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Spatial and Temporal Distribution of Glucocorticoid and Estrogen Receptor-Mediated Bioactivities in Relation to a Wastewater Input on the South Platte River (Denver, CO, USA)
Citation:
Cavallin, J., C. Adams, L. Barber, B. Blackwell, P. Bradley, A. Cole, D. Ekman, N. Evans, S. Keefe, K. Keteles, J. Kinsey, E. MedlockKakaley, K. Romanok, K. Santana Rodriguez, K. Smalling, E. Stacy, D. Winkelman, AND Dan Villeneuve. Spatial and Temporal Distribution of Glucocorticoid and Estrogen Receptor-Mediated Bioactivities in Relation to a Wastewater Input on the South Platte River (Denver, CO, USA). Society of Environmental Toxicology and Chemistry (SETAC) North America, Pittsburgh, PA, November 13 - 17, 2022. https://doi.org/10.23645/epacomptox.21424551
Impact/Purpose:
Poster presented to the Society of Environmental Toxicology and Chemistry (SETAC) annual meeting November 2022. There are thousands of chemicals present in surface waters across the United States. Regions, states, tribes, and communities have a need to screen ambient mixtures of contaminants for their potential to adversely affect ecosystems. Likewise, where possible, identification of the sources and drivers of those biological effects are needed to take appropriate management action. However, most monitoring programs rely solely on chemical monitoring and existing toxicity data from the literature, leaving significant data gaps in relation to chemicals of immediate and emerging concern for which toxicity benchmarks are limited. Such approaches often overlook contaminants that are not quantified through targeted analytical methods and have only limited ability to account for potential impacts of mixtures. The present case study on the South Platte River demonstrates how new approach methodologies (NAMs) can be employed in effects-based evaluations of chemical mixtures. Building upon several years of chemical and bioactivity monitoring, surface water samples were collected in two studies (temporal and spatial evaluations) to evaluate in vitro glucocorticoid and estrogen receptor bioactivities during low-flow conditions on the South Platte River to capture the worst-case scenario relative to percent wastewater contribution to the system. This poster abstract will be submitted for consideration in the SETAC session “Novel methods and approaches for assessing effluents and ambient water toxicity (1.08).” Water samples collected from the South Platte River over the winter of 2022 will be screened for estrogen- and glucocorticoid-mediated biological activity. Additionally, samples were collected over an 80 km reach of the South Platte River to determine how far downstream of a major WWTP input the bioactivity can be detected. These data will be used to define the temporal and spatial scope of potential adverse effects associated with these bioactivities in the South Platte River system (Region 8).
Description:
Previous studies on the South Platte River near Denver, Colorado, USA have detected in vitro bioactivity, including estrogen receptor (ER) and glucocorticoid receptor (GR) activity, at some of the highest levels in surface waters of the U.S. Building upon previous research, the present case study demonstrates how new approach methodologies (e.g., in vitro bioassays) can be employed in biological effects-based evaluations of environmental field samples. Surface water samples were collected for two studies including temporal and spatial evaluations. For the temporal evaluation, total ER and GR agonist bioactivities were determined over the course of winter and spring 2022, the time period with the lowest river flow and corresponding greatest percent effluent contribution to the South Platte River system. Surface water samples were collected monthly at three South Platte River sites located around a major wastewater treatment plant (WWTP) to capture temporal (monthly) variations in the bioactivities: upstream, proximal to the discharge, and 1.5 km downstream from the discharge. A more spatially intensive study was conducted during November 2021 in which water samples were collected at 12 sites over an 80 km reach of the South Platte River to determine how far downstream of the WWTP the biological activities could be detected. GR-mediated bioactivity remained around 40 ng dexamethasone equivalents/L as far as ~30 km downstream, before dropping about 60% over 8 km and diminishing thereafter. The bioeffects-based data, along with targeted analytical chemistry data, will be compared with hydrological/wastewater modeling aimed at predicting the concentrations of chemicals in wastewater impacted stream systems. These data will be used to help define the temporal and spatial scope of potential adverse effects associated with ER- and GR-mediated bioactivities in the hydrologically complex South Platte River system. The contents of this presentation neither constitute, nor necessarily reflect, US EPA policy.
URLs/Downloads:
DOI: Spatial and Temporal Distribution of Glucocorticoid and Estrogen Receptor-Mediated Bioactivities in Relation to a Wastewater Input on the South Platte River (Denver, CO, USA)
CAVALLIN ET AL. 2022.SETAC.SPLATTE.PDF (PDF, NA pp, 6582.626 KB, about PDF)