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Relating field bioaccumulation metrics for chemicals in a benthic
and pelagic food web with existing bioconcentration data H. Leslie, S. van Leeuwen, B. van Hattum, F. Gobas, P. Leonards
Bioaccumulation assessment criteria Table 1. An overview of regulatory bioaccumulation assessment endpoints and criteria. 1
Regulatory agency Bioaccumulation endpoint Criteria (log values) Program
Environment Canada KOW 100,000 (5) CEPA 1999 *
Environment Canada BCF 5,000 (3.7) CEPA 1999
Environment Canada BAF 5,000 (3.7) CEPA 1999
European Union ‘bioaccumulative’ BCF 2,000 (3.3) REACh †
European Union ‘very bioaccumulative’ BCF 5,000 (3.7) REACh
United States ‘bioaccumulative’ BCF 1,000 (3) – 5,000 (3.7) TSCA ‡, TRI
United States ‘very bioaccumulative’ BCF 5,000 (3.7) TSCA, TRI
United Nations Environment Programme KOW 100,000 (5) Stockholm Convention §
United Nations Environment Programme BCF 5,000 (3.7) Stockholm Convention
* CEPA - Canadian Environmental Protection Act, 1999 (Government of Canada 1999; 2
Government of Canada 2000) 3 †
Registration, Evaluation and Authorisation of Chemicals (REACh) Annex XII (European 4
Commission 2001) 5 ‡
Currently being used by the US Environmental Protection Agency in its Toxic Substances 6
Control Act (TSCA) and Toxic Release Inventory (TRI) programs (U.S. EPA 1976) 7 §
Stockholom Convention on Persistent Organic Pollutants (UNEP 2001) 8
9
How reliable is the prediction of bioaccumulation in food webs in the field
based on lab-derived BCF values?
Understand the important factors impacting BCF and BAF measurements
Our approach
A. Existing BCF data
B. Generate bioaccumulation data for real food web
C.Which factors influence bioaccumulation?
D.Model mechanisms/processes that control bioaccumulation
E. Explore relationship between BCF and TMF (trophic
magnification factor)
Does BCF from lab tests predict/underpredict/overpredict the
field bioaccumulation we observe?
• Large land-based pollution input
• Western Scheldt discharges into
the North Sea
• Various industries at Terneuzen
• Textile industry Antwerp
Study area: Western Scheldt estuary
Western Scheldt
Terneuzen
Saeftinge
Tern colony
Food chain collection
Sediment
Western Scheldt
Terneuzen
Tern colony
Food chain collection
Common tern food web
Piscivoreous
bird Common tern
Bottom
invertebrates
Grazers and filter feeders
Primary producers First level predators
Second level predators
Pelagic
phytoplankton
Benthic
microalgae
Fish Zooplankton
Benthic
fish
Piscivorous
fish
Fish
Cockles
Worms
Crabs
Shrimps
Benthic
algae
Mysids Herring
Sandeel
Sole
Flounder
Plaice
Goby
Sculpin
Seabass
Whiting
Algae
Sediment
SPM
Pelagic and benthic food chains
2 4 6 8 10
LogKow
4
8
12
16
Diisopropyl naphthalene
BDE99
BDE153
BDE47
BDE209
HBCD
β- α HCH
γ-HCH
PCB28
PCB153
PCB180
HCB
a-endosulfan
TiBP
TCPP
TEHP
TDCPP
TPP EHDP
TBEP
TCEP
Pyrene
BaP
o-Terphenyl
logKow2-5, Koa>5-12 logKow5-9, Koa>5 logKow>9
OC pesticides
PAHs
organo-bromine
PCBs
Organophoshate
PFCs
logKow<2
TCP
PFOS PFOA
PFDA
Chemical substances
How similar are our BAFsfield to BCFslab?
PC
B52
PC
B15
3
HC
B
Pyre
ne
PF
OA
PF
DA
PF
OS
HB
CD
BD
E47
BD
E99
HC
H
BAF BCF
BCF vs. BAF total and dissolved
9
BAFs based on total
concentrations in water phase BAFs based on dissolved
concentrations in water phase
Pyrene
HCB
PCB153
PCB52
Pyrene
PCB153
PCB52
BCF BAF
What are the links between
BCF, BAF and TMF?
Trophic Magnification Factor approach
Biotransformation…
TL
log conc. TMF>1
TL
log conc. TMF<1
TMF: Factor by which concentrations in biota change per trophic level in a food web
PCB 153 as ‘reference’ compound
Log C
oncentr
ations P
CB
153 (
ng/g
lw
)
Trophic level
00
01
01
02
02
03
03
04
04
00 02 04 06
PelagicBenthic
TMF 2.5
00
01
02
03
04
05
00 02 04 06
PelagicBenthic
Trophic dilution pyrene and BDE209 Log c
oncentr
ations p
yre
ne (
ng/g
lw
)
Pyrene TMF 0.2
Biotransformation and bioavailability important factors
-01
01
02
03
04
05
00 02 04 06
BDE209 TMF 0.1
Trophic level
Benthic Pelagic
Trophic magnification PFOA
-01
00
01
01
02
02
00 02 04 06
Pelagic
log
con
cen
trat
ion
s P
FOA
(n
g/g
ww
)
Bird
SPM plankton Invert
Fish
-02
-01
00
01
02
00 02 04 06
Benthic
TMF 3.8
Trophic level
High bioaccumulation in birds probably due to high gastrointestinal
uptake and slow respiratory elimination
Biotransformation impacts bioaccumulation
0,1
1
10
1 10 100 1000
TMF
Measured biotransformation S9 rat liver
Non-persistent Persistent
0.1
1
10
0.01 0.10 1.00 10.00 100.00 1000.00
TMF
Predicted biotransformation T1/2 (days) Episuite, Arnot and Gobas
Non-persistent Persistent
• Concentration dependence of rates
• Induction by other chemicals in the field
0.1
1
10
100
1000
10000
100000
1000000
10000000
0.01 0.1 1 10TMF
BA
F (L
/kg
we
t w
eig
ht)
PFOA
PFDA
PFOS
PFOSA
PCB 28
PCB 52
PCB 101
PCB 118
PCB 138
PCB 153
PCB 180
HCB
Pyrene
Benzo-a-pyrene
BDE 28
BDE 49
BDE 47
BDE 100
BDE 99
BDE 154 + BB 153
BDE 153
BDE 209
a-HBCD
y-HBCD
BAF Criteria
TMF Criteria
BAF = 5,000
TMF = 1
BAF vs. TMF
Error bars are 95% confidence intervals
0.1
1
10
100
1000
10000
100000
1000000
10000000
0.01 0.1 1 10TMF
BA
F (L
/kg
we
t w
eig
ht)
PFOA
PFDA
PFOS
PFOSA
PCB 28
PCB 52
PCB 101
PCB 118
PCB 138
PCB 153
PCB 180
HCB
Pyrene
Benzo-a-pyrene
BDE 28
BDE 49
BDE 47
BDE 100
BDE 99
BDE 154 + BB 153
BDE 153
BDE 209
a-HBCD
y-HBCD
BAF Criteria
TMF Criteria
BAF = 5,000
TMF = 1
Type I Error
(false positives)
Type II Error
(false negatives)
BAF vs. TMF
Error bars are 95% confidence intervals
0.1
1
10
100
1000
10000
100000
1000000
10000000
0.01 0.1 1 10TMF
BC
F (L
/lg
we
t w
eig
ht)
PCB 52
PCB 101
PCB 118
PCB 138
PCB 153
PCB 180
HCB
Pyrene
Benzo-a-pyrene
BDE 209
BCF Criteria
TMF Criteria
PFOA
PFDA
PFOS
BDE 47
a-HBCD
y-HBCD
BCF = 5,000
TMF = 1
Type I Error
(false positives)
Type II Error
(false negatives)
BCF vs. TMF
Error bars are 95% confidence intervals
2.00 4.00 6.00 8.00 10.00
LogKow
4.00
8.00
12.00
16.00
Diisopropyl naphthalene
BDE99
BDE153
BDE47
BDE209
HBCD
β- α HCH
γ-HCH
PCB28
PCB153
PCB180
HCB
a-endosulfan
TiBP
TCPP
TEHP
TDCPP
TPP EHDP
TBEP
TCEP
Pyrene
BaP
o-Terphenyl
logKow2-5, Koa>5-12 logKow5-9, Koa>5 logKow>9
OC pesticides
PAHs
organo-bromine
PCBs
Organophoshate
PFCs
Koa<2
TCP
PFOS PFOA
PFDA
Narrow Kow range of test compounds…
0.5 logKow window
logKow logBCF TMF
PCB52 5.84 6.5 1.4
HCB 5.86 4.5 1.5
a-HBCD 5.62 4.4 1.6
y-HBCD 5.62 4.4 0.3
BDE47 6.00 4.2 2.2
Pyrene 6.11 4.1 0.3
PFOS 6.28 3.6 2.6
EHDP 6.30 2.6 0.2
Bioaccumulation assessment
logBCF logBAF BMF TMF PCB52 6.5 5.0 2.6 1.4 PCB153 4.7 6.0 12 2.6 HCB 4.5 3.9 0.8 1.5 Pyrene 4.1 3.1 0.0 0.3 BDE47 4.2 5.9 2.1 2.2 BDE49 5.7 1.3 0.2 BDE209 0.0 0.2 a-HBCD 4.4 5.6 0.5 1.6 y-HBCD 4.4 3.2 0.01 0.3 PFOA 3.1 1.9 0.9 1.2 PFDA 3.4 3.4 1.0 1.7 PFOS 3.6 3.6 4.2 2.6 PFOSA 4.6 9.7 1.9 TCPP 0.6 0.6 0.2 TPP 1.9 0.1 0.2 TBEP 1.3 0.1 0.3
Above threshold
Below threshold
Main conclusions
• BCF values are subject to variability
• General relationship exists for BCF-BAF-TMF for water breathers, but NOT air breathers
• BCF and BAF have less predictive value for the TMF in an aquatic food web that includes air breathing organisms.
• Reliance on BCF or BAF sometimes gives rise to false positives and false negatives in “B” assessments
• BCF more uncertain than BAF in predicting TMF
• TMF is more information rich than BCF
• Properties such as biotransformation rates can have a major impact on TMF
• B-assessments that make use of all available bioaccumulation metrics can avoid potential biases due to applying only BCF (or Kow)
If possible, rely on or determine the TMF rather than the BCF because the TMF is
the “real thing” while the BCF is a “surrogate”.
TMF > BAF > BCF
Classify chemicals in groups with chemical-class appropriate B testing and
evaluation methodologies. Bioaccumulation models can be used to do this.
Include provisions in the B evaluation to identify substances that can biomagnify
in organisms other than fish, i.e. humans, mammals, birds, insects. The TMF or
BMF is a useful descriptor.
Recommendations
24
Cefic & Ecetoc
Deltares RWS Waterdienst
Acknowledgements