2022-2023 Executive Summary
Contaminants of emerging concern (CECs) refer to the thousands of chemical contaminants in aquatic environments for which evidence is emerging that they may pose a threat to ecosystem and human health. SCCWRP’s research on CECs also encompasses microplastics. 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. California’s water-quality management community has historically struggled to manage these chemical contaminants and document their 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 prioritize chemical classes posing health risks to wildlife and humans.
SCCWRP’s CEC research is centered around building, testing, and refining tools for measuring chemical contaminants and microplastics in aquatic environments, and in applying these tools to understand occurrence, fate, and effects of CECs. 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 triggering adverse biological impacts. SCCWRP’s research focuses on three main themes: (1) Exposure tool development such as of bioanalytical cell screening assays to screen water bodies for bioactive chemicals such as endocrine disruptors, and targeted as well as non-targeted chemical analysis to identify unknown chemicals; (2) effects assessment, to understand biological dose-response of CECs and develop relevant bioindicators; and (3) environmental fate and transport of CECs to understand their physical, chemical, biological, and ecological behavior that controls exposure levels and informs remediation strategies to mitigate their presence.
This year, SCCWRP will continue advancing bioanalytical screening methods for screening aquatic environments for a wide variety of CECs. 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. Finally, SCCWRP will continue supporting ongoing efforts to standardize microplastics measurement methods and understand the biological effects of microplastics exposure. SCCWRP’s focus for 2022-2023 will be on:
- Advancing 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. SCCWRP is working to expand the number of cell assay endpoints that can be used for screening multiple additional classes of contaminants in aqueous matrices, including recycled water and ambient water. SCCWRP also is continuing to apply these tools to monitoring programs (e.g., Surface Water Ambient Monitoring Program, Southern California Bight Regional Monitoring Program) and to support their transition into routine adoption and use by water-quality agencies. In parallel, SCCWRP is continuing 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 are developing novel sublethal endpoints (e.g., RNA-based gene biomarkers, developmental and immune endpoints) and comparing these endpoints to bioscreening results.
- Pursuing novel chemical sampling and measurement methods: SCCWRP is continuing to pursue development and application of novel water sampling technology, in conjunction with targeted and non-targeted chemical analysis methods, to more effectively and efficiently identify and track an increasingly wide universe of CECs in aquatic systems. SCCWRP is hosting an Expert Panel that is advising the State about which contaminants of emerging concern deserve the most attention, and then using that outcome to determine which measurement methods are most in need of further development or standardization.
- Investigating microplastics measurement methods and health effects: As the State Water Resources Control Board and California Ocean Protection Council develop 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 health effects of microplastics exposure. SCCWRP is working to standardize methods (and variation of these methods) for measuring microplastics in source water, sediments, and tissues, and ensuring that laboratories are capable of producing accurate, reproducible results. SCCWRP also is conducting a series of studies to quantify the inputs, fate and transport, and bioaccumulation of various microplastic types and shapes for the region’s streams, estuaries and coastal ocean. Finally, SCCWRP is studying how aquatic life is affected by environmentally relevant exposure scenarios, including developing risk-based exposure thresholds that define for managers the levels and types of microplastics exposure that can be expected to trigger adverse biological effects.