Arch. Environ. Contam. Toxicol. 42, 313–318 (2002)
DOI: 10.1007/s00244-001-0003-8
A R C H I V E S O F
Environmental
Contamination
a n d Toxicology
© 2002 Springer-Verlag New York Inc.
Perfluorooctane Sulfonate in Oysters, Crassostrea virginica, from the Gulf of
Mexico and the Chesapeake Bay, USA
K. Kannan,1 K. J. Hansen,2 T. L. Wade,3 J. P. Giesy1
1
National Food Safety and Toxicology Center, Department of Zoology, Institute for Environmental Toxicology, Michigan State University,
East Lansing, Michigan 48824, USA
2
3M Environmental Laboratory, 935 Bush Avenue, St. Paul, Minnesota 55133, USA
3
Geochemical and Environmental Research Group, Texas A&M University, 833 Graham Road, College Station, Texas 77845, USA
Received: 4 June 2001 /Accepted: 21 September 2001
Abstract. Concentrations of perfluorooctane sulfonate (PFOS), a
metabolite of several sulfonated perfluoroorganic compounds,
were measured in oysters collected from 77 locations in the Gulf
of Mexico and Chesapeake Bay of the United States. PFOS was
detected in oysters collected from 51 of the 77 locations at concentrations ranging from ⬍ 42 to 1,225 ng/g on a dry weight basis.
This study provides baseline data for future monitoring programs
to examine long-term trends in concentrations of PFOS.
Since the 1970s, there has been a steady increase in the use of
fluorinated organic compounds for a variety of industrial applications (Kissa 2001). Fluorinated surfactants are an important class of organic chemicals that have been used in soil- and
stain-resistant coatings for fabrics, carpets, and leather and in
grease- and oil-resistant coatings for paper products and food
containers (Key et al. 1997; US EPA 2000; Kissa 2001).
The use of sulfonyl-based fluorochemicals can be divided
into three main categories: (1) surface treatments, (2) paper
protectors, and (3) performance chemicals. Surface treatment
applications provide soil, oil, and water resistance to personal
apparel and home furnishings. Specific applications in the
surface treatment category include protection of apparel,
leather, fabric, upholstery, and carpet. According to the U.S.
Environmental Protection Agency, 37% of the production of
fluorinated surfactants is used for surface treatment applications (US EPA 2000). Surface treatments are applied in industrial settings, such as textile mills, leather tanneries, finishers,
fabric producers, and carpet manufacturers (US EPA 2000).
Sulfonyl-based fluorochemicals have also been used by consumers to treat apparel, leather, upholstery, carpet, and automobile interiors. Historically, sulfonated fluorochemicals were
also applied to paper products, such as plates, food containers,
bags, and wraps, to provide grease, water, and oil resistance. In
2000, coatings on paper products accounted for 42% of 3M’s
total sulfonyl-based fluorochemical production (US EPA
Correspondence to: K. Kannan
2000). Fluorochemicals in the performance chemicals category
are used in a wide variety of industrial, commercial, and
consumer applications, such as fire-fighting foams, mining and
oil well surfactants, acid mist suppressants for metal plating
and electronic etching baths, alkaline cleaners, floor polishes,
photographic film, denture cleaners, shampoo, and an ant insecticide (US EPA 2000; Moody and Field 2000).
Salts of perfluorocarboxylic acids and perfluoroalkane sulfonic acids are considered to be thermally stable and resistant
to the effects of acids, bases, oxidants, and reductants (Kissa
2001). The wide use of these relatively stable compounds has
raised concerns about the fate of fluorochemicals in the environment and, ultimately, the potential for inadvertent exposure
to humans and wildlife. Perfluorooctane sulfonate (PFOS) has
been identified in sera samples of nonoccupationally exposed
humans (Hansen et al. 2001). Recent studies have documented
the occurrence of PFOS in fish, mammals, and birds from
various parts of the world, including the Arctic Ocean (Giesy
and Kannan 2001; Kannan et al. 2001a, 2001b).
Bivalves (oysters and mussels) have been widely used as
sentinel organisms for monitoring spatial and temporal distribution of trace metals and organic residues in marine coastal
and estuarine ecosystems (O’Connor 1996). The Mussel Watch
project within the National Status and Trends program of the
National Oceanic and Atmospheric Administration annually
monitors residues in bivalves collected from US coastal waters.
In this study, American oysters, Crassostrea virginica, collected in the Gulf of Mexico and the Chesapeake Bay during
December 1996 –February 1998 were analyzed for the presence
of PFOS to establish baseline concentrations of this organic
fluorochemical. Archived samples, which were collected as a
part of National Status and Trends program, were analyzed.
Materials and Methods
Samples
Sampling of oysters and the selection of sites have been described
elsewhere (Sericano et al. 1990; Lauenstein et al. 1993; O’Connor and
314
K. Kannan et al.
Fig. 1. Map of Gulf of Mexico
showing sampling locations of oysters. Details of the locations for the
corresponding numbers are presented in Table 1
Beliaeff 1995; O’Connor 1996). Briefly, sampling locations have been
selected with the intention of collecting samples that are representative
of the surroundings. Small patches of contamination and known points
of waste discharge have been avoided (this is how sampling was
performed for the Mussel Watch program). Sampling locations for
oysters are shown in Figures 1 and 2, and sampling quadrants are given
in Table 1. Samples were collected from December to February of
1996 –1998. Depending on the depth of the water column, which
ranged from 0.5 to 3.5 m, oysters were collected by hand, tongs, or
dredge. Composite samples of 20 oysters from each location were
collected and prepared by homogenizing the soft parts. For each
composite sample, an aliquot (⬃ 2 g) of oyster tissue was dried in an
oven at 60°C for determination of dry weight.
blanks, and continuing calibration verification. Recoveries of PFOS
spiked into oyster tissues and passed through the analytical procedure
varied from 64% to 83% (n ⫽ 6), with a mean recovery of 74 ⫾ 8%.
Concentrations of PFOS were not corrected for the recoveries of the
surrogate standard or matrix spike recoveries. The PFOS standard was
86.4% pure. Concentrations were not corrected for purity of the PFOS
standard. Radiolabeled material was not available to verify the accuracy of matrix spikes studies. However, assuming that matrix spike
studies are a suitable indication of endogenous analyte levels and
taking into account the analytical quality control, this data is estimated
to be accurate to ⫾ 40%.
Results and Discussion
Analysis
Concentrations of PFOS in oyster tissues were determined by use of
high-performance liquid chromatography (HPLC) coupled with electrospray tandem mass spectrometry (Hansen et al. 2001). Briefly, 1 g
of oyster tissues was homogenized with Milli-Q water and combined
with an ion-pairing reagent. After thorough mixing, the fluorochemical
ion pair was partitioned into organic solvent and concentrated prior to
analysis.
Analyte separation and detection was performed as described earlier
(Hansen et al. 2001) with the following exceptions. Ten microliters of
extract was injected onto the column with a 2 mM ammonium acetate/
methanol mobile phase starting at 10% methanol. At a flow rate of 300
␮l/min, the gradient increased to 100% methanol at 11.5 min before
reverting to original conditions at 13 min. For quantitative determination, the HPLC system was interfaced to a Micromass威 (Beverly, MA)
Quattro II atmospheric pressure ionization tandem mass spectrometer
operated in the electrospray negative mode. Instrumental parameters
were optimized to transmit the [M-K]⫺ ion. When possible, multiple
daughter ions were monitored, but quantitation was based on a single
product ion, evaluated versus an unextracted standard curve. The
presence of PFOS was verified by quantitative agreement (⫾ 30%)
between two or more product ions. The limit of quantitation (LOQ) for
PFOS was 10 ng/g, wet weight.
Data quality assurance and quality control protocols included surrogate matrix blanks, matrix spikes, surrogate spikes, laboratory
PFOS was found (at concentrations above the LOQ) in 64% of
the oyster samples analyzed. Concentrations of PFOS in oysters ranged from ⬍ 42 to 1,225 ng/g on a dry weight (DW)
basis (Table 1). The highest concentrations were found at
Lavaca River Mouth in Matagorda Bay, Texas. Median concentration of PFOS in oysters among all 77 sites was 387 ng/g
DW. Except for one oyster sample from Hog Point in the
central part of the Chesapeake Bay, none of the oysters collected from Chesapeake Bay contained detectable concentrations of PFOS.
Concentrations of PFOS varied widely within a given water
body. For instance, oysters collected from Joe’s Bayou in
Choctawhatchee Bay, Florida, were determined to contain 608
ng PFOS/g DW, whereas those collected at Santa Rosa in
Choctawhatchee Bay did not contain quantifiable concentrations. Similarly, though oysters from Hanna Reef in Galveston
Bay were determined to contain 74 ng PFOS/g DW, samples
from Confederate Reef, located within a distance of 50 km,
contained 883 ng/g DW.
The mean concentrations of PFOS in oysters from Texas,
Mississippi, Alabama, and Florida were similar (p ⬎ 0.05;
Student t-test) and significantly greater than those found in
Virginia (Figure 3). In other words, within a 95% probability,
PFOS in Oysters
315
Fig. 2. Map of Chesapeake Bay showing sampling
locations of oysters
concentrations of PFOS in oysters from TX, MS, AL, and FL
were similar, with the exception of VA. In general, concentrations of PFOS in oysters from the Chesapeake Bay were low.
A notable exception to this observation was Hog Point, MD, in
the central part of Chesapeake Bay, where one sample was
determined to contain 1,100 ng PFOS/g DW; this was the
second highest level measured in this study.
The range of PFOS concentrations measured in oyster tissues
was slightly less than that of PCBs (3.6 –1740 ng/g DW) or
DDTs (3–3570 ng/g DW) in oysters collected from the Gulf of
Mexico in 1987 (Sericano et al. 1990).
This study provides baseline concentrations of PFOS in
oysters collected from the Gulf of Mexico. These baseline
measurements in oysters will be useful for evaluating the
temporal trends in PFOS concentrations in the future.
Acknowledgement. This study was supported by 3M, St. Paul, MN.
Technical assistance of Lisa Clemen and Harold Johnson, 3M Environmental Laboratory, Minnesota, is gratefully acknowledged. We
thank Stephen Sweet, Texas A&M University, Texas, for his assistance with samples.
Fig. 3. Concentrations (mean ⫾ SD) of PFOS
(ng/g DW) in oyster, Crassostrea virginica, from
various coastal locations in the Gulf of Mexico
and Chesapeake Bay. Concentrations are presented state-wise
316
K. Kannan et al.
Table 1. Concentrations of PFOS in oyster, Crassostrea virginica, collected from the Gulf of Mexico and the Chesapeake Bay during 1996 –
1998
Latitude
Longitude
Collection
Date
FL
FL
FL
FL
FL
FL
27°47.32⬘
25°54.13⬘
30°20.98⬘
26°01.55⬘
27°37.28⬘
28°01.42⬘
82°45.26⬘
81°30.85⬘
87°09.29⬘
81°44.21⬘
82°43.60⬘
82°38.00⬘
01/26/98
02/01/98
01/07/98
01/27/98
02/03/98
01/25/98
21
9
11
11
15
14
339
733
564
630
387
429
FL
30°28.72⬘
86°28.72⬘
01/22/98
18
494
FL
FL
FL
FL
30°24.63⬘
27°51.27⬘
25°08.45⬘
25°12.91⬘
86°29.45⬘
82°23.39⬘
80°55.41⬘
80°32.04⬘
01/22/98
02/02/98
01/28/98
01/29/98
13
12
15
15
608
131
100
98
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
FL
30°24.70⬘
30°3.8⬘
30°8.55⬘
30°9.07⬘
25°8.47⬘
30°24.65⬘
29°40.35⬘
25°12.73⬘
26°33.5⬘
29°43.45⬘
29°12.4⬘
30°24.72⬘
30°15.08⬘
86°12.27⬘
84°19.32⬘
85°37.93⬘
85°39.78⬘
80°55.42⬘
86°29.45⬘
85°3.94⬘
80°32.04⬘
81°55.37⬘
84°53.05⬘
83°4.17⬘
86°12.22⬘
85°40.86⬘
Mobile Bay
Mobile Bay
AL
AL
30°18.91⬘
30°35.50⬘
88°08.06⬘
88°02.40⬘
01/23/98
01/24/97
01/23/97
01/23/97
01/26/97
01/21/97
01/30/97
01/26/97
01/27/97
01/24/97
01/29/97
01/22/97
01/22/97
Mean ⫾ SD
01/08/98
01/09/98
8.7
14
20
20
18
19
17
15
21
20
18
20
20
16
14
11
153
639
330
330
513
494
544
636
391
82
76
⬍50
⬍50
367 ⫾ 219
379
545
Mobile Bay
AL
30°33.81⬘
88°04.51⬘
LA
LA
LA
LA
LA
LA
LA
29°15.83⬘
30°03.51⬘
29°35.93⬘
29°15.57⬘
29°49.82⬘
29°52.01⬘
29°56.69⬘
90°23.88⬘
93°18.45⬘
89°37.29⬘
90°35.66⬘
93°23.22⬘
89°40.71⬘
89°50.14⬘
01/09/98
Mean ⫾ SD
01/05/98
12/04/97
01/21/98
01/05/98
12/03/97
01/14/98
01/21/98
20
15
20
12
8.3
12
15
13
9.4
⬍50
325 ⫾ 206
292
703
997
717
93
118
⬍106
LA
29°38.21⬘
92°46.01⬘
01/12/97
18
485
LA
LA
LA
LA
LA
29°24.29⬘
29°47.45⬘
29°15.19⬘
29°34.77⬘
29°15.33⬘
89°59.93⬘
93°54.38⬘
90°55.6⬘
92°3.06⬘
91°8.17⬘
22
16
15
20
20
15
13
17
19
16
13
⬍45
⬍63
⬍67
⬍50
⬍50
291 ⫾ 312
661
538
⬍53
417 ⫾ 263
674
16
13
540
101
Location
Numbera
Site Name
Location
40
41
42
43
44
45
Navarez Park
Faka Union Bay
Sabine Point
Henderson Creek
Mullet Key
Old Tampa Bay
46
Postil Point
47
48
49
50
Joe’s Bayou
Hillsborough Bay
Flamingo
Joe Bay
51
52
53
54
55
56
57
58
59
60
61
62
63
Off Santa Rosa
Apalachee Bay
St. Andrew Bay
Panama City
Florida Bay
Choctawhatchee Bay
Apalachicola Bay
Florida Bay
Charlotte Harbor
Apalachicola Bay
Cedar Key
Choctawhatchee Bay
Panama City
Tampa Bay
Everglades
Pensacola Bay
Rookery Bay
Tampa Bay
Tampa Bay
Choctawhatchee
Bay
Choctawhatchee
Bay
Tampa Bay
Florida Bay
Florida Bay
Choctawhatchee
Bay
Spring Creek
Watson Bayou
Municipal Pier
Flamingo
Joe’s Bayou
Dry Bar
Joe Bay
Fort Myers
Cat Point Bar
Black Point
Off Santa Rosa
Little Oyster Bar
37
38
Cedar Point Reef
Dog River
Hollingers Island
Channel
39
21
22
23
24
25
26
27
State
28
Terrebonne Bay
Calcasieu Lake
Bay Gardene
Terrebonne Bay
Calcasieu Lake
Malheureux Point
Gulf Outlet
Joseph Harbor
Bayou
29
30
31
32
33
Barataria Bay
Sabine Lake
Caillou Lake
Vermilion Bay
Atchafalaya Bay
Lake Felicity
Lake Charles
Breton Sound
Lake Barre
St. Johns Island
Lake Borgne
Lake Borgne
Joseph Harbor
Bayou
Bayou Saint
Denis
Blue Buck Point
Caillou Lake
Southwest Pass
Oyster Bayou
34
35
36
Biloxi Bay
Pass Christian
Pascagoula Bay
Mississippi Sound
Mississippi Sound
Mississippi Sound
MS
MS
MS
30°23.56⬘
30°18.14⬘
30°20.17⬘
88°51.47⬘
89°19.66⬘
88°35.35⬘
1
South Bay
TX
26°02.49⬘
97°10.68⬘
2
3
Port Isabel
Bill Days Reef
Lower Madre
Lower Laguna
Madre
Espiritu Santo
01/08/97
01/13/97
01/09/97
01/10/97
01/11/97
Mean ⫾ SD
01/13/98
01/13/98
01/05/98
Mean ⫾ SD
12/08/97
TX
TX
26°04.65⬘
28°24.22⬘
97°12.26⬘
96°28.85⬘
12/08/97
12/10/97
Dry Weight
Mass %
PFOS ng/g, DW
PFOS in Oysters
317
Table 1. Concentrations of PFOS in oyster, Crassostrea virginica, collected from the Gulf of Mexico and the Chesapeake Bay during 1996 –
1998
Location
Numbera
Latitude
Longitude
Collection
Date
Dry Weight
Mass %
PFOS ng/g, DW
TX
27°50.17⬘
97°22.81⬘
12/16/96
12
685
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
TX
28°39.62⬘
28°3.29⬘
28°55.27⬘
29°15.8⬘
28°10.38⬘
29°17.04⬘
29°37.32⬘
27°51.13⬘
29°30.18⬘
28°51.48⬘
29°28.82⬘
28°34.73⬘
28°8.52⬘
28°39.98⬘
28°39.9⬘
28°42.67⬘
96°35.07⬘
96°57.07⬘
95°20.37⬘
94°54.98⬘
96°50.1⬘
94°50.18⬘
94°59.75⬘
97°21.59⬘
94°53.76⬘
95°27.88⬘
94°44.51⬘
96°33.78⬘
97°7.68⬘
96°14.01⬘
96°22.98⬘
95°53⬘
Dandy Point
James River
Mattox Creek
Ragged Point
Cape Charles
Ross Rock
VA
VA
VA
VA
VA
VA
37°5.9⬘
37°3.92⬘
38°13.4⬘
38°9.3⬘
37°17.07⬘
37°54.12⬘
76°17.69⬘
76°37.93⬘
76°57.69⬘
76°35.05⬘
76°0.92⬘
76°47.27⬘
MD
MD
MD
38°18.74⬘
38°16.9⬘
38°36.44⬘
76°23.87⬘
76°56.02⬘
76°7.2⬘
7.5
18
17
10
13
18
13
14
15
14
20
12
23
14
14
21
15
15
24
21
19
21
22
20
9
17
17
1,225
508
480
883
625
430
508
407
549
106
74
⬍ 83
⬍ 43
⬍ 71
⬍ 71
⬍ 48
406 ⫾ 320
⬍ 67
⬍ 42
⬍ 48
⬍ 53
⬍ 48
⬍ 45
⬍ 50 ⫾ 8
1,106
⬍ 59
⬍ 59
Chesapeake Bay
Chesapeake Bay
Chesapeake Bay
Hog Point
Swan Point
Choptank River
Mountain Point
Bar
Bodkin Point
Hackett Point Bar
12/18/96
12/17/96
12/03/96
12/05/96
12/17/96
12/05/96
12/06/96
12/16/96
12/04/96
12/03/96
12/04/96
12/19/96
12/19/96
12/20/96
12/18/96
12/20/96
Mean ⫾ SD
01/12/97
01/14/97
01/09/97
01/09/97
01/14/97
01/11/97
Mean ⫾ SD
01/08/97
01/09/97
01/07/97
MD
MD
MD
39°4.32⬘
39°9.44⬘
38°58.17⬘
76°24.76⬘
76°24.29⬘
76°24.88⬘
Bahia de Boqueron
Bahia de Jobos
Puerto Rico
Puerto Rico
PR
PR
18°00.48⬘
17°56.37⬘
67°10.69⬘
66°10.89⬘
01/06/97
01/06/97
01/07/97
Mean ⫾ SD
02/17/98
02/18/98
Mean
20
23
18
17
13
16
15
⬍ 50
⬍ 43
⬍ 56
229 ⫾ 392
543
331
437
Site Name
Location
4
Corpus Christi
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Matagorda Bay
Aransas Bay
Brazos River
Galveston Bay
Mesquite Bay
Galveston Bay
Galveston Bay
Corpus Christi
Galveston Bay
Brazos River
Galveston Bay
Matagorda Bay
Copano Bay
Matagorda Bay
Matagorda Bay
Matagorda Bay
Boat Harbor
Lavaca River
Mouth
Long Reef
Freeport Surfside
Confederate Reef
Ayres Reef
Offatts Bayou
Yacht Club
Nueces Bay
Todd’s Dump
Cedar Lakes
Hanna Reef
Gallinipper Point
Copano Reef
Tres Palacios Bay
Carancahua Bay
East Matagorda
Chesapeake Bay
Chesapeake Bay
Potomac River
Potomac River
Chesapeake Bay
Rappahannock River
Chesapeake Bay
Potomac River
Chesapeake Bay
State
a
Location numbers correspond to those presented in Figure 1.
Values below the LOQ were assigned at that concentration of 10 ng/g WW for the calculation of mean and SD.
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