Citation:

MedlockKakaley, E., M. Cardon, J. Conley, N. Evans, E. Gray, P. Hartig, C. Lambright, AND V. Wilson. In vitro water quality screening tools for quantifying human and ecological-related endocrine activity. National Water Quality Monitoring Council Meeting, Denver, Colorado, March 25 - 29, 2019.

Impact/Purpose:

Endocrine disrupting compounds associated with human and ecological health have been detected in waste and surface waters domestically and around the world. Novel in vitro technologies, specifically effects-based tools for detecting endocrine activity in water samples, have shown promise in water quality screening applications. This presentation will summarize the design, development and application of the androgen, estrogen, and glucocorticoid in vitro effects-based tools. A description of case studies and overall conclusions will also be included.

Description:

Abstract describing value of specific water quality monitoring approach and overall conclusions after multiple years of application of tools to several case studies. Summary will be presented in platform format to attendees of the 2018 National Water Quality Monitoring Council Meeting. ---- Until recently, detection of EDCs in water samples primarily relied on pre-determined, targeted analytical chemical methods. However, novel in vitro technologies have shown promise for water quality screening and monitoring applications due to their high sensitivity and the ability to quantitatively assess biological endpoints (such as hormone receptor-mediated gene transactivation) associated with potential adverse effects to organisms and/or populations. The benefits of these effects-based methods also include the ability to cumulatively detect the biological activity of complex chemical mixtures that may include non-target compounds or compounds present below the detection limits of some traditional chemical analysis methods. Our research group has developed multiple in vitro cell-based tools, or bioassays, applicable to estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) signaling pathways with minimum detectable concentrations, i.e., detection limits, in the ng/L bioanalytical equivalent (BioEq) range. These bioassays have been applied as value-added tools to complement analytical chemical determinations in collaborative national water quality monitoring efforts between the USEPA and the USGS. Thus far, estrogen agonism has been the most often detected in vitro bioactivity. For example, in a recent study, where 32 impacted and 3 reference surface water sites were sampled, 32/32 impacted and 2/3 reference sites had ER activity above detection limits. While estrogenic activity was highly variable in the impacted sites (0.095-116 ng E2Eq/L), the reference sites had the two lowest activity detection values (0.054 and 0.060 ng E2Eq/L). Linear regressions comparing observed bioassay estrogenic activity and predicted bioassay estrogenic activity using detected environmental estrogen concentrations yielded high positive correlations, where estrone often is primarily responsible (≥90%) for estrogenic activity with minor contributions from estriol, 17β-estradiol, and 17α-ethinyl estradiol. We have observed much fewer detections of AR or GR activation in surface or source waters and typically with only minimal explanation of activity by the paired chemical analyses. Overall, effects-based methods like the ER, AR, and GR bioassays, have provided effective non-targeted approaches to complement chemical screening, and they have shown potential to serve in initial water sample screens to guide subsequent water sample chemical analyses. Disclaimer: Abstract does not necessarily reflect USEPA policy.

Record Details: