Air pollution is a key component to understanding the Public Health of populations globally, with Diesel Exhaust Particles (DEP) being a significant contributor to traffic-related air pollution. Exposure to DEPs varies across populations and is therefore crucial to understanding the continual impacts of traffic-related air pollution on the public. Prior research has indicated that the formation of Amyloid-𝛽 (A-𝛽) plaques and activation of the  nucleotide-binding domain, leucine-rich–containing family, pyrin domain–containing-3 (NLRP3) inflammasome is linked with the development of Alzheimer’s disease (AD) later in life. AD is a form of progressive disease that impairs memory and other cognitive functions and impacts the lives of tens of millions of people globally. This study aims to confirm the linkage between exposure to DEP and memory impairment through NLRP3 inflammasome activation, utilizing an animal model to investigate a potential increase in AD later in life. We exposed male and female low-density lipoprotein receptor knockout (LDLR KO) mice chronically to inhaled DEP or filtered air as a control for 18 weeks. We then utilized the Object Location Memory (OLM) and Object Recognition Memory (ORM) behavioral tests to investigate the immediate impact of multi-week DEP exposure on short-term memory, another indicator in AD progression. Afterward, we sacrificed the mice and harvested a variety of tissues, including the brain. I conducted Immunohistochemistry (IHC) on cryosections of the exposed and non-exposed brain to assess DEP-induced AD-like brain architectural changes and to quantify the impact of DEP exposure in activating the NLRP3 inflammasome, ultimately leading to neurotoxicity, and to the development and progression of AD. Confirming the association between diesel exhaust and the NLRP3 pathway provides a potential therapeutic target in populations at an elevated risk for AD.

It is increasingly recognized that exposures during sensitive developmental time windows may lead to delayed onset of diseases later in life. Polybrominated diphenyl ethers (PBDEs) are legacy flame retardants that bioaccumulate in the environment as well as human breast milk. In both animal models and humans, PBDE exposure is linked to thyroid toxicity, neurodevelopmental disorders, and hepatotoxicity. Our previous work showed that neonatal oral exposure to BDE-99, a human breast milk-enriched PBDE congener, produced dysbiosis of the gut microbiome associated with a pro-inflammatory transcriptomic signature with the gut-liver axis. However, very little is known whether the BDE-99 mediated host effect is caused by the changes in the gut microbiome. To address this knowledge gap, large intestinal contents from adult male pups that were neonatally exposed to BDE-99 (57 mg/kg p.o. once daily from postnatal days 2-4) or corn oil (10 ml/kg) were transplanted to adult germ-free mice (i.e., mice without microbiome). After one month colonization period, total RNA was isolated from the colon and subjected to RT-qPCR. Ex-germ-free mice receiving the microbiome from BDE-99 exposed pups had decreased expression of genes involved in gut barrier integrity (tight junction protein 2 and claudin 7 [Cldn7]), indicating increased gut permeability. These mice also had increased expression of several pro-inflammatory cytokines including interferon gamma (Ifng) and interleukin 17 (Il17), but decreased expression of the major drug-metabolizing enzyme cytochrome P450 (Cyp) 3a11. In summary, our results suggest that early life BDE-99 exposure mediated persistent dysbiosis in the gut microbiome mechanistically contributes to a proinflammatory and leaky gut state with reduced xenobiotic metabolism capacities.

Inhalation toxicology is a rising field of study as respirable toxicants become increasingly prevalent in our environment. Our research focuses on commonly inhaled toxicants: diesel exhaust (DE) and electronic cigarette aerosols (e-cig). Exposure to traffic-related air pollution and the use of e-cigs has rapidly increased, yet molecular pathways and health effects, and innate factors that impact health outcomes, remain largely unexplored. To assess cardiometabolic and neurodegenerative effects of DE, we exposed male and female mice (low-density lipoprotein receptor knockout, Ldlr KO) to filtered air or freshly generated DE for 18 weeks while fed a high-fat or Chow diet. We then conducted Object-Recognition and Object-Location Memory neurobehavioral tests to assess cognition, specifically hippocampus-independent recognition memory and hippocampus-dependent spatial memory and discrimination, respectively. We sacrificed mice and harvested brain, liver, and lung tissue for histopathological staining and biochemical measurements, including 3-nitrotyrosine, a biomarker of oxidative stress, via Western blot. To assess cardiopulmonary effects of e-cig aerosols, we exposed different mouse strains to acute (5 days) and chronic (3 months) e-cig aerosols with and without nicotine. We then harvested lung tissue and quantified glutathione (reduced and oxidized), an antioxidant and essential nucleophilic scavenger of electrophiles, via high-pressure liquid chromatography; and protein 3-nitrotyrosine. Statistical analyses of all the results obtained were carried out using R. Initial results revealed sex differences in biomarker levels between control and exposed mice. We plan to expand analyses by measuring an additional biomarker of oxidative stress, 8-oxo-dG. Additionally, we will quantify heavy metal accumulation in liver and brain in DE-exposed mice, along with metabolites of carcinogens such as acrolein in e-cig exposed mice. Forthcoming measurements will provide a more comprehensive understanding of biological responses to exposures and elucidate potential health implications. Our research in inhaled toxicants helps reveal critical insights for emerging public health challenges.

Seattle is known to be infested with invasive rodents such as the Norway rat or the roof rat; both of which are considered public health nuisances, causing damage to the built environment, carrying zoonotic diseases, and causing overall mental unrest as a communal species. This project collected community-level data using two urban rodent survey (URS) methodologies: The Centers for Disease Control (CDC) URS methodology, which focuses on identifying causative conditions for rodents, and a newer method, Indexing, which focuses on active rodent surveillance. We surveyed census tracts spanning the University of Washington Seattle campus, UDistrict, and Ravenna neighborhoods using both URS methodologies. We then assessed the effectiveness and efficiency of both methods in determining the severity of rodent infestation within these communities. The data collected was used to inform a URS classroom model for ENVH 442, Zoonotic Diseases and their Control, offered by the Department of Environmental and Occupational Health and Safety at the University of Washington Seattle. In addition, this project was shared with the Public Health Seattle & King County Rodent Control Program, to help inform their work on active rodent surveillance in the city of Seattle.

The gut microbiome regulates the gut-brain axis, impacting metabolic and neurological health. Dysbiosis in the gut microbiome through a wide range of environmental neurotoxins can negatively influence microbial imbalance or dysfunction, leading to various health effects as well as gastrointestinal and neurological disorders, such as autism. In this study, I explore the potential of microbial metabolites to ameliorate social deficits induced by environmental neurotoxins. While the mechanisms underlying these prospective rescue effects remain elusive, our high-throughput behavioral analysis in larval zebrafish offers a platform to uncover the therapeutic potential of specific microbial metabolites. Using this analysis system, I screened larval zebrafish treated with the environmental toxin chlorpyrifos to induce a social deficit; from this, the larvae were screened with microbial metabolites that have been observed to have beneficial effects on mental health. Sodium butyrate and butyric acid are two short-chain fatty acid metabolites that were observed to have a significant rescue effect on the social behavior of larval zebrafish. Warranting further investigation into the precise mechanism underlying this rescue effect, these findings point to a potential therapeutic strategy for butyrate derivatives in addressing neurobehavioral abnormalities associated with environmental stressors.

Seattle airport communities are communities that are located near and underneath flight paths headed to and from Seattle airports– the largest of these airports being Seattle-Tacoma International Airport. Communities located on these flight paths are exposed to ultrafine pollution particles from aircraft emissions, negatively impacting air quality in these areas. This research project aims to investigate the dispersion of aircraft pollution from Seattle-Tacoma International Airport and how it’s associated with communities’ health outcomes. By using an air quality dispersion modeling system (AERMOD), I can track how air pollution from aircrafts spreads based on atmospheric conditions such as rain and wind patterns. With AERMOD and public databases of health disparities, my project produces overlayed geospatial data that combines aircraft emissions and health disparity factors to study how aircraft emissions correlates with the health of vulnerable communities. My expected results are the communities that are the most impacted by aircraft emissions, as modeled by AERMOD, will have worsened health outcomes in a range of categories once compared to communities located outside of the Sea-Tac Airport flight path. These results could serve to notify affected residents of their level of exposure from aircraft emissions and how it may be impacting their health, improving residents’ agency over their health. Additionally, these results could inform policy and regulation of aircraft emissions standards.

The use of pesticides in the Pacific Northwest is essential in the process of safeguarding public health, most notably by mitigating pests, protecting our food supply, and aiding in distribution to supermarkets, restaurants, and our homes. However, long-term exposure to pesticides can result in illness for those handling the substances as well as their families. Prior research has shown that current pesticide application methods play a role in accelerating illness. Newer methods, such as aerial drone spraying and “smart” sprayers, involve the use of emerging technologies that are poised to change the landscape of the agricultural industry and health outcomes of farmworkers. Under the supervision of the Pacific Northwest Agricultural Health and Safety (PNASH) Center, my project will be assessing thoughts regarding adoption of these technologies. Through the creation of an electronic REDCap survey, I will be obtaining a variety of responses from agricultural workers, farm decisionmakers, and others involved in the application of pesticides on farms. Once the survey is deployed, I will analyze responses both quantitatively and qualitatively using Dedoose and R statistical methods, respectively. From these responses, I will work with the PNASH team to evaluate the adoption of current and emerging pesticide technologies among Northwest fruit growers, as well as their impacts on occupational health and safety. Through this project, I hope to collect a wide range of perspectives and thoughts regarding the implementation of new pesticide application technologies, particularly unique opinion points (positive and negative) I did not otherwise consider in my initial research with the PNASH Center. The main objective of my research project is to capture the attitudes of the pesticide application technologies to inform policy, regulations, and decision-making regarding their uses.

The poster highlights our study of shared pantry operators in Washington State. Shared pantries are generally small, unattended, open-access food-sharing areas that operate on a "take what you need, leave what you can" concept, supplied by donations from members of the local community. Professor Emily Hovis and I developed and deployed an operator survey to examine the differences between pantry operational structures. This research was prompted by a pattern we noticed during previous fieldwork: many pantries located at private residences were no longer active. I was involved in developing the survey, analyzing the data, and creating the poster. Over 300 current or former share pantry operators were contacted to participate in an online survey focused on operator demographics and operations. We received 62 survey responses in Autumn 2023. The majority of survey respondents (95.2%) identified their pantry is located outdoors, open 24/7, and accepts community drop-off food donations. More than half of the pantries are operated by individuals. Most of the organizations or groups operating the pantries were churches, schools, university groups, neighbors, and advocacy services. The majority (87%) of the pantries do not have a fridge/freezer section. More than half of the operators visit the pantry site more than four times a week. Only half of the respondents indicated that they provided guidelines on appropriate/safe donations. This study not only emphasizes the critical role of shared pantries in community solidarity but also raises an important future research question: How could the development and implementation of standardized guidelines and support systems impact the sustainability and effectiveness of shared pantries, particularly in enhancing community participation, donation quality, and pantry longevity?

The acceleration of antimicrobial resistance (AMR) in pathogens and commensal organisms is an emerging global health crisis due to the overuse and misuse of antimicrobial drugs. In addition, it is unknown how other factors such as a changing climate may impact AMR. We utilized wastewater surveillance to investigate if the diversity of antimicrobial resistant genes (ARGs) in influent wastewater is associated with rainfall. We utilized our workflow for the detection of specific ARGs in the greater Seattle area, contributing to AMR stewardship efforts. I conducted qPCR, PCR, and nanopore sequencing of CTX-M genes, an antimicrobial resistance gene, extracted from influent wastewater from wastewater treatments plants servicing the Seattle area. The purpose of this approach is to assess diversity of AMR gene alleles with high accuracy to contribute to the surveillance of AMR genes in populations. I hypothesize that higher rainfall—typically occurring from October to March—leads to a lower diversity of AMR genes due to increased dilution and decreased potential for horizontal gene transfer between organisms. During the dry season—April to September—I hypothesize we will find more unique alleles of AMR genes. In this poster, I will present the results of my statistical analyses investigating the relationships between ARG abundance, ARG diversity, and rainfall The utility of contextualizing the diversity of targeted antimicrobial resistance genes can inform clinical practices that benefit the health of populations.