2019-2020 Executive Summary
Managers are challenged with addressing contaminants of emerging concern (CECs) in the face of a limited but rapidly growing knowledge base about their sources, pervasiveness and effects. There are tens of thousands of chemicals to triage, making the traditional chemical-by-chemical approach to monitoring and regulation unwieldy. Moreover, CECs are a “moving target,” as new chemicals are substituted for ones that are being phased out. In some cases, their potential for impact occurs at much lower levels and is manifested over longer periods of time when compared with chemicals already being regulated, which has presented additional challenges for their detection and assessment. As a result, a new approach to monitoring and assessment of aquatic contaminants is needed.
SCCWRP is developing three types of tools for sampling and measurement of chemical and biological parameters that will best inform whether CECs associated with permitted discharges are negatively impacting aquatic systems in California. Methods that employ state-of-the-art engineered cell biology (“bioanalytical tools”) can screen for many chemicals at the same time, making monitoring more efficient, relevant and comprehensive than the status quo. New chemical techniques that identify CECs responsible for exerting toxicity and that accumulate in wildlife (“targeted” and “non-targeted” chemical analysis) will provide a means for interpreting biological monitoring results. Tools that concentrate chemicals directly from the environment (“passive sampling methods”) will make sampling and collection of CECs more efficient and relevant. Integration of these tools with diagnostic toxicity testing and monitoring for CEC impacts in situ using a tiered monitoring framework will allow managers to make informed decisions concerning the level of treatment, discharge and occurrence of CECs.
This year, SCCWRP will continue investigating new bioanalytical tools that screen for CECs responsible for non-endocrine modes of action, while continuing to assess the quantitative linkage between cellular (“bioscreening”) assay responses and effects to organisms for endocrine-disrupting CECs (“EDCs”). SCCWRP will also continue developing and applying targeted and non-targeted chemical methods for identifying water-soluble CECs and biotoxins. Finally, SCCWRP will test different passive sampling materials that can efficiently sample and concentrate CECs, including biotoxins, from the environment. SCCWRP’s focus for 2019-20 will be on:
- Bioanalytical screening methods: To expand the current bioanalytical toolbox, SCCWRP is using high-throughput cellular assays to screen for a wider variety of CECs, including those identified as bioactive using chemical analysis. These assays are being evaluated using spiked chemicals and mixtures of chemicals, as well as on ambient (field-collected) samples. This year, SCCWRP will employ these tools for ocean outfall monitoring and for an ongoing, large-scale pilot study as part of the Southern California Bight 2018 Regional Monitoring Program (see Regional Monitoring research theme). In parallel, SCCWRP is extending 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).
- Analytical methods for biotoxins and source fingerprinting: To identify the type of biotoxins that occur in State waters, SCCWRP is developing targeted methods that quantify the occurrence of microcystin, cylindrospermopsin and anatoxin variants in water, sediment and tissue. Researchers also are developing and applying non-targeted methods to distinguish among sources of contamination in receiving environments subject to stormwater and/or wastewater discharge.
- Passive sampling of CECs: SCCWRP is applying and developing passive sampling methods to more efficiently collect CECs of interest that occur at low concentrations in water and sediment, but could still exert biological effects. Passive samplers have the potential to facilitate improved sampling and enhanced analysis of CECs (e.g., pharmaceuticals, current use pesticides and biotoxins) by increasing speed, reducing labor, minimizing cross-contamination, and measuring CECs in a more bioavailable form to species of concern.