SEPA

2022 National Lakes Assessment
Human Health Fish Tissue Study

John Healey1, Katie Davis1, Blaine Snyder2, Harry McCarty3, and Tara Cohen2

Background

Obtaining statistically representative data on contaminants in fish is a
priority area of interest for EPA. In the early 2000s, EPA's Office of
Science and Technology (OST), within the Office of Water (OW),
conducted the first national probability-based study of chemical
contamination in fish from U.S. lakes, ponds, and reservoirs (hereafter
referred to as lakes), known as the National Lake Fish Tissue Study.
Mercury and PCBs were detected in all fish samples collected from 500
sampling locations in the lower 48 states, and it was estimated that 49%
of U.S. lakes, at the time, contained fish with mercury levels that
exceeded the human health screening level of 300 parts per billion (i.e.,
EPA's fish tissue-based water quality criterion for methylmercury).

Twenty years later, the 2022 National Lakes Assessment (NLA), one of
EPA's National Aquatic Resource Surveys (NARS), has provided an
opportunity to conduct a contemporary national-scale assessment of
chemical contaminants in fish from U.S. lakes. The NLA is a probability-
based national survey that includes collection and analysis of physical,
chemical, and biological indicator data to allow a statistically valid
characterization of the condition of the Nation's lakes. OST is
collaborating with the Office of Wetlands, Oceans, and Watersheds and
with the Office of Research and Development to complete the 2022
National Lakes Assessment Human Health Fish Tissue Study, which
will compare current

chemical concentrations
of certain chemicals in
lake fish to results from the
National Lake Fish Tissue
Study, and will evaluate
lake fish fillet contaminant
changes over time.

Study Design

The NLA Human Health Fish Tissue Study involves:

¦	Attempting to collect whole fish samples from 636 randomly selected lakes in
the coterminous U.S.

¦	Obtaining one fish composite sample from each lake (optimally, five similarly
sized adult fish of the same species that are commonly consumed by humans]

¦	Shipping whole fish samples to sample repository freezers in Baltimore,
Maryland for interim storage

¦	Transferring the frozen whole fish samples to the sample preparation
laboratory in Owings Mills, MD

¦	Preparing fillet tissue samples by scaling and filleting each fish in the
composite sample, homogenizing the fillets from all the fish in the sample, and
dividing homogenates into aliquots for chemical analyses

¦	Analyzing the fillet samples for mercury, 40 per- and polyfluoroalkyl
substances (PFAS), and 209 polychlorinated biphenyl (PCB] congeners

Author Affiliation

XU.S. Environmental Protection Agency
OW/Office of Science and Technology
1200 Pennsylvania Avenue, NW
Washington, DC 20460

2Tetra Tech

Center for Ecological Sciences
10711 Red Run Boulevard, Suite 105
Owings Mills, MD 21117

3 General Dynamics Information
Technology

3170 Fair view Park Drive
Falls Church, VA 22042

Target Chemicals

National Lakes Assessment Human Health Fish Tissue Study

• Second statistically based assessment of contaminants in fish from inland lakes of the conterminous
United States, mirroring EPA's National Lake Fish Tissue Study of 2000-2003 to assess change over time

• Fish successfully collected from 413 of the 636 randomly selected sampling locations.











Sample Collection

Sample Preparation

Analysis

1

1

1

The target population consisted of all lakes
and reservoirs in the lower 48 states with
a surface area >1 hectare and that contain
1,000 square meters of open, unvegetated
space and a permanent population of
predator fish species.

•	A total of 636 randomly selected lakes were
targeted for fish sampling.

•	Sampling procedures for collection of whole
fish samples are detailed in EPA's National
Lakes Assessment 2022 Quality Assurance
Project Plan and National Lakes Assessment
2022 Field Operations Manual.

•	Procedures included a list of 12 primary
target predator fish species and 10
secondary predator fish species (all
commonly consumed by humans).

•	Most fish samples were collected by hook
and line or electrofishing.

•	A total 1,512 fish were collected, which
yielded 413 valid whole fish composite
samples from the 636 sites targeted for fish
sampling.

•	A total of 21 species were collected,
and the majority of samples (66%) were
Largemouth Bass.

Whole fish samples were stored in freezers
at < -20° Celsius (C).

•	The sample preparation laboratory is scaling
and filleting each fish, homogenizing the
fillet tissue, and preparing the required
number offish fillet tissue aliquots for
analysis.

> Sample preparation quality control
procedures include analysis of lipids
in ground fillet tissue samples for
homogeneity testing and analysis of
mercury, PCBs, and PFAS in equipment
rinsates to test the adequacy of equipment
cleaning.

•	The filleting process involves removing the
fillet (with skin on and "belly flap" or ventral
muscle attached) from both sides of each
fish, combining fillets from all fish in the
composite sample, and homogenizing them
together using an electric meat grinder.

' Sample preparation procedures are detailed
in EPA's Quality Assurance Project Plan for
2022 National Lake Assessment (NLA) Fish
Tissue Study Sample Preparation.

Fillet tissue homogenates will be prepared
and analyzed for mercury using Appendix to
Method 1631, Total Mercury in Tissue, Sludge,
Sediment and Soil by Acid Digestion and
BrCI Oxidation Revision B and Revision E,
respectively.

» Fillet homogenates will also be analyzed for
40 PFAS and 209 PCB congeners (Analytical
method requirements for PFAS and PCB
analyses will be described in the Quality
Assurance Project Plan for Analysis of the
2022 National Lake Assessment Fish Fillet
Samples for Mercury, Per- and Polyfluoroalkyl
Substances, and Polychlorinated Biphenyls.

> Statistical analysis will include an estimation
of the number and proportion of lakes in the
sampled population, and an estimation of
the cumulative distribution and percentile
concentrations of the target chemicals in
fillets.

» The percentage of the sampled population
of U.S. lakes containing fish with fillet
concentrations that exceed screening
levels for human health protection will be
estimated by overlaying these screening
levels on cumulative distribution plots for
the target chemicals.

Disclaimer: The views expressed in this poster are those of the authors and do not
necessarily represent the views or policies of the U.S. Environmental Protection Agency.

For more information on EPA fish tissue contaminant studies visit: https://www.epa.qov/fish-tech/studies-fish-tissue-contamination

Polychlorinated Biphenyls (PCBs)

Target Analyte

Full congener analysis providing results for 209 congeners

Target Analyte

CAS Number

Mercury (total)

7439-97-6

Per- and Polyfluoroalkyl Substances (PFAS)

Target Analyte

Abbreviation

CAS Number

Perfluoroalkyl carboxylic acids

Perfluorobutanoic acid

PFBA

375-22-4

Perfluoropentanoic acid

PFPeA

2706-90-3

Perfluorohexanoic acid

PFHxA

307-24-4

Perfluoroheptanoic acid

PFHpA

375-85-9

Perfluorooctanoic acid

PFOA

335-67-1

Perfluorononanoic acid

PFNA

375-95-1

Perfluorodecanoic acid

PFDA

335-76-2

Perfiuoroundecanoic acid

PFUnA

2058-94-8

Perfluorododecanoic acid

PFDoA

307-55-1

Perfluorotridecanoic acid

PFTrDA

72629-94-8

Perfluorotetradecanoic acid

PFTeDA

376-06-7

Perfluroalkyl sulfonic acids

Perfluorobutanesulfonic acid

PFBS

375-73-5

Perfluoropentansulfonic acid

PFPeS

2706-91-4

Perfluorohexanesulfonic acid

PFHxS

355-46-4

Perfluoroheptanesulfonic acid

PFHpS

375-92-8

Perfluorooctanesulfonic acid

PF0S

1763-23-1

Perfluorononanesulfonic acid

PFNS

68259-12-1

Perfluorodecanesulfonic acid

PFDS

335-77-3

Perfluorododecanesulfonic acid

PFDoS

79780-39-5

Fluorotelomer sulfonic acids

1H,1H, 2H, 2H-Perfluorohexane sulfonic acid

4:2FTS

757124-72-4

1H,1H, 2H, 2H-Perfluorooctane sulfonic acid

6:2FTS

27619-97-2

1H/IH, 2H, 2H-Perfluorodecane sulfonic acid

8:2FTS

39108-34-4

Perfluorooctane sulfonamides





Perfluorooctanesulfonamide

PF0SA

754-91-6

N-methyl perfluorooctanesulfonamide

NMeFOSA

31506-32-8

N-ethyl perfluorooctanesulfonamide

NEtFOSA

4151-50-2

Perfluorooctane sulfonamidoacetic acids

N-methyl perfluorooctanesulfonamidoacetic acid

NMeFOSAA

2355-31-9

N-ethyl perfluorooctanesulfonamidoacetic acid

NEtFOSAA

2991-50-6

Perfluorooctane sulfonamide ethanols

N-methyl perfluorooctanesulfonamidoethanol

NMeFOSE

24448-09-7

N-ethyl perfluorooctanesulfonamidoethanol

NEtFOSE

1691-99-2

Per- and Polyfluoroether carboxylic acids

Hexafluoropropylene oxide dimer acid

HFPO-DA

13252-13-6

4,8-Dioxa-3H-perfluorononanoic acid

ADONA

919005-14-4

Perfluoro-3-methoxypropanoic acid

PFMPA

377-73-1

Perfluoro-4-methoxybutanoic acid

PFMBA

863090-89-5

Nonafluoro-3,6-dioxaheptanoic acid

NFDHA

151772-58-6

Ether sulfonic acids

9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid

9CI-PF30NS

756426-58-1

11-Chloroeicosaf!uoro-3-oxaundecane-1-sulfonic acid

11CI-PF30UdS

763051-92-9

Perf)uoro(2-ethoxyethane)sulfonic acid

PFEESA

113507-82-7

Fluorotelomer carboxylic acids

3-Perfluoropropyl propanoic acid

3:3FTCA

356-02-5

2H,2H,3H,3H-Perfluorooctanoic acid

5:3FTCA

914637-49-3

3-Perfluoroheptyl propanoic acid

7:3FTCA

812-70-4

Sample Collection
Ending

Fish Preparation
Completed

Data Analysis
Completed

Anticipated Study Milestones J 2022

2023

2024

Sample Collection
Beginning

Fish Fillet
Analysis Completed

2025

Reporting
Completed


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