Geology topics

Kristen Keteles

Publications and source records attributed to Kristen Keteles.

4 recordsLinked to original sources

USGS2020

Effects-based monitoring of bioactive chemicals discharged to the Colorado River before and after a municipal wastewater treatment plant replacement

Monitoring of the Colorado River near the Moab, Utah, wastewater treatment plant (WWTP) outflow has detected pharmaceuticals, hormones, and estrogen-receptor (ER)-, glucocorticoid receptor (GR)-, and peroxisome proliferator-activated receptor-gamma (PPARγ)-mediated biological activities. The aim of the present multi-year study was to assess effects of a WWTP replacement on bioactive chemical (BC) concentrations. Water samples were collected bimonthly, pre- and post-replacement, at 11 sites along the Colorado River upstream and downstream of the WWTP and analyzed for in vitro bioactivities (e.g., agonism of ER, GR, and PPARγ) and BC concentrations; fathead minnows were cage deployed pre- and post-replacement at sites with varying proximities to the WWTP. Before the WWTP replacement, in vitro ER (24 ng 17β-estradiol equivalents/L)-, GR (60 ng dexamethasone equivalents/L)-, and PPARγ-mediated activities were detected at the WWTP outflow but diminished downstream. In March 2018, the WWTP effluent was acutely toxic to the fish, likely due to elevated ammonia concentrations. Following the WWTP replacement, ER, GR, and PPARγ bioactivities were reduced by approximately 60–79%, no toxicity was observed in caged fish, and there were marked decreases in concentrations of many BCs. Results suggest that replacement of the Moab WWTP achieved a significant reduction in BC concentrations to the Colorado River.

Utah↗

USGS2018

Evaluation of targeted and untargeted effects-based monitoring tools to assess impacts of contaminants of emerging concern on fish in the South Platte River, CO

Rivers in the arid Western United States face increasing influences from anthropogenic contaminants due to population growth, urbanization, and drought. To better understand and more effectively track the impacts of these contaminants, biologically-based monitoring tools are increasingly being used to complement routine chemical monitoring. This study was initiated to assess the ability of both targeted and untargeted biologically-based monitoring tools to discriminate impacts of two adjacent wastewater treatment plants (WWTPs) on Colorado's South Platte River. A cell-based estrogen assay ( in vitro , targeted) determined that water samples collected downstream of the larger of the two WWTPs displayed considerable estrogenic activity in its two separate effluent streams. Hepatic vitellogenin mRNA expression ( in vivo , targeted) and NMR-based metabolomic analyses ( in vivo , untargeted) from caged male fathead minnows also suggested estrogenic activity downstream of the larger WWTP, but detected significant differences in responses from its two effluent streams. The metabolomic results suggested that these differences were associated with oxidative stress levels. Finally, partial least squares regression was used to explore linkages between the metabolomics responses and the chemical contaminants that were detected at the sites. This analysis, along with univariate statistical approaches, identified significant covariance between the biological endpoints and estrone concentrations, suggesting the importance of this contaminant and recommending increased focus on its presence in the environment. These results underscore the benefits of a combined targeted and untargeted biologically-based monitoring strategy when used alongside contaminant monitoring to more effectively assess ecological impacts of exposures to complex mixtures in surface waters.

Colorado↗

USGS2018

Bioactive contaminants of emerging concern in National Park waters of the northern Colorado Plateau, USA

Pharmaceuticals and personal care products (PPCPs), wastewater indicators (WWIs), and pesticides (herein, Contaminants of Emerging Concern [CECs]) have been documented in surface waters throughout the world and have associated risks to aquatic life. While much research has focused on temperate and urbanized watersheds, less is known about CEC presence in semi-arid landscapes, where water availability is limited and populations are low. CEC presence in water and sediment is reported for 21 sites in eight U.S. national parks in the northern Colorado Plateau region. From 2012 to 2016, at least one PPCP and/or WWI was detected at most sites on over half of sampling visits, indicating that CECs are not uncommon even in isolated areas. CEC detections were generally fewer and at lower concentrations than in urbanized or agricultural watersheds. Consistent with studies from other U.S. regions, the most frequently detected CECs in this study include DEET, caffeine, organophosphorus flame retardants, and bisphenol A in water and fecal indicators and polycyclic aromatic hydrocarbons in sediment. Maximum concentrations in this study were generally below available water quality benchmarks, sediment quality guidelines, and risk assessment thresholds associated with vertebrates. Additional work is needed to assess the potential activity of hormones, which had high reporting limits in our study, and potential bioactivity of environmental concentrations for invertebrates, microbial communities, and algae. Potential sources of CEC contamination include upstream wastewater effluent discharges and National Park Service invasive-plant-control herbicide applications. CEC occurrence patterns and similarities between continuous and isolated flow locations suggest that direct contamination from individual visitors may also occur. While our data indicate there is little aquatic health risk associated with CECs at our sites, our results demonstrate the ubiquity of CECs on the landscape and a continued need for public outreach concerning resource-use ethics and the potential effects of upstream development.

Colorado Plateau↗

USGS2017

Tools to minimize interlaboratory variability in vitellogenin gene expression monitoring programs

The egg yolk precursor protein vitellogenin is widely used as a biomarker of estrogen exposure in male fish. However, standardized methodology is lacking and little is known regarding the reproducibility of results among laboratories using different equipment, reagents, protocols, and data analysis programs. To address this data gap we tested the reproducibility across laboratories to evaluate vitellogenin gene ( vtg ) expression and assessed the value of using a freely available software data analysis program. Samples collected from studies of male fathead minnows ( Pimephales promelas ) exposed to 17α-ethinylestradiol (EE2) and minnows exposed to processed wastewater effluent were evaluated for vtg expression in 4 laboratories. Our results indicate reasonable consistency among laboratories if the free software for expression analysis LinRegPCR is used, with 3 of 4 laboratories detecting vtg in fish exposed to 5 ng/L EE2 ( n = 5). All 4 laboratories detected significantly increased vtg levels in 15 male fish exposed to wastewater effluent compared with 15 male fish held in a control stream. Finally, we were able to determine that the source of high interlaboratory variability from complementary deoxyribonucleic acid (cDNA) to quantitative polymerase chain reaction (qPCR) analyses was the expression analysis software unique to each real-time qPCR machine. We successfully eliminated the interlaboratory variability by reanalyzing raw fluorescence data with independent freeware, which yielded cycle thresholds and polymerase chain reaction (PCR) efficiencies that calculated results independently of proprietary software. Our results suggest that laboratories engaged in monitoring programs should validate their PCR protocols and analyze their gene expression data following the guidelines established in the present study for all gene expression biomarkers.

Environmental Toxicology and Chemistry↗