An inexpensive, temporally integrated system for monitoring occurrence and biological effects of aquatic contaminants in the field

Self Cite

The ability to focus on the most biologically relevant contaminants affecting aquatic ecosystems can be challenging because toxicity-assessment programs have not kept pace with the growing number of contaminants requiring testing. Because it has proven effective at assessing the biological impacts of potentially toxic contaminants, profiling of endogenous metabolites (metabolomics) may help screen out contaminants with a lower likelihood of eliciting biological impacts, thereby prioritizing the most biologically important contaminants. The authors present results from a study that utilized cage-deployed fathead minnows (Pimephales promelas) at 18 sites across the Great Lakes basin. They measured water temperature and contaminant concentrations in water samples (132 contaminants targeted, 86 detected) and used H-nuclear magnetic resonance spectroscopy to measure endogenous metabolites in polar extracts of livers. They used partial least-squares regression to compare relative abundances of endogenous metabolites with contaminant concentrations and temperature. The results indicated that profiles of endogenous polar metabolites covaried with at most 49 contaminants. The authors identified up to 52% of detected contaminants as not significantly covarying with changes in endogenous metabolites, suggesting they likely were not eliciting measurable impacts at these sites. This represents a first step in screening for the biological relevance of detected contaminants by shortening lists of contaminants potentially affecting these sites. Such information may allow risk assessors to prioritize contaminants and focus toxicity testing on the most biologically relevant contaminants. Environ Toxicol Chem 2016;35:2493-2502. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

Section: Methodsmentioning

confidence: 99%

Linking field‐based metabolomics and chemical analyses to prioritize contaminants of emerging concern in the Great Lakes basin

Davis

Ekman

Teng

et al. 2016

Self Cite

“…Seven day composite water samples were collected weekly from each treatment during the 21-d exposure, and also from control water during the last week of the onsite acclimation period. Every 20 min, autosamplers (see Kahl et al [10]) pumped a 28-mL sample into a 20-L, 5-mil Norton R MPTFE Film bag (Welch Fluorocarbon), yielding a 14-L composite sample over 7-d. After each 7-d collection period, the sample bags for each treatment were exchanged to collect a series of 3, 7-d composite samples over the course of the 21-d test. A 3-L aliquot was removed and shipped on ice overnight to the US Geological Survey (USGS) National Water Quality Laboratory (Denver, CO) for analysis of organic chemicals.…”

Section: Water Collection and Analysesmentioning

confidence: 99%

“…Chemicals that act as estrogen receptor (ER) agonists are frequently detected in WWTP effluents and receiving waters [6][7][8][9][10], and typically include endogenous ER agonists (e.g., 17b-estradiol [E2] and estrone) and exogenous estrogens (e.g., 17a-ethinylestradiol [EE2], bisphenol A [BPA]), alkylphenols, and plant-derived phytoestrogens [8,9,[11][12][13][14][15]. Feminization of male fish has been linked to ER agonist exposure, as indicated by changes in different types of biomarkers.…”

Section: Introductionmentioning

confidence: 99%

“…Shortterm (typically 4 d) field studies with fathead minnows caged at varying distances from the WWTP discharge site have documented detectable concentrations of estrogenic chemicals (e.g., estrone, BPA; [G.T. Ankley, unpublished data]) and significant in vitro estrogenic activity [10]. Taken together, this suite of laboratory and field studies examining a combination of chemical analyses, in vitro assays, and in vivo biomarkers of estrogen exposure, have shown that the effluent contains multiple potential ER agonists and is consistently estrogenic.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pathway‐based approaches for assessment of real‐time exposure to an estrogenic wastewater treatment plant effluent on fathead minnow reproduction

Cavallin

Jensen²,

Kahl³

et al. 2016

Self Cite

Wastewater treatment plant (WWTP) effluents are known contributors of chemical mixtures into the environment. Of particular concern are endocrine-disrupting compounds, such as estrogens, which can affect the hypothalamic-pituitary-gonadal axis function in exposed organisms. The present study examined reproductive effects in fathead minnows exposed for 21 d to a historically estrogenic WWTP effluent. Fathead minnow breeding pairs were held in control water or 1 of 3 effluent concentrations (5%, 20%, and 100%) in a novel onsite, flow-through system providing real-time exposure. The authors examined molecular and biochemical endpoints representing key events along adverse outcome pathways linking estrogen receptor activation and other molecular initiating events to reproductive impairment. In addition, the authors used chemical analysis of the effluent to construct a chemical-gene interaction network to aid in targeted gene expression analyses and identifying potentially impacted biological pathways. Cumulative fecundity was significantly reduced in fish exposed to 100% effluent but increased in those exposed to 20% effluent, the approximate dilution factor in the receiving waters. Plasma vitellogenin concentrations in males increased in a dose-dependent manner with effluent concentration; however, male fertility was not impacted. Although in vitro analyses, analytical chemistry, and biomarker responses confirmed the effluent was estrogenic, estrogen receptor agonists were unlikely the primary driver of impaired reproduction. The results provide insights into the significance of pathway-based effects with regard to predicting adverse reproductive outcomes.

“…Site 3 is also positioned near a WWTP discharge, in this case discharging approximately 130 million gal/d into the Maumee River, a tributary of Lake Erie (OH, USA; 41.6888°N, 83.47740°W). Composite (4 d) water samples were collected using methods described in Kahl et al . Samples were split, with 1 portion submitted for analytical chemistry analysis (see Supplemental Data, Table S1 for complete list) and the other portion extracted and reconstituted in dimethyl sulfoxide, a carrier compatible with the high‐throughput toxicity testing platforms employed by the ToxCast and Tox21 programs.…”

Section: Moving Toward the Next Frontiermentioning

confidence: 99%

Environmental surveillance and monitoring—The next frontiers for high‐throughput toxicology

Schroeder

Ankley

Houck

et al. 2016

Self Cite

High-throughput toxicity testing technologies along with the World Wide Web are revolutionizing both generation of and access to data regarding the biological activities that chemicals can elicit when they interact with specific proteins, genes, or other targets in the body of an organism. To date, however, most of the focus has been on the application of such data to assessment of individual chemicals. The authors suggest that environmental surveillance and monitoring represent the next frontiers for high-throughput toxicity testing. Resources already exist in curated databases of chemical-biological interactions, including highly standardized quantitative dose-response data generated from nascent high-throughput toxicity testing programs such as ToxCast and Tox21, to link chemicals detected through environmental analytical chemistry to known biological activities. The emergence of the adverse outcome pathway framework and the associated knowledge base for linking molecular-level or pathway-level perturbations of biological systems to adverse outcomes traditionally considered in risk assessment and regulatory decision-making through a series of measurable biological changes provides a critical link between activity and hazard. Furthermore, environmental samples can be directly analyzed via high-throughput toxicity testing platforms to provide an unprecedented breadth of biological activity characterization that integrates the effects of all compounds present in a mixture, whether known or not. Novel application of these chemical-biological interaction data provides an opportunity to transform scientific characterization of potential hazards associated with exposure to complex mixtures of environmental contaminants.