Novel approaches to characterize the ecological impacts of contaminants of emerging concern in the coastal environment

Contaminants of emerging concern (CEC) represent a host of pharmaceutical agents and personal care products (PPCPs) and other agents released into aquatic ecosystems. Assessing the ecological impacts of these... [ view full abstract ]

Contaminants of emerging concern (CEC) represent a host of pharmaceutical agents and personal care products (PPCPs) and other agents released into aquatic ecosystems. Assessing the ecological impacts of these structurally-diverse contaminants is a formidable challenge. Using a biomarker approach, based on understanding modes of action of these chemicals in cell and animal models and incorporating laboratory and field studies, is enabling us to define cause-and-effect relationships from exposures to these compounds and identify species at risk. Multi-analyte HPLC/MS/MS analysis was used to identify elevated concentrations of particular PPCPs in Chinook salmon in estuarine surface waters of the Puget Sound, WA. Several of the PPCPs identified are inhibitors of the mitochondrial electron transport system (ETS) and elicit cellular oxidative stress in hepatic tissues of laboratory models. Based on this knowledge and our field studies, we conducted a dietary feeding study with juvenile Chinook exposed to an environmentally relevant CEC mixture, including 13 pharmaceuticals and personal care products (PPCPs) and 3 perfluorinated compounds. Exposure to the CEC mixture inhibited Chinook liver mitochondrial function as evidenced by an elevation of State 4 respiration and loss of efficiency of oxidative phosphorylation relative to controls. Other endpoints under investigation include analysis of metabolic parameters, high throughput analysis of liver antioxidant and mitochondrial gene expression, and analysis of hepatic oxidative damage. In summary, using an integrated approach involving field and laboratory studies and incorporating molecular and biochemical and cellular endpoints is enabling us to identify the impacts of CEC on ecologically sensitive aquatic species.