Per- and Polyfluoroalkyl Substances (PFAS) found in Smallmouth Bass (Micropterus dolomieu) throughout the mid-Atlantic United States
Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals that have been recognized as concerns for both human and ecosystem health. There is a need to understand the effects of PFAS on fish health and populations.
Issue
PFAS are called “forever chemicals” as they do not easily breakdown, and so build up in the environment and in tissues. Human exposure to PFAS has been linked to health issues, such as kidney and testicular cancer, thyroid disease, liver damage, developmental toxicity, ulcerative colitis, high cholesterol, and immune dysfunction. However, much less is known about the effects of PFAS on fish health and fish populations. Smallmouth bass are an economically important sportfish that have experienced disease outbreaks and populations declines in numerous Chesapeake Bay watersheds. PFAS may have adverse health impacts on smallmouth bass. Therefore, the goal of this study was to evaluate the concentration of PFAS in smallmouth bass tissue samples.
USGS Study
Adult smallmouth Bass were collected at ten sites between 2014 and 2021 by the U.S. Geological Survey (USGS), Maryland Department of Natural Resources (MD DNR), Pennsylvania Fish and Boat Commission (PA FBC), Pennsylvania Department of Environmental Protection (PA DEP) and West Virginia Division of Natural Resources (WV DNR). The sampled sites represent a gradient of urban, agricultural, and forested lands in and around the Chesapeake Bay watershed (Figure 1). Plasma samples were obtained from smallmouth bass collected at these ten sites and were analyzed for 13 PFAS compounds. The tissue distribution (plasma, whole blood, liver, gonad, skeletal muscle) of 28 PFAS compounds was documented at two sites.
Major Findings
- Four PFAS (PFOS, PFDA, PFUnA, PFDoA) were detected in every smallmouth bass plasma sample.
- Concentrations of PFOS were considerably higher than the other three compounds.
- The highest total plasma concentrations of PFAS were found in smallmouth bass collected from two sites (Figure 2). These two sites had the highest percentage of developed land and the most number of EPA-identified sources of PFAS (including military installations and airports). Intermediate PFAS concentrations were found at sites with agricultural land. The lowest PFAS concentrations were found at sites with the highest percentage of forested land.
- PFAS concentrations were lowest in smallmouth bass muscle/fillet and higher in blood and liver, however tissue distribution differed between the two sites.
Management Implications
- PFAS were detected in the plasma of smallmouth bass at all sites, including sites with a low percentage of developed land and sites with a low number of PFAS sources. This suggests that PFAS may be widespread in Chesapeake Bay waters and in smallmouth bass.
- Developed and agricultural landuses may be associated with PFAS in surface water and/or the food chain.
- PFAS concentrations were low in the muscle tissue of smallmouth bass, even in fish that had high plasma concentrations. The low concentration of PFAS in muscles suggests a minimal risk of human exposure to PFAS from eating smallmouth bass.
- Concentrations measured in blood and other organs may be associated with health effects observed in smallmouth bass populations and require further study.
For More Information
For questions, contact Vicki Blazer (vblazer@usgs.gov).
The full study has been published with open access in the journal Environmental Science and Pollution Research at https://doi.org/10.1007/s11356-024-35097-6.
Tissue distribution and temporal and spatial assessment of per- and polyfluoroalkyl substances (PFAS) in smallmouth bass (Micropterus dolomieu) in the mid-Atlantic United States
Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals that have been recognized as concerns for both human and ecosystem health. There is a need to understand the effects of PFAS on fish health and populations.
Issue
PFAS are called “forever chemicals” as they do not easily breakdown, and so build up in the environment and in tissues. Human exposure to PFAS has been linked to health issues, such as kidney and testicular cancer, thyroid disease, liver damage, developmental toxicity, ulcerative colitis, high cholesterol, and immune dysfunction. However, much less is known about the effects of PFAS on fish health and fish populations. Smallmouth bass are an economically important sportfish that have experienced disease outbreaks and populations declines in numerous Chesapeake Bay watersheds. PFAS may have adverse health impacts on smallmouth bass. Therefore, the goal of this study was to evaluate the concentration of PFAS in smallmouth bass tissue samples.
USGS Study
Adult smallmouth Bass were collected at ten sites between 2014 and 2021 by the U.S. Geological Survey (USGS), Maryland Department of Natural Resources (MD DNR), Pennsylvania Fish and Boat Commission (PA FBC), Pennsylvania Department of Environmental Protection (PA DEP) and West Virginia Division of Natural Resources (WV DNR). The sampled sites represent a gradient of urban, agricultural, and forested lands in and around the Chesapeake Bay watershed (Figure 1). Plasma samples were obtained from smallmouth bass collected at these ten sites and were analyzed for 13 PFAS compounds. The tissue distribution (plasma, whole blood, liver, gonad, skeletal muscle) of 28 PFAS compounds was documented at two sites.
Major Findings
- Four PFAS (PFOS, PFDA, PFUnA, PFDoA) were detected in every smallmouth bass plasma sample.
- Concentrations of PFOS were considerably higher than the other three compounds.
- The highest total plasma concentrations of PFAS were found in smallmouth bass collected from two sites (Figure 2). These two sites had the highest percentage of developed land and the most number of EPA-identified sources of PFAS (including military installations and airports). Intermediate PFAS concentrations were found at sites with agricultural land. The lowest PFAS concentrations were found at sites with the highest percentage of forested land.
- PFAS concentrations were lowest in smallmouth bass muscle/fillet and higher in blood and liver, however tissue distribution differed between the two sites.
Management Implications
- PFAS were detected in the plasma of smallmouth bass at all sites, including sites with a low percentage of developed land and sites with a low number of PFAS sources. This suggests that PFAS may be widespread in Chesapeake Bay waters and in smallmouth bass.
- Developed and agricultural landuses may be associated with PFAS in surface water and/or the food chain.
- PFAS concentrations were low in the muscle tissue of smallmouth bass, even in fish that had high plasma concentrations. The low concentration of PFAS in muscles suggests a minimal risk of human exposure to PFAS from eating smallmouth bass.
- Concentrations measured in blood and other organs may be associated with health effects observed in smallmouth bass populations and require further study.
For More Information
For questions, contact Vicki Blazer (vblazer@usgs.gov).
The full study has been published with open access in the journal Environmental Science and Pollution Research at https://doi.org/10.1007/s11356-024-35097-6.