Targeted EPA Fish Tissue Contamination Studies
The U.S. Environmental Protection Agency investigates the presence of chemicals in fish for which the risk to human health and the environment is unknown. These include contaminants of emerging concern such as pharmaceuticals and personal care products, perfluorinated compounds (used in a wide variety of household and industrial products) and polybrominated diphenyl ethers (widely used as flame retardants).
For more information about what the EPA is doing to improve our understanding on a number of contaminants in addition to the fish tissue studies associated with the National Aquatic Resource Surveys, refer to the following fact sheets and studies.
Use of Aluminum Foil for Fish Samples
Fish tissue contaminant studies require careful sample handling, wrapping, and storage to reduce the chance of cross-contamination. The objective of this study was to test whether “untreated” heavy-duty food-grade aluminum foil can be used instead of solvent-rinsed foil.
Polybrominated Diphenyl Ethers (PBDEs)
Per- and Polyfluoroalkyl compounds or PFAS (formerly called perfluorinated compounds or PFCs)
Pharmaceuticals and Personal Care Products (PPCPs)
The EPA initiated a pilot study of PPCPs in fish tissue in 2006. This study investigated the occurrence of PPCP chemicals in fish tissue at several stream locations across the country. The EPA partnered with Baylor University to conduct the study from 2006‐2008 and to publish the study results in 2009. Read the final report, fact sheet, Quality Assurance Report, and Quality Assurance Project Plans.
Mercury and Selenium
The EPA collected and analyzed fish during 2007-2008 to assess levels of mercury at 95 randomly selected mercury advisory sites within the continental United States using a statistically based, regionally stratified design, where sites represented all major regions of the country. Methods established in the EPA’s Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories were used to collect and analyze fish fillet tissue for total mercury. Site samples comprise three composites of five fish per composite. Total selenium was also measured and is included in the dataset.
The EPA continued to analyze fish fillet tissue for mercury and selenium under the 2008-2009 National Rivers and Streams Assessment Fish Tissue Study. Results from the study are available on the EPA’s website.
In 2021, the EPA conducted a study to test the applicability of fillet biopsy plugs for monitoring fish tissue for selenium and mercury, and to better define the relationship between selenium or mercury concentrations in muscle plugs and muscle fillets. The EPA found that there were no statistically significant differences between log concentrations of fillet plugs and log concentrations of homogenized fillets at the community level. However, the authors of this study did caution that when using a selenium plug monitoring alternative, samplers must employ a sufficiently sensitive analytical method and consider total solids in the tissue samples.