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