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Bisphenols are a class of synthetic, mobile, endocrine-disrupting chemicals. Bisphenol A (BPA), the most well-studied bisphenol, is produced and used in vast quantities worldwide—especially in polycarbonate plastics and as a polymer additive. Recently, some manufacturers have begun using alternative bisphenol compounds, such as bisphenol F (BPF) and bisphenol S (BPS). These uses of bisphenols have led to widespread bisphenol detections in the environment and wildlife. The present study examined wastewater effluent in the San Francisco Bay Area and San Francisco Bay sediment samples for 17 bisphenols. The effluent samples were compared to available stormwater runoff data to better understand bisphenol transport, fate, and potential risks to wildlife.

The Dredged Material Management Office (DMMO) is responsible for annually approving dredging and disposal of millions of cubic yards of sediment to maintain safe navigation in San Francisco Bay. Dredged sediment is characterized for physical, chemical, and biological characteristics to ensure sediment disposed of in the Bay or at beneficial use locations does not cause adverse environmental impacts. Bioaccumulation thresholds and total maximum daily loads (TMDLs) have been established for several contaminant classes, including PCBs, and are used by the DMMO to determine whether sediment contaminant levels trigger subsequent bioaccumulation testing. Sediment with contaminant concentrations above any TMDL levels cannot be disposed of within the Bay but may be further evaluated for upland reuse and ocean disposal. The objective of this study was to evaluate PCB bioaccumulation data from navigational dredging projects to assess the existence of correlations between sediment chemistry and bioaccumulation test results. The motivation for this study was to determine whether the current PCB bioaccumulation trigger is effective in differentiating sediment bioaccumulation concerns. The DMMO may use the results of this study to inform evaluation requirements for PCBs, particularly in support of modifying the terms of the Long-term Management Strategy for San Francisco Bay (LTMS) programmatic Essential Fish Habitat (EFH) agreement concerning PCB bioaccumulation testing. 

Per- and polyfluoroalkyl substances (PFAS), a family of thousands of synthetic, fluorine-rich compounds commonly referred to as “forever chemicals,” are known for their thermal stability, non-reactivity, and surfactant properties. These unique compounds have widespread uses across consumer, commercial, and industrial products, resulting in widespread occurrence in the environment and wildlife across the globe. This study analyzed ambient surface water in San Francisco Bay for 40 PFAS to discern the occurrence, fate, and potential risks to ecological and human health.

Eleven of 40 PFAS were detected in ambient surface water collected in 2021 from 22 sites in the Bay. Seven PFAS (PFPeA, PFHxA, PFHpA, PFOA, PFBS, PFHxS, and PFOS), were found in at least 50% of samples. PFHxA and PFOA were the most frequently detected analytes (detection frequencies of 86% and 77%, respectively). PFPeA and PFHxA were generally found at the highest concentrations across sites, with median and maximum concentrations of 1.6 and 4.8 ng/L and 1.5 and 5.7 ng/L, respectively. Pairwise Spearman's correlations revealed strong positive correlations  (p <0.001; r > 0.77) among the seven PFAS detected in at least 50% of sites, suggesting significant similarities between their sources, pathways, and/or fate in the environment. PFBA, PFNA, PFDA, and 6:2 FTS were found at a limited number of sites in the Bay. 6:2 FTS was found at a single site at 14 ng/L, the highest concentration of any individual PFAS in the Bay. The sums of detected PFAS for all sites had median and maximum concentrations of 10 and 29 ng/L, respectively.

This is a sampling and analysis plan for the Bay Status and Trends (S&T) Prey Fish and Near-field / Margins Sediment monitoring for the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP). Bay margins are defined by the RMP as extending from Mean Higher High Water (MHHW) to 1 foot below Mean Lower Low Water (MLLW). These mud flats and adjacent shallow areas of the Bay are productive and highly utilized by biota of interest (humans and wildlife). Near-field stations are located near watershed inputs in the Bay. Prey fish are a key matrix to monitoring the status and impacts of contaminants, especially near margin areas where they have shown strong contamination signals in previous RMP studies. This monitoring design provides a spatially-distributed characterization of contaminant concentrations in fish and sediment found within the margins of Central Bay, South Bay, and Lower South Bay. This study builds on previous S&T efforts to characterize surface sediment contamination across the Bay while piloting routine monitoring of prey fish. Additional samples outside of S&T will be collected for special studies. A subset of samples will be archived for potential future analysis of emerging contaminants or other analyte groups.