Potential Health Risks of Methylmercury Contamination to Largemouth Bass in the Southeastern United States.

Widespread mercury (Hg) contamination of freshwater systems, due primarily to deposition of atmospheric inorganic Hg (IHg), poses a potential threat to recreational fisheries. In aquatic ecosystems, IHg is converted by bacteria to methylmercury (MeHg), a potent toxin that bioaccumulates in consumers and biomagnifies through the food web, reaching elevated concentrations in fish. Methylmercury has concentration-dependent sublethal effects on fish, including reductions in reproductive output. In the present study, we conducted the first analysis of the potential health risks of MeHg contamination to largemouth bass (Micropterus salmoides), a popular game fish, in the southeastern United States. To assess the potential health risk posed by MeHg to largemouth bass, we compared MeHg concentrations in three sizes of adult largemouth bass to benchmarks associated with the onset of adverse health effects in fish. We also determined how the risk posed by MeHg to largemouth bass varied spatially throughout the southeastern United States. Our study suggests that in the southeastern United States MeHg poses a potential risk to largemouth bass health and that MeHg contamination may be detrimental to the fisheries of this economically important species of game fish. Environ Toxicol Chem 2023;42:1755-1762. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

FEASIBILITY AND SAFETY OF A FIELD CARE CLINIC AS AN ALTERNATIVE AMBULANCE DESTINATION DURING THE COVID-19 PANDEMIC.

Background: Anticipating an increased utilization of healthcare facilities during the COVID-19 surge, the San Francisco Department of Public Health developed a plan to deploy neighborhood-based Field Care Clinics (FCCs) that would decompress emergency departments by serving patients with low acuity complaints. These clinics would receive patients directly from the Emergency Medical Services (EMS) system. Transports were initiated by a paramedic-driven protocol, originally by EMS crews and later by the Centralized Ambulance Destination Determination (CADDiE) System. In this study, we evaluated the outcomes of EMS patients who were transported to the FCC, specifically as to whether they required subsequent transfer to the emergency department. Methods: We performed a retrospective study of all patients transported to the Bayview-Hunters Point (BHP) neighborhood FCC by EMS between April 11th, 2020, and December 16th, 2020. Descriptive statistics and Chi-Square Tests were used to analyze patient data. Results: In total, 35 patients (20 men, 15 women, average age of 50.9 years) were transported to the FCC. Of these, 16 were Black/African American, 7 were White, 3 were Asian, with 9 identifying as of other races and 9 of Hispanic ethnicity. Twenty-three of these transports resulted from a CADDiE recommendation. Approximately half (n=20) of calls originated within the BHP neighborhood. The most frequent patient complaint was "Pain." Of patients transported to the FCC, 23 were treated and discharged. The 12 remaining patients required hospital transfer, with 3 being discharged after receiving treatment in the emergency department and 9 requiring hospital admission, psychiatric, or sobering services. The likelihood of hospital transfer did not significantly vary by sex (p=0.41), 9-1-1 call origination relative to BHP neighborhood (p=0.92), or CADDiE recommendation (p=0.51). Conclusion: Three-fourths of patients who required subsequent hospital transfer were admitted or required specialized services, suggesting that the FCC was viable for managing low acuity conditions. However, the underutilization of the FCC by EMS as a transport destination and a high hospital transfer rate indicates training and protocol refinement opportunities. Despite the small cohort size, this study demonstrates that an FCC alternative care site can act as a viable source for urgent and emergency care during a pandemic.

Effects of developmental exposure to neurotoxic algal metabolites on predator-prey interactions in larval Pimephales promelas.

Harmful algal blooms are a growing environmental concern in aquatic systems. Although it is known that some of the secondary metabolites produced by cyanobacteria can alter predator-prey dynamics in aquatic communities by reducing foraging and/or predator evasion success, the mechanisms underpinning such responses are largely unknown. In this study, we examined the effects of a potent algal neurotoxin, ß-N-methylamino-L-alanine (BMAA), on the development and behavior of larval Fathead Minnows, Pimephales promelas, during predator-prey interactions. We exposed eggs and larvae to environmentally relevant concentrations of BMAA for 21 days, then tested subjects in prey-capture and predator-evasion assays designed to isolate the effects of exposure at sequential points of the stimulus-response pathway. Exposure was associated with changes in the ability of larvae to detect and respond to environmental stimuli (i.e., a live prey item and a simulated vibrational predator), as well as changes in behavior and locomotor performance during the response. Our findings suggest that chronic exposure to neurodegenerative cyanotoxins could alter the outcomes of predator-prey interactions in natural systems by impairing an animal's ability to perceive, process, and respond to relevant biotic stimuli.

Effect of Land Cover on Ecoregion-Scale Spatial Patterns of Mercury Contamination of Largemouth Bass in the Southeastern United States.

Consumption of methylmercury (MeHg)-contaminated fish is the primary source of MeHg in humans and poses a hazard to human health. Because of widespread atmospheric deposition of inorganic mercury (IHg), all water bodies in the United States have been contaminated with Hg. In aquatic ecosystems, IHg is converted to MeHg, which biomagnifies, reaching high concentrations in piscivorous fish. It is not possible for governmental agencies to monitor fish from every waterbody to determine if concentrations of MeHg in fish are hazardous to human health. To help government agencies focus their monitoring efforts, it is critical that we develop the ability to predict regions where waterbodies are most likely to contain fish with hazardous concentrations of MeHg. The objective of the present study was to examine the relationship between MeHg contamination of largemouth bass (Micropterus salmoides), a popular piscivorous gamefish, and land cover in 24 ecoregions across 15 states in the southeastern United States. In our study we demonstrate for the first time that 72% of the variance in average concentrations of MeHg in largemouth bass between ecoregions of the southeastern United States can be explained by the percentage coverage by evergreen forests, emergent herbaceous wetlands, and pasture/hay. Land cover determines the sensitivity of freshwater systems to atmospheric IHg deposition, and the present study suggests that at the ecoregion scale, MeHg bioaccumulation in piscivorous gamefish, and ultimately the health hazard that these MeHg-contaminated fish pose to humans, can be in part predicted by land-cover type. Environ Toxicol Chem 2022;41:2386-2394. © 2022 SETAC.

Centralized Ambulance Destination Determination: A Retrospective Data Analysis to Determine Impact on EMS System Distribution, Surge Events, and Diversion Status.

INTRODUCTION: Emergency medical services (EMS) systems can become impacted by sudden surges that can occur throughout the day, as well as by natural disasters and the current pandemic. Because of this, emergency department crowding and ambulance "bunching," or surges in ambulance-transported patients at receiving hospitals, can have a detrimental effect on patient care and financial implications for an EMS system. The Centralized Ambulance Destination Determination (CAD-D) project was initially created as a pilot project to look at the impact of an active, online base hospital physician and paramedic supervisor to direct patient destination and distribution, as a way to improve ambulance distribution, decrease surges at hospitals, and decrease diversion status. METHODS: The project was initiated March 17, 2020, with a six-week baseline period; it had three additional study phases where the CAD-D was recommended (Phase 1), mandatory (Phase 2), and modified (Phase 3), respectively. We used coefficients of variation (CV) statistical analysis to measure the relative variability between datasets (eg, CAD-D phases), with a lower variation showing better and more even distribution across the different hospitals. We used analysis of co-variability for the CV to determine whether level loading was improved systemwide across the three phases against the baseline period. The primary outcomes of this study were the following: to determine the impact of ambulance distribution across a geographical area by using the CV; to determine whether there was a decrease in surge rates at the busiest hospital in this area; and the effects on diversion. RESULTS: We calculated the CV of all ratios and used them as a measure of EMS patient distribution among hospitals. Mean CV was lower in Phase 2 as compared to baseline (1.56 vs 0.80 P < 0.05), and to baseline and Phase 3 (1.56 vs. 0.93, P <0.05). A lower CV indicates better distribution across more hospitals, instead of the EMS transports bunching at a few hospitals. Furthermore, the proportion of surge events was shown to be lower between baseline and Phase 1 (1.43 vs 0.77, P <0.05), baseline and Phase 2 (1.43 vs. 0.33, P < 0.05), and baseline and Phase 3 (1.43 vs 0.42, P < 0.05). Diversion was shown to increase over the system as a whole, despite decreased diversion rates at the busiest hospital in the system. CONCLUSION: In this retrospective study, we found that ambulance distribution increased across the system with the implementation of CAD-D, leading to better level loading. The surge rates decreased at some of the most impacted hospitals, while the rates of hospitals going on diversion paradoxically increased overall. Specifically, the results of this study showed that there was an improvement when comparing the CAD-D implementation vs the baseline period for both the ambulance distribution across the system (level loading/CV), and for surge events at three of the busiest hospitals in the system.