About

Dr. Jun Wu is a Professor in Environmental and Occupational Health at the Joe C. Wen School of Population & Public Health, University of California, Irvine. She earned her Ph.D. in Environmental Health Sciences from the University of California, Los Angeles in 2004. Dr. Wu's research focuses on population-based studies in environmental exposure assessment, environmental epidemiology, and environmental health disparity. She has extensive expertise in examining the combined effects of various environmental exposures such as air pollution, climate, and built environment factors like green space, alongside socioeconomic determinants, on reproductive outcomes including maternal and fetal health, children's health, and other health endpoints. Additionally, Dr. Wu is deeply engaged in research on environmental justice and health disparities, often collaborating closely with communities to address these issues. Her work has been recognized with multiple awards including the 2023 Athalie Clarke Achievement Award in Public Health, the 2023 Delta Omega Public Health Faculty Honoree, the 2014 Joan M. Daisey Outstanding Young Scientist Award from the International Society of Exposure Science, and the 2010 Walter A. Rosenblith New Investigator Award from the Health Effects Institute.

Research topics

• Environmental health
• Medicine
• Biology
• Environmental science
• Ecology
• Geography
• Sociology
• Environmental planning
• Computer Science
• Chemistry
• Socioeconomics
• Obstetrics
• Internal medicine
• Endocrinology
• Regional science
• Demography
• Environmental protection

Selected publications

• Fusing Time-Series Harmonic Phenology and Ensemble Learning for Enhanced Paddy Rice Mapping and Driving Mechanisms Analysis in Anhui, China

  Agriculture · 2026-02-16

  articleOpen access

  Accurate and timely mapping of paddy rice is essential for agricultural management, food security, and climate-resilient policy. However, high-precision mapping remains challenging in subtropical monsoon regions due to persistent cloud cover, long revisit intervals, and striping noise, which compromise satellite data quality and availability. To address these limitations, a rice mapping framework suitable for different geographical environments was developed based on a random forest (RF) by combining time-series harmonic analysis (HANTS) with Sentinel-1 and Sentinel-2 multi-source data. To address these limitations, a rice mapping classification algorithm for different geographical environments was developed by combining Harmonic Analysis of Time Series (HANTS) with Sentinel-1/2 multi-source data. The research obtained annual maps of single-season and double-season rice in the research area from 2019 to 2024, with a spatial resolution of 10 m. The results indicated that the Sentinel-1, Sentinel-2, GEE, and HANTS algorithm can effectively support the yearly mapping of single- and double-season paddy rice in Anhui Province, China. The resultant paddy rice map has a high accuracy with overall accuracies exceeding 92% and Kappa coefficients above 0.84. HANTS effectively captures key phenological features of paddy rice, and it can especially enhance the discrimination between single- and double-season rice; compared to existing rice mapping products, the proposed approach reduces classification errors by an average of 3.92% in six major rice-producing cities, each with cultivation areas exceeding 1 million hectares; spatial correlation analysis indicates substantial heterogeneity in rice cultivation patterns across northern, central, and southern Anhui, associated with both biophysical and anthropogenic factors. These results indicate that integrating phenological data with machine learning can enhance the accuracy of long-term, high-resolution crop monitoring, and annual rice maps will offer valuable support for food security assessment, water resource management, and policy planning.

  PublisherDOI

• Area deprivation, social vulnerability, and post-pregnancy blood pressure

  medRxiv · 2026-02-12

  articleOpen access

  Abstract Introduction Pregnancy is a critical test of women’s cardiovascular risk. Structural factors may influence long-term cardiovascular health beyond individual, social experiences. We examined associations of neighborhood-level deprivation and individual-level social vulnerability (SV) during pregnancy with postpartum blood pressure (BP). Methods This secondary analysis of a prospective cohort study used data from 3,728 nulliparous women in the nuMoM2b-HHS cohort followed from early pregnancy to 2-7 years post-delivery (Mage: 30.8 years, 65% non-Hispanic White, 14% with adverse pregnancy outcomes [APOs]). Multivariable linear and logistic regression models tested relations of the Area Deprivation Index (ADI) and SV (a composite of perceived stress, discrimination, pregnancy experiences, social support, health literacy, depression, and anxiety) with systolic BP (SBP), diastolic BP (DBP), and incident hypertension, adjusting for demographic and behavioral covariates. Effect modification by APO history was assessed. Results In unadjusted models, both ADI and greater SV were positively associated with SBP and DBP (all ps <0.001). After adjustment, ADI remained positively associated with BP: each 10-unit increase in ADI was associated with 1.0 mmHg higher SBP ( p =0.008) and 0.6 mmHg higher DBP ( p =0.013). However, SV was no longer associated with BP after adjustment. ADI and SV were not associated with incident hypertension. No evidence of effect modification by APO history was observed (interactions p >0.20). Conclusions Neighborhood deprivation during pregnancy was associated with higher BP up to seven years later, independent of individual social vulnerability. Structural context during pregnancy may contribute to early maternal cardiovascular risk.

  PublisherOA PDFDOI

• Ambient Air Pollution and Chronic Obstructive Pulmonary Disease: The Multiethnic Cohort Study

  Annals of the American Thoracic Society · 2025-01-23 · 5 citations

  articleOpen access

  Abstract Rationale Globally, chronic obstructive pulmonary disease (COPD) was the third leading cause of death in 2019. Although tobacco smoking is the predominant risk factor, the role of long-term air pollution exposure in increasing the risk of COPD remains unclear. Moreover, few studies that account for smoking history and other known risk factors have been conducted in racially and ethnically minoritized and socioeconomically diverse populations. Objectives We sought to evaluate the association of ambient air pollution with COPD in a multiethnic population in California. Methods In the Multiethnic Cohort Study of 38,654 African-American, Japanese-American, Latino, and White California participants who were enrolled in the fee-for-service component of Medicare, we used Cox proportional hazards regression to estimate the association of time-varying ambient air pollutants—particulate matter with an aerodynamic diameter ⩽2.5 μm or ⩽10 μm, nitrogen dioxide, carbon monoxide, ozone, benzene, and ultrafine particles (UFPs)—with COPD risk (n = 10,915 cases; 8.8 yr of follow up). Subgroup analyses were conducted by race and ethnicity, sex, smoking status as recorded on the Multiethnic Cohort Study baseline questionnaire, and neighborhood socioeconomic status. Results We observed a positive association of nitrogen oxide (per 50 ppb) with risk of COPD (hazard ratio = 1.45; 95% confidence interval = 1.35–1.55). The associations of nitrogen dioxide (per 20 ppb), particulate matter with an aerodynamic diameter ⩽2.5 μm (10 μg/m3) or ⩽10 μm (10 μg/m3), carbon monoxide (1,000 ppb), and UFPs (interquartile range = 5,241.7 particles/cm3) with risk of COPD were in similar directions, as these air pollutants are highly correlated with nitrogen oxide. These associations were found in African-American, Latino, and Japanese-American participants, but not in Whites (P heterogeneity across race and ethnicity <0.04). These associations also differed by neighborhood socioeconomic status, with effects being stronger in racially and ethnically minoritized populations and residents of low-SES neighborhoods. Conclusions Long-term ambient air pollutant exposure is associated with COPD risk in a multiethnic, older adult (age >65 yr) population.

  PublisherOA PDFDOI

• Dual-responsive copper complex delivered by dissolvable microneedle promotes polymicrobial infection eradication and cutaneous wound healing

  Materials Today Bio · 2025-08-21 · 1 citations

  articleOpen access

  release, offering a streamlined management of cross-kingdom polymicrobial infections and immunomodulation wound healing.

  PublisherDOI

• Wildfire risk perception and communication in disadvantaged communities: Insights from Eastern Coachella Valley in Southern California

  International Journal of Disaster Risk Reduction · 2025-01-09 · 6 citations

  articleOpen accessSenior authorCorresponding

  Understanding factors associated with wildfire risk perception and preferences for risk communication strategies is crucial for promoting individual risk reduction behaviors and enhancing educational campaigns. Given a lack of research focusing on disadvantaged communities with low socioeconomic status, we administered an in-person survey from February to April 2023 in four unincorporated communities in Eastern Coachella Valley to collect information on wildfire experiences and community preparedness. We used multivariate logistic regressions to identify potential predictors of wildfire risk perception, such as sociodemographic characteristics, previous wildfire experiences, and social participation. We performed Chi-square or Fisher’s exact tests to examine whether preferences for risk communication varied across sociodemographic groups. Among 115 participants with wildfire experiences, 113 (98.3%) were self-identified as Hispanic/Latino and 69 (60.0%) had an annual household income below $25,000. Higher safety awareness, more participation in community or social groups, and poorer health were associated with increased wildfire risk perception. Short messages were preferred for wildfire alerts, and television was the most favored information channel. Social media was the most preferred channel among young adults. Elderly individuals and those lacking a high school education were more likely to seek information from doctors than other groups. Agricultural workers relied more on mobile phone texts and personal observations than those in other occupations. Our study highlights significant gaps in preparedness and the inadequacies of current wildfire risk communication in these disadvantaged communities, underscoring the importance of leveraging social interactions to enhance wildfire risk awareness and implementing tailored communication strategies that effectively reach targeted populations. • Social interaction can positively influence wildfire risk perception. • Safety awareness was significantly associated with wildfire risk perception. • Wildfire risk communication preferences vary by sociodemographic factors. • There is a severe inadequacy of risk communication in disadvantaged communities.

  PublisherDOI

• Knowledge-Informed Deep Learning to Mitigate Bias in Joint Air Pollutant Prediction

  SSRN Electronic Journal · 2025-01-01

  preprintOpen access
  PublisherDOI

• Abstract B155: Association between mortgage lending bias and smoking cessation: The Multiethnic Cohort and Southern Community Cohort Study

  Cancer Epidemiology Biomarkers & Prevention · 2025-09-18

  article

  Abstract Purpose: Structural racism, measured by mortgage lending bias, has been shown to have persistent effects on health inequities and may impact lung cancer disparities. Smoking cessation is crucial in reducing lung cancer risk, particularly in communities affected by structural racism, where discriminatory practices are associated with higher smoking rates. We examined the association between structural racism, as measured by residence in areas subjected to contemporary redlining and racial and ethnic bias in mortgage lending, with smoking cessation. Methods: Our study population includes two cohorts, the Multiethnic Cohort Study (MEC) and the Southern Community Cohort Study (SCCS), consisting of well-characterized older adult participations with up to 27 years of follow-up. The MEC was assembled between 1993-1996 in California and Hawaii and SCCS was recruited between 2002-2009 in the southeastern United States. Contemporary redlining and racial and ethnic bias in mortgage lending measures were developed using Home Mortgage Disclosure Data Act (HMDA) data. Redlining and racial and ethnic bias was measured as the odds ratio of denial of a mortgage application on the basis of the property location compared to property location in the county and applicant race and ethnicity compared to White applicants, respectively. This current study, comprises of a subgroup of MEC and SCCS participants who smoked at baseline with follow-up smoking status data (n=10,349 and 10,498, respectively). Among these participants, 6,134 MEC and 2,164 SCCS particpants reported changing smoking status on a follow-up survey (21 years). Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between smoking cessation status and structural racism, with age as the time-scale and adjusting for baseline age, sex, education, marital status, body mass index, alcohol consumption, smoking (pack-years), and state, with clustering by census tracts at baseline. Results: In MEC, among Black/African American participants, living in areas with the highest mortgage lending bias against Black/African American residents (e.g., lower racial and ethnic composition of Black/African American residents) was associated with higher hazard ratio of of smoking cessation (adjusted HR: 1.55, 95% CI: 1.17, 2.07) compared to the lowest mortgage lending bias. In SCCS, participants living in the most redlined areas were associated with lower rates of smoking cessation (adjusted HR: 0.83, 95% CI: 0.72, 0.95) compared to the least redlined areas. No association was found for other mortgage bias lending measures. Conclusions: We found that a place-level measure of structural racism, i.e., mortgage lending bias, were associated with smoking cessation for Black/African American populations. Findings differ by area and race/ethnicity, highlighting the complexity of the relationship between structural racism and smoking, a factor that influences lung cancer risk. Citation Format: Mimi Ton, Dian Gu, Cherie Guillermo, Yuhong Zhou, Meera Sangaramoorthy, Katherine Lin, Pushkar Inamdar, Jun Wu, Kirsten Beyer, Mindy C. DeRouen, Alexandra Binder, Daniel Stram, Scarlett L. Gomez, Salma Shariff-Marco, Lynne Wilkens, Loïc Le Marchand, Melinda C. Aldrich, S Lani Park, Iona Cheng. Association between mortgage lending bias and smoking cessation: The Multiethnic Cohort and Southern Community Cohort Study [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr B155.

  PublisherDOI

• A review of the optimal configuration of fault current limiter in power system

  IET conference proceedings. · 2025-01-08

  review1st authorCorresponding

  With the continuous development of new power systems, the short-circuit currents at each node of the grid continue to increase, and there will be multiple sites with excessive short-circuit currents and insufficient margins, and the optimal configuration of fault current limiters will effectively and economically limit the system short-circuit currents. The paper first introduces the modeling method for optimal configuration of fault current limiters in power grids, and lists the commonly used objective functions and constraints. Then three approaches to multi-objective functions and their modeling and solution algorithms are presented. Finally, combined with the future development trend of the power grid, it summarizes the problems that need to be considered in the future research on the optimal configuration of fault current limiters, such as the consideration of the optimal configuration of new energy sources after joining the power grid, the development of new algorithms, and so on, to make an outlook for the direction of the research on the optimal configuration of fault current limiters.

  PublisherDOI

• Interaction Between Traffic-Related Air Pollution and Parkinson Disease Polygenic Risk Score

  JAMA Network Open · 2025-03-17 · 8 citations

  articleOpen access

  Importance: Genetic and environmental factors are linked to Parkinson disease (PD), but the role of genetic susceptibility in the association between traffic-related air pollution (TRAP) and PD remains unclear. Objective: To assess the gene-environment interaction between the polygenic risk score (PRS) for PD and long-term TRAP exposure and to estimate the joint effect with PD risk. Design, Setting, and Participants: This population-based case-control study used a meta-analytical assessment of studies conducted in central California and Denmark. The Parkinson Environment and Genes (PEG) study in California (June 1, 2000, to July 31, 2017) included 634 patients with PD and 733 controls; the Parkinson Disease in Denmark (PASIDA) study (January 1, 2006, to December 31, 2017) included 966 patients with PD and 1045 controls. Data were analyzed from July 1 to October 31, 2024. Exposures: PRS was computed by summing the effect estimates of well-known risk alleles from an existing genome-wide association study's summary statistics using participants' genetic arrays. TRAP exposure was estimated using dispersion models to calculate long-term exposure (10- or 15-year means with a 5-year lag) to traffic-related pollutants (represented by carbon monoxide [CO] levels) at participants' residences. Main Outcomes and Measures: The main outcome was diagnosis of PD. Using multivariable logistic regression, PD risk was estimated from interactions between PRS (per SD) and TRAP exposure (per IQR), with joint effects based on low (quartiles 1-3) and high (quartile 4) exposure levels. Results: A total of 1600 patients with PD (mean [SD] age, 65.1 [9.9] years; 990 [61.9%] male) and 1778 controls (mean [SD] age, 64.5 [10.3] years; 992 [55.8%] male) were included. Meta-analytical estimates suggest that both higher PRS and increased TRAP exposure increased PD risk, with an interaction effect estimate of 1.06 (95% CI, 1.00-1.12). Joint effect analysis indicated that individuals with both high PRS and high TRAP exposure were at greatest risk of PD (odds ratio, 3.05; 95% CI, 2.23-4.19) compared with the reference group with a low PRS and low TRAP exposure, suggesting a synergistic effect. Conclusions and Relevance: In this gene-environment interaction study, a combination of long-term air pollution exposure and genetic susceptibility strongly contributed to the risk of developing PD. Widespread exposure to air pollution makes TRAP an important modifiable risk factor affecting large populations globally, particularly individuals with genetic vulnerability.

  PublisherOA PDFDOI

• Abstract TH271: Area Deprivation, Social Vulnerability, and Blood Pressure Among Women 2-7 Years after Delivery: The nuMoM2b-HHS Study

  Hypertension · 2025-09-01

  article

  Introduction: Cardiovascular disease remains a leading cause of morbidity among women, with pregnancy offering a critical window to identify future risk. Structural factors, such as neighborhood disadvantage, may have lasting effects on cardiovascular health beyond individual behaviors or experiences. This analysis evaluated if neighborhood-level deprivation and individual-level social vulnerability (SV; i.e., social determinants of health and exposures of daily living such as discrimination and perceived stress) in pregnancy were related to blood pressure (BP) 2- to 7-years after delivery. Hypothesis: Neighborhood disadvantage and SV would each be prospectively associated with elevated BP in women. Methods: This was a secondary analysis of the nuMoM2b-HHS study. The study followed a diverse cohort of healthy nulliparous women in 8 U.S. medical centers from the first trimester through 2-7 years after delivery of their first child to characterize adverse pregnancy outcomes and subsequent cardiovascular risk. In this analysis, Area Deprivation Index (ADI; a measure of structural disadvantage) and SV (a composite of residential history, health literacy, financial stress, discrimination, perceived stress, social connectivity, and perceived pregnancy experiences) were examined in relation to systolic and diastolic BP (SBP and DBP) at the 2- to 7-year postpartum study visit. Covariates were age, race/ethnicity, first trimester BP, and pre-pregnancy body mass index and smoking. General linear models first included each predictor separately, and final models included both ADI and SV to investigate their distinct associations. Results: The sample (n=3728) had a mean age 31±5.6 and 65% were White race; mean follow-up was 3.2±0.9 years after delivery. ADI and SV were each associated with greater SBP and DBP at follow-up in unadjusted models (Table), but after covariate adjustment, only ADI was associated with SBP and DBP. In models including mutual adjustment for ADI and SV, only ADI was associated with SBP and DBP. Conclusions: Area-level social deprivation – but not individual SV during pregnancy – was associated with elevated BP about 3 years later. Where a woman lives during pregnancy may have a greater impact on her later cardiovascular health than her social experiences or vulnerabilities during pregnancy. These findings show a need to understand structural and neighborhood-level health determinants during pregnancy for long-term maternal cardiovascular health.

  PublisherDOI

Recent grants

• Air Pollution and Pregnancy Complications in Complex Urban Environments: Risks, Heterogeneity, and Mechanisms

  NIH · $3.2M · 2019–2025

• Exposure to mobile source air pollution and adverse birth outcomes in the Los Ang

  NIH · $552k · 2008–2012

Frequent coauthors

• Loı̈c Le Marchand

  Cancer Center of Hawaii

  84 shared

• Lianfa Li

  Chinese Academy of Sciences

  59 shared

• Beate Ritz

  UCLA Health

  55 shared

• Iona Cheng

  UCSF Helen Diller Family Comprehensive Cancer Center

  44 shared

• Tarik Benmarhnia

  University of California, San Diego

  44 shared

• Yi Sun

  Qufu Normal University

  39 shared

• Shahir Masri

  University of California, Irvine

  39 shared

• Salma Shariff‐Marco

  University of California, San Francisco

  36 shared

Awards & honors

• distinguished faculty award for research (March 6, 2025)
• UC Irvine Wen Public Health climbs three spots in federal re…
• UC Irvine-led study finds common foods may expose California…
• UC Irvine-community partnership honored for environmental ju…
• UC Irvine wins NIH grant to study environmental impacts on m…