About

Georgia Kayser, PhD, is an Assistant Professor of Global and Environmental Health at the Herbert Wertheim School of Public Health & Human Longevity Science at UCSD. She is also the Deputy Director of the UC Global Health Institute Center for Planetary Health. Her environmental health research focuses on adolescent and children’s environmental health, water quality, environmental determinants of risk, and environmental health inequities and disparities. Her work explores factors that limit access to safe and sustainable drinking water, sanitation, and hygiene (WaSH) services globally, and identifies environmental determinants of risk, including pesticide and microbiological contaminants in drinking water. She examines environmental health disparities resulting from gender, racial/ethnic, and geographic inequities, with the aim of informing environmental health programs and policy. Her methodological expertise includes cross-sectional studies, formative research, experimental and quasi-experimental methods, and geospatial analysis, and she has conducted research in over 20 countries across the Americas, sub-Saharan Africa, and South Asia. Dr. Kayser is involved in projects funded by government, international organizations, and the private sector, including studies on pesticide exposures, mental health, endocrine disruption among children near pesticide spray sites in Ecuador, and WaSH access among people who inject drugs in the US-Mexico border region. She enjoys mentoring students and teaching environmental and global health courses at UCSD.

Research topics

• Sociology
• Environmental health
• Medicine
• Socioeconomics
• Ecology
• Environmental engineering
• Biology
• Nursing
• Psychiatry
• Geography
• Environmental science
• Economic growth
• Demography
• Toxicology

Selected publications

• Predictors of Water Point Sustainability and Water Quality in Gulu, Uganda

  Journal of Water Resources Planning and Management · 2026-04-13

  articleSenior author

  Understanding the predictors of nonpiped water source system water quality and operational sustainability as measured by functionality and length of breakdowns is essential to sustain functioning water systems, remediate nonfunctioning systems, and maintain water safety of nonpiped water sources in sub-Saharan Africa. We investigated the predictors of nonpiped water source system operational sustainability and water quality using least absolute shrinkage and selection operator (LASSO) regression on a cross-sectional data set of all 354 known, recently active nonpiped water sources in Gulu, Uganda collected in 2018. On sustainability, this study found that certain water source technology types, risk of contamination scores, and certain water source management practices are significant predictors of water source operational sustainability. This study failed to find significant evidence that water source management structure, most management practices, geographic relationships between water sources, and most water source technology types are significant predictors of water source operational sustainability in Gulu, Uganda. For water quality, we found that water sources that were farther from the town center (in less urbanized areas), water sources farther from low-lying marshland, and water sources that had undeveloped (rather than developed) land cover were less likely to suffer fecal contamination. This study failed to find evidence that water source management type, water source management practices, and risk of contamination scores are significant predictors of fecal contamination of water sources. Together, these findings suggest that the determinants of operational sustainability and fecal contamination of nonpiped water sources are nuanced, require local assessment, remain poorly understood, and merit future investigation.

  PublisherDOI

• Relationships of residential distance to greenhouse floriculture and organophosphate, pyrethroid, and neonicotinoid urinary metabolite concentration in Ecuadorian Adolescents

  International Journal of Health Geographics · 2025-04-18 · 4 citations

  articleOpen access

  BACKGROUND: Adolescents living in agricultural areas are at higher risk of secondary pesticide exposure; however, there is limited evidence to confirm exposure by pesticide drift for greenhouse floriculture, like rose production. METHODS: 525 adolescents (12-17, 49% male) living in Pedro Moncayo, Ecuador were assessed in 2016. Urinary concentrations of creatinine and pesticide biomarkers (organophosphates, neonicotinoids, and pyrethroids) were measured using mass-spectrometry. Home distance to the nearest greenhouse and surface area of greenhouses within various buffer sizes around the home were calculated. Linear regression assessed whether home distance and surface area of greenhouses was associated with creatinine-adjusted metabolite concentration, adjusting for demographic, socioeconomic, and anthropometric variables. Geospatially weighted regression (GWR) was conducted, adjusting for similar covariates. Getis-ord Gi* identified hot and cold spots using a 1994 m distance band. RESULTS: The associations between residential distance to greenhouses and urinary pesticide metabolites differed by metabolite type. The adjusted mean concentrations of OHIM (neonicotinoid) were greater (p-difference = 0.02) among participants living within 200 m (1.08 ug/g of creatinine) vs > 200 m (0.64 ug/g); however, the opposite was observed for 3,5,6-Trichloro-2-pyridinol (TCPy, organophosphate; 0-200 m: 3.63 ug/g vs > 200 m: 4.30 ug/g, p-diff = 0.05). In linear models, greater distances were negatively associated with para-nitrophenol (PNP, organophosphate; percent difference per 50% greater distance [95% CI]: - 2.5% [- 4.9%, - 0.1%]) and somewhat with 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy, organophosphate; - 4.0% [- 8.3%, 0.4%]), among participants living within 200 m of greenhouses. Concurring with the adjusted means analyses, opposite (positive) associations were observed for TCPy (2.1% [95%CI 0.3%, 3.9%]). Organophosphate and pyrethroid hotspots were found in parishes with greater greenhouse density, whereas neonicotinoid hot spots were in parishes with the lowest greenhouse density. CONCLUSION: We observed negative associations between residential distance to greenhouses with OHIM, PNP and to some extent IMPy, suggesting that imidacloprid, parathion and diazinon are drifting from floricultural greenhouses and reaching children living within 200 m. Positive TCPy associations suggest greenhouses weren't the chlorpyrifos source during this study period, which implies that non-floricultural open-air agriculture (e.g. corn, potatoes, strawberries, grains) may be a source. Further research incorporating diverse geospatial constructs of pesticide sources, pesticide use reports (if available), participant location tracking, and repeated metabolite measurements is recommended.

  PublisherOA PDFDOI

• Associations of PFAS and pesticides with lung function changes from adolescence to young adulthood in the ESPINA study

  International Journal of Hygiene and Environmental Health · 2025-02-02 · 8 citations

  articleOpen access
  PublisherOA PDFDOI

• Occurrence of insecticides, fungicides, and herbicides in household drinking and irrigation water in an intensive floriculture region of Ecuador

  SSRN Electronic Journal · 2025-01-01

  preprintOpen accessSenior author
  PublisherDOI

• Associations between concurrent neonicotinoid, pyrethroid, and organophosphate insecticide metabolites and neurocognitive performance in Ecuadorian adolescents

  The Science of The Total Environment · 2025-11-17

  articleOpen access
  PublisherOA PDFDOI

• Serum PFAS and lipid concentrations in Ecuadorian adolescents

  Archives of Environmental & Occupational Health · 2025-04-21 · 1 citations

  articleOpen access

  There is growing evidence that per- and polyfluoroalkyl substances (PFAS) may alter serum lipid concentrations; however, this topic is understudied in adolescents and Latin American populations. We aimed to characterize these associations among adolescents in Ecuador's main floricultural region. This cross-sectional study included 97 adolescents ages 11-17 years from Pedro Moncayo County, Ecuador. Generalized estimating equation models were applied to estimate the associations of serum perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) concentrations with serum lipids. Models were adjusted for age, gender, height, body mass index (BMI), acetylcholinesterase (AChE) activity, and hemoglobin concentrations. Significant inverse relationships between PFAS and triglycerides were observed in females (% lipid difference per 50% increase in: PFOS= -15.0% [95%CI: -24.72, -4.06], PFNA= -25.49% [-36.93, -12.00], and PFOA= -16.55% [-28.16, -3.07]) but not in males. No associations were observed between total cholesterol, high-density lipoprotein (HDL), or low-density lipoprotein (LDL) cholesterol and any PFAS. PFOS, PFOA, and PFNA were inversely associated with triglycerides in adolescent females but not males. Further characterization of gender-specific associations of PFAS and blood lipids in adolescents is warranted.

  PublisherOA PDFDOI

• Relationships of residential distance to Greenhouse Floriculture and Organophosphate, Pyrethroid, and Neonicotinoid Urinary Metabolite Concentration in Ecuadorian Adolescents

  medRxiv · 2024-10-23

  preprintOpen access

  Abstract Background Adolescents living in agricultural areas are at higher risk of secondary pesticide exposure; however, there is limited evidence to confirm exposure by pesticide drift for greenhouse floriculture, like rose production. Methods 525 adolescents (12-17, 49% male) living in Pedro Moncayo, Ecuador were assessed in 2016. Urinary concentrations of creatinine and pesticide biomarkers (organophosphates, neonicotinoids, and pyrethroids) were measured using mass-spectrometry. Home distance to the nearest greenhouse and surface area of greenhouses within various buffer sizes around the home were calculated. Linear regression assessed whether home distance and surface area of greenhouses was associated with creatinine-adjusted metabolite concentration, adjusting for demographic, socioeconomic, and anthropometric variables. Geospatially weighted regression (GWR) was conducted, adjusting for similar covariates. Getis-ord Gi* identified hot and cold spots using a 1994m distance band. Results The associations between residential distance to greenhouses and urinary pesticide metabolites differed by metabolite type. The adjusted mean concentrations of OHIM (neonicotinoid) were greater (p-difference=0.02) among participants living within 200m (1.08 ug/g of creatinine) vs >200m (0.64 ug/g); however, the opposite was observed for 3,5,6-Trichloro-2-pyridinol (TCPy, organophosphate; 0-200m: 3.63 ug/g vs >200m: 4.30 ug/g, p-diff= 0.05). In linear models, greater distances were negatively associated with para-nitrophenol (PNP, organophosphate; percent difference per 50% greater distance [95% CI]: -2.5% [-4.9%, -0.1%]) and somewhat with 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy, organophosphate; -4.0% [-8.3%, 0.4%]), among participants living within 200m of greenhouses. Concurring with the adjusted means analyses, opposite (positive) associations were observed for TCPy (2.1% [95%CI: 0.3%, 3.9%]). Organophosphate and pyrethroid hotspots were found in parishes with greater greenhouse density, whereas neonicotinoid hot spots were in parishes with the lowest greenhouse density. Conclusion We observed negative associations between residential distance to greenhouses with OHIM, PNP and to some extent IMPy, suggesting that imidacloprid, parathion and diazinon is drifting from floricultural greenhouses and reaching children living within 200m. Positive TCPy associations suggest greenhouses weren’t the chlorpyrifos source during this study period, which implies that non-floricultural open-air agriculture (e.g. corn, potatoes, strawberries, grains) may be a source. Further research incorporating diverse geospatial constructs of pesticide sources, pesticide use reports (if available), participant location tracking, and repeated metabolite measurements is recommended.

  PublisherOA PDFDOI

• A brief instrument measuring the water, sanitation and hygiene domain of menstrual health among women who inject drugs

  PLoS ONE · 2024-05-10 · 4 citations

  articleOpen accessSenior author

  BACKGROUND: Domains of adequate menstrual health (MH) include access to water, sanitation, and hygiene (WASH). People who menstruate with social disadvantages-such as homelessness or drug injection practices-often face barriers to WASH access. However, validated instruments to measure MH are limited among marginalized populations, and available instruments involve lengthy surveys. We developed and evaluated psychometric properties of a novel 'MH WASH Domain Scale-12' among people who menstruate and who inject drugs in the Tijuana-San Diego region and identified correlates of MH access using this scale. METHODS: We constructed a MH-scale based on access to twelve WASH-related items: (1) menstrual products, (2) body hygiene (bathing per week), (3) water sources for bathing, (4) improved, (5) non-shared, (6) available, (7) private, (8) nearby, (9) and safe sanitation facilities, (10) availability of soap, (11) water source for handwashing, and (12) handwashing facilities with soap/water. Variables were dichotomized and summed, with scores ranging from 0-12 points and higher scores indicating better MH access. We assessed the scale's reliability and construct and content validity using data from a binational cross-sectional study. The sample included people who inject drugs (PWID) who had ever menstruated in their lifetime and were 18+ during 2020-2021. MH-WASH items were described, and the scale was further used as an outcome variable to identify correlates. RESULTS: Among 125 (124 cis-female and 1 trans-male) PWID that reported menstruating, our 'MH WASH Domain Scale-12' was reliable (Cronbach's alpha = 0.81, McDonald's Omega total = 0.83) and valid. We identified two sub-domains: Factor-1 included items describing 'WASH availability' and Factor-2 contained items related to 'WASH security'-encompassing physical and biological safety. Scale scores were significantly lower among participants experiencing unsheltered homelessness compared to participants experiencing sheltered homelessness or living in permanent housing. CONCLUSION: We constructed and validated a novel and reliable scale to measure MH-related WASH access that can be used to assess MH among marginalized populations in English- and Spanish-speaking contexts. Using this scale we identified disparities in MH-WASH access among PWID and who menstruate in the US-Mexico border region.

  PublisherOA PDFDOI

• Associations of PFASs and Pesticides with Lung Function Changes from Adolescence to Young Adulthood in the ESPINA study

  medRxiv · 2024-10-10 · 1 citations

  preprintOpen access

  ABSTRACT Per- and polyfluoroalkyl substances (PFASs) and pesticides are ubiquitous environmental exposures with increasingly recognized adverse health outcomes; however, their impact on lung function, particularly in combination, remains poorly understood. We included 381 adolescent participants from a prospective cohort study in Ecuador who underwent measurements of serum PFAS (perfluorooctanoic acid [PFOA], perfluorooctanesulfonic acid [PFOS] and perfluorononanoic acid [PFNA]) and urinary herbicides (glyphosate, 2,4D) and fungicides (ethylene thiourea) and had spirometric measurements in either 2016 or 2022. We characterized the association between each PFAS or pesticide and each lung function measure in log-log models estimated via ordinary least squares regression. We used quantile g-computation to assess the association of the mixture of PFAS and pesticides with lung function outcomes. After accounting for multiple hypothesis testing, and in models adjusting for household income, parental education, and exposure to tobacco, we found that, individually, PFOA, glyphosate, and ETU were associated with slight increases in FEV 1 /FVC between 2016 and 2022. No other individual associations were significant. In mixtures analyses, a one quartile increase in all PFASs and pesticides simultaneously was also not associated with statistically significant changes in lung function outcomes after accounting for multiple hypothesis testing. In large part, we do not provide evidence for associations of PFAS and herbicide and fungicide pesticides with lung function among adolescents in moderate-to-high-altitude agricultural communities in Ecuador.

  PublisherOA PDFDOI

• Water, sanitation and hygiene insecurity predict abscess incidence among people who inject drugs in a binational US–Mexico metropolitan area: A longitudinal cohort study

  International Journal of Drug Policy · 2024-06-19 · 5 citations

  articleOpen accessSenior author

  INTRODUCTION: People who inject drugs (PWID) are at high risk of developing injection-related infections, including abscesses. Access to water, sanitation, and hygiene (WASH) are key human rights and services; yet these services have been underexplored as predictors of abscesses among PWID. METHODS: Longitudinal analysis was employed among a cohort of PWID to determine if WASH insecurity (lack of access) was associated with abscess incidence in the Tijuana, Mexico and San Diego, United States metropolitan area during 24-months of follow-up survey data from 2020 to 2023. We calculated abscess prevalence at baseline and tracked the incidence of new abscesses among individuals without an abscess during the previous visit. Time dependent Cox regression modeling was employed with variance clustered by participant to characterize the relationship between WASH insecurity and abscess incidence. RESULTS: At baseline, hand hygiene insecurity, bathing insecurity in the previous six months and open defecation in the last week, were reported by 60 %, 54 % and 38 % of participants, respectively; 21 % reported an abscess in the last six months. The incidence of abscesses was 24.4 (95 %CI: 21.1-27.6) per 100 person-years. After adjusting for covariates, the hazard of developing an abscess remained significantly elevated among individuals using non-improved (with risk of contamination) water sources (e.g., surface water) for preparing drugs (adjusted HR [adjHR]: 1.49 [95 %CI: 1.01-2.21], experiencing bathing insecurity (adjHR: 1.59 [95 %CI: 1.12-2.24]) and open defecation (adjHR: 1.65 [95 %CI: 1.16-2.35]). CONCLUSIONS: PWID in the Tijuana-San Diego metropolitan area reported facing high rates of insecurity accessing WASH services. Abscess incidence was higher (four to nine times) than observed rate among PWID cohorts in other settings. Access to continuously available toilet facilities, bathing infrastructure, and safe water sources for preparing drugs for injection could prevent abscesses among PWID. Accessible WASH infrastructure should be ensured among PWID communities and promoted as a key component of harm reduction infrastructure.

  PublisherDOI

Frequent coauthors

• Jamie Bartram

  23 shared

• Urooj Amjad

  University of North Carolina at Chapel Hill

  16 shared

• Alhelí Calderón-Villarreal

  San Diego State University

  15 shared

• Lourdes Johanna Avelar Portillo

  Human Longevity (United States)

  14 shared

• José Suárez-Torres

  12 shared

• Harvey Checkoway

  Human Longevity (United States)

  9 shared

• Audrey R. Yang

  Human Longevity (United States)

  9 shared

• José R. Suárez-López

  University of California, San Diego

  8 shared

Education

• Ph.D., Public Health

  University of California, San Diego

  2015

• M.S., Public Health

  University of California, San Diego

  2011

• B.A., Biology

  University of California, San Diego

  2009

Awards & honors

• NIH K01ES031697 (2020 - 2023)