United States
Environmental Protection
Agency
Chesapeake Bay
Program
Annapolis MD 21401
Research and Development
EPA-600/S3-83-Q18 June 1983
Project Summary
Organic Compounds in Surface
Sediments and Oyster Tissues
from the Chesapeake Bay
R. J. Huggett and R. H. Bieri
Detailed in the first part of this report
is a development and discussion of the
methodology used to extract and
analyze sediment and oyster tissue
samples from Chesapeake Bay for
organic compounds. The method
includes extraction, fractionation, and
subsequent analysis using glass
capillary gas chromatography and glass
capillary gas chromotography-mass
spectrometry (GC-MS). An extensive
list of the mass spectral data and related
information is contained in the
appendices. The complete bank of
processed data is also available on
computer tapes at the Virginia Institute
of Marine Science and at the
Environmental Protection Agency's
Chesapeake Bay Program. Also
included in this report are the results of
volatile halogenated organic
compounds determined in water
collected near the outfalls of several
facilities using chlorine, as well as from
river mouths. Distributions of the total,
and some specific, organic compounds
within the Bay are presented in
histograms. Analyses clearly show that
unsubstituted polynuclear aromatic
hydrocarbons are the most prominent
toxic pollutants in the Bay. The applica-
tion of two different search routines,
one concentrating on compounds at
levels greater than 50 ppb and the other
on temporal changes, allows a quick
determination of where problem areas
may exist and where additional
investigation may be indicated.
This Project Summary was developed
by EPA's Chesapeake Bay Program.
Annapolis. MD. to announce key
findings of the research project that is
fully documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
The production and use of synthetic
organic compounds has greatly increased
since the Second World War, and the
loadings of these chemicals into the
environment have thus greatly increased.
Many of these chemicals are absorbed by
plants, ingested by animals, and
accumulated through food webs; this
may lead to acute or chronic toxic effects
in the organisms or make them unfit for
human consumption.
The purpose of this project was to
monitor the concentrations of synthetic
organic compounds in sediments and in
oyster tissue samples at representative
areas of the Bay, at the mouths of the
major tributaries, and at locations where
high concentrations of organic
compounds are likely to be present. Also,
the concentrations of volatile
halogenated organic compounds in the
water column were determined at
outfalls of several facilities where
chlorine is used and at the mouths of the
major tributaries.
An analytical scheme was developed to
extract, identify and quantitate as broad a
spectrum of organic compounds as
possible with glass capillary gas
chromatography and gas chromatography-
mass spectrometry. This analysis limited
the compounds that could be identified to
those that are stable and volatile enough
to pass through a gas chromatograph.
-------
Procedure/ Methodology
A Hewlett-Packard 3354B laboratory
automation system was used to collect,
process, and store chromatographicdata,
and software packages were used to do
the following:
a) calculate concentrations of gas
chromatographic (G.C.) peaks by
reference to internal standards,
discriminate against peaks with
less than a predetermined
minimum concentration, and
calculate the relative aromatic
retention index and the pesticide
retention index,
b) display both processed and nor-
malized data on the HP3354B
system console (H.P. 2648 termi-
nal) and line printer (H.P. 9866B),
c) plot bar graphs from processed data,
d) plot chromatograms from raw data,
e) compare G.C. peaks in samples
collected at a particular station at
different times an'd flag samples
with concentrations of a given peak
that are either ten times larger or
smaller than the concentration in
the first sample,
f) compare peaks in gas chromato-
grams of samples from all Bay
stations and flag stations where
the concentrations of some peaks
exceed 50 ppb, and
g) search data files for peaks eluting
within a specified retention index
window and list sample identifi-
cation codes, retention times, and
concentrations.
Results
Baltimore Harbor, The Chesapeake and
Delaware Canal, and the Susquehanna
River may be sources of organic
pollutants in the sediments of the
Chesapeake Bay. In the search for
organic compounds at concentrations
greater than 50 ppb in sediments, it was
generally found that more uniform and
more highly concentrated organic
pollutants were contained in the upper
portion of the Bay than in the lower part
and that unsubstituted polynuclear
aromatics (PNAs) are the major group of
compounds present. Concentration sums
of organic compounds in lower Bay
sediments tended to be higher at river-
mouth stations than at open Bay stations
or at stations close to the Eastern Shore.
In the upper Bay, samples collected from
river-mouth stations also tended to
contain high concentrations. In the
search for changes in concentration over
time, it was observed that sediment
concentrations from the mouth of the
Susquehanna River are highly variable.
This is due to the differences in sediment
composition (percent silt/clay and sand)
over time and indicates that Bay
sediments may be static for some time
but may shift in response to storms and
seasonal changes. Thus, areas that are
sinks for organic pollutants at some times
of the year may become sources at other
times. Organic compounds at
concentrations greater than 50 ppb in
oyster tissue primarily included the
higher substituted naphthalenes,
fluorenes, dibenzo thiophenes, and
phenanthrenes.
The volatile halogenated organic
compounds identified were chloroform,
1,1,1 -trichloroethane, carbor
tetrachloride, trichloroethylene, bromo
dichloromethane, dibromochlorometh-
ane, tetrachloroethylene, and bromoform
Recommendations
This study was developed as an
investigation of organic compounds in
estuarine sediments and in oyster tissue.
Although many organic compounds, both
natural and synthetic, can be found in the
sediments, this research focused on
those compounds most likely to exhibit
toxicity to Bay biota.
Sediment composition is a major
determinant of the content of organic
compounds; therefore, sampling for
organic compounds in sediments should
include some sediment particle size
analysis.
Further research into organic
compounds in estuarine sediments
should accomplish the following: (a]
further delineation of oyster/sediment
concentration relationship, (b) more
sampling to define temporal changes in
sediment concentrations, (c) investiga-
tion of sources of PNAs, and (d]
investigation of the toxicity of sediment
concentrations to biota.
R. J. Huggett and R. H. Bieri are with Virginia Institute of Marine Science,
Gloucester Point, VA 23062.
Duane Wilding is the EPA Project Officer (see below).
This Project Summary covers the following two reports:
"Organic Compounds in Surface Sediments and Oyster Tissues from the
Chesapeake Bay," (Order No. PB 83-187 443; Cost: $ 17.50, subject to change).
"Organic Compounds in Surface Sediments and Oyster Tissues from the
Chesapeake Bay—Appendices," (Order No. PB 83-187 450; Cost: $23.50,
subject to change).
The above reports will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Research Laboratory
U.S. Environmental Protection Agency
Gulf Breeze, FL 32561
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
PS 0000329
. U S ENVIR PROTECJION A6ENCY
REGION 5 LIBRARY
230 S DEARBORN STREET
CHICAGO IL 6060*1
------- |