary material to "Constraining Light Dependency in Modeled Emissions Through Comparison to Observed BVOC Concentrations in a Southeastern US Forest"

  2024-06-18

  preprintOpen access
  PublisherOA PDFDOI

• Minor contributions of daytime monoterpenes are major contributors to atmospheric reactivity

  Biogeosciences · 2023-01-04 · 12 citations

  articleOpen accessCorresponding

  Abstract. Emissions from natural sources are driven by various external stimuli such as sunlight, temperature, and soil moisture. Once biogenic volatile organic compounds (BVOCs) are emitted into the atmosphere, they rapidly react with atmospheric oxidants, which has significant impacts on ozone and aerosol budgets. However, diurnal, seasonal, and interannual variability in these species are poorly captured in emissions models due to a lack of long-term, chemically speciated measurements. Therefore, increasing the monitoring of these emissions will improve the modeling of ozone and secondary organic aerosol concentrations. Using 2 years of speciated hourly BVOC data collected at the Virginia Forest Research Lab (VFRL) in Fluvanna County, Virginia, USA, we examine how minor changes in the composition of monoterpenes between seasons are found to have profound impacts on ozone and OH reactivity. The concentrations of a range of BVOCs in the summer were found to have two different diurnal profiles, which, we demonstrate, appear to be driven by light-dependent versus light-independent emissions. Factor analysis was used to separate the two observed diurnal profiles and determine the contribution from each emission type. Highly reactive BVOCs were found to have a large influence on atmospheric reactivity in the summer, particularly during the daytime. These findings reveal the need to monitor species with high atmospheric reactivity, even though they have low concentrations, to more accurately capture their emission trends in models.

  PublisherOA PDFDOI

Recent grants

• CAREER: Observational Constraints on Neighborhood-level Air Quality in Major United States cities and Dakar, Senegal

  NSF · $678k · 2021–2026

• Collaborative Research: Understanding Ozone-Ecosystem Controls and Feedbacks across Landscapes through Leaf- and Canopy-Scale Measurements

  NSF · $367k · 2018–2022

Frequent coauthors

• R. C. Cohen

  University of California, Berkeley

  84 shared

• E. C. Browne

  Cooperative Institute for Research in Environmental Sciences

  43 shared

• Glenn S. Diskin

  36 shared

• K.‐E. Min

  State Key Laboratory For Conservation and Utilization of Subtropical Agro-Bioresources

  34 shared

• Xinrong Ren

  31 shared

• Alan Fried

  Institute of Arctic and Alpine Research

  31 shared

• Joshua P. DiGangi

  Langley Research Center

  30 shared

• A. H. Goldstein

  28 shared

Education

• PhD, Chemistry

  University of California Berkeley

  2014

Awards & honors

• Presidential Early Career Award for Scientists and Engineers…
• Future Horizons in Climate Science Turco Lectureship, Americ…
• National Science Foundation (NSF) CAREER Award, 2021
• NASA New Investigator Program Award, 2021
• Environmental Sciences Organization Faculty Teaching Award,…