Air pollution is a major public health concern and its wide-ranging effects have been linked to >7 million premature deaths annually.Air pollution exposure is estimated to account for >30% of global stroke burden and has been linked to 4.9% of stroke-relateddisability-adjusted life-years.With more stroke survivors than ever before, stroke remains a leading cause of severe long-term disability, resulting in immense economic burden.Epidemiological studies have observed strong relationships between air pollution exposure and both stroke incidence and mortality. Recent experimental work in mice suggests that particulate matter pollution may play an important role in both stroke severity and stroke recovery. However, the relationship of ambient and traffic-related air pollutants to stroke severity and long-term recovery has not been explored in epidemiological studies. To investigatethis question, we will leverage the “Field Administration of Stroke Therapy-Magnesium” (FAST-MAG)the first prehospital trial of its kind,enrolling a large number of acute stroke patients in the hyperacute “golden hour” time window, providing unique insight into ultra-early stroke outcomes.Further, FAST-MAG provides detailed in-person follow-up of functional outcomes; a rare resource for studies of this size. In this pilot we propose to assign ambientandtraffic-related air pollutant exposuresto ischemic stroke patientsone year prior to and three months after incident stroketo investigate associations between air pollutants and presenting stroke severity, as well as functional recovery at 3 months post-stroke. We predict that higher exposurestoambient and traffic-related air pollutants will result in greater initial stroke severity upon presentation and also contribute to poorer functional recovery outcomes at 3 months after incident stroke.The results of this workwill contribute novel insights into the relationship between air pollutants and stroke severity and functional recovery outcomes, with thepotential to inform health protective interventions, as well as post-stroke recommendations.

Exposure to heat and air pollution are each associated with increased cardiovascular, respiratory, and allcause mortality. Both are projected to worsen as a result of climate change. Ambient particulate matter <2.5 µm (PM2.5) and ozone (O3) are increased by climate change through pathways including weather changes such as stagnation events and wind/dust storms, increased photochemistry due to higher temperature, and drier and warmer conditions that increase pollutant formation from biogenic volatile organic compounds and frequency and magnitude of wildfires. Standard practice is to examine effects of high heat and air pollution in isolation. However, because they are both impacted by climate change, they occur together. Better understanding of the potentially synergistic effects on mortality of co-occurring high heat and air pollution is needed so that life-saving adaptation interventions can be developed. We propose to investigate the independent and synergistic effects of heat and air pollution co-exposure on mortality. In Aim 1, we will use a time-stratified case-crossover study design and daily neighborhood modeling of air pollution and temperature to assess effects on cardiovascular, respiratory, and all-cause mortality in Southern California during the years 2015-2016 (two of four highest global temperatures ever recorded). In Aims 2a and 2b, we will examine how the heat and pollution effect estimates vary by census tract air conditioning use, assessed using a novel method applied to smart meter electricity data in a representative sample of 200,000 Southern California households, and across modifiable built environment factors (green space [e.g., tree canopies, parks] and surface reflectivity [e.g., traditional versus solar reflective “cool” roofs]) to help identify effective targets for climate change interventions. The study will produce accurate mortality effect estimates of heat and air pollution co-exposure needed for climate change health impact assessment.

Humans are exposed to complex, real-world mixtures of ambient air pollutants. In studies of air pollution health effects, exposures are typically examined one at a time due to issues of multi-collinearity. There have been considerable advances in the statistical methodology to investigate multipollutant effects, but these methods are limited in their ability to account for the temporal dimension of exposure. We propose an innovative method using multivariate self-organizing maps (SOM) to investigate the acute effect on airway inflammation of multiple correlated pollutants based on temporally resolved multipollutant exposure profiles during a 24-hour period. The broad objective of this proposal is to characterize typical 24-hour multipollutant patterns and evaluate their association with early adverse respiratory health response. We will relate daily multipollutant patterns to exhaled nitric oxide (FeNO) assessed in participants of the Southern California Children’s Health Study (CHS). We will initially train the SOM on a large sample of 24-hour air monitoring data (hourly data) over several years from monitoring sites across Southern California, to capture the full range of distinct daily multipollutant exposure profiles. Next, using CHS central site air pollution data, we will classify day prior to FeNO testing into one of the SOM-identified multipollutant exposure profiles, which will be related to FeNO using regression modeling. Results from this pilot project will inform a future NIH R01 application studying complex mixtures in environmental health which will expand application of the novel multivariate SOM methodology to different time scales (e.g., daily, seasonally, annually, etc.), potentially taking advantage of the rich CHS data resource by extending our analysis to the up to 6 longitudinal measurements of FeNO and including other respiratory health endpoints (e.g., lung function).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 25 million people in the United States with nearly 500,000 deaths. The pandemic has surged nationwide with Los Angeles County (LAC) being a major epicenter for the pandemic with almost 1 million cases and over 13,000 deaths. Large variations in clinical presentation of the SARS-CoV-2 infection exist, ranging from asymptomatic cases to death. Emerging evidence indicates that exposure to environmental pollutants can exacerbate COVID-19 severity. Per-and poly-fluorinated compounds (PFAS) and heavy metals constitute two classes of contaminants with known immunotoxic effects. PFAS exposure can result in perturbation of numerous immune response pathways including activation ofperoxisome proliferator-activated receptor-alpha (PPARα), an anti-inflammatory component, and activation of nuclear factor-kappa B (NF-kB), which can suppress cytokine secretion by immune cell function. Heavy metals, including cadmium and mercury, are well known pulmonary toxicants with immunotoxicant properties, which have been linked to alterations in antigen and cell mediated immunity. We propose the first human study to evaluate the impact of exposure to both heavy metals and PFAS on COVID-19 severity. We aim to use the existing Southern California Clinical and Translational Science Institute Biospecimen Repository(SC CTSI), which includes urine and blood specimens as well as access to electronic medical records for COVID+ individuals. We propose to use archived samples to characterize PFASandheavy metalconcentrations in this cohort of COVID+ individuals. We also aim to use detailed electronic medical records to establish a range of case severityto evaluate the association between environmental exposures and disease progression. Findings from this pilot project will be highly relevant to a planned R01 application to investigate further the role of the environmental exposures in COVID-19 disease severity. Our new multidisciplinary collaboration will also be relevantto future directions and other major COVID-19 related research projects at USC

There is a large body of evidence noting the importance of prenatal exposure to environmental factors on pregnancy outcomes. The growing fetus is indirectly exposed to the air the mother breathes, water she drinks, food she eats, and place she lives, to name a few sources. Exposure to metals can result in maternal oxidative stress and altered DNA methylations leading to systemic inflammation and the byproducts of these processes can pass through the placenta. Some metals, in certain forms (inorganic, elemental or methylated) can pass through the placenta, while others can accumulate in the placental tissue and exert their toxic effect. Metal exposures often happen in clusters- exposure to a specific group of metals form a single source (i.e. traffic, smelting, brick kiln and others). Overall, exposure to different metals is ubiquitous and recent epidemiological studies have shown that prenatal exposure to metals can affect neurodevelopment in children. However, most studies report the effect of metals individually on neurodevelopment, and the findings have been inconsistent. Few recent studies have considered the joint effect of different metals and have reported complex interrelationships among metals on neurodevelopment. Both synergistic and antagonistic interactions, as well as bi-phasic (‘U’ shaped) dose dependent effects of metals on neuro- development have been observed. In the current study we will investigate the joint effect of prenatal exposure to metals on neurodevelopment of infants during the 1st year of life in a well characterized pregnancy cohort. We will leverage extensive exposure and health data available from a pregnancy cohort that has been followed from early pregnancy to 1 year after delivery. The findings from this project will provide epidemiological data on the joint effects of PM2.5 and metals on neurodevelopment and will pave the way for future research.

The study of gene-environment (GxE) interactions iscritical for understanding how individuals with diverse genotypic backgrounds can bedifferentially affected by exposure to the same environmental factors, which canlead to disparate health outcomes. For example, airpollution may have a stronger influence on asthma onset in children who are genetically suspectable.Dietary and smoking habits can differentially increase cancer risk in individuals with certain genetic profiles. Althoughthestatistical framework to estimate and test theseinteractioneffectsis well developed for case-control studies and for quantitative traits, there are a lack of counterpart methods for time-to-event outcomes with cohort designs.To bridgethis gap, we will develop new procedures for identifying GxEinteractions in epidemiological/environmentalhealth cohortstudies. Specifically, we will extend and evaluate two-step hypothesis testing strategies for studies with a time-to-event endpoint and where the cohort was sampled using either a nested case-control or case cohort design. The proposed methods are expected to improve the statistical power in identifying novel loci that could have been missed in a primary GWAS through their modified effect with an environmental factor.Theseprocedureswill then be applied to two USC-sponsored longitudinal cohort studies, the Children’s Health Study and the Multiethnic Cohort Studyto identifynovel risk-associated loci. In the Children’s Health Study, wewill scan forgenetic variantswhose associated risk profile on asthma may be modified by air pollution.In the Multiethnic Cohort study, we will investigate the potentially interactive role of genetic variants and smoking habits on the risk of colorectal cancer.The development of these novel methods will enable environmental health researchers to identify genetically-defined subgroups who may benefit from reduced exposure to environmental risk factors, which will in turn lead to studies furthering the understanding of the biology of complex diseases.

Consumers are inadvertently exposed to various metallic nanoparticles everyday. The results generated from this work are meant to enable a better understanding of the cellular interactions taking place within the body and where these nanoparticles ultimately reside. This information will be important in determining how to better regulate these nanomaterials as we continue to engineer new nano-enabled products. The research objective of this proposal is to develop a deeper understanding of how metallic nanoparticles behave in living systems using a new luminescence imaging technique. Metallic nanoparticle biodistribution has been previously studied by my laband others, but their real-time dynamics in circulation and ultimate fate are poorly understood on the microscopic level. The proposed research addresses this critical need using an innovative microscopy imaging approach. Briefly, our scientific objectives are: Objective 1: Study the circulation half-life of metallic nanoparticles in-vivo and evaluate how it is affected bynanoparticle size and concentration. Objective 2: Determine nanoparticle fate and biodistribution by assessing which tissues and cellular components within those tissues contain metallic nanoparticles over time. These objectives will be accomplished using an entirely new luminescence imaging approach that allows for real-time label-free imaging of metallic nanoparticles in the body. This cutting edge imaging strategy allows visualization ofunlabeled metallic nanoparticles in an unperturbed vascular environment for the first time with frame rates fast enough to achieve individual particle tracking. The results will lead to a better understanding of metallic nanoparticle behavior in a dynamic living system and willprovide important information on their safety. Ultimately, the results obtained here have the potential to inform new environmentalpolicies and better tailor dosing regimens for biomedical applications.Further development and assessment of this transformative imaging strategy could open new avenues of investigation throughout the environmental research-community to further exploit this intrinsic luminescence effect.

Childhood acute lymphoblastic leukemia (ALL) is the most common childhood cancer. While certain environmental risk factors such as air pollution and pesticide use have been previously associated with childhood ALL, little is known about the effects of other factors of the built environment such as greenspace and biodiversity. Our study objective is to evaluate the risk associated with greenspace and biodiversity and childhood ALL risk and survival. The study will be conducted within the California Linkage Study of Early-onset Cancers (CALSEC) and Childhood Cancer Record Linkage Project (CCRLP), two large, population based, case-control studies of childhood cancer in California. The cohort links birth registry data and diagnoses from the statewide California Cancer Registry. Residential history has been geocoded previously, allowing for geospatial coding of our exposures of greenspace and biodiversity. The association between our exposures and ALL risk will be examined using logistic regression, and survival analysis will be examined with a Cox proportional hazards model. We will also leverage genome-wide association data from newborn bloodspots that are part of the CCRLP to conduct gene-environment analyses involving FOXO3A, a gene that has been reported to be associated with both ALL and greenspace. The identification of modifiable environmental exposures related to ALL will help provide a clearer understanding of the mechanisms behind ALL etiology and identification of strategies for intervention.

Autism spectrum disorder (ASD) imposes large costs on our population. The prevalence of ASD has increased by 2.5-fold in the US since the year 2000. Causes of ASD are multi-factorial. Although genes and maternal malnutrition are well-known risk factors of ASD, increasing evidence suggests that early-life air pollution exposure has a critical role in causing ASD. Emerging evidence from human studies and animal models converges on neurotoxic effects of small particles. However, the mechanism linking prenatal fine particle exposure to ASD in children is unknown. We hypothesize that prenatal fine and ultrafine particle exposure may affect maternal and neonatal metabolism, which imposes the risk of ASD development in children. This study is built upon a large pregnancy cohort at Kaiser Permanente Southern California (KPSC) (400,000 mother-child pairs) and a novel resource of biospecimen stored in the California Biobank. We will select 50 children with doctor diagnosed ASD before age 5 (cases) and 50 typically developing controls who are matched with cases on birth year, sex, ethnicity and KPSC service area. Further, we will identify the mothers of these selected children and will retrieve both the mothers’ serum samples collected at mid-pregnancy and the newborn dry blood spots from the California Biobank. We will then perform high-resolution metabolomics on these samples and will examine key metabolic pathways in pregnant women and newborns that may be influenced by air pollution exposure and induce ASD risk. These targeted metabolic pathways are selected based on current literature. The pilot data will help build a foundation for our future R01 application to pursue the research in the entire KPSC cohort with ~4,400 ASD cases. Findings from this line of research will advance our knowledge about the biological responses to prenatal air pollution exposure and will help to detect early biomarkers (metabolomic signatures) for ASD.

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer, and one of the leading causes of cancer-related deaths in children. The etiology of ALL in most cases is unknown, although case control studies have reported associations between environmental exposures in early life, including pesticides, paint, and tobacco smoke, and leukemia risk. Such studies largely relied on parent questionnaire data, which are prone to bias and do not provide accurate measures or critical windows of exposure. Therefore, we propose the novel concept of using deciduous teeth (“milk teeth”) to capture accurate data on environmental exposures throughout the life course (i.e., “the exposome”) of childhood ALL patients. This approach has been used in studies of autism and other neurodevelopmental disorders, but not yet in childhood cancer; thus, this study has the potential to shift the paradigm of childhood cancer epidemiology research. Through existing collaboration with Dr. Philip Lupo, we have access to deciduous teeth and diagnostic bone marrow (tumor) material from childhood ALL patients. Reconstructing the early-life exposome of 20 ALL patients forms the basis of Aim 1. Exposome analysis will be performed in the laboratory of Dr. Manish Arora, who has pioneered methods to measure environmental components (e.g. metals, organic chemicals, nutrients) at tooth layers corresponding to specific life stages. In Aim 2, we will perform tumor whole genome sequencing to assess the somatic mutational landscape of each patient. We will then test for association between environmental exposures and patterns of somatic alterations, with a particular focus on gene deletions and mutational signatures. This study would demonstrate, for the first time, the use of teeth as biomarkers in epidemiologic studies of childhood cancer, and lay the groundwork for future funding efforts to pinpoint environmental risk factors and their critical windows of exposure that will be essential for prevention of childhood leukemia.

Hepatocellular carcinoma (HCC) and cirrhosis rates have continued to increase over the past three decades. The health impact of the increasing incidence of HCC is compounded by its dismal prognosis, with overall 5- year survival of 18%. The major HCC and cirrhosis underlying etiology includes hepatitis C and B infections, alcohol-related liver disease, and non-alcoholic fatty liver disease (NAFLD). NAFLD is now recognized as a major contributor to cirrhosis and HCC development. Emerging evidence indicates that exposure to perfluorinated compounds (PFAS) disrupts lipid homeostasis in the liver and has an influence on the initiation and progression of a cascade of pathological conditions associated with NAFLD. Epidemiological evidence is scarce and there are no studies on the impact of PFAS exposure on NAFLD-related cirrhosis and HCC. Our objective is to examine the associations between plasma PFAS concentrations and NAFLD-related cirrhosis and HCC in the Multiethnic Cohort (MEC). We hypothesize that increased PFAS concentrations are associated with NAFLD-related cirrhosis and HCC and with alterations in key metabolic pathways implicated in NAFLD pathophysiology. We will conduct a nested case-control study of NAFLD-related cirrhosis and HCC (n=100) and matched controls (n=100). Plasma concentrations of PFAS and metabolomics profiling prior to disease onset will be determined using liquid chromatography with high resolution mass spectrometry. The proposed study is novel and cost efficient (leveraging existing data and samples from MEC), has the potential to advance our understanding of hepatotoxic effects of environmental pollutants, and may open new avenues for liver cirrhosis and HCC prevention. Findings from these pilot data will support a future R01 application to investigate the role of PFAS and metabolomics signatures in other liver diseases and cancers in the MEC.

Hepatocellular carcinoma (HCC) and cirrhosis rates have continued to increase over the past three decades. The health impact of the increasing incidence of HCC is compounded by its dismal prognosis, with overall 5- year survival of 18%. The major HCC and cirrhosis underlying etiology includes hepatitis C and B infections, alcohol-related liver disease, and non-alcoholic fatty liver disease (NAFLD). NAFLD is now recognized as a major contributor to cirrhosis and HCC development. Emerging evidence indicates that exposure to perfluorinated compounds (PFAS) disrupts lipid homeostasis in the liver and has an influence on the initiation and progression of a cascade of pathological conditions associated with NAFLD. Epidemiological evidence is scarce and there are no studies on the impact of PFAS exposure on NAFLD-related cirrhosis and HCC. Our objective is to examine the associations between plasma PFAS concentrations and NAFLD-related cirrhosis and HCC in the Multiethnic Cohort (MEC). We hypothesize that increased PFAS concentrations are associated with NAFLD-related cirrhosis and HCC and with alterations in key metabolic pathways implicated in NAFLD pathophysiology. We will conduct a nested case-control study of NAFLD-related cirrhosis and HCC (n=100) and matched controls (n=100). Plasma concentrations of PFAS and metabolomics profiling prior to disease onset will be determined using liquid chromatography with high resolution mass spectrometry. The proposed study is novel and cost efficient (leveraging existing data and samples from MEC), has the potential to advance our understanding of hepatotoxic effects of environmental pollutants, and may open new avenues for liver cirrhosis and HCC prevention. Findings from these pilot data will support a future R01 application to investigate the role of PFAS and metabolomics signatures in other liver diseases and cancers in the MEC.

Despite the fact that numerous human epidemiology and animal model studies have implicated a pathogenic role of developmental exposure to endocrine disrupting chemicals (EDCs) in promoting obesity, type 2 diabetes, and cardiovascular diseases, the underlying molecular mechanisms remain poorly understood. We have recently conducted a systems biology study in mice to comprehensively examine the multi-tissue transcriptome, epigenome, and gut microbiome alterations altered by developmental EDC exposure. As a result, we identified key genes, pathways, and tissue-specific regulatory networks that are perturbed in endocrine and metabolic tissues (hypothalamus, liver, and adipose tissues) and associated with metabolic dysfunctions. However, all previous molecular studies of EDCs, including ours, examined bulk tissues that represent mixtures of heterogeneous cell populations, thereby missing the opportunity to pinpoint the most sensitive and pathogenic cell types and cell-specific molecular pathways. Building on our recent success in implementing high-throughput single cell sequencing technology Drop-seq, here we propose to understand the multi-tissue, multi-cellular molecular perturbations induced by in utero exposure in mice to two common EDCs, namely, the model chemical Bisphenol A (BPA) and its much less well-understood substitute Bisphenol S (BPS) at single cell resolution. We will focus on the liver, adipose, and hypothalamic tissues due to their pivotal roles in obesity and metabolic dysfunction. Using Drop-seq, we will identify the most sensitive cell types and molecular pathways in individual cell types in each metabolic tissue that are affected by developmental exposure to BPA and BPS, and subsequently test the roles of the molecular changes in metabolic dysregulation. Our proposed pilot study will offer the first comprehensive map of the in vivo molecular activities of common EDCs in individual cell types of key metabolic tissues and will reveal key mechanistic commonalities and differences between BPA and BPS to facilitate precision medicine. The findings will help direct future therapeutic strategies to counteract EDC-induced cardiometabolic disorders.

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children has almost tripled over the past 20 years, currently affecting on average 8-12% of the general pediatric population and 34-40% of obese children in the US. Mounting evidence suggests that early life environmental exposures contribute to the etiology of NAFLD. Animal studies show hepatotoxic effects even at low levels of exposure to perfluorinated compounds (PFASs), persistent compounds widely used in water repellant textiles, nonstick coatings, and food packaging products. PFASs have long half-lives (up to a decade) in humans. Despite abundant evidence from experimental studies demonstrating liver toxicity by PFASs, epidemiologic evidence is limited to a few cross-sectional studies in adults. We therefore propose a novel study design for investigating PFASs hepatotoxic effects, based on clinical and liver histopathological data leveraged from the Follow-up of Adolescent Bariatric Surgery (FABS) study that offers a unique archive of liver tissue and blood samples collected at the time of surgery. We hypothesize that higher plasma and liver PFASs concentrations will be associated with more advance stages of NAFLD and with attenuated improvement in liver injury after bariatric surgery. We will use archived samples collected at the time of surgery to measure PFASs concentrations in plasma and liver. Existing liver gene expression data in the FABS cohort will allow characterization of PFASs associations with underlying mechanistic pathways of NAFLD, including lipid metabolism and inflammation pathways. Findings from these pilot data will support a planned R01 application to investigate further the role of the PFASs chemicals and multi-omics signatures in pediatric liver disease. Our new multidisciplinary collaboration will also be relevant to future directions planned for the upcoming renewal of the Southern California Children’s Environmental Health Center and other major ongoing research projects at USC [e.g., MADRES and ECHO projects].

This pilot project aims to determine the relationship between ambient air pollution exposures and survival after diagnosis with breast cancer in the California Teachers Study (CTS). Using data from the California Cancer Registry (CCR), our group has previously shown that air pollution exposures after diagnosis are associated with shortened survival in lung and liver cancer patients. This work is based on the exposures occurring at the residential address at the date of diagnosis, the only address available in the CCR data. Despite biological plausibility for a role of air pollutants in breast cancer, we have not observed similar associations in breast cancer patients. We believe this is due to the longer survival of breast cancer patients, which requires access to longitudinal, individual-level data on address history (to produce more accurate exposure assignments) and data on other determinants of survival (potential confounders) which are not available in cancer registries. The CTS is a unique and rich data resource with extensive baseline and follow-up questionnaires, and addresses updated throughout follow-up. Data for those CTS participants residing in California at the time of breast cancer diagnosis are already included in the CCR. This pilot project will result in at least one publication and will lay the groundwork for subsequent NIH grant proposals: (a) an R01 to investigate the combined roles of air pollution and other risk factors on breast cancer survival with improved air pollution exposure modeling and (b) an R21 to investigate the impact of air pollution on lung cancer survival, accounting for smoking.

Hepatocellular carcinoma (HCC) and cirrhosis rates have continued to increase over the past three decades. The health impact of the increasing incidence of HCC is compounded by its dismal prognosis, with overall 5- year survival of 18%. The major HCC and cirrhosis underlying etiology includes hepatitis C and B infections, alcohol-related liver disease, and non-alcoholic fatty liver disease (NAFLD). NAFLD is now recognized as a major contributor to cirrhosis and HCC development. Emerging evidence indicates that exposure to perfluorinated compounds (PFAS) disrupts lipid homeostasis in the liver and has an influence on the initiation and progression of a cascade of pathological conditions associated with NAFLD. Epidemiological evidence is scarce and there are no studies on the impact of PFAS exposure on NAFLD-related cirrhosis and HCC. Our objective is to examine the associations between plasma PFAS concentrations and NAFLD-related cirrhosis and HCC in the Multiethnic Cohort (MEC). We hypothesize that increased PFAS concentrations are associated with NAFLD-related cirrhosis and HCC and with alterations in key metabolic pathways implicated in NAFLD pathophysiology. We will conduct a nested case-control study of NAFLD-related cirrhosis and HCC (n=100) and matched controls (n=100). Plasma concentrations of PFAS and metabolomics profiling prior to disease onset will be determined using liquid chromatography with high resolution mass spectrometry. The proposed study is novel and cost efficient (leveraging existing data and samples from MEC), has the potential to advance our understanding of hepatotoxic effects of environmental pollutants, and may open new avenues for liver cirrhosis and HCC prevention. Findings from these pilot data will support a future R01 application to investigate the role of PFAS and metabolomics signatures in other liver diseases and cancers in the MEC.

Prenatal and early life environmental exposures to air pollutants have been associated with low birth weight and increased risk for childhood obesity. Additionally, results from the Children’s Health Study have shown that in utero near-roadway air pollution (NRAP) exposure is associated with increased childhood body mass index. While the mechanisms underlying these associations remain uncertain, animal studies and our recent preliminary data suggest that NRAP exposure may alter the gut microbiota and modify risk for obesity. Despite this, no studies have examined the potential impact of NRAP exposure on the human microbiome during critical periods of development, including pregnancy and early life. Therefore, we propose a pilot study that will examine a subset of pregnant Hispanic women from the ongoing Maternal and Developmental Risks from Environmental Stressors (MADRES) cohort, a newly established pregnancy cohort with an end-target of 1,000 predominantly Hispanic mother-child pairs living in the greater Los Angeles region. This pilot study will support the collection and analysis of stool samples needed to perform detailed gut microbial profiling in 40 women during pregnancy and 40 infants at 1 and 12 months of age. To our knowledge, this will be the first study to examine the relationships between prenatal and early life air pollution exposure and the gut microbiome, providing novel preliminary data for future grant applications. We postulate that increased NRAP exposure will be associated with alterations in the gut microbiome, which will contribute to alterations in infant growth trajectories in the first year of life. Results from the proposed pilot study will test the feasibility of stool collection in MADRES and will generate preliminary data for external grant applications aimed to examine these relationships in a larger cohort of mother-infant pairs with repeated stool sampling.

Cardiovascular disease (CVD) accounts for the largest proportion of mortality and morbidity worldwide. While a strong body of evidence supports a role for long-term air pollution exposure in CVD among adults, relatively little is known about how air pollution exposures during key developmental windows may affect subclinical markers of atherogenesis, and potential disease development, over the lifecourse. Early markers of these pathogenic processes, including measures of carotid artery intima-media thickness and arterial stiffening, can be measured in children and young adults and may provide insight into the beginnings of disease. The overall goal of this pilot is to generate key preliminary data for a competitive R01 submission to leverage existing cardiovascular health data from the Southern California Children’s Health Study (CHS) to inform the relationship between air pollution exposure and subclinical markers of CVD risk and begin to define how environmental air pollutants may relate to changes in cardiovascular risk from childhood and to early adulthood. We propose to recontact and reevaluate 20 CHS emerging adult participants, who provided carotid artery ultrasounds at age ~10. Using the childhood imaging data as a baseline measure of cardiovascular health, we will collect a second ultrasound scan from these participants to 1) calibrate newer instrumentation to enable longitudinal modeling of subclinical markers of CVD as measured by carotid ultrasound 2) explore calculation of echogenicity, a novel marker of arterial wall composition, from childhood ultrasound images and 3) begin to explore trajectories subclinical markers of atherosclerosis from childhood into adulthood and how these markers may relate to air pollution exposure over the lifecourse. These data will inform a larger study with a long-term goal to begin to characterize environmental contributions to early cardiovascular risk factors from childhood into early adulthood, which will be key to identifying those at risk to prevent later life disease.

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children has almost tripled over the past 20 years, currently affecting on average 8-12% of the general pediatric population and 34-40% of obese children in the US and in Europe. Mounting evidence suggests that early life environmental exposures contribute significantly to the genesis of metabolic diseases including NAFLD. Animal studies show hepatotoxic effects even at low levels of exposure to many endocrine disrupting chemicals (EDCs), and chronic exposures to ambient fine particulate matter have been shown to induce liver steatosis, inflammation and fibrosis in mice. Human evidence is limited to few cross-sectional studies in adults. We propose an innovative approach to evaluate the role of targeted environmental exposures measured prenatally in the subsequent development of childhood NAFLD. We will leverage the extraordinary existing resources of the “HELIX-The Human Early-Life Exposome” project, which includes harmonized prenatal geospatial data for air pollutants and targeted EDCs in 1200 pregnant mothers and children from 6 European countries. We propose to use archived blood samples collected during the childhood examination at ages 6-10 years to measure alanine aminotransferase (ALT), a validated surrogate biomarker for NAFLD in epidemiological studies of children, and cytokeratin-18 (CK-18), a marker of hepatocyte apoptosis. Existing omics signature data already measured in these samples will allow characterization of exposure associations with underlying mechanistic pathways of NAFLD, including metabolic, inflammatory and adipokine dysregulation pathways. Findings from this pilot project will be highly relevant to a planned R01 application to investigate further the role of the “human exposome” and multi-omics signatures in pediatric liver disease. Our new multidisciplinary collaboration will also be relevant to future directions planned for the upcoming renewal of the Southern California Children’s Environmental Health Center and other major ongoing research projects at USC [e.g., MADRES and ECHO pregnancy cohort projects].

In Bangladesh, acute lower respiratory infections (ALRI) have been estimated to cause 24% of deaths among children under five years of age. Increased exposure to particulate matter (PM) has been shown to contribute to ALRI. While the mechanisms underlying these associations remain uncertain, studies and our recently preliminary data suggest that PM exposure may alter the respiratory and gut microbiota, thereby modifying risk for ALRI. Despite this, no studies have examined the potential impact of PM exposure on the infant microbiota during critical periods of development, including the first year of life. Therefore, we propose a pilot study that will examine a subset of infants from the ongoing Bangladesh Pregnancy Cohort, which is evaluating the health effects of indoor PM exposure on ALRI in a large cohort (n=900) of women and their children. Through existing NIH funding (Fogarty), participants are already being extensively phenotyped for environmental exposures and infant health outcomes that include ALRI. This pilot study will support the analysis of respiratory and stool samples needed to perform detailed microbial profiling in 80 infants at 6 months of age. To our knowledge, this will be the first study to examine therelationships between the infant respiratory and gut microbiota and their associations with PM exposure and ALRI. Therefore, this pilot study will provide novel preliminary data for future grant applications. We hypothesize that increased PM exposure will be associated with alterations in the respiratory and gut microbiota, which will contribute to increased ALRI in the first year of life. Results from the proposed pilot study will test the feasibility of stool and nasal sample collection in the Bangladesh Pregnancy Cohort and will generate preliminary data for external funding applications that will examine these relationships in a larger cohort of participants with repeated microbiome sampling during the first year of life.

Exposure to air pollution and nano-sized particulate matter (nPM) has been associated with effects in neurologic pathologies due to generation of inflammation and oxidative stress. Specifically, nPM exposure exacerbates stroke cortical damage and neurological injury in mouse models. Neural stem cells (NSC) represent a critical population of renewing neural cells, with migration towards cortical lesions. The effect of nPM exposure on NSC proliferation and migratory capacity in stroke has not been studied. We hypothesize that exposure to nPM decreases the population of NSCs in the subventricular zone (SVZ) and capable of responding and migrating to cortical injury sites (in stroke), and increases apoptotic and cell stress markers in NSCs. nPM obtained with a high-volume ultrafine particle sampler is administered through whole-body exposure chamber to transgenic mice. A model of cortical ischemic injury, via middle cerebral artery (MCA) occlusion, will then be evaluated for SVZ and stroke site neurosphere formation. We will subsequently evaluate SVZ activated and quiescent NSC density and gene expression. Following exposure to either filtered air or aerosolized nPM, we will follow neurosphereforming capacity of SVZ and ischemia sites, as well density of quiescent and activated NSCs following stroke. We will also evaluate NSC expression profiles. This study utilizes common NSC genetic profiling and phenotype studies to evaluate NSC SVZ and cortical behavior to a novel nPM exposure. We hypothesize that exposure to nPM will result in decreased neurosphere production at both SVZ and stroke sites, as well as a decreased population of SVZ NSCs (with a proportionally increased effect on activated NSCs) with expression of genetic upregulation of apoptosis and cell stress.

The consequences of reduced lung function contribute to significant but preventable clinical and public health issues, such as COPD and asthma. Two important components in the pathophysiology of reduced lung function are dysregulated lung inflammation and exposure to environmental pollutants, such as traffic-related air pollution (TRAP). Using a variety of experimental approaches, we identified an important role in new subset of immune cells, Group 2 innate lymphoid cells (ILC2s). ILC2s constitute a recently identified cell population that produces type 2 cytokines such as IL-5 and IL-13 in response to a growing number of environmental signals and epithelial cell-derived cytokines. Initially described as a key source of IL-13 in anti-helminth innate in models of asthma, ILC2s are sufficient to provoke lung inflammation accompanied by airway hyperreactivity (AHR) independent of adaptive immunity. Based on these findings, identifying agents capable of modulating ILC2 function is an important step towards advancing treatment of air pollutant induced asthma. Moreover, we found that sodium butyrate, a short chain fatty acid (SCFA) naturally present in our body’s tissues and fluids, significantly suppresses the production of type 2 cytokines by ILC2s and relieves ILC2-dependent AHR. We additionally found that pulmonary ILC2s highly express a receptor for sodium butyrate, GPR109a. Further transcriptome analyses revealed GATA-3, a key transcription factor in ILC2 development and function, was significantly down-regulated after treatment with sodium butyrate. Given that intestinal bacteria are the predominant source of butyrate in mammals, we now propose to characterize the mechanisms by which microbial-derived sodium butyrate potentially modulates ILC2 effector function and reduces air pollutant ILC2-dependent AHR in vivo. The overall goal of this research project is to discover a comprehensive set of molecular signatures and markers that can be used as therapeutic targets to treat lung inflammation associated with TRAP. In order to achieve this objective, we will first fully characterize the phenotype, function, and mechanisms of action of sodium butyrate in animal models of AHR. Next, we will assess the capacity for therapeutic intervention in translational animal models deficient for GPR109a receptor. Finally, we will aim to prevent development of air pollutant AHR via altering microbiome of mice with high butyrate producing strains of bacteria and compare the results to the recipients of microbiome without capacity to produce butyrate. Because of the novelty of animal models, translational approaches and clinical relevance nature of this project, great progress is expected.

Neighbors of a local active lead-acid battery recycler that processes millions of spent automotive batteries per year have raised concerns about residential exposure pathways and the resulting public health threat. Battery recycling operations (i.e. secondary lead smelters) are notoriously associated with airborne and suspended dust releases of toxins, including lead (Pb), arsenic (As), cadmium (Cd), and antimony (Sb). The Quemetco Inc. secondary lead smelter in City of Industry, CA is no exception and has drawn recent attention for violations of air quality standards and excessive emissions of toxic metals. The extent to which these emissions may be impacting the surrounding low-income community of color are, as yet unknown, but initial screening of soil samples found concentrations of Pb, Cd, and As 30, 400, and 500 times higher, respectively, than California health screen ‘safety’ standards for residential soil. We propose a community-engaged research study in the vicinity surrounding the battery recycling operations in the San Gabriel Valley of Los Angeles County to characterize individual biomarkers of toxic metal exposures in the communities adjacent to the smelter. It is critical to understand the body burden of multiple metals in the community in order to evaluate the impact of metal mixtures on human health. We will enroll 100 children and assess potential smelter-related exposures, by measuring concentrations of metals, including Pb, As, Cd, and Sb, in samples of blood and toenails. Lead by two junior investigators, this research will produce key data on the internal dose of metal mixtures to support the development of a long-term study to relate biomarkers of toxic metal exposures to child health outcomes.

The prevalence of obesity is rising worldwide, and excess food consumption and lack of physical activity do not fully explain the current obesity epidemic. The “environmental obesogen hypothesis” proposes that early life exposure to environmental pollutants that can interfere with endocrine and metabolic systems can alter metabolic programming and growth patterns, thereby increasing the risk for obesity and related diseases, such as type 2 diabetes and cardiovascular disease. Although the mechanisms remain uncertain, the impact of lipophilic environmental obesogens (including persistent and non-persistent organic pollutants) on adipose tissue (AT) development and expansion is thought to be mainly through the direct modulation of adipogenesis, lipogenesis and lipolysis. Indirect effects in AT are also possible through pollutant-induced alterations in the functions of other metabolically relevant tissues, including the liver and the central nervous system. We propose a new approach to investigating the environmental obesogen hypothesis by studying human AT. We hypothesize that environmental pollutant concentrations accumulated in AT will be associated with alterations in AT metabolic pathways related to fatty acid metabolism, inflammation and steroid hormone biosynthesis and metabolism. To evaluate this hypothesis, we will collect AT samples at the time of bariatric surgery from 15 obese adolescents at Cincinnati Children’s Hospital. We will use high-resolution mass spectrometry techniques pioneered by investigators at the Emory HERCULES Exposome Research Center and Children’s Health Exposure Analysis Resource (CHEAR) laboratory to measure the environmental pollutant burden and associated targeted and untargeted biological responses in AT. Metabolic pathways will be characterized using novel metabolomics approaches. This is the first study, to our knowledge, aiming to apply highresolution mass spectrometry techniques to identify known and potentially unknown obesogenic environmental pollutants, and to evaluate the associations of environmental pollutant mixtures with the metabolome directly in human AT.

Exposure to atmospheric pollutants causes toxic cellular effects largely through the promotion of oxidative stress. The Nrf2 transcription factor plays a critical role in mediating adaptive responses to cellular stress by directing the expression of cytoprotective genes that function to detoxify reactive oxygen species produced by these pollutants. However the mechanisms underlying the regulation of Nrf2 activity by environmental toxins in multicellular organisms are not well understood. My laboratory investigates cellular and molecular pathways that regulate the activity of the Nrf2 homolog SKN-1 in vivo using the genetic model system C. elegans. We recently identified a role for the nervous system in promoting resistance to oxidative stress by activating SKN-1 in distal tissues through the release of neuropeptides from specific neurons. Our findings suggest that neuroendocrine regulation of the oxidative stress response may have evolved as a survival mechanism to protect organisms from environmental toxicants. This proposal describes a set of genetic, molecular, and behavioral experiments, designed to uncover the cellular and molecular mechanisms by which neuroendocrine signaling promotes the activation of SKN-1/Nrf2. In Aim 1 we will determine how neuropeptide signaling activates SKN-1/Nrf2 in distal tissues. In Aim 2 we will determine whether neuropeptide release is regulated by oxidative stress. In Aim 3 we will examine whether neuroendocrine signaling regulates stress responses to atmospheric pollutants known to activate Nrf2. Pilot grant funding will allow generation of preliminary data to support NIH funding aimed at understanding how Nrf2 is regulated by the nervous system and for developing therapeutics that target the pathway for prevention of respiratory, cardiovascular, and neurological diseases caused by pollution.

Exposure to heat and air pollution are each associated with increased cardiovascular, respiratory, and allcause mortality. Both are projected to worsen as a result of climate change. Ambient particulate matter <2.5 µm (PM2.5) and ozone (O3) are increased by climate change through pathways including weather changes such as stagnation events and wind/dust storms, increased photochemistry due to higher temperature, and drier and warmer conditions that increase pollutant formation from biogenic volatile organic compounds and
frequency and magnitude of wildfires. Standard practice is to examine effects of high heat and air pollution in isolation. However, because they are both impacted by climate change, they occur together. Better understanding of the potentially synergistic effects on mortality of co-occurring high heat and air pollution is needed so that life-saving adaptation interventions can be developed. We propose to investigate the independent and synergistic effects of heat and air pollution co-exposure on mortality. In Aim 1, we will use a time-stratified case-crossover study design and daily neighborhood modeling of air pollution and temperature to assess effects on cardiovascular, respiratory, and all-cause mortality in Southern California during the years 2015-2016 (two of four highest global temperatures ever recorded). In Aims 2a and 2b, we will examine how the heat and pollution effect estimates vary by census tract air conditioning use, assessed using a novel method applied to smart meter electricity data in a representative sample of 200,000 Southern California
households, and across modifiable built environment factors (green space [e.g., tree canopies, parks] and surface reflectivity [e.g., traditional versus solar reflective “cool” roofs]) to help identify effective targets for climate change interventions. The study will produce accurate mortality effect estimates of heat and air pollution co-exposure needed for climate change health impact assessment.

Evidence that the fecal microbiome plays an important role in immune system regulation is accumulating. Although diet has a profound effect on the fecal microbiome, little is known about other environmental influences. Agricultural exposures include both organic (animals, crops) and inorganic (pesticides) exposures and are known to be associated with risk of chronic diseases, in particular, lymphoma. B-cell activation, inflammation and immune suppression are the pathways thought to lead to lymphoma development and it is not known whether agricultural exposures influence these pathways. Moreover, the association between farm exposures and fecal microbiota has not been extensively studied. The goal of this proposal is to conduct a feasibility study for a future R01 with the goal of understanding the effect of agricultural exposures on the immune system and microbiome. We will compare the fecal microbiome from stool samples and serum molecules associated with systemic immune activation, in 30 twin pairs discordant for occupational and residential farm exposures. Validated questionnaires from the Iowa/Mayo NHL study (Cerhan) will be used to document current and past exposures to farms, crops, animals and pesticides. Laboratory methods include multiplex cytokine/chemokine assays and 16S rRNA sequencing of microbiome samples. A matched-twin design will be used to compare microbiome and immune response markers in the identical, exposure discordant twins. We will choose twins with extreme exposure differences to enhance the likelihood that we will observe an effect. The chief advantage of identical twins is that the commonality of their genetic, early life and cultural identity simplifies the interpretation of biological associations, approximating an experiment of nature. This proposal will provide feasibility and preliminary data for an R01 to more comprehensively examine the interaction between farm exposures, the microbiome and the immune response to provide critical information for understanding the underlying biological mechanisms, which could lead to new prevention strategies.

In the United States, the burden of obesity disproportionally affects the Hispanic population, with prevalence in excess of 21% nationally compared to 14% in non-Hispanic whites. This obesity disparity is already present by preschool age, suggesting that it may have its origins in the earliest stages of life. In California, the Hispanic population also carries the highest cumulative burden of multiple harmful environmental exposures 1, and air pollution is a pervasive exposure of concern. In-utero exposure to particulate matter air pollution is associated with decreased birth weight in full term births, with many studies pointing to the 3rd trimester as the exposure window with highest impact. Low birth weight as a result of environmentally-induced intrauterine growth restriction (IUGR) is associated with higher risk of metabolic syndrome and obesity later in life. This proposal aims to investigate whether in-utero, third trimester exposure to fine particulate matter (PM2.5) air pollution, measured using cutting-edge, personal exposure monitoring, is associated with infant birth weight in 100 pregnant, Hispanic women enrolled in the ongoing MADRES pregnancy cohort and living in the Los Angeles, CA, area. We hypothesize that third-trimester PM2.5 exposure will be inversely related to infant birth weight in this Hispanic population experiencing a disproportionate burden of environmental exposure and obesity risk.