PFAS, or per- and poly-fluoroalkyl substances, are synthetic chemicals mainly found in lubricants, polishes, coatings, and pesticides that are now ubiquitous in humans and the environment. Recent studies have shown that bioaccumulated PFAS can decrease immune function, act as a carcinogen, cause liver disease, increase cholesterol levels, and lead to a host of chronic diseases such as hyperthyroidism and inflammatory bowel disease. Community water systems have become increasingly threatened by nearby agricultural sources of PFAS, including the application of sewage sludge from municipal waste, or biosolids, to land as fertilizer. There is little research on water contamination in California caused by PFAS discharged through biosolids application. Our research will fill this gap by mapping biosolids application sites across California and highlighting community water systems at risk for PFAS contamination. This map layer will be incorporated into the California Drinking Water Tool, a website that allows Californians to identify potential threats to their groundwater, and will empower them to determine whether they are at an increased risk of PFAS exposure. Our data will be shared with the California State Water Resources Control Board so that in the future, the map layer can be used to locate water supplies in high-risk areas for PFAS contamination and inform future policy and testing requirements

While concentrated animal feeding operations (CAFOs) are known sources of environmental antimicrobial resistance, multidrug resistance (MDR) in proximity to CAFOs is relatively understudied. The World Health Organization has deemed that extended spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) is target for monitoring AMR in the environment, and some protocols recommend selection with cefotaxime before further analysis of isolates for MDR. However, the predictive value of ESBL-EC for MDR is unknown. EC and ESBL-EC were quantified in Michigan waterways near dairy and swine farms as well as from an unimpacted site (UI) and a wastewater impacted site. To assess MDR, purified isolates of EC selected without antibiotics were characterized by the Kirby Bauer Disk Diffusion method. Ampicillin and tetracycline resistance ranged up to 67% and 62% of the EC isolates, respectively, at livestock-impacted sites, but was low at UI. Multidrug resistance (MDR) was not observed at all at UI but was observed up to 76% and 67% of isolates from dairy and swine/dairy, respectively. Notably, resistance to cefotaxime did not correlate with MDR, indicating that preselection for ESBL-EC before further AMR testing, which is currently recommended as part of the World Health Organization’s Tricycle Protocol, will not successfully characterize AMR or MDR from culturable EC. This work highlights the importance of MDR characterization at livestock-impacted surface water sites and how that can translate into affecting human health.

Dark Sky Reserves, and the world as a whole, are under persistent threat from increasing light pollution. Artificial light at night (ALAN), caused by unshielded lights, glare, and skyglow, has a direct impact on natural circadian rhythms, causing detrimental effects to human and animal health, bird migration, and plant reproduction cycles. Increasing ALAN jeopardizes the integrity of dark sky preservation, specifically in the Central Idaho Dark Sky Reserve (CIDSR). In order to identify the targeted threats to the CIDSR, and reasons for the evident increase in overall light pollution, we employed two tactics: ground measurements and remote sensing. Ground measurements have been conducted annually via a week-long trip to the CIDSR since 2022, using tools such as the Sky Quality Camera and the Sky Quality Meter. Remote sensing data shows the magnitude and distribution of reflected light from the regions surrounding the reserve, and was obtained from the VIIRS satellite and analyzed via QGIS. We detected an overall increase in light pollution coming from Boise, Idaho, with less drastic changes coming from other nearby towns, such as Hailey, Idaho and Ketchum, Idaho. Ground measurements also demonstrate an increase in light pollution along the horizon, though differing weather conditions affects data variability. With the information from our ground measurements and remote sensing data, we plan to encourage local legislation for stricter residential and commercial ALAN regulations.

Tramete versicolor (TV) and Pleurotus ostreatus (PO) are wood-rot fungi which exhibit laccase and many other oxidoreductase enzyme activities. Past research has shown that these enzymes, with high oxidative potential, can facilitate lignin degradation allowing for their use in bioremediation, such as in the degradation of synthetic chemicals and many organic environmental pollutants. Thus, this study sought out to measure laccase activity in both TV and PO when grown on the solid substrate, sorghum, supplemented by two different types of liquid state media, the simple yeast peptone dextrose (YPD) and complex potato dextrose agar (PDA) to observe their impact on enzyme expression. Enzyme activity was measured every 3-4 days and PO activity peaked between days 13 and 16 at 3.5 U/g SSF, while TV activity peaked on day 30 at 2 U/g SSF. When comparing activity trends, laccase activity peaked much faster in PO and decreased to below 0.5 U/g SSF by day 24, while activity in TV was initially low before steadily increasing between day 20 and 30. There seemed to be no significant difference between PO grown on YPD versus PDA, while TV grown on PDA exhibited higher activity than YPD. These novel results allow for future research regarding modulating the environmental or growth conditions for fungal species to preferentially alter their bioremediation capabilities.

Airports and associated aircraft are significant sources of particulate matter (PM), which has been shown to have significant impacts on human health, including elevated stroke and heart attack risk and increased rates of adverse birth outcomes. Indeed, the air traffic at Los Angeles International Airport (LAX) is a significant emitter of these ultrafine particles (UFP), with elevated concentrations found up to 10 km downwind of the airport. In efforts to improve national air traffic efficiency and reduce emissions, the Federal Aviation Administration (FAA) introduced the Next Generation Air Transportation System (NextGen), which has made various changes to airspace technology and procedure to reduce aviation’s environmental impact. To evaluate NextGen’s predictions of decreased local air pollution, both mobile monitoring and stationary measurement downwind of the airport were utilized to visualize UFP concentration, which have largely illustrated a clear emissions plume originating from the airport. However, future mobile monitoring routes are required to make a confident comparison to previous studies. Upon satisfactory completion of data collection, an average of each run will be combined to create a representative pollution map, which will be compared to mapping prior to NextGen implementation to evaluate if there has been any reduction in downwind air pollution. Considering the public health and environmental impacts of aircraft emissions, these findings may have significant implications for aviation policy.

Salt pans, which are flat lower-elevation wetland areas that fill with saltwater during rainfall and high tides, and importantly serve as habitats for attracting birds and supporting biodiversity. Though crucial for conservation, salt pans are under researched habitats, as well as being reduced to very small remaining acreage in coastal metropolitan areas such as the Ballona Wetlands of Los Angeles. The Friends of Ballona, a nonprofit dedicated to the restoration of the last remaining wetland in Los Angeles, are currently seeking a foundation of scholarly research to accomplish long-term restoration goals for their salt pan habitat. This project examines the how salt pans form and function, the role the habitat plays for associated wildlife, and benefits of restoration. By consulting relevant literature from other salt pan habitats in North America, Africa, and Oceania, this research aims to provide actionable insights which will support ongoing restoration plans at the Ballona Wetlands Ecological Preserve as well as inform new practices. In addition to a literature review, interviews with experts specializing in wetland ecology and conservation will serve as a key component in understanding Los Angeles-specific site considerations. Our goal is to ensure that future restoration efforts at Ballona have a strong scientific foundation and support long-term ecological function for our salt pans.