About

Jill Johnston, PhD, is an Associate Professor and Director of Community Engagement in the Department of Environmental & Occupational Health at the University of California, Irvine. Her research focuses on addressing unequal exposures to harmful contaminants that affect the health of working poor and communities of color. She collaborates with grassroots organizations to conduct community-engaged, action-oriented research aimed at supporting environmental health. Dr. Johnston works to build strong partnerships with local organizations, community health workers (promotoras), policymakers, and residents to address issues such as air pollution, upstream oil and gas extraction, and incompatible land use. Prior to her academic career, she worked as a community organizer on environmental and economic justice issues in South Texas. She earned her PhD in environmental sciences and engineering from the University of North Carolina at Chapel Hill, where her research focused on hazardous waste sites and industrial animal production.

Research topics

• Social Science
• Computer Science
• Sociology
• Political Science
• Environmental science
• Public relations
• Psychology
• Engineering ethics
• Engineering
• Geography
• Environmental planning
• Environmental resource management
• Business
• Ecology

Selected publications

• Particulate matter levels and children’s lung function in a rural cohort near a drying saline lake

  Environmental Epidemiology · 2026-01-08 · 2 citations

  articleOpen accessSenior author

  Introduction: The drying Salton Sea in California is a growing source of wind-blown dust, raising particulate matter (PM) levels in surrounding areas. The impacts of these exposures on children’s lung function remain poorly understood. We examined the relationship between PM levels and lung function in children near the Salton Sea. Methods: We enrolled 491 children (mean age: 10.2 years), who were followed over ~1.5 years, contributing 1,269 lung function assessments. Forced expiratory volume in the first second of exhalation (FEV 1 ) and forced vital capacity (FVC) were measured using a commercial spirometer. Average PM concentrations were estimated for 3 and 12 months preceding each spirometry assessment, using 12 stationary monitors operated by the California Air Resources Board. Analyses were performed using mixed effects linear models adjusting for demographics and underlying health conditions. Measurements and Results: Each 1 µg/m³ increase in average PM 2.5 exposure over 12 months before assessment was associated with a 31.5 ml lower FVC (95% confidence interval [CI] = −57.2, −5.9) and a 32.7 ml lower FEV 1 (95% CI = −56.4, −8.9). A 10-µg/m 3 increase in average PM 10 exposure over 12 months was associated with a 146.6 ml reduction in FVC (95% CI = −230.4, −62.9) and a 122.0 ml reduction in FEV 1 (95% CI = −197.8, −46.2). Associations within a 3-month exposure window showed similar results. PM exposure was associated with impaired lung function in both asthmatic and non-asthmatic children, with a slightly greater impact observed in those with asthma. Conclusion: PM exposure near the Salton Sea is related to reduced lung function of pediatric residents.

  PublisherDOI

• Supplementary material to "Evaluating machine learning model performance in a two-step colocation process for TVOC and BTEX sensor calibration"

  2025-10-29

  articleOpen access
  PublisherDOI

• Evaluating machine learning model performance in a two-step colocation process for TVOC and BTEX sensor calibration

  Atmospheric measurement techniques · 2025-10-29

  articleOpen access

  Abstract. Calibration of low-cost air quality sensors (LCSs) for total volatile organic compound (TVOC) and benzene, toluene, ethylbenzene, and xylenes (BTEX) quantification remains challenging due to the sensors' cross-sensitivity to temperature and humidity and their tendency to drift over time. In this study, we aimed to improve TVOC and BTEX metal oxide (Figaro TGS 2600, 2602, 2611) sensor calibration using a two-step colocation strategy. A two-step colocation places one LCS (the secondary standard) with a reference monitor while others operate in the field, then briefly colocates the field sensors with the secondary standard to address inter-sensor variability and drift. This strategy made it possible to develop the calibration model under environmental conditions closely matching those of the field, which is essential for model transferability from colocation to field conditions. In addition to TVOC and BTEX, we applied the two-step colocation process to NO2 electrochemical (Alphasense B-4) sensors to demonstrate the broader applicability of our approach beyond TVOC and BTEX quantification. Next, we compared the performance of multiple machine learning models, including ridge, lasso, random forest, gradient boosting, extreme gradient boosting, support vector regression, and linear regression, to investigate the optimal model choice for calibration. We found that no single model performed best across all pollutants. For example, gradient boosting excelled at capturing peak TVOC concentrations, while linear regression performed best for BTEX. Conversely, linear regression was the worst-performing model for NO2. Overall, the models showed satisfactory RMSE around 40–50 ppb for TVOC, 1.25–1.75 ppb for BTEX, and 4–6 ppb for NO2. However, all models also overestimated baseline concentrations and underestimated peaks. The severity of this bias depended on the reference concentration distribution, with the most severe peak underestimation occurring in the more heavily skewed TVOC and BTEX data. The systematic bias at baseline and peak concentrations was not evident in the overall mean bias error, which was near zero for all pollutants. This result underscores the need to evaluate model performance across the entire concentration distribution. Finally, we found that calibration performance was sensitive to the choice of training and testing data split. Future research could seek to optimize the training and testing split to ensure robust model transferability to field data.

  PublisherDOI

• Multiple chemical sensitivity (MCS) validity, prevalence, tools and interventions: systematic review protocol

  BMJ Open · 2025-05-01 · 4 citations

  articleOpen accessSenior author

  INTRODUCTION: Multiple chemical sensitivity (MCS) describes reported adverse reactions to exposure to common chemical agents (solvents, odourants, air pollutants, material or substances) in low doses tolerated by most people. Symptoms involve more than one organ system and responses are triggered by multiple, chemically unrelated substances. METHODS AND ANALYSIS: The systematic review will aim to answer six questions: Which definitions of MCS have been validated? What is the diagnostic performance of tools for identifying MCS? What is the prevalence and incidence of MCS? What is the empirical evidence that MCS is a distinct disorder? What is the empirical evidence for underlying biological mechanisms for MCS? What are the effectiveness and safety of treatment and management strategies for MCS?We will conduct a comprehensive search in 22 multidisciplinary databases for primary and secondary research, research registries and clinical practice guideline repositories. We will reference-mine reviews and included studies, and confer with experts. Screening will be conducted in duplicate against prespecified eligibility criteria. Data abstraction will be pilot tested using detailed data abstraction forms to ensure accuracy and minimise ambiguity. Critical appraisal will be specific to the key question. We will synthesise data in comprehensive tables and figures. Where possible, meta-analysis will use random effects models to determine effect sizes. ETHICS AND DISSEMINATION: This study was determined to be exempt from review (UP-22-00516). The results will be disseminated through a journal manuscript, and the data will be publicly accessible through an online data repository. PROSPERO REGISTRATION NUMBER: CRD420250645577.

  PublisherDOI

• Dust Events and Children’s Lung Function Near a Drying Saline Lake

  American Journal of Respiratory and Critical Care Medicine · 2025-10-10 · 2 citations

  articleSenior author
  PublisherDOI

• A co-created, community-informed model for electric vehicle adoption in disadvantaged communities

  Transportation Research Part D Transport and Environment · 2025-06-05 · 3 citations

  articleOpen access

  To co-create a community-informed model of EV adoption, we conducted one English-speaking and two Spanish-speaking focus groups with 29 residents from six disadvantaged urban communities in Southeast Los Angeles. Participants were asked whether they owned an EV or hybrid vehicle, benefits and obstacles to EV ownership, and recommendations for making EV adoption feasible and acceptable. A Community Advisory Council participated in preparation of an interview guide and a review of findings. Social, environmental and personal benefits were cited as reasons for EV ownership but were considered secondary to cost, limited infrastructure (e.g., chargers), and lack of information. This information was used to generate a logic model listing adoption determinants, strategies, causal mechanisms and outcomes. A community informed model serves as a potential tool for promoting the adoption of EVs in disadvantaged communities and creating the conditions necessary for such adoption to be perceived by residents as acceptable, feasible, and appropriate.

  PublisherDOI

• Adverse Birth Outcomes Associated with Heat Stress and Wildfire Smoke Exposure During Preconception and Pregnancy

  Environmental Science & Technology · 2025-06-18 · 7 citations

  articleOpen access

  We investigated associations between preconception and prenatal heat stress and wildfire (WF) smoke exposures on adverse birth outcomes and whether neighborhood climate vulnerability is an effect modifier in the Maternal And Developmental Risks from Environmental and Social stressors cohort (N = 713). Generalized linear models were fit to test the association between exposures and small-for-gestational-age (SGA), low birthweight (LBW), and Fenton growth z-score outcomes, adjusting for confounders. Living in a high climate vulnerability index neighborhood was tested as an effect modifier. During preconception, increases in heat stress and WF measures were associated with higher odds of SGA. Living in the most climate-vulnerable neighborhoods during preconception significantly modified and nearly doubled the odds of SGA with exposure to heat stress. Similarly, heat stress and WF exposure in trimester-specific time periods were associated with adverse birth outcomes. Conversely, third-trimester exposures were associated with lower odds of LBW. Throughout pregnancy, two measures of infant size (SGA and Fenton z-scores) were lower among those with greater exposure to multiple WF exposures. This study highlights how living in more climate-vulnerable neighborhoods significantly modifies the effect of heat stress on SGA, suggesting that the increasing adaptation capacity of communities may strengthen climate change resilience.

  PublisherDOI

• Development of the Navigation Guide Evidence-to-Decision Framework for Environmental Health: Version 1.0

  SSRN Electronic Journal · 2025-01-01

  articleOpen access
  PublisherDOI

• Wastewater Disposal Wells, Fracking, and Environmental Injustice in Southern Texas

  UNC Libraries · 2025-09-20

  articleOpen accessSenior author

  OBJECTIVES: To investigate race and poverty in areas where oil and gas wastewater disposal wells, which are used to permanently inject wastewater from hydraulic fracturing (fracking) operations, are permitted. METHODS: With location data of oil and gas disposal wells permitted between 2007 and 2014 in the Eagle Ford area, a region of intensive fracking in southern Texas, we analyzed the racial composition of residents living less than 5 kilometers from a disposal well and those farther away, adjusting for rurality and poverty, using a Poisson regression. RESULTS: The proportion of people of color living less than 5 kilometers from a disposal well was 1.3 times higher than was the proportion of non-Hispanic Whites. Adjusting for rurality, disposal wells were 2.04 times (95% confidence interval = 2.02, 2.06) as common in areas with 80% people of color or more than in majority White areas. Disposal wells are also disproportionately sited in high-poverty areas. CONCLUSIONS: Wastewater disposal wells in southern Texas are disproportionately permitted in areas with higher proportions of people of color and residents living in poverty, a pattern known as "environmental injustice."

  PublisherDOI

• Prenatal Psychosocial Stressors and Blood Pressure Across 4 Years Postpartum

  Hypertension · 2025-02-10 · 2 citations

  articleOpen access

  BACKGROUND: Psychosocial stress is a cardiovascular risk factor; however, little is known about whether prenatal psychosocial stressors influence postpartum cardiovascular health. We aimed to examine the associations of multiple measures of prenatal psychosocial stress on maternal blood pressure (BP) in the first 4 years after birth. METHODS: Among 225 MADRES cohort (Maternal and Developmental Risks From Environmental and Social Stressors) participants, we examined associations of average prenatal Perceived Stress Scale (PSS), Center for Epidemiological Studies Depression (CES-D) scores, and second-trimester neighborhood social cohesion scores on systolic and diastolic BP collected at annual postpartum study visits (1–4 years) using linear mixed-effects models, adjusted for covariates. RESULTS: Higher prenatal PSS and CES-D scores were associated with greater diastolic BP at 1 year postpartum (0.24 [95% CI, 0.01–0.46] and 0.24 [95% CI, 0.08–0.40] mm Hg per 1-unit higher PSS and CES-D, respectively) and greater systolic BP (0.25 [95% CI, 0.02–0.48] mm Hg per 1-unit higher CES-D). Overall associations of PSS and CES-D with BP were attenuated over the 4-year postpartum period ( P <0.05). Stratified analyses suggested larger associations of PSS and CES-D among US-born participants and participants with normotensive pregnancies. While neighborhood social cohesion was not associated with postpartum BP overall, higher neighborhood social cohesion scores were associated with lower BP at 1 year postpartum among participants with normotensive pregnancies and lower systolic BP among foreign-born Hispanic participants. CONCLUSIONS: Higher prenatal perceived stress and depressive symptoms were associated with greater 1-year postpartum BP, whereas neighborhood cohesion was associated with lower 1-year postpartum BP. These results suggest prenatal psychosocial factors may impact cardiovascular health within the first year after birth.

  PublisherOA PDFDOI

Frequent coauthors

• Jeffry Nugent

  Southern California University for Professional Studies

  4 shared

• Enrico Lombardino

  4 shared

• Henri Theil

  3 shared

• Hunna J. Watson

  University of North Carolina at Chapel Hill

  3 shared

• E.L. Dougherty

  2 shared

• Bascer Zagalai

  Southern California University for Professional Studies

  2 shared

• Bascer Zaga

  Southern California University for Professional Studies

  2 shared

• Carl Johan Åberg

  2 shared

Labs

• Community & Environment Research LabPI

Education

• PhD, Environmental Sciences & Engineering

  University of North Carolina

Awards & honors

• Robert M. Zweig, M.D. Memorial Award, South Coast Air Qualit…
• Clean Air Award, South Coast Air Quality Management District
• Anita Tarr Turk Fund Award for breast Cancer Research, Commu…
• Clean Air Unsung Hero Award, California Clean Air Day, Coali…
• Angel Award, Barrio Planners & East Los Angeles Community Yo…