SERAFM: Ecological Risk Assessment Tool
for Evaluating Wildlife Exposure Risk
Associated with IVIercury-Contaminated
Sediment in Lake and River Systems

Christopher D. Kriightes, ORD/NERL/ERD/RSB Athens GA

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INTRODUCTION

Mercury (Hg) is an important environmental pollutant because of its suspected
neurotoxicity and is classified as a priority pollutant by the United States Environmental
Protection Agency (USEPA) (USEPA, 1997). The primary pathway of mercury
exposure to humans and wildlife is via ingestion of mercury-contaminated fish.

Under CERCLA and RCRA, remediation goals for sites with mercury contamination:
are not typically developed for surface water,
are often developed for sediment.

However, fish do not demonstrate a strong correlation with concentrations in sediment
but rather with methyl-mercury concentration in water (Brumbaugh, 2001).

So Region 1 asked us: How can one develop a remediation goal for mercury in
sediment when the sediment mercury concentration may be a poor predictor of
mercury exposure to biota?

2003 ERASC Request #10 from Region 1

In 2003, NERL-ERD (Athens, GA) received a request through the Ecological Risk
Assessment Support Center (ERASC) from Region 1.

In response ORD/NERL/ERD:

Developed an easy-to-use, straight-forward model to assist in deriving a remediation

and thus SERAFM was borri.

SERAFM is the Spreadsheet-based Ecological Risk Assessment for the Fate of
Mercury. We wrote and designed this model to be used as a stand-alone, risk
assessment tool for mercury contaminated ecosystems.

*	Process-based, Steady-state

•	Spreadsheet Framework

•	transparent

•	series of linked modules, each kept on separate sheet

•	results linked sequentially

Mercury Cycle

Methvl-H

Settling! » / /'''

X Hg2+ J

Hg2+<-->Mrthyl-Hg

Resuspension
Diffusion

REFERENCES

Brumbaugh, W.G., D.P. Krabbenhoft, D.R. Helsel, J.G. Wiener, arid K.R. Echols. 2001. A National Pilot Study of
Mercury Contamination of Aquatic Ecosystems Along Multiple Gradients: Bioaccumulation in Fish. USGS/BRD/BSR-
2001-0009, iii+25pp.

USEPA, 1997. Mercury Study Report to Congress. EPA-452/R-97-005, Office of Air Quality Planning and
StandardsUnited States Environmental Protection Agency, Washington.

SERAFM Modules

~	Atmospheric Deposition

~	Watershed Erosion

~	Equilibrium Partitioning

~	Water Body Mercury Calculations

~	Contaminated Sediment
Background Conditions

~	Watershed Runoff

~	Water Body Solids Balance

~	Mercury Speciation

~	Remediation Goal

~	Wildlife Risk Calculations

Calculates Exposure Concentrations

Exposure Concentrations

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Identifies
Sensitive
Species





Calculates Wildlife Hazard Indices

Human and Wildlife Exposure Risk Results





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Coittn m in .»te •!

Cleaned

Clean Up Level

Wildlife



Mink
Oner

2M£4
»!.»7

0.52
0.70

0.20
0.27

Klmjflshei

886.71

1.58

0.6 i

1 Uflll

IM.fiJI

063

[I ;>4

Q&piey
Eagle

Tree Swallow

35I.WI
290.11
MJ1.W

0&3
052
5.56

0,24
0.20
2.0I>

Hnnchiil Ml*H|.iivioi

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11HS

tl 33

Wuiiil line K

-»U.h4 n *.

I114







Human





Man

IT, M

UUI

U.Ui!

		



LI 114

tl 0?

Adult
Child

NMM American

30.80
113.71

275.23

001
0C6
012

002
0.10
0.19





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*1 CHOI4-0 d

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Disclaimer: Although this work was reviewed by EPA and approved for presentation, it may not necessarily reflect official Agency policy. Mention of trade names or commercial products does net constitute endorsement or recommendation for use.

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