&EPA
United States
Environmental Protection
Agency
                                                 Office of Water
                                                 4305T
EPA-823-F-05-012
   October 2005
                  Fact Sheet:  2005  Update
      The National Study of Chemical Residues in Lake Fish  Tissue

      Summary

      The U.S. Environmental Protection Agency is conducting a national freshwater fish
      contamination survey to estimate the national distribution of selected persistent,
      bioaccumulative and toxic chemicals in fish tissue from lakes and reservoirs of the contiguous
      United States (lower 48 states). This study will provide the first national estimates of mean
      concentrations of 268 chemicals in lake fish, define a national baseline to track progress of
      pollution control activities, and identify areas where contaminant levels are high enough to
      warrant  further investigation.
     Background

     Monitoring fish for chemical contamination
     in lakes and reservoirs is a critical activity
     for protecting human health because these
     areas are important for sport fishing and
     other recreational activities. The 2004
     update to EPA's National Listing of Fish and
     Wildlife Advisories reports that 35% of the
     Nation's lake acres are under fish
     consumption advisories.

     Lakes and reservoirs occur in a variety of
     landscapes and can receive contaminants
     from several sources, including direct
     discharges into the water, air deposition,
     and agricultural or urban runoff. Lakes are
     the focus of this study because they are
     environments where contamination
     accumulates and is more readily detectable.

     EPA initiated the National Study of
     Chemical Residues  in Lake Fish Tissue (or
     National Lake Fish Tissue Study) in 1998 as
     a priority activity under the Agency's
     Persistent, Bioaccumulative and Toxic
     (PBT) Chemical Program. It supports the
     PBT Program by providing data for a large
     set of chemicals in fish that could affect the
     health of people and wildlife that eat fish
     from these environments.
                               Why is this study important?

                               The National Lake Fish Tissue Study is
                               important because it:

                               +     Allows EPA for the first time to
                                     develop national estimates of the
                                     mean levels of persistent,
                                     bioaccumulative and toxic chemicals
                                     in lake fish.

                               +     Provides a national baseline for
                                     tracking reductions of persistent,
                                     bioaccumulative and toxic chemicals
                                     in freshwater fish as a result of
                                     pollution control activities.

                               What are the basic  elements of
                               the study design?

                               EPA worked with partner agencies over a
                               four-year period (2000-2003) to collect fish
                               from 500 lakes and reservoirs selected
                               randomly from the estimated 147,000 target
                               lakes and reservoirs in the lower 48 states.
                               The lakes are divided into  6 size categories,
                               ranging from 2.5 to over 900,000 surface
                               acres, with a similar number of lakes in
                               each category. Before sampling, field
                               teams verified that each lake is a permanent
                               body of water with a depth of at least one
                               meter.

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Sampling teams applied consistent methods
nationwide to collect composites of one
predator species and one bottom-dwelling
species at each lake. Composites
consisted of 5 adult fish of similar size that
were large  enough to provide 560 grams
(20 ounces) of tissue for analysis of fillets
for predators and whole bodies for bottom
dwellers. EPA analyzed each composite for
268 chemicals (including PCB congeners)
and added  PBDE analysis for fourth year
fish samples only.


       500 Sampling Locations
What chemicals did EPA select
for the study?

EPA analyzed the fish tissue for:

-0-       2 metals (mercury and 5 forms
                 of arsenic)
-0-      17 dioxins and furans
-0-      159 PCB congener measurements
-0-      46 pesticides
-0-      40 other organics (e.g., phenols)
-0-      46 PBDE congeners (1 year only)

Who is  participating in the
study?

EPA formed a national network of partners
to evaluate lakes and collect fish for the
study, including:

4-      47 States
•0-      3 Tribes
-0-      National Park Service and
       Tennessee Valley Authority
What are the key study
accomplishments and
milestones?

The study consists of four phases:

Planning (1998-1999)
•     study design development
•     statistical lake selection
•     target chemical selection

Mobilization (1999-2000)
•     orientation workshops
•     production of quality assurance
      plans and field sampling plan
•     lake reconnaissance

Sampling and Tissue Analysis (2000-2005)
•     sampling of 500 lakes through 2003
•     chemical analysis of 1003 fish
      samples through 2005
•     chemical analysis of 352 fish
      samples for PBDEs in 2005

Data Analysis and Reporting (2005-2006)
>     statistical analysis of fish tissue data
>     production of final report
>     data upload into EPA's STORET

What results are  currently
available?

Quality-assured results from all 500 lakes
sampled during 2000 through 2003 are now
available. To obtain these results on CDs,
see contact information below.

Who do I contact for more
information?

Leanne Stahl
OW/OST (4305T)
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, N.W.
Washington, DC  20460
(202) 566-0404
stahl.leanne@epa.gov

Visit the Fish Study website at:
www. epa. gov/waterscience/f ishstudy/

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