Water and Soil Sampling of Per- and Polyfluorinated Substances (PFAS) Near Chrome Plating Facilities and Blood Concentration of PFAS among Chrome Plating Workers: community-engaged research in Santa Ana

Per- and poly-fluoroalkyl substances (PFAS) contaminate our environment and persist in our body causing various health effects. Metal plating, especially chrome plating, is a process that applies a thin layer of metal on the surfaces of automobiles, aircraft, and household products to prevent erosion. PFAS, primarily perfluorooctanesulfonic acid (PFOS) and 6:2 fluorotelomer sulfonate (6:2 FTS), are used as fume suppressors or wetting agents in the metal plating process. Therefore, chrome plating facilities are an important source of PFAS exposure to chrome plating workers and communities living near these facilities. In California, Orange County has the second highest number of chrome plating facilities (n = 40), and most of them are located in Santa Ana, where a majority of the residents are Hispanic/Latino population. The unequal distribution of the chrome plating facilities in these Hispanic/Latino communities in Santa Ana raises concerns about disparities in PFAS pollution and exposure which could lead to disparities in PFAS-related health outcomes in the future. Moreover, no previous study in the US has focused on PFAS concentrations in blood among chrome plating workers. The project aims to first provide information on PFAS, and sources of PFAS in the neighborhood through hosting informational sessions in the communities within 5 miles of chrome plating facilities. At the same time, we will collect soil and water samples in neighborhoods within 5 miles of current and past chrome plating facilities to compare the levels of PFAS contamination in these neighborhoods. Lastly, we will utilize a self-collection blood testing kit for PFAS available from Eurofins Scientific to test for PFAS concentrations in capillary blood from 20 chrome plating workers and their family members (n = 40). Findings from the project will inform future regulations of chrome plating facilities and large-scale biomonitoring efforts in communities living near chrome plating facilities and chrome plating workers.

Efficacy of Reducing Indoor Air Pollution on Cognitive Health in Older Adults: A Pilot Study Built Upon HEPA Purifier Intervention Studies in Los Angeles Communities

Air pollution, especially fine particulate matter (PM2.5), is well-established for its negative health impacts, including respiratory and cardiovascular diseases, and is increasingly recognized for its role in cognitive decline. This study, as an adjunct to the SAPIA and UL2 parent studies, investigates the impact of indoor air pollution on cognitive function trajectories, with a focus on how reducing PM2.5 through HEPA filtration affects cognitive decline in the elderly population. Building on the foundational work of the parent studies—conducted between 2022 and 2027 with 152 participants aged 65-84 who have preexisting conditions such as ischemic heart disease or prediabetes across communities in Los Angeles—we will conduct a more focused intervention study with a subset of 52 participants. These participants will be randomly assigned to HEPA or sham groups (26 per group) to examine cognitive function changes over either 4.5 months with 2 visits or 9 months with 3 visits (SAPIA), or 6 months with 2 visits (UL2), depending on feasibility. Cognitive performance will be assessed using the NIH Toolbox Cognition Battery, which evaluates key cognitive domains such as episodic memory, executive function, and processing speed. In addition, daily cognitive fluctuations will be monitored continuously via Ecological Momentary Assessment (EMA), targeting the same cognitive domains as the NIH Toolbox, during the intervention period to evaluate short-term cognitive changes in relation to PM2.5 reduction.

We propose two aims: Aim 1 assesses the impact of reducing indoor PM2.5 exposure through HEPA filtration on cognitive function using the NIH Toolbox. Aim 2 investigates the short-term effects of PM2.5 reduction on cognitive fluctuations using EMA for real-time cognitive testing.

This innovative study employs a two-arm randomized trial design and leverages advanced digital health monitoring to evaluate HEPA filtration as a preventive strategy against the cognitive effects of PM2.5 exposure. By integrating comprehensive exposure assessment and cognitive testing, this study will generate preliminary data to address a critical gap in understanding the relationship between air quality and cognitive health, laying the groundwork for future large-scale investigations.

Unveiling Brain Mechanisms Linking Environmental Stressors to Learning and Memory in Children and Adolescents

Environmental factors such as neighborhood resource availability and exposure to fine particulate matter (PM2.5) air pollution contribute to adverse neurocognitive outcomes. Whereas these factors negatively impact brain structure and function in adults—particularly in regions critical for learning and memory like the hippocampus—their effects on brain development and cognition during childhood and adolescence remain underexplored. These periods are critical windows for neurodevelopment, making it imperative to investigate environmental influences on cognitive outcomes. The overall objective of this proposal is to investigate the pathways through which neighborhood resources and air pollution exposure affect neurocognitive outcomes in youth. We aim to identify the mediating roles of brain structure and function, focusing on brain regions involved in learning and memory. By leveraging advanced neuroimaging techniques and statistical modeling on data from the Adolescent Brain Cognitive Development (ABCD) Study—a large, longitudinal developmental cohort—we aim to address this critical gap.

In our first aim, we plan to employ a multi-mediation analysis to explore whether sequential brain measures—including brain microstructure, volume, and function treated as “neuro-omic” mediators—mediate the relationship between socio-environmental exposures and learning and memory outcomes. In this underexplored line of research, we hypothesize that these exposures impact cognitive outcomes through neural pathways. For our second aim, we plan to investigate potential joint effects of neighborhood resource availability and air pollution exposure on learning and memory neural circuitry. For the brain mediators identified in Aim 1, we will conduct post-hoc analyses to determine unique versus joint effects of neighborhood resources and air pollution exposure. Completion of these aims will advance our understanding of how socio environmental stressors influence neurodevelopment and cognition during a critical period in life. This work will help address cognitive differences arising from environmental inequalities, promoting healthier neurodevelopmental trajectories in vulnerable populations.

Project Firestorm: Assessing Respiratory and Mental Health Impacts of Wildland-Urban Interface Fires and Long-Term Toxic Exposures

The Palisades and Eaton fires in January 2025 burned over 50,000 acres, destroyed over 16,000 homes and other structures, and displaced over 150,000 Los Angeles County residents. In addition to the displacement of thousands of families and destruction of schools and other essential infrastructure, the fires have gravely affected air quality and released toxins that settle on surfaces as ash. Airborne pollutants include fine particulate matter (PM2.5 and PM10), which penetrate deep into the respiratory system, as well as volatile organic compounds (VOCs), carbon monoxide (CO), nitrogen oxides (NOx), and ozone precursors, all of which can exacerbate respiratory and cardiovascular conditions. Additionally, fires that burn urban areas release toxic metals (e.g., lead, arsenic, mercury, and cadmium) and persistent organic pollutants (POPs), such as dioxins, furans, and polycyclic aromatic hydrocarbons (PAHs), which are carcinogenic and capable of bioaccumulation. Ash deposits often contain heavy metals, alkaline compounds that can irritate the skin and mucous membranes, and residual chemicals from burned household and industrial materials.

Understanding the health effects of these catastrophic wildfires is an urgent public health priority for Los Angeles. Collecting biological samples from affected individuals and analyzing the ash as soon as possible after a wildfire is critical to assessing exposure levels and characterizing the composition of toxins before environmental factors, such as wind and rain, alter their distribution or concentrations. Early sampling also provides essential data for evaluating immediate health risks, designing protective interventions for affected communities, and informing longer-term remediation efforts to mitigate soil and water contamination. Prompt collection ensures that the dynamic nature of wildfire emissions and deposition is captured, facilitating robust epidemiological studies and public health responses.

We propose to conduct Project Firestorm, a study to quantify the health effects of the wildfires. We will leverage an existing cohort of over 9,000 USC faculty, staff, and students who participated in a longitudinal

COVID-19 study in 2021-2022. These participants, most of whom live in or around Los Angeles, have completed extensive surveys about their physical and mental health and sociodemographics, providing an

essential baseline assessment. Importantly, they have signed consent forms giving their permission to be recontacted for future studies, enabling us to launch the study quickly without extensive recruitment time.

We propose to recontact these participants and invite them to participate in a study about the effects of the fires on physical and mental health over the next year. From those who agree to participate, we will purposively recruit a sample of 200 participants--100 who lived near the fires and 100 who live over 15 miles away from the burn site. These participants will provide respiratory data, hair samples, and samples of their house dust and yard soil for analysis, in February-March 2025 and again in February-March 2026. We will analyze (1) differences between fire-affected households and more distant households, and (2) change over a one-year period among both fire-affected households and more distant households