2020-2021 Executive Summary
Contaminants of emerging concern (CECs) refer to the thousands of chemical contaminants in aquatic environments that are rarely monitored, but for which emerging evidence shows they may pose a threat to ecosystem and human health. Introduced to water bodies through a wide array of human activities, CECs have the potential to impact the health of fish and other animals over time. But because these effects generally are not acutely lethal, California’s water-quality management community has historically struggled to manage these contaminants and document their long-term, chronic biological impacts. SCCWRP is developing next-generation strategies and tools for comprehensively monitoring emerging contaminants in aquatic environments. SCCWRP’s goal is to help water-quality managers efficiently and cost-effectively zero in on which chemicals and chemical classes pose potential health risks to wildlife and humans.
SCCWRP’s CEC research is centered around building, testing and refining tools and strategies that improve how chemical contaminants are monitored in aquatic environments, particularly during the initial screening and diagnostic stages. This CEC management paradigm is designed to help managers more cost-effectively and efficiently zero in on which of the tens of thousands of CECs in aquatic environments are potentially triggering adverse biological impacts. SCCWRP’s research focuses on three main technologies: (1) Bioanalytical cell screening assays, which have the potential to screen water bodies for bioactive chemicals such as endocrine disruptors; a key component is reliably linking results from cell assay screenings to adverse biological effects in animals in the environment; (2) Passive sampling methods, which consist of commercially available sorbents or exchange media, such as polyethylene and silicon, that have the potential to detect chemical contaminants at low concentrations in the water column over time; and (3) Non-targeted chemical analysis, which involves identifying chemicals with similar physical and chemical characteristics by cross-referencing them with non-targeted chemical libraries.
This year, SCCWRP will continue expanding the bioanalytical screening toolbox and investigating the quantitative linkage between bioassay responses and biological effects in living animals. SCCWRP will also continue developing and applying targeted and non-targeted chemical analysis methods, as well as novel approaches to passive sampling, to identify and monitor water-soluble CECs and biotoxins in the environment. SCCWRP’s focus for 2020-21 will be on:
- Bioanalytical screening methods: SCCWRP is continuing to advance the use of high-throughput cellular assays as a cost-effective, rapid tool for screening a wide variety of bioactive CECs in aquatic environments. This year, SCCWRP will continue to transition these tools into routine adoption and use by water recycling agencies, as well as facilitate the incorporation of these tools into large-scale pilot studies, including via the Southern California Bight 2018 Regional Monitoring Program. In parallel, SCCWRP will continue to expand the scope of linkage testing using freshwater and estuarine/marine fish species (e.g., fathead minnow, inland silverside) to look for concordance between bioscreening results and the degree of both lethal and non-lethal harm for fish exposed in the lab and in the field. To accomplish the latter, researchers will compare bioscreening results with sublethal toxicity endpoints as measures of aquatic health (e.g., gene biomarkers, developmental and behavioral endpoints).
- Novel chemical sampling and measurement methods: SCCWRP is continuing to pursue development and application of both novel water sampling technology as well as targeted and non-targeted chemical analysis methods to more effectively and efficiently identify and track an increasingly wide universe of CECs in aquatic systems. This year, SCCWRP is continuing to develop and use passive sampling and targeted analysis methods to quantify the occurrence of microcystin, cylindrospermopsin and anatoxin variants – all harmful algal toxins – in water, sediment and tissue. SCCWRP also will continue developing and applying non-targeted methods to distinguish among sources of contamination in receiving environments subject to stormwater and/or wastewater discharge, and to evaluate how such methods can be adapted to estimate concentrations of unknown compounds lacking available standards.
- Microplastics measurement methods and health effects: As the State Water Board and California Ocean Protection Council pursue development of statewide strategies for managing microplastics in aquatic systems, SCCWRP is building a scientific foundation for crafting informed strategies that optimally protect wildlife and humans from the potential health impacts of microplastics exposure. First, SCCWRP is leading an intercalibration study with nearly 40 participating laboratories worldwide that will quantitatively evaluate multiple candidate measurement methods (and their variants) for microplastics in drinking water and source water to determine accuracy, repeatability and reproducibility among labs, including the level of resources required for labs to make optimal measurements. Second, SCCWRP is convening scientists from around the world to guide managers in ascertaining how much microplastics in water is too much, and what (if any) are the environmental health risks from microplastics exposure. Finally, SCCWRP will be evaluating the occurrence of microplastics in southern California river waters, sediments and biota to determine existing exposure levels.