Toxicity Risks Associated With the Beta-Blocker Metoprolol in Marine and Freshwater Organisms: A Review.

The detection of pharmaceuticals in aquatic ecosystems has generated concern for wildlife and human health over the past several decades. ß-adrenergic blocking agents are a class of drugs designed to treat cardiovascular diseases and high blood pressure. Metoprolol is a second-generation ß1-adrenergic receptor inhibitor detected in effluent derived from sewage treatment plants. Our review presents an updated survey of the current state of knowledge regarding the sources, occurrence, and toxicity of metoprolol in aquatic ecosystems. We further aimed to summarize the current literature on the presence of metoprolol in various classes of aquatic species and to consider the trophic transfer of these contaminants in marine mammals. The biological impacts of metoprolol have been reported in 20 aquatic organisms, with a primary focus on cardiac function and oxidative stress. Our review reveals that concentrations of metoprolol that cause toxicity in aquatic species are above levels that are typical of marine and freshwater environments. Future studies should investigate the effects of metoprolol at lower concentrations in aquatic organisms. Other recommendations include (1) a further focus on noncardiac endpoints, because computational assessments of currently available molecular data identify gonadotropins, vitellogenin, collagen, and cytokines as potential targets of modulation, and (2) development of adverse outcome pathways for cardiac dysfunction in aquatic species to improve our understanding of molecular interactions and outcomes following exposure. As the next generation of ß-blockers is developed, continued diligence is needed for assessing environmental impacts in aquatic ecosystems to determine their potential accumulation and long-term effects on wildlife and humans. Environ Toxicol Chem 2024;00:1-14. © 2024 SETAC.

Retrospective Analysis of Wastewater-Based Epidemiology of SARS-CoV-2 in Residences on a Large College Campus: Relationships between Wastewater Outcomes and COVID-19 Cases across Two Semesters with Different COVID-19 Mitigation Policies.

Wastewater-based epidemiology (WBE) has been utilized for outbreak monitoring and response efforts in university settings during the coronavirus disease 2019 (COVID-19) pandemic. However, few studies examined the impact of university policies on the effectiveness of WBE to identify cases and mitigate transmission. The objective of this study was to retrospectively assess relationships between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wastewater outcomes and COVID-19 cases in residential buildings of a large university campus across two academic semesters (August 2020-May 2021) under different COVID-19 mitigation policies. Clinical case surveillance data of student residents were obtained from the university COVID-19 response program. We collected and processed building-level wastewater for detection and quantification of SARS-CoV-2 RNA by RT-qPCR. The odds of obtaining a positive wastewater sample increased with COVID-19 clinical cases in the fall semester (OR = 1.50, P value = 0.02), with higher odds in the spring semester (OR = 2.63, P value < 0.0001). We observed linear associations between SARS-CoV-2 wastewater concentrations and COVID-19 clinical cases (parameter estimate = 1.2, P value = 0.006). Our study demonstrated the effectiveness of WBE in the university setting, though it may be limited under different COVID-19 mitigation policies. As a complementary surveillance tool, WBE should be accompanied by robust administrative and clinical testing efforts for the COVID-19 pandemic response.

Transcriptomic Analysis of the Differential Nephrotoxicity of Diverse Brominated Flame Retardants in Rat and Human Renal Cells.

Brominated flame retardants (BFRs) are environmentally persistent, are detected in humans, and some have been banned due to their potential toxicity. BFRs are developmental neurotoxicants and endocrine disruptors; however, few studies have explored their potential nephrotoxicity. We addressed this gap in the literature by determining the toxicity of three different BFRs (tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), and tetrabromodiphenyl ether (BDE-47)) in rat (NRK 52E) and human (HK-2 and RPTEC) tubular epithelial cells. All compounds induced time- and concentration-dependent toxicity based on decreases in MTT staining and changes in cell and nuclear morphology. The toxicity of BFRs was chemical- and cell-dependent, and human cells were more susceptible to all three BFRs based on IC50s after 48 h exposure. BFRs also had chemical- and cell-dependent effects on apoptosis as measured by increases in annexin V and PI staining. The molecular mechanisms mediating this toxicity were investigated using RNA sequencing. Principal components analysis supported the hypothesis that BFRs induce different transcriptional changes in rat and human cells. Furthermore, BFRs only shared nine differentially expressed genes in rat cells and five in human cells. Gene set enrichment analysis demonstrated chemical- and cell-dependent effects; however, some commonalities were also observed. Namely, gene sets associated with extracellular matrix turnover, the coagulation cascade, and the SNS-related adrenal cortex response were enriched across all cell lines and BFR treatments. Taken together, these data support the hypothesis that BFRs induce differential toxicity in rat and human renal cell lines that is mediated by differential changes in gene expression.

Implications of Insecticide-Treated Mosquito Net Fishing in Lower Income Countries.

INTRODUCTION: Insecticide-treated mosquito nets (ITNs) are highly effective for the control of malaria. Yet widely distributed ITNs have been repurposed as fishing nets throughout the world. OBJECTIVES: Herein we present a synthesis of the current knowledge of ITN fishing and the toxicity of pyrethroids and discuss the potential implications of widespread fishing with ITNs. We further review effective management strategies in tropical fisheries to explore a framework for managing potential ITN fishing impacts. DISCUSSION: Pyrethroids are toxic to fish and aquatic environments, and fishing with ITNs may endanger the health of fisheries. Furthermore, although human toxicity to the pyrethroid insecticides that impregnate ITNs is traditionally thought to be low, recent scientific advances have shown that pyrethroid exposure is associated with a host of human health issues, including neurocognitive developmental disorders, diabetes, and cardiovascular disease. Although it is known that ITN fishing is widespread, the implications for both fisheries and human communities is understudied and may be severe. https://doi.org/10.1289/EHP7001.