NIEHS - National Institute of Environmental Health Sciences Grants

NIEHS - National Institute of Environmental Health Sciences

The Gordon Research Conference on Environmental Sciences: Water is to be held June 14-19, 2026, in Holderness, NH. The 2026 conference theme is Novel Approaches and Tools to Address Aquatic Impacts on Human and Environmental Health and will feature a program of thought-provoking research by leading researchers and experts in the field of water quality science and technology. The conference will bring together 190 participants from multiple countries in an immersive and informal setting. The program will feature a series of plenary talks by established and emerging researchers, as well as daily poster sessions by conference attendees. The overarching theme of the 2026 conference recognizes that state-of-the-art research is needed to understand challenges facing water resources, and to develop solutions to address these challenges. Ensuring water quality is critical for protecting human and ecosystem health, as well as maintaining ecosystem services. This conference will showcase innovative researchers who focus on current water resources challenges, including the presence of persistent contaminants and pathogens, access to clean water for communities, and environmental stresses on water. This aspect of the conference will provide a forum for discussing and evaluating the most pressing water issues of our time. The conference will highlight scientists who directly study environmental impacts through field measurements and community engagement, along with those working at the science-policy interface. Specific aims of the conference are to: 1) Feature a scientific program that links water quality issues, the protection of human health, and sustainability of environmental resources through a plenary program of leading researchers from different fields and perspectives - themes include chemical and biological exposures, human health impacts, and innovative solutions for the management of water resources; 2) Advance discovery while promoting mentoring, networking and learning by offering a platform for graduate student and postdoctoral researchers to present their research at the full conference, as well as provide a venue for informal interactions between senior scientists and trainees and broad participation of scientists from different professional settings; and 3) Provide a conference that fosters discussion and debate of research results through close interaction of participants from academia, industry, and government laboratories. Funds will be used to support the attendance of invited plenary speakers, as well as graduate students and postdoctoral trainees. Outcomes related to the quality of the scientific program, discussion, management, and atmosphere will be evaluated through surveys of conference attendees. 1

NIEHS - National Institute of Environmental Health Sciences

PROJECT SUMMARY The objective of this study is to determine epigenetic mechanisms that impact genomic imprinting upon in utero exposure of mice to human-relevant levels of lead (Pb). Pb is an infamous environmental exposure to human populations in the US and around the world, due in part to its neurotoxic effects. Pb exposure during early development has been linked to adverse health outcomes later in life. Preliminary data generated for this grant indicates that in utero and perinatal Pb exposure increases placenta/embryo size, and alters the DNA methylation of imprinted genes, respectively. However, the molecular mechanisms by which Pb exposure reprograms genomic imprinting during early gestation remain largely unknown. Imprinted genes are epigenetically regulated in a parent-of-origin specific manner with their mono-allelic expression driving critical periods of development. Known mechanisms of genomic imprinting include the 1) long non-coding RNA (lncRNA) and 2) insulator models, each of which program allele-specific regulation of imprinting control regions. Although dysfunctional genomic imprinting is implicated in several human diseases, the mechanisms leading to toxicant-induced imprinting dysregulation by the two models remain poorly understood. Using an established Pb exposure mouse model, this study seeks to determine in utero mechanisms that impact genomic imprinting and health effects from altered epigenetic reprogramming. Thus, female animals exposed to Pb two weeks prior to mating through 13-14 days post-conception will be used in the following Aims: 1) Determine fetal sex-specific imprinting dysregulation associated with in utero Pb exposure in mouse placenta, 2) Assess allele- and sex-specific mechanisms of in utero Pb exposure regulating genomic imprinting in the brain. Pb-exposed animals will be compared against controls to investigate genomic imprinting mechanisms in the lncRNA and insulator models by characterizing sex-, tissue-, and developmental stage-specific imprinted gene dysregulation via phenotypic, gene expression, DNA methylation, and immunohistochemical analyses. This study will reveal Pb-associated lncRNA mechanisms that inform the current epigenetic reprogramming by fetal sex. The University of Michigan provides an ideal environment to conduct the proposed research in collaboration with multiple core facilities outlined herein. The candidate will receive mentorship from a multidisciplinary team of experts to: 1) Gain proficiency in computational and statistical skills required for data analysis; 2) Acquire expertise in developmental toxicological research and mechanistic investigation; and 3) Build skills critical for leadership, teaching and mentoring, laboratory management, and grantsmanship. The proposed study will address fundamental knowledge gaps of genomic imprinting in the field to inform potential Pb-induced disease interventions. The training and research goals established in this K01 proposal constitute an exceptional foundation to ensure the candidate success in obtaining research independence.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT The International Society for Environmental Epidemiology (ISEE) is the preeminent scientific society focused on relationships between environmental agents and human health. Its Annual Conference serves as a critical forum for the exchange of ideas and advancement of solutions to pressing environmental health challenges of regional, national, and global significance. The conference is regularly attended by prominent epidemiologists from academia, industry, and government. As one of the most important forums for the presentation of human health research related to environmental exposures, it provides a unique opportunity for scientists, policymakers, and public health professionals to present their work, cultivate new collaborations, and develop solutions to emerging environmental health issues. It also plays a key role in training, education, and professional networking for students and early-career investigators. The 38th ISEE Annual Conference will be hosted in Munich, Germany from August 30th to September 2nd, 2026. It will feature interdisciplinary presentations of new research and methods that are of profound significance to the field of environmental epidemiology. In doing so, the conference also aims to facilitate open and respectful exchange of ideas and information between epidemiological investigators and public health practitioners from around the world. Scholarships will be provided to distinguished experts, young investigators, students, and promising new scientists who might not otherwise be able to participate in this meeting. In addition, funds will be allocated to cover journal publication fees so that accepted abstracts are publicly accessible to all to promote transparency and dissemination of science that is rigorous, reproduceable, and generalizable. Collectively, this meeting will strengthen the environmental health work force, promote scientific collaboration, and enhance knowledge exchange.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT/PROJECT SUMMARY The International Society for Environmental Epidemiology (ISEE) North America Chapter (NAC) was formed in 2019 focusing on promoting research collaborations across North American institutions. Since then, it has grown to host 1055 members from or residing in the United States (US), Bermuda, Canada, and Greenland. Although ISEE Global hosts an annual international meeting, this meeting is held on different continents each year, and visa issues and travel expenses often inhibit attendance by students, trainees, and early career researchers. Therefore, the ISEE-NAC started hosting regional meetings in 2023 to accommodate members with barriers to attending the global meeting when the location is not in America. Given the success of our previous regional meeting, recent changes in institutional funding allocation, and travel restrictions for international students and trainees and federal employees, we have experienced an increased interest in hosting the ISEE-NAC meeting in 2026. This meeting will enhance the mission of ISEE-NAC by providing a venue for environmental health and epidemiologic researchers, practitioners, and government personnel located in North America to network with potential new collaborators. The 2026 ISEE-NAC regional meeting will be held with a theme of “translating environmental health research to inform public health practice” and will be critical to moving our field forward. Meeting planning is already underway. Together with the organizing committee, we are planning a 2.5 day in-person meeting in Baltimore, MD (June 1-4, 2026) at the Johns Hopkins University Homewood Campus. The purpose of this meeting is to: provide networking and professional development opportunities for students, trainees, and early career scientists in environmental epidemiology (Aim 1); illuminate environmental epidemiology research throughout North America (Aim 2); and highlight research related to environmental health and epidemiology intervention, translational research, and community engagement (Aim 3). By focusing on community engagement, translation, and implementation, this meeting supports NIEHS Strategic Plan 2025-2029 items related to solutions-focused research and translation, building collaboration and partnership, and supporting training and workforce development through increasing public access to important environmental health findings.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT The Measuring Micro- and Nanoplastics in Environmental Samples Workshop (“the Workshop”) will be held as part of a Great Lakes Microplastic and Health Symposium (June 17-18, 2026) in Rochester, New York. This Workshop aims to pool existing expertise, establish new collaborations, and prioritize future needs for characterizing micro- and nanoplastics (MNP) in complex environmental matrices relevant to health research in the Great Lakes ecosystem. This Workshop will bring together national experts on MNP analysis with researchers studying the interactions between Great Lakes ecosystems (particularly water and air) and health. The Workshop will be hosted by two multidisciplinary centers that are part of the NIH/NSF Centers for Oceans and Human Health program. The University of Rochester and Rochester Institute of Technology co-host the Lake Ontario MicroPlastics (LOMP) Center, a transdisciplinary hub for research, translation and engagement on how MNPs affect human health and the Great Lakes environment (particularly water and near shore air). The Great Lakes Center for Fresh Water and Human Health is based at the University of Michigan (the Great Lakes Center). Its central goal is to better understand the increasing risks that cyanobacterial harmful algal blooms (cHAB) pose to freshwater ecosystems and human health. One aspect of the Great Lakes Center’s research is to explore the association of aerosolized microplastics and cHABs. Fostering collaboration and scientific exchange between the Great Lakes Center, LOMP, and national experts studying MNPs is one example of how this workshop may have long-term impacts on regional MNP research collaborations that may yield results of global significance. The Workshop has three objectives: 1) Bring together scientists from multiple laboratories and institutions to present new findings, identify methodological challenges, and share analytical approaches to better understand environmental exposures to MNPs and their potential impact on human and environmental health; 2) Develop new collaborations between researchers and trainees across institutions, both regionally and nationally; and 3) Identify priorities and opportunities for analytical advances to support this rapidly growing field. The objectives will be met through a Workshop format with a limited number of participants (30-40) to encourage close interaction. The requested R13 conference funds will be used to pay for expenses for the June 17 Workshop, including travel expenses for trainees, invited experts, and researchers from other institutions. R-13 support will also enable these attendees to participate in the full Great Lakes Microplastic and Health Symposium, to be held on June 18 at the University of Rochester’s Memorial Art Gallery, that will include a larger number of researchers, trainees, and community partners (120-150) on a broad range of topics related to Microplastics and Health with a focus on the Great Lakes region.

NIEHS - National Institute of Environmental Health Sciences

Project Summary (Abstract) We are requesting partial funding for the 25th Midwest DNA Repair Symposium. This symposium will be held in Kansas for the first time, at the University of Kansas Medical Center in Kansas City on May 30-31, 2026. This is the only continuously running Midwestern DNA repair meeting, and has been on-going since 1999, with only a hiatus during the 2020-23 pandemic. This meeting has established itself as one with exceptionally high value for the cost, which allows investigators to take or send several trainees to the meeting in addition to attending themselves. The oral presentations are selected from the submitted abstracts, and historically this meeting chooses trainees and early career investigators for the talks to boost their careers. The remaining abstracts present posters. The 2026 meeting will also have four keynote speakers: Dr. Joann Sweasy from the University of Nebraska Medical Center; Dr. Scott Williams from the NIEHS; Dr. Anja Bielinsky from the University of Virginia; and Dr. Alessandro Vindigni from Washington University in St. Louis. These speakers are all internationally recognized experts in DNA repair and genome stability and will help attract participants to the meeting. Two of our invited keynotes are supported by NIEHS, and we plan to build a session around them that focuses on environmental sources of DNA damage. The remaining sessions will be planned according to the submitted abstracts. The meeting is being co-chaired by Dr. Ryan Barnes and Dr. Bret Freudenthal. Both are experts in DNA repair and genome stability and represent an early career investigator (Barnes) and an established investigator (Freudenthal). Funding through this R13 mechanism is requested to defray costs for keynote, as well as selected trainee and early career investigator, travel and lodging, awards for trainees, and expenses such as poster boards and audio/visual support. We expect that participants will leave the meeting with new ideas for their own research, new collaborations, and new leads for career opportunities for the trainees.

NIEHS - National Institute of Environmental Health Sciences

PROJECT SUMMARY/ABSTRACT Per- and polyfluoroalkyl substances (PFAS) comprise a class of several thousand compounds that present a major public health problem worldwide. The 5th National Conference on Per- and Polyfluoroalkyl Substances, will be held in Tucson, AZ, a region affected by PFAS drinking water contamination, to grow the impact of the national conference through facilitating PFAS information sharing, collaborative research, and remediation across the U.S. This meeting uniquely convenes scientists, government officials, environmental advocates, affected community members, Tribal Nations, journalists, utility managers, and attorneys to support and better inform the priorities of PFAS sectors. The 5th PFAS conference will utilize the new geographic location to cultivate novel cross-sector collaborations to help prevent future PFAS contamination and exposure-related health risks and leverage an enhanced diversity of perspectives to more effectively prevent future exposure and protect human health. By moving the 5th meeting location to Tucson, AZ, another PFAS-affected community in a state that has become a leader in PFAS testing and action, we will expand the access, impact, and participation from affected communities at this conference. This proposed meeting will bring together all involved groups to examine the complex set of social, scientific, political, and environmental health issues associated with PFAS exposure. The planning committee will utilize principles from funds of knowledge and ensure that the conference is designed around multi-directional environmental health dialogue.

NIEHS - National Institute of Environmental Health Sciences

PROJECT SUMMARY The 16th Biennial Conference of the International Society for Trace Element Research in Humans (ISTERH-16) will take place in the World Trade Center Events Center in São Paulo, Brazil, June 3-6, 2026. The title of this conference is ISTERH-16: Toxicology and Trace Elements: The Intersection of Health and Disease; highlighting integration of the central theme of trace element and toxicology research at the intersection of health and disease outcomes. In addition, ISTERH is partnering with the Brazilian Congress of Toxicology (CBTox) and the International Society for Zinc Biology (ISZB) to expand the interdisciplinary interactions among international researchers working within this research theme. This partnership is anchored in the success of ISTERH-14 in Aachen, Germany with ISZB and expands participation with researchers with complementary interests in CBTox. The overall objective of the conference is to bring together global experts from academia, medical institutions, industry, government, and non-government organizations to assess research advances, to identify knowledge gaps, and to define future research and regulatory needs in areas related to trace element research. ISTERH- 16 will build upon the most recent ISTERH meetings in Murcia, Spain (2024), Aachen, Germany (2022), and Bali, Indonesia (2019) including expanding participation with researchers in South America. São Paulo is a central location in Brazil with major transportation and hotel networks to accommodate international participants and provides a unique setting to strengthen collaborative networks and strategic partnerships. 150-180 ISTERH members are expected from all continents to attend and present their research in 14 symposia (including a trainee focused symposium), 3 plenary sessions, and 3 poster sessions. Symposia will cover scientific topics within the conference theme including transport and metabolism of trace elements, trace element nutritional health considerations in children, epidemiological approaches for study of metal-induced toxicities, mitochondrial mechanisms of metal toxicity, mechanisms of metal carcinogenesis, environmental biomonitoring of trace elements, among other topics. Furthermore, ISTERH participants will be joined with colleagues from CBTox (~500 researchers expected) and ISZB (~150 researchers expected), expanding reach and impact of ISTERH- 16 through co-hosting of joint plenary and poster sessions and parallel symposia. Dr. Jennifer Freeman, ISTERH President and Chair of the Scientific Program Committee, has been working closely with ISTERH leadership and Scientific Program Committee members, along with leadership from CBTox and ISZB towards conference planning and logistics. Funding is needed to support travel of early career investigators and trainees, along with symposium chairs and speakers. The purpose of this support is to provide travel assistance to ISTERH researchers at US-based institutions to attend, share their research, and interact with international colleagues. Meeting proceedings will be featured in a special issue of the Journal of Trace Elements in Medicine and Biology.

NIEHS - National Institute of Environmental Health Sciences

PROJECT SUMMARY/ABSTRACT The Developmental Origins of Health and Diseases (DOHaD) hypothesis, which posits that early-life events or exposures determine the health outcomes across the life span, is foundational to the U.S. DOHaD Society. The U.S. DOHaD Society has held annual meetings since its inception in 2016. These meetings bring together investigators from a wide array of disciplines who otherwise may not be likely to interact. Our membership includes clinicians, scientists and trainees across a wide array of specialties including developmental biology, nutrition, environmental toxicology, cancer, stress, and endocrinology. Such individuals span institutions geographically across the U.S. including Universities, companies/corporations, and government agencies (NIH, EPA, NIEHS). The annual meeting provides a critical opportunity for members to share knowledge and recent advancements on how environmental toxicants, nutrients, pharmaceutical agents, pathogens, gut microbiota, stress, and emerging factors influence developing fetuses and newborns, and thereby contribute to their health and disease across the life span. Presentations and discussions explore how environmental factors may lead to harmful effects in subsequent generations. The major goals of the U.S. DOHaD Society's annual meeting are to foster multidisciplinary interactions, promote collaborations on applicable scientific and clinical topics, and provide opportunity for trainees (graduate students, postdoctoral fellows, clinical residents/fellows, and junior faculty) to interact with world-renown experts to facilitate the development of future scientists and career opportunities in the field. The past eight conferences have been enormously successful, with significant growth in membership and attendance during each subsequent meeting. Such successes provide impetus for continued and permanent annual meetings. The 10th will be held at North Carolina State University (Raleigh, NC) and the theme will be “The Exposome and DOHaD Science”. In short, the strength of the U.S. DOHaD Society lies in its ability to integrate an impressive range of science among individuals in varying levels of their education and careers.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT Per- and polyfluoroalkyl substances (PFAS) contamination in drinking remains a major environmental and public health issue, as these persistent pollutants resist natural degradation, accumulate in water supplies, and pose long-term health risks. As a result, the Environmental Protection Agency (EPA) has set enforceable Maximum Contaminant Levels (MCLs) for per- and polyfluoroalkyl substances (PFAS) in drinking water at 4.0 parts per trillion (ppt) for PFOA and PFOS. Metrics Water Catalyst (MWC) holds the exclusive license from Arizona State University (ASU) for a novel two- stage treatment process that couples catalytic defluorination with biological mineralization for complete PFAS destruction. ASU selected MWC as the licensee based on our proven engineering capabilities and ability to translate laboratory advances into deployable technologies. Bench-scale experiments at ASU Biodesign Institute have demonstrated effluent concentrations below EPA’s proposed maximum contaminant levels for PFOA and PFOS in drinking water. This Phase I project will address the required engineering efforts in membrane reactor material selection and construction methods, a critical step toward developing durable, field- deployable treatment systems for municipal use. Specific Aims: (1) Establish a scalable membrane manufacturing method for both reactors, including substrate selection, catalyst-film application (MCfR), surface preparation (MBfR), and documented SOPs with QC checks (yield, bubble-point/pressure-hold, gas flux/kLa, film loading/adhesion). (2) Verify mechanical and chemical durability under plant-like stress—pressure and temperature cycling, representative drinking-water chemistry (pH, alkalinity, hardness, NOM), and clean-in-place (CIP)—while maintaining integrity and gas- transfer performance within preset acceptance limits. (3) Optimize module geometry—packing density, fiber dimensions, flow path, and header/housing design—to increase specific surface area and gas-transfer coefficients at acceptable pressure drop and fouling risk, and to fit standard sanitary housings. Research Design and Methods: We will fabricate pilot lots of membranes and sub-scale modules; implement SOP-driven QC; run pre/post stress testing with integrity, flux/kLa, adhesion, and ΔP endpoints; and execute a structured geometry design-of-experiments. Deliverables include manufacturing SOPs and a QC plan, durability data packs, optimized drawings/BOM, and vendor-informed manufacturability recommendations (e.g., suggested processes, tolerances, and design improvements) suitable for future scale-up. Expected Outcome and Impact: A manufacturable, stress-tolerant, geometry-optimized membrane platform that de-risks Phase II pilot builds of destruction-based PFAS treatment and advances a practical route to lowering PFAS exposure at the tap.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT/ SUMMARY An estimated 21,000 Americans die from radon-induced lung cancer every year, making radon gas the second leading cause of lung cancer among smokers and the primary risk factor for non-smokers. Lack of awareness coupled with outdated maps, and gaps in testing areas leave many, especially in high-risk areas, unaware of the danger. A significant challenge in radon risk management is obtaining real-time data on radon gas variability as a function of geology, meteorology, and structure factors. Traditionally used static, low-resolution county and zip-code level radon potential zone maps make determining radon levels at the neighborhood-level impossible to interpret, particularly since radon concentrations are known to fluctuate wildly due to weather and dwelling characteristics. Homeowners, real-estate agents, construction companies, policymakers, and state and local health and environmental departments need an easily accessible high-resolution, interactive map that provides accurate, real-time radon predictions and solutions for mitigating radon health risks. Although attempts have been made to gather measurement data and utilize advanced computing for predicting radon risk zones, none to date have integrated all known contributing factors with AI models and been made commercially available. AI-Solutions 87 (AIS), a Wisconsin based small business, is developing an end-to-end software development and real-time data platform for people, businesses and elected officials concerned about radon risks for their families, customers, and constituents. Preliminary studies have shown the AIS’s ability to provide a secure application with the ability to upload static measurements and share real-time IoT sensor data onto an interactive map that integrates geological, and meteorological data. In Phase 1, the PI, AIS staff, and collaborating parties will determine the feasibility and user acceptability of the platform as well as AIS’s ability to generate predictive models. Aim 1: Engineer software that aggregates and analyzes radon measurements, environmental, geological, atmospheric and soil data, enables role-based social collaboration, and provides advanced computational resources for a web and mobile application. Aim 2: Construct an ultra-high resolution radon prediction map for Bozeman, MT using available indoor radon measurements from national laboratories, state and local environmental departments, and local radon testing specialists. Aim 3: Establish the blueprint for a dynamic radon prediction map by enabling real-time radon exposure data integration using progressively interconnected IoT radon monitors. By the end of Phase 1, AIS will have established a robust framework for data integration, manufactured a data pipeline, implemented AI/ML techniques, and deployed scalable cloud solutions to enhance dynamic radon prediction mapping. Phase II efforts include expanding coverage to the state and then national level. A significant market opportunity exists for AIS’s AI-powered technology to determine current and future radon exposure risk. This preemptive intervention protects families and saves lives.

NIEHS - National Institute of Environmental Health Sciences

SUMMARY Per- and polyfluoroalkyl substances (PFAS) are a large class of synthetic chemicals used in consumer products, industry, and firefighting foams. Their persistence and mobility have caused widespread contamination of drinking water, wastewater, soil, sediments, and food webs. Chronic exposure has been linked to cancer, immune suppression, and developmental harm. New U.S. EPA regulations, including maximum contaminant levels (MCLs) and Method 1633, are driving unprecedented demand for PFAS analysis. However, current laboratory methods rely on solid-phase extraction (SPE), a slow and labor-intensive procedure that creates severe analytical bottlenecks. As a result, sample to result times can exceed 6–12 weeks, at costs above $500 per sample, limiting organizations’ ability to monitor and respond to contamination in real time. To address these challenges, Biota, Inc. is developing a fully automated PFAS sample preparation solution. The platform leverages advanced nanoparticle chemistry paired with a high-throughput magnetic handling system to streamline PFAS isolation and concentration. This technology eliminates key bottlenecks in current workflows, reduces solvent use, and minimizes analyst time. The result is a method compatible with LC- MS/MS that can process 90 samples in under one hour with less than 10 minutes of operator involvement. By dramatically reducing time, cost, and variability, this solution will make high-quality PFAS testing accessible to more laboratories and communities. In turn, it will enable faster decision-making by utilities, regulators, and remediation professionals who depend on timely data to protect public health. This Phase I project will establish feasibility of the platform in water and wastewater, demonstrating compatibility with regulatory performance criteria. In Phase II, the system will be validated more broadly across the full panel of analytes and environmental sample types required under Method 1633, paving the way for commercialization and adoption in testing laboratories nationwide. Successful development of this platform will transform PFAS monitoring from a weeks-long process into a near real-time capability, empowering stakeholders to address contamination more rapidly, affordably, and effectively.

NIEHS - National Institute of Environmental Health Sciences

Project Summary: Correctly identifying a substance’s acute oral toxicity is crucial for labeling with the proper safety precautions needed for health and safety. The classification, handling, and labeling requirements of substances is determined by their oral toxicity category, based on their acute exposure hazard as determined by the Environmental Protection Agency (EPA) and Globally Harmonized System (GHS). Acute oral toxicity data from rat mortality studies are needed to ascertain the median lethal dose of 50% (LD50). This LD50 is a requirement needed to specify governmental agencies' labeling demands and for risk assessment for human health and environmental hazards. The determination of the LD50 (a single endpoint of lethality) meets the oral and systemic toxicity data requirements of categorization for international regulatory authorities in the areas of industrial chemicals, consumer products, and mixtures such as pesticides [1] [2] [3] [4]. Under considerable public pressure, the US government now has an interest in fostering the development of in vitro and alternative replacements for animal tests [1]. Although in vitro and alternative assays have been developed and codified for other toxicity hazards (i.e., eye and skin irritation, skin sensitization), the alternative assays developed for assessing acute oral systemic toxicity are limited and inaccurate. Additionally, the high cost of the zebrafish models, in vitro 3D constructs, and organ-on-a-chips generally dissuade chemical registrants and product stewards who only rely upon the lower expense and accuracy of LD50 assays. The Egg LD50 Assay for Categorization (ELDAC) would fill a large gap between mammalian LD50 testing and other anticipated but yet-to-be-validated and very complex alternatives. ELDAC uses an already well-characterized network of organ systems. Since the yolk and albumen are the sole nutrition sources for the embryo, test chemical administration to these food sources is a good approximation of oral administration. To demonstrate the feasibility of the ELDAC, we administered 18 chemicals (from GHS 1-5 and EPA IV oral toxicity categories) by injecting directly into the yolk or the albumen of fertilized chicken eggs. Our work demonstrates that these fertilized chicken eggs respond to different chemicals’ toxicity in a potency-responsive manner. We correctly predicted the exact GHS or EPA category for 16 of the 18 (88.9%) chemicals (and all 18 of 18 were predicted correctly within one category). Thus, the ELDAC can easily stratify lethality responses based on the oral toxicity categories as well as the rat LD50 values of these chemicals. Our research establishes the novel utility and the approach necessary for evaluating the LD50 of chemicals specifically, or for acute oral toxicity categories assignment. In summary, we conducted requisite studies for establishing the ELDAC as a feasible non-mammalian test system that is very capable of categorizing oral toxicity hazards of chemicals according to their relative toxicity.

NIEHS - National Institute of Environmental Health Sciences

Wildfires are occurring across the US and globally with potentially harmful impacts on maternal and child health. Although research into health effects specific to wildfire smoke exposure in pregnancy is nascent, a recent meta-analysis on more than 1.7 million births showed that maternal exposure during late pregnancy was linked to reduced birth weight and preterm birth. However, the short and long-term effects of repeated wildfire smoke exposure during pregnancy on maternal and fetal health outcomes have not been investigated in depth, nor are any molecular mechanisms responsible for such effects well understood. Therefore, there is an urgent need to understand the how wildfire smoke exposure affects health and wellbeing. One hypothesized mechanism to facilitate biological communication from pollutants inhaled in the lung to distal organs and tissues is through extracellular vesicles (EVs). EVs contain a variety of biologically active molecules including microRNAs (miRNAs) which are small ~22 nucleotide-long noncoding RNA molecules. EV-miRNA might be the ideal candidates to mediate effects of wildfire smoke exposures on pregnancy because they can be produced by the respiratory system where the initial exposure occurs and then enter the circulation to affect distant tissues and organs. We hypothesize that prenatal exposure to wildfire smoke triggers a biological response that can be measured in EV-miRNA, and that these wildfire smoke-related biological signatures are negatively associated with fetal and infant growth. We will additionally investigate the interplay between smoke exposure and miRNA signatures with neighborhood characteristics, including housing, infrastructure, and other factors that may modify effects on fetal and infant growth. We will examine this hypothesis in 466 participants in MADRES—a cohort representative of the population living in Los Angeles, CA – in the following aims: Aim 1) Identify unique EV-miRNA transcriptomic signatures of wildfire smoke across pregnancy and the biological pathways associated with their predicted gene targets in a population of 466 pregnant participants with 666 maternal biospecimens. Aim 2) Evaluate the influence of wildfire-associated EV-miRNA signatures on ultrasound-measured fetal growth, infant birthweight, body composition and child growth through age 7. We will additionally evaluate effect modification by sex of child and neighborhood characteristics. Aim 3) In exploratory analyses in a subset of 96 mother/child pairs, we will test whether wildfire smoke exposures affect newborn miRNA levels in cord blood and further investigate the correlation of EV-miRNA expression profiles between mother and infant. Findings from this study may inform future screening, diagnostic, or treatment, interventions by helping us understand the biological effects of wildfire smoke.

NIEHS - National Institute of Environmental Health Sciences

Abstract. The developing fetus is exceptionally vulnerable to chemicals in the environment. Prenatal exposure to environmental contaminants, such as heavy metals, PFAS compounds and pesticides, impose a substantial societal cost due to the intellectual disability burden to children exposed early in life. Adverse chemical exposures are unavoidable in many cases, due to contaminated environments or the co-exposure that come with foodstuffs and with contaminated drinking water. Therefore, understanding how maternal handling of toxicant exposure, and particularly how the pregnant state may enhance or compromise this function, are a top priority. Mercury (Hg) is among the top environmental contaminants that pose human health risks, ranking third on the U.S. Agency of Toxic Substances Disease Registry priority list of hazardous substances. Methylmercury (MeHg) is the most highly toxic form of mercury and is commonly consumed with fish where it ultimately poses its greatest health risk to the developing fetus. In this proposal we investigate the potential impact of pregnancy on moderating MeHg clearance kinetics in the mother and thus, toxicity for the fetus. We will expand upon exciting and unexpected preliminary evidence that as pregnancy progresses, maternal elimination of MeHg increases, potentially reducing the exposure to the fetus. By optimizing tools that we have previously developed to monitor MeHg metabolism and excretion in non-pregnant adults, we will now evaluate pregnant women, who choose to eat fish routinely, for changes in MeHg elimination over time. With prior knowledge that the gut microbiome is responsible for MeHg metabolism (demethylation) that promotes its faster excretion, we will evaluate the maternal gut microbiome for demethylation activity in parallel. In addition, we will perform metagenomic sequencing to resolve the entirety of species in the gut microbiome to attempt to identify the organisms responsible for faster elimination. Finally, we will compare the mother’s MeHg elimination rate to that the fetus in third trimester. We anticipate the outcomes of this study will determine whether or not: 1) increased MeHg elimination with the progression of pregnancy is generalizable to all mothers, 2) the gut microbiome is a potential mediator of pregnancy-induced MeHg elimination and 3) fetal elimination of MeHg is entirely dictated by the mother or is moderated in part by the fetus itself. We view this as a high-risk, high-reward study, with great potential to reveal generalizable traits of the maternal microbiome that can limit toxicant exposures and furthermore be accessible to modifications that will ultimately reduce toxicity risk to the fetus.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT Plastic additives are widely used in consumer products, yet thousands of plastic additives remain uncharacterized for their potential to disrupt endocrine function - posing significant public health risks. This project aims to develop an integrated computational (Aim 1) and experimental (Aim 2) workflow to systematically predict and validate the endocrine-disrupting potential of plastic additives. In Aim 1, we will design novel machine learning models trained on publicly available datasets to predict AR and ERα modulating activity of plastic additives and then used to predict the potential effects of all plastic additives to select the most promising based on novelty and predictive uncertainty for further in vitro and in vivo testing. In Aim 2, we will validate our predictions through a multi-step experimental characterization approach using our in-house AR and ERα assays, followed by dose-response studies in AR- and ERα-responsive cell lines to measure target gene activation and cell proliferation. The top three plastic additives with the strongest in vitro effects will be further evaluated in vivo using mice to assess systemic hormonal changes caused by the plastic additives. This work will have a substantial positive societal impact by establishing a first-in-kind machine learning-assisted predictive toxicological model to pinpoint plastic additives of highest concern to induce adverse health effects as well as generate a large dataset of plastic additive effects on endocrine function. Taken together, this work can serve to provide policy guidance on plastic additives to ban or remove from products, with potentially beneficial health outcomes for billions of consumers.

NIEHS - National Institute of Environmental Health Sciences

Project Summary The majority of Parkinson’s disease (PD) cases are not caused by an inherited monogenic mutation, and disease etiology involves a combination of genetic and environmental factors. Epidemiological studies show that pesticide exposure, particularly to organochlorine pesticides such as dieldrin, increases the risk of sporadic PD. In a model of increased PD susceptibility, mice exposed to dieldrin during development show male-specific increased susceptibility to adult exposure to the dopaminergic toxicant MPTP and, in data from our previously NIEHS-funded work, α-synuclein (α-syn) preformed fibrils (PFFs). Results in this two-hit model demonstrate that developmental exposure to dieldrin leads to largely sex-specific changes in epigenetic modifications from birth to 9 months of age within pathways related to critical steps in early neurodevelopment, dopaminergic neuron differentiation, synaptogenesis, synaptic plasticity, and glial-neuron interactions, suggesting that developmental dieldrin exposure disrupts critical neurodevelopmental pathways, thereby impacting risk of late-life diseases, including PD. However, the early neurodevelopmental effects of this exposure remain incompletely understood. In addition, while these effects are thought to be mediated by direct impacts of dieldrin on the developing brain as dieldrin crosses the placenta and can be detected in the neonatal brain, disruption of placental serotonin (5HT) has emerged as a potential indirect mechanism of developmental neurotoxicity (DNT). Because the placenta is the primary source of 5HT for the developing fetal brain and proper regulation of placental serotonin is essential for proper fetal neurodevelopment, disruption of placental 5HT can cause behavioral and neurological changes throughout the lifespan. Such disruption by genetic, pharmacologic, or toxicologic mechanisms increases the risk of neurodevelopmental disorders, but long-term outcomes on late-life diseases are largely unexplored. This grant aims to test two related yet independent hypotheses. In Aim 1, we hypothesize that dieldrin, known to disrupt monoaminergic systems in the adult brain, may also affect these systems within the placenta; this disruption of placental 5HT may be an additional indirect mechanism of DNT. In Aim 2, we hypothesize that developmental dieldrin exposure alters the development of fetal and neonatal monoamine systems.

NIEHS - National Institute of Environmental Health Sciences

Project Summary Environmental exposure can alter pseudouridine (Ψ) landscape in cellular RNA. Ψ is the most abundant modified nucleoside in nature and it regulates many RNA processes. Similar to N6-methyladenosine (m6A), whose functions in RNA are modulated in part by its reader proteins, we reason that environmental exposure-mediated changes in RNA pseudouridylation and the resulting changes in RNA-protein interactions constitute a major regulatory mechanism of RNA processes that may underlie disease pathogenesis. Yet up to now, few Ψ reader proteins are known, and our knowledge is limited in the mechanisms through which environmental exposure- mediated aberrant RNA pseudouridylation and the ensuing perturbations of RNA-protein interactions contribute to the pathogenesis of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Our proposed study aims to bridge this knowledge gap by uncovering the mechanistic link between environmental exposure and ALS pathology through the lens of RNA pseudouridylation and Ψ-protein interactions. Our preliminary data showed that: (1) at physiological concentration, profilin-1 (PFN1) binds directly and preferentially to Ψ-containing RNA; (2) ALS-linked point mutations in an ALS-associated protein, i.e., PFN1 reduce its affinity for Ψ-containing RNA, and (3) Ψ modification reduces RNA affinity for another ALS-associated protein. We organize our proposed research into three specific aims: Aim #1, to examine how RNA pseudouridylation is modulated by xenobiotic exposure in human neuronal cells; Aim #2, to investigate the impacts of RNA pseudouridylation on the transcriptome-wide occupancy of an ALS-associated protein; and Aim #3, to explore the impacts of RNA pseudouridylation and Ψ-protein interactions in xenobiotic and ALS pathological contexts. To accomplish these research aims and facilitate my transition to an independent academic career, I have assembled a mentoring committee with outstanding expertise in environmental toxicology, bioinformatics and neurobiology. The proposed research is built upon my extensive research skill sets, strong preliminary data, and the proposed mentoring/training plan. The outcome of the proposed research will unveil how environmental exposure-elicited aberrant RNA pseudouridylation alters RNA-protein interactions and contributes to ALS, thereby potentially leading to new biomarkers and therapeutic interventions. Moreover, the proposed career development and research plans will bridge gaps in my training and collect robust data for my independent publications and research grant applications, thereby transitioning me to an independent career at the intersection of environmental health science and neurodegeneration.

NIEHS - National Institute of Environmental Health Sciences

PROJECT SUMMARY/ABSTRACT Air pollution is a leading health threat, and 131 million people in the US live in a county with unhealthy levels of air pollution. Pregnancy is a period of increased susceptibility to the effects of air pollution, which is a complex mixture of hazardous chemicals. Common pollutants, including fine particulate matter (PM2.5), ozone (O3), nitrogen dioxide (NO2) and excess heat, have each been associated with placental insufficiency. This condition affects half a million pregnancies annually in the US and is a major source of perinatal morbidity and mortality. PM2.5, O3, NO2, and heat may interact to potentially exacerbate risk of placental insufficiency, but most methods lack the flexibility and interpretability to characterize this risk. The goal of this study is to determine whether mixtures of PM2.5, O3, NO2, and heat synergistically increase risk of placental insufficiency during pregnancy. This will be done using an emerging machine learning method for causal inference, which adjusts for confounders and calculates confidence intervals. Residential exposure to ensemble-modeled 1 km2 estimates of these pollutants are available for all 9,447 participants in our existing prospective pregnant cohort. In AIM 1A, we use the causal random forest algorithm to estimate the effects of mixtures exposure on placental insufficiency for each gestational week, accounting for time-to-event structure. Variability in these effects will be characterized in AIM 1B with an uplift model, which will describe effect modification across body mass index, a risk factor for placental insufficiency. Although residential air pollution exposure is commonly used in health models, this exposure assignment contributes to uncertainty in the health effects of air pollution. In AIM 2A we will use a microsimulation activity space model developed at Oak Ridge National Laboratory to create simulated movement patterns for our pregnant cohort. The effect of activity space exposures on risk of placental insufficiency will be compared against the effect of residential exposures in AIM 2B. This study will provide insight into the effects of air pollution mixtures on placental insufficiency, as well as effect modifiers and uncertainty. The results could alter our conclusions about the safety of air pollution during pregnancy. Training will take place at the University of Utah and Oak Ridge National Laboratory under the mentorship of experts in maternal-fetal medicine, atmospheric science, machine learning, computation, and trustworthy data science. Through this training plan, the applicant will develop the foundational skills to prepare for an academic career dedicated to studying maternal air pollution exposure with advanced methods.

NIEHS - National Institute of Environmental Health Sciences

PROJECT SUMMARY The objective of my proposal is to apply a novel, interdisciplinary approach with its combination of spatial analysis, implementation science, and exposure assessment to understand respiratory health and gaps in resource availability in the San Francisco Bay Area. My proposal builds on my past and current expertise in environmental engineering to use a systematic approach to assimilate across multiple data source to detect wildfire smoke risk changes due to exposure reduction strategies. I seek additional training to develop and apply innovative spatial and exposure analytical and qualitative methods to better characterize respiratory risk due to wildfire smoke exposure across all populations and identify specific factors influencing the success or implementation of strategies designed to increase community resilience. Due to evolving climate trends, environments in the western United States (U.S.) as well as more broadly across Canada have become drier and warmer resulting in more frequent and intense wildfire fire events. Year after year, wildfire smoke and particularly, wildfire-specific fine particulate matter (PM2.5) remain significant contributors to the air pollution burden on population health in the U.S. and beyond. While numerous guidance documents exist, especially in California, it unknown whether these strategies are adopted and enacted across communities and specifically in those most vulnerable to respiratory health outcomes. Historical patterns have led some communities to face higher risk for adverse respiratory outcomes and therefore these communities must be the public health priority when examining respiratory health effects of wildfire smoke and identifying effective risk reduction strategies. This proposal will advance the field of environmental health by applying spatial analysis to examine the distribution of risk reduction strategies and the factors driving these patterns (Aim 1); identifying individual, organizational, and societal factors that influence the presence of wildfire smoke risk reduction strategies using implementation research methods (Aim 2); and quantifying the impact of these strategies on the association between wildfire smoke and respiratory outcomes, with a focus on how effectiveness may vary based on community characteristics (Aim 3).The K99 training will enhance my research expertise through targeted coursework, mentorship, and active engagement in: (1) advanced spatial analysis; (2) implementation science and community-based participatory research; (3) quasi-experimental methods and epidemiology; and (4) career development. The skills gained through this award are essential to achieving my long-term goal of advancing multidisciplinary statistical and methodological approaches to quantify the respiratory health impacts of air pollution and exposure reduction strategies. This work will generate new scientific knowledge to improve understanding of respiratory health disparities and resource distribution, while equipping me with the expertise to plan and execute independent, innovative studies on the health effects of hazardous air pollutants using multi- dimensional analysis techniques.

NIEHS - National Institute of Environmental Health Sciences

The growing burden of kidney disease in the U.S. and worldwide is attributed in part to non-traditional risk factors. The potential public health impact is staggering, with over 850 million people currently affected by chronic kidney disease (CKD) alone and global costs for CKD projected to top $400 billion by 2027. Exposure to airborne hazards is one prominent but poorly understood CKD risk. Air pollution has been convincingly linked to adverse kidney health outcomes, including incident CKD, CKD progression, end stage kidney disease, albuminuria, and hospitalization for acute kidney injury. Occupational exposure to silica dust has been linked to renal-related mortality and inhalation of silica dust from kilns, silica-rich crops, ash, and other sources is implicated in the complex pathogenesis of CKD of unknown etiology (CKDu), an emerging disease now reported in over 35 tropical countries and manifest primarily as chronic tubulointerstitial injury. The mechanisms by which inhaled toxins such as respirable silica contribute to remote renal tubule injury and subsequent kidney disease, particularly in communities experiencing high heat exposures, are unclear. This is a critical knowledge gap and highlights the need for rigorous preclinical studies. We propose that kidney cells are injured indirectly by endogenous soluble nephrotoxic mediators released into the bloodstream from damaged lung, noting that lung- kidney communication has already been implicated in glomerulopathies. Our long-term goal is to identify molecular mechanisms of interorgan communication that mediate remote organ injury after environmental exposures that impact human health. The short-term goals are to document kidney injury using complementary sensitive functional assays and to determine if circulating microRNAs (MiRs) are altered early after silica inhalation at time points likely to reflect injury-modulating pathways. Our hypothesis is that silica exposure alters renal function in part by inducing circulating MiR capable of engaging cognate mRNAs in critical kidney cell compartments, and that concurrent heat stress, a common co-exposure, exacerbates this response. Our transdisciplinary team will test this hypothesis in two complementary but independent Aims, the feasibility of which is supported by preliminary data: Aim 1: Quantify early changes in kidney function and cell transcriptomes induced by exposure to inhaled silica, with and without concurrent simulated heat wave co-exposure, and Aim 2: Identify circulating MiRs as candidate mediators of interorgan signaling, using prediction and prioritization algorithms in both aims to gain novel insight into molecular mechanisms. Ultimately these proof-of-principle studies aim to establish regulation of kidney mRNA and/or circulating MiRs as plausible molecular events involved in lung-kidney crosstalk and kidney injury early after inhalational exposures. Our results should stimulate new ideas to prevent and treat exposure-related remote organ injury, particularly for individuals facing multiple CKD risks.

NIEHS - National Institute of Environmental Health Sciences

Project Summary/Abstract Genital malformation including hypospadias represents the second most common male birth defect after cardiac defect. In the past 50 years, hypospadias incidence has doubled along with other male reproductive abnormalities. It is suspected that fetal exposure to endocrine disruptors may have contributed to this increase. However, the etiology of hypospadias is still largely unclear. Both environmental and genetic factors are involved. Thus, there is an urgent need to understand genetic pathways regulating urethral closure as well as lower urinary tract development in general. Unfortunately, insufficient prospective screening tools have prevented the rapid identification of causative genes. We have recently developed a streamlined forward genetic screening technology combining in vivo and in vitro approaches to rapidly identify crucial regulators of genital masculinization and lower urinary tract development. As a result, we have identified 31 high priority candidate transcription factors downstream of androgen receptor, regulating genital masculinization. In light of recent discovery that an extra-genital cell population migrates into the developing genitalia and is required for urethral closure, this proposal will use two purified GT mesenchymal populations to increase the cellular and functional resolution of our established high-throughput screening system. We will use these novel screening systems to reevaluate the function of transcription factors during urethral closure. In Aim I, we will use two tissue-specific mouse Cre lines to isolate pure populations of mesenchymal cells in the developing GT and test their cellular response to androgen stimulation. In Aim II, we will perform a proof-of-concept screen for transcription factors governing either their proliferation or migration. Together, these studies should greatly accelerate the discovery progress for master regulators of urethral closure. Our long-term goal is to use mouse molecular genetics to understand the process of urethral closure and the etiology of genital malformations, such as hypospadias.

NIEHS - National Institute of Environmental Health Sciences

ABSTRACT The Los Angeles urban wildfires (LA Fires), which began on January 7, 2025, have become one of the most destructive disasters in U.S. history. Although officially contained by February 7, 2025, emerging evidence sug- gests that exposure risks persist long after active burning due to post-fire degassing and cleanup activities. LA Fires released a complex mix of volatile and semi-volatile organic compounds (VOCs and SVOCs) from burned structures, vehicles, and household products. These emissions can last weeks to months, as damaged materials release pollutants back into the air. Cleanup activities, including debris removal and demolition, may further re- suspend contaminated dust and release VOCs, prolonging exposure risks for returning residents. However, post- fire indoor air quality remains an understudied yet critical issue in wildfire research. Since January 8, 2025, our team has monitored indoor and outdoor air quality in 25 households near both fires. We found outdoor concen- trations of benzene, toluene, ethylbenzene, xylenes (BTEX), and toxic heavy metals were over 100 times higher during active burning. In the post-fire phase, indoor BTEX levels in burn zone homes exceeded outdoor concen- trations, even in the absence of indoor activities, suggesting prolonged off-gassing from building materials. Ad- ditionally, real-time monitoring detected persistently elevated ultrafine and sub-micron particles in the burn zones weeks after the fires were contained. These findings underscore the urgent need to characterize post-fire expo- sure pathways, particularly in indoor environments where people spend most of their time.To address these critical gaps, we propose two aims. Aim 1: Assess indoor and outdoor exposure to fine and ultrafine particles and VOCs post-fire. We will expand sampling to 50 homes (25 per fire) and monitor air quality over one year or until cleanup is complete. Homes will include affluent, predominantly White communities (Palisades) and pre- dominantly Black communities (Altadena). We hypothesize that indoor VOC levels will remain elevated due to prolonged off-gassing, while fine and ultrafine particles will persist outdoors due to dust resuspension and sec- ondary aerosol formation. Aim 2: Evaluate how building characteristics and mitigation measures influence indoor air quality. We hypothesize that older, leakier homes will experience greater infiltration of outdoor fire smoke, leading to higher post-fire indoor VOC levels. We further hypothesize that wealthier residents in the Palisades will implement more effective mitigation measures (e.g., HVAC upgrades, air purifiers) compared to residents in Altadena, leading to lower indoor exposures. With over 16,000 structures destroyed, the LA Fires released highly toxic pollutants, posing persistent exposure risks to affected communities. This study will provide time-sensitive data to guide returning residents, inform evidence-based policies, and improve indoor air quality recommenda- tions for filtration and ventilation. Findings will also lay the groundwork for future research on the long-term health impacts of toxic urban wildfire smoke, a growing concern as wildfires increasingly threaten densely populated areas.

NIEHS - National Institute of Environmental Health Sciences

Proposal Abstract Traditionally, live animals have been used to assess the toxicity of candidate chemicals in pharmaceutical drug development. However, animal tests are increasingly scrutinized for being time- consuming, costly, and ethically challenging. This has driven demand for non-animal alternative tests, or new approach methodologies (NAMs). The recent FDA Modernization Act 2.0 supports this shift by permitting the adoption of validated NAMs in place of animal tests for safety assessments and regulatory approval of human trials. NAMs can serve as first-tier screening tools to identify potentially toxic drugs, allowing only those with no apparent toxicity to proceed to animal testing if necessary. This tiered approach could significantly reduce live animal use. To achieve this goal, rigorous validation of individual NAMs according to international standards is essential to ensure regulatory acceptance. The proposed project aims to establish validated NAMs for developmental and reproductive toxicity (DART) assessment using morphogenesis models derived from pluripotent stem cells. My lab has previously developed these morphogenesis models from mouse and human stem cells, which recapitulate key morphological and molecular events of early embryogenesis in vitro. In published studies, we showed that these models exhibit significant morphological and gene expression changes in response to chemicals known to cause birth defects or miscarriages. To validate these models as NAMs for DART assessment, we will apply the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guideline, which provides a list of reference drugs with comprehensive in vivo toxicokinetics data, such as rodent plasma concentrations linked to embryotoxicity and non-embryotoxicity. These data can serve as benchmarks to evaluate the effectiveness of NAMs in predicting embryotoxic drug concentrations in alignment with in vivo results. To accomplish our objective, we propose three Specific Aims. Aim 1 is to examine the impact of embryotoxic drug exposures on the gene expression profiles in the mouse morphogenesis model. Aim 2 is to enhance detection capabilities through molecular augmentation of the mouse morphogenesis model. Aim 3 is to examine the response of a human stem cell-based morphogenesis model in reference to available rodent toxicokinetics data. This project is significant in its potential to establish validated NAMs as non-animal alternatives for preclinical DART assessments. It is innovative in its use of advanced stem cell technology to model embryological processes, facilitating precise concentration-specific analyses aligned with high international standards.