Emerging Contaminants Research Plan

View SCCWRP’s full thematic Research Plan for Contaminants of Emerging Concern (PDF)

2021-2022 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. And these strategies are not always focused on dissolved chemicals because new and potentially threatening CECs come in many forms – the latest being microplastics.  SCCWRP’s goal is to help water-quality managers efficiently and cost-effectively zero in on which CECs 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 emerging contaminants are monitored in aquatic environments. 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: (1) developing measurement tools for quantifying exposure to CECs; (2) understanding the ambient environmental occurrence of CECs; (3) characterizing the dose-response of CEC effects and the likelihood of these effects manifesting in sentinel species; (4) understanding sources, fate, and transport of CECs; (5) characterizing remediation strategies for CECs; and (6) transferring technology to end-user managers. SCCWRP is pursuing three main technologies to achieve these goals: (1) Bioanalytical cell screening assays to screen water bodies for bioactive chemicals, including development of reliable, quantitative linkages between cell screening assay responses and adverse effects at individual, population, and community levels of biological organization in southern California; (2) passive sampling methods to detect chemical contaminants at low concentrations in the environment for minimal cost; and (3) non-targeted chemical analysis to identify which of the thousands of chemicals that cannot be reliably measured using targeted methods might be generating biological effects.

This year, SCCWRP will continue expanding the bioanalytical screening toolbox and investigating the quantitative linkage between bioassay responses and biological effects in key species. 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 2021-22 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 develop additional cell assay endpoints to screen for multiple additional classes of contaminants in aqueous matrices, including recycled water and ambient water. SCCWRP will also continue to apply these tools to monitoring programs (e.g., Surface Water Ambient Monitoring Program) and support their transition into routine adoption and use by water-quality agencies. 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 develop novel sublethal endpoints (e.g., RNA-based gene biomarkers, developmental and immune endpoints) and compare these endpoints to bioscreening results.
  • 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 evaluating how to obtain semi-quantitative estimates of mean concentration for suspect and unknown CECs collected in passive sampling. SCCWRP also is evaluating whether non-targeted CEC results from passive samplers are comparable to those from traditional grab sampling, which would broaden the management utility of passive sampling. SCCWRP also is ascertaining occurrence of novel tire wear compounds shown to have acute toxicity to fish in southern California waters. Finally, SCCWRP is continuing to develop and apply non-targeted methods to distinguish among sources of contamination in receiving environments subject to stormwater and/or wastewater discharge.
  • Microplastics measurement methods and health effects: As the State Water 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 potential health impacts of microplastics exposure. SCCWRP is continuing an international intercalibration study, with nearly 40 participating laboratories worldwide, to evaluate multiple candidate measurement methods (and their variants) for microplastics in source water, sediments, and tissues; the goal is to determine accuracy, repeatability and reproducibility among labs, including the level of resources required for labs to make optimal measurements. 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. Complimented by studies that measure the effects from environmentally relevant exposure scenarios on the health of aquatic organisms, these studies will form the foundation of environmental risk assessments – and the basis of the statewide strategies – for microplastics.