lipids water. cwater gill uptake gill elimination fish-water two compartment model dc f / dt = k 1.c...

Lipids

Water

Cwater

GILL UPTAKE

GILL ELIMINATION

Fish-Water Two Compartment Model

dCF / dt = k1.CW – k2.CF

CF: Concentration in Fish

CW: Concentration in Water

k1 : Uptake clearance rate

k2 : Elimination rate constant

CF = CW (k1/k2).(1 - exp(- k2.t))

1

10

100

1000

10000

0 20 40 60 80

Time (days)

Co

nc

en

tra

tio

n in

org

an

ism Elimination PeriodUptake Period

Slope = -kt

CB/CWD = k1/k2

CWD

Slope = - k2

3

4

5

6

7

8

3 4 5 6 7 8 9

log Kow

log

BC

F (

lip

id b

ased

)Loss of linear correlation for super-hydrophobics

Metabolizing substances

BCFL = Kow

Bioconcentration :

Equilibrium Partitioning

fbiota fwater

1

10

100

1000

10000W

ater

sed

imen

t

Ph

yto

pla

nkt

on

Mys

ids

Po

nto

po

reia

affi

nis

Olig

och

aete

s

Scu

lpin

Ale

wif

e

Sm

elt

4+R

ain

bo

wTr

ou

t

4+L

ake

Tro

ut

Her

rin

g g

ull

egg

s

Fu

ga

cit

y (

10

-9.P

a)

Connolly, J.P. and Pedersen, C.J. 1988. A thermodynamic-based evaluation of

organic chemical accumulation in aquatic organisms. Environ. Sci. Technol.

22:99-103.

Woodwell, (1967)

Sci Amer.

Biomagnification :

fbiota fwater

fpredator fprey

0.000001

0.0001

0.01

1

100

10000

1000000

100000000

10000000000

0 2 4 6 8 10

log Kow

BCFeq

k2

k1

kE

BCFd

BAF

BCFt

kg

-2

0

2

4

6

8

0 2 4 6 8 10 12 14

log Kow

log

BA

F/lo

g B

CF

BAF MODEL

BCF MODEL

BCFWIN MODEL

EC BCF/BAF 5000

BCF DATASET (1568 pts)

BAF DATASET (913 pts)

Criteria for Bioaccumulation*

Parameter Value

Bioaccumulation Factor BAF > 5,000

Bioconcentration Factor BCF > 5,000

Octanol - Water Partition log KOW > 5

Coefficient

* - BAF is better than BCF is better than KOW

• Calves are born in June and weaned after 130 days

• Grazing: Lichen Diet (C. rangiferina, and C. nivalis)

• Female wolves gives birth in may (litter of 2 to 7 pups, 0.5 kg each)

• Pups are weaned after 70 days

• 100% caribou diet (GD) =1.5 kg/day: 5 calves, 2 yearlings and 16 adults)

Field Study Results: Spatial distribution of PCB 153

Inuvik Cambridge Bay Bathurst

Inlet

-13

-12

-11

-10

-9

-8

-7

log

fuga

city

(Pa)

-13

-12

-11

-10

-9

-8

-7

log

fuga

city

(Pa)

-13

-12

-11

-10

-9

-8

-7lo

g fu

gaci

ty (P

a)

LichenCaribo

uWolf

Observed biomagnification in Bathurst Inlet food-chain

logKOW 4.0 4.0 4.5 5.5 6.9

Chemical

-13.0-12.0-11.0-10.0-9.0-8.0-7.0-6.0

gam

ma-

HC

H

bet

a-H

CH

TC

B

HC

B

PC

B15

3

log

Fu

gac

ity

(Pa)

LichenCaribouWolf

0.01

0.1

1

10

2 3 4 5 6 7 8 9 10

Log KOW

BM

F

BMF - KOW relationship BMF - KOA relationship

1

10

100

4 5 6 7 8 9 10 11 12

log Koa

BM

F

L

G

Diet (mol d-1)

Growth

Lactation (mol d-1)

Metabolism (kM)

Fecal Excretion(mol d-1)

Urine (mol d-1)

GIT

Air (mol d-1)

Canada’s Domestic Substance List

0

20

40

60

-10 0 10 20 30log KO W

log

KO

A

69.7%

2.6%

20.8%

7.0%

TCPMeOH

dalapon

PFOS

HCHs

TCBz

musk xylene

PCP

nonlyphenol

atrazine

DBPDEP

methoxychlrendosulfan

octanol

nitrobenzene

BCPS

-2-10123456789

10111213

-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12

log KOW

log

KO

A

styrene

vinyl chloride

PCBs

(PNVs) (NPNVs)

(PVs) (NPVs)

United Nations LRTAP POPs Protocol (1998)

Targets chemicals that are:

Persistent

Bioaccumulative

Toxic

Canadian Environmental Protection Act:Framework for Evaluating DSL Chemicals

Inherently Toxic

Persistentor

Bioaccumulative

Screening Assessment

List of Toxic Substances No Further Action

at this Time

Substances on the DSL

and

NoYes

PHASE 1:Categorization

PHASE 2:Screening levelrisk assessment

OutcomesPriority

Substances List

nofurther action

under thisprogram

Bioconcentration Factor: BCF = CF / CW

Biota-Sediment Accumulation Factor :

BSAF = CF / CS

Bioaccumulation Factor : BAF = CF / CW

Measures of Bioaccumulation

Octanol-Water Partition Coefficient:

Kow = CO / CW

Biomagnification Factor: BMF = CF / CDiet

BCF or BAF = CFish / CWater

CFish = g substance/ kg wet weight organism

CWater = g substance / L water

BCFWW = L/kg wet weight

CFish = g substance/ kg lipid

CWater = g substance / L

BCFL = L/kg lipid

Units of Bioaccumulation

BCFWW = L.BCFL

BCFWW : Wet weight based BCF

BCFL : Lipid weight based BCF

L : Lipid content organism (kg lipid/kg wet weight organism)

BSAF = CBiota / CSediment

CBiota = g substance / kg wet weight biota

CSediment = g substance / kg dry sediment

BSAF = kg dry sediment/kg wet weight biota

CFish = g substance / kg lipid

CSediment = g substance / kg organic carbon

BSAFL = kg organic carbon L/kg lipid

Units of Bioaccumulation

Units of Bioaccumulation

BSAFWW = (L/OC).BSAFL

BSAFWW : Wet weight based BSAF (kg dry sediment/kg wet weight biota)

BSAFL : Lipid & Organic carbon normalized BSAF (kg organic carbon/ kg lipid)

L : Lipid content biota (kg lipid/kg wet weight biota)

OC : Organic carbon content sediment (kg organic carbon/kg dry weight sediment)

BMF = CF / CD

CF = g / kg wet weight

CW = g / L

BCFW = L/kg wet weight

CF = g / kg lipid

CW = g / L

BCFL = L/kg lipid

Units of Bioaccumulation

BCFW = L.BCFL

BCFW : Wet weight based BCF

BCFL : Lipid weight based BCF

L : Lipid content organism (kg lipid/kg wet weight organism)

Read

Environ. Sci. Technol. 16: 274-278 (1982)

LakeTrout

Alewife

Smelt

SlimySculpin

45

55

15-70

30-450-55

81-97

0-2522-28

1-7

Zooplankton

3-19

54-72

93-99

HerringGull

Benthos

Phytoplankton

Cs

Cw

PCBs

-3

-2

-1

0

1

2

3

4

5

0.5 1.5 2.5 3.5 4.5Trophic Position

Log

Lipi

d E

quiv

alen

t C

once

ntra

tion

(ng/

g)

18

52/73

101/90118132/15

177

180

194

206209

PCBs

-3

-2

-1

0

1

2

3

4

5

7 9 11 13 15 17d 15N

Lo

g L

ipid

Eq

uiv

ale

nt

Co

nce

ntr

atio

n (

ng

/g)

18

52/73

101/90118132/153

177

180

194

206

209

Read:

Environ. Sci. Technol. 22: 99-103 (1988)

High Kow PEs

-3

-2

-1

0

1

2

3

4

5

0.5 1.5 2.5 3.5 4.5

Trophic Position

Lo

g L

ipid

Eq

uiv

ale

nt

Co

nce

ntr

atio

n (

ng

/g) DEHP

DnOPDnNP

C8C9

C10

Trophic Dilution

Criteria for BioaccumulationUNEP & CEPA*

Parameter Value

Bioaccumulation Factor BAF > 5,000

Bioconcentration Factor BCF > 5,000

Octanol - Water Partition log KOW > 5

Coefficient

* - BAF is better than BCF is better than KOW

Aquatic organisms Air-breathing animals

GIT

Lipid-Air partitioningLipid-Water partitioning

(KOW)

GIT

• (KOA) may better assess bioaccumulation potential in air-breathing animals

• Food-Chain Biomagnification is observed for

chemicals with a log Kow as low as 3.8.

• Koa is a better predictor of bioaccumulation in

terrestrial food-chains than Kow

• Current bioaccumulation protocols in CEPA &

UNEP do not identify low Kow- high Koa substances

that have a biomagnification potential in terrestrial

food-chains

• Preliminary data and models indicate that in

absence of metabolism, chemicals with log Koa > 4

biomagnify in terrestrial food-chains.

Conclusions

0

10

20

30

40

50

60

-15 -5 5 15 25 35log KOW

log

KO

A

Chemicals on the DSL

-2

0

2

4

6

8

0 2 4 6 8 10 12 14

log Kow

log

BA

F/lo

g B

CF

BAF MODEL

BCF MODEL

BCFWIN MODEL

EC BCF/BAF 5000

BCF DATASET (1568 pts)

BAF DATASET (913 pts)

LakeTrout

Alewife

Smelt

SlimySculpin

45

55

15-70

30-450-55

81-97

0-2522-28

1-7

Zooplankton

3-19

54-72

93-99

HerringGull

Benthos

Phytoplankton

Cs

Cw

Algae

Suspended Sediments

Bottom Sediments

Cwater

Csediment

LakeTrout

Alewife

Smelt

SlimySculpin

45

55

15-70

30-450-55

81-97

0-2522-28

1-7

Zooplankton

3-19

54-72

93-99

HerringGull

Benthos

Phytoplankton

Cs

Cw

Chemical Equilibrium

Kd = CA/CW

fA = fW

f : Fugacity (Pa)

C : Concentration (mol/m3)

Z : Fugacity Capacity (mol/Pa.m3)

C = f.Z

Algae

Suspended Sediments

Bottom Sediments

fWATER

fALGAE

fSUSP-SED

fSEDIMENT

=

=

=

Kd = CA/CW

Kd = CSS/CW

Kd = CBS/CW

f = C/Z

Zwater = 1/H

Zalgae = OC.0.41.Kow.da/H

Zssed = OC.0.41.Kow.dss/H

Zbsed = OC.0.41.Kow.dbs/H

1.00E+00

1.00E+01

1.00E+02

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

2.0 4.0 6.0 8.0log Kow

pa

rtit

ion

co

eff

icie

nt

Kpw obs'd

Kpw prd't

Kssw obs'd

Kssw prd't

Ksw obs'd

Ksw prd't

Lake Ontario

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

2.0 3.0 4.0 5.0 6.0 7.0 8.0

log Kow

fug

ac

ity

ra

tio

algae/water

susp.sed/water

bot. sed/water

Lake Ontario

0.01

0.1

1

10

100

1000

10000

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5

log Kow

fug

ac

ity

ra

tio

algae/water

bot. sed/water

Lake Ontario

0.1

1

10

100

5.0 5.5 6.0 6.5 7.0 7.5 8.0

log Kow

fug

ac

ity

ra

tio

algae/water

bot.sed/water

Lake Erie

0.1

1

10

100

1000

10000

4.5 5.0 5.5 6.0 6.5 7.0 7.5

log Kow

fug

ac

ity

ra

tio

susp. Sed/water, 1980

susp. Sed/water, 1983

Lake Superior

0.1

1

10

100

4.5 5.0 5.5 6.0 6.5 7.0 7.5

log Kow

fug

ac

ity

ra

tio

bot. sed/water, freely dissolved

bot. sed, total

Lake St. Clair

Observations:

1. There is no equilibrium

2. fBS > fSS > fA > fW

3. fBS/fw , fSS/fW , fA/fW increase when Kow decreases

26%

4%

1.5%

1

0.15

0.058

1

6.5

17.3

Mineralization

OC Z f

fa

fbs

fss

fW3

fW2

fW1

Dp

Ds

Dbs

Dwp

Dpw

Dsw

Dbsw

Dwbs

Dws

fa

fbs

fss

fW3

fW2

fW1

Dp

Ds

Dbs

Dwp

Dpw

Dsw

Dbsw

Dwbs

Dws

fa / fw = Dpw / (Dpw + Dp)

fss / fa = Gp . Zp / Gs . Zs

fbs / fs = Gss . Zss / Gbs . Zbs

fa

fssfW2

Dp

Ds

Dsw

Dws

fss / fa = (Dp + Dsw ) / (Ds + Dsw)

fss / fa = Dp / Ds = Gp . Zp / Gs . Zs

fbs

fss

fW3

Ds

Dbs

fbs / fs = (Ds + Dssw ) / (Dss + Dssw)

fbs / fs = Ds / Dss = Gs . Zs / Gss . Zss

100

2000

490

1900

110

100 1

20

5

20

100

100

Log Kow =4 Log Kow =7

DISEQUILIBRIUM

•Between sediment, suspended sediments & water

•Fugacity pump

•Increases when Kow decreases

•Organic carbon mineralization

•Affects the degree to which the sediments & water and diet & water contribute to body burdens

•Affects BAFs & BSAFs