2023-2024 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 – a category that 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. Because these effects generally are not lethal or acute, California’s water-quality management community has historically struggled to manage these chemical contaminants and document their biological effects. SCCWRP is developing and applying 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 that pose potential 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 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 potentially triggering adverse biological effects. SCCWRP’s research focuses on three main themes: (1) Exposure tool development, including bioanalytical cell screening assays to screen water bodies for bioactive chemicals such as endocrine disruptors, and both targeted and 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 analysis methods, as well as passive sampling, to identify and monitor water-soluble CECs and other chemical stressors in the environment. Finally, SCCWRP will continue supporting ongoing efforts to standardize microplastics measurement methods, develop and standardize collections methods, and understand the biological effects of microplastics exposure. SCCWRP’s focus for 2023-2024 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, including in California and Europe.
- Pursuing novel chemical sampling and measurement methods: SCCWRP is continuing to pursue development and application of novel targeted sampling methodology to identify and track the increasingly widening universe of CECs in aquatic systems more effectively and efficiently. SCCWRP is developing multi-class methods for processing and analyzing a wide suite of pesticides that have been collected from both traditional grab sampling and from passive samplers for both single-laboratory and multi-laboratory validation. SCCWRP is also providing training on accredited methods for assessors to enable more efficient evaluation of laboratories seeking accreditation.
- Understanding occurrence and fate of chemical stressors: SCCWRP is using previously developed sampling and measurement tools to understand occurrence, fate, and transport of chemical contaminants. SCCWRP is using passive samplers to measure levels and fluxes of legacy persistent organic contaminants, as well as “DDT+” (i.e., DDT plus DDT breakdown products that are poorly understood), in the Southern California Bight at existing Superfund sites and at oil platforms that could be decommissioned, to assess hazards that may be associated with exposure.
- Investigating microplastics 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 management actions 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 sampling and measuring microplastics in source water, sediments, and tissues, and ensuring that laboratories are capable of producing accurate, reproducible results. SCCWRP is initiating efforts to develop standardized methods to collect representative microplastics samples in these matrices, plus in stormwater. SCCWRP 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, and in drinking water Finally, SCCWRP is studying how aquatic life is affected by environmentally relevant exposure scenarios, including evaluating the effects of microfiber exposure on local fish and bivalve species to refine existing risk thresholds.