Lipids
Water
GILL UPTAKE
Cwater
GILL ELIMINATION
Fish-Water Two Compartment Model
dCF / dt = k1.CW – k2.CF
CF: Concentration in Fish
CW: Concentration in Water
CF = CW (k1/k2).(1 - exp(- k2.t))
k1 : Uptake clearance rate
k2 : Elimination rate constant
Concentration in organism
10000
Uptake Period
Elimination Period
1000
Slope = -k t
Slope = - k2
100
CB/CWD = k 1 /k 2
10
CWD
1
0
20
40
Time (days)
60
80
8
Loss of linear
correlation for
superhydrophobics
log BCF (lipid based)
BCFL = Kow
7
6
5
Metabolizing
substances
4
3
3
4
5
6
log Kow
7
8
9
Bioconcentration :
Equilibrium Partitioning
fbiota  fwater
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.
1000
100
Herring gull
eggs
4+Lake Trout
4+Rainbow
Trout
Smelt
Alewife
Oligochaetes
Pontoporeia
affinis
Mysids
Phytoplankton
sediment
1
Sculpin
10
Water
Fugacity (10-9.Pa)
10000
Woodwell,
(1967)
Sci Amer.
Biomagnification :
fbiota  fwater
fpredator  fprey
10000000000
BCFeq
100000000
BAF
1000000
BCFd
10000
BCFt
100
k1
1
k2
0.01
kg
0.0001
kE
0.000001
0
2
4
6
log Kow
8
10
log BAF/log BCF
8
BAF MODEL
6
BCF MODEL
BCFWIN MODEL
4
EC BCF/BAF 5000
BCF DATASET (1568 pts)
2
BAF DATASET (913 pts)
0
0
-2
2
4
6
8
log Kow
10
12
14
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)
-9
-10
-11
Inuvik
-8
log fugacity (Pa)
log fugacity (Pa)
-8
-9
-10
-11
-12
-12
-13
-13
Spatial distribution of
Cambridg
e Bay
-7
Bathurst
Inlet
-8
log fugacity (Pa)
Field Study Results:
-7
-7 153
PCB
-9
-10
-11
-12
-13
Lichen
Caribo
Wolf
u
HCB
PCB153
logKOW
TCB
Chemica
l
beta-HCH
-6.0
-7.0
-8.0
-9.0
-10.0
-11.0
-12.0
-13.0
Lichen
Caribou
Wolf
gamma-HCH
log Fugacity (Pa)
Observed biomagnification in
Bathurst Inlet food-chain
4.0
4.0
4.5
5.5
6.9
BMF - KOW relationship
BMF - KOA relationship
100
1
BMF
BMF
10
10
0.1
0.01
1
2 3 4 5 6 7 8 9 10
Log KOW
4
5
6
7
8
9 10 11 12
log Koa
Metabolism
(kM)
Fecal
Excretion
(mol d-1)
Air
G
GI
T
Lactation
(mol d-1)
L
Urine
(mol d-1)
Growth
(m
ol d-1)
Diet
(m
ol d-1)
Canada’s Domestic Substance List
log K OA
60
40
2.6%
20.8%
20
69.7%
0
-10
7.0%
0
10
20
log KOW
30
log KOA
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-1
-2
dalapon
(PNVs)
PFOS
(NPNVs)
PCP
atrazine
musk xylene
BCPS
HCHs
endosulfan TCPM eOH
DBP
methoxychlr
nonlyphenol
DEP
octanol TCBz
nitrobenzene
styrene
PCBs
vinyl chloride
(PVs)
(NPVs)
-2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12
log KOW
United Nations LRTAP POPs
Protocol (1998)
Targets chemicals that are:
Persistent
Bioaccumulative
Toxic
Canadian Environmental Protection Act:
Framework for Evaluating DSL Chemicals
Substances on the DSL
Persistent
or
Bioaccumulative
PHASE 1:
Categorization
and
No
Inherently
Toxic
Yes
PHASE 2:
Screening level
risk assessment
Screening Assessment
Priority
Outcomes
List of Toxic Substances
no
further action
under this
program
Substances List
No Further Action
at this Time
Measures of Bioaccumulation
Bioconcentration Factor: BCF = CF / CW
Biomagnification Factor: BMF = CF / CDiet
Bioaccumulation Factor : BAF = CF / CW
Biota-Sediment Accumulation Factor :
BSAF = CF / CS
Octanol-Water Partition Coefficient:
Kow = CO / CW
Units of Bioaccumulation
BCF or BAF = CFish / CWater
CFish = g substance/ kg wet weight organism
CWater = g substance / L water
BCFWW = L/kg wet weight
BCFWW = L.BCFL
CFish = g substance/ kg lipid
BCFWW : Wet weight based BCF
CWater = g substance / L
BCFL : Lipid weight based BCF
BCFL = L/kg lipid
L : Lipid content organism (kg
lipid/kg wet weight
organism)
Units of Bioaccumulation
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
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)
Units of Bioaccumulation
BMF = CF / CD
CF = g / kg wet weight
CW = g / L
BCFW = L.BCFL
BCFW = L/kg wet weight
CF = g / kg lipid
CW = g / L
BCFL = L/kg lipid
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)
Herring
Gull
45
55
Alewife
15-70
93-99
30-45
1-7
0-55
Smelt
Lake
Trout
54-72
22-28
Zooplankton
Phytoplankton
Cw
0-25
Slimy
Sculpin
3-19
81-97
Cs
Benthos
PCBs
132/15
118
101/90
180
52/73
177
194
18
206
209
Log Lipid Equivalent
Concentration (ng/g)
4
3
2
1
0
-1
4
3
2
0
-1
-2
-3
-3
1.5
2.5
3.5
Trophic Position
4.5
18
209
1
-2
0.5
132/153
118
101/90
180
52/73
177
194
206
5
Log Lipid Equivalent
Concentration (ng/g)
5
PCBs
7
9
11
13
d N
15
15
17
Read:
Environ. Sci. Technol. 22: 99-103 (1988)
Trophic Dilution
High Kow PEs
5
C8
C9
DEHP
C10
Log Lipid Equivalent
Concentration (ng/g)
4
3
2
DnNP
DnOP
1
0
-1
-2
-3
0.5
1.5
2.5
Trophic Position
3.5
4.5
Criteria for Bioaccumulation
UNEP & 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
Lipid-Water partitioning
Air-breathing animals
Lipid-Air partitioning
(KOW)
GIT
• (KOA) may better assess
bioaccumulation potential in airbreathing animals
Conclusions
• 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.
Chemicals on the DSL
60
log KOA
50
40
30
20
10
-15
0
-5
5
15
log KOW
25
35
log BAF/log BCF
8
BAF MODEL
6
BCF MODEL
BCFWIN MODEL
4
EC BCF/BAF 5000
BCF DATASET (1568 pts)
2
BAF DATASET (913 pts)
0
0
-2
2
4
6
8
log Kow
10
12
14
Herring
Gull
45
55
Alewife
15-70
93-99
30-45
1-7
0-55
Smelt
Lake
Trout
54-72
22-28
Zooplankton
Phytoplankton
Cw
0-25
Slimy
Sculpin
3-19
81-97
Cs
Benthos
Algae
Cwater
Suspended
Sediments
Bottom
Sediments
Csediment
Herring
Gull
45
55
Alewife
15-70
93-99
30-45
1-7
0-55
Smelt
Lake
Trout
54-72
22-28
Zooplankton
Phytoplankton
Cw
0-25
Slimy
Sculpin
3-19
81-97
Cs
Benthos
Chemical Equilibrium
Kd = CA/CW
fA = f W
C = f.Z
f : Fugacity (Pa)
C : Concentration (mol/m3)
Z : Fugacity Capacity (mol/Pa.m3)
fWATER
Algae
=
fALGAE
Suspended
Sediments
=
fSUSP-SED
=
Bottom
Sediments
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
Lake Ontario
1.00E+07
partition coefficient
1.00E+06
1.00E+05
1.00E+04
Kpw obs'd
1.00E+03
Kpw prd't
Kssw obs'd
1.00E+02
Kssw prd't
Ksw obs'd
Ksw prd't
1.00E+01
1.00E+00
2.0
4.0
6.0
log Kow
8.0
Lake Ontario
100000.00
algae/water
10000.00
susp.sed/water
bot. sed/water
fugacity ratio
1000.00
100.00
10.00
1.00
0.10
0.01
2.0
3.0
4.0
5.0
log Kow
6.0
7.0
8.0
Lake Ontario
10000
algae/water
1000
fugacity ratio
bot. sed/water
100
10
1
0.1
0.01
5.0
5.5
6.0
6.5
7.0
log Kow
7.5
8.0
8.5
Lake Erie
100
algae/water
fugacity ratio
bot.sed/water
10
1
0.1
5.0
5.5
6.0
6.5
log Kow
7.0
7.5
8.0
Lake Superior
10000
susp. Sed/water, 1980
1000
fugacity ratio
susp. Sed/water, 1983
100
10
1
0.1
4.5
5.0
5.5
6.0
log Kow
6.5
7.0
7.5
Lake St. Clair
100
fugacity ratio
10
1
bot. sed/water, freely dissolved
bot. sed, total
0.1
4.5
5.0
5.5
6.0
log Kow
6.5
7.0
7.5
Observations:
1. There is no equilibrium
2. fBS > fSS > fA > fW
3. fBS/fw , fSS/fW , fA/fW increase when
Kow decreases
Mineralization
OC
Z
f
26%
1
1
4%
0.15
6.5
1.5%
0.058
17.3
fW1
Dwp
Dpw
fa
Dp
fW2
Dws
fss
Dsw
fW3
Dwbs
Dbsw
fbs
Ds
Dbs
fW1
Dwp
Dpw
fa
fa / fw = Dpw / (Dpw + Dp)
Dp
fW2
Dws
fss
Dsw
fW3
Dwbs
Dbsw
fss / fa = Gp . Zp / Gs . Zs
Ds
fbs
fbs / fs = Gss . Zss / Gbs . Zbs
Dbs
fa
Dp
fW2
Dws
fss
Dsw
Ds
fss / fa = (Dp + Dsw ) / (Ds + Dsw)
fss / fa = Dp / Ds = Gp . Zp / Gs . Zs
fss
fW3
fbs
Ds
Dbs
fbs / fs = (Ds + Dssw ) / (Dss + Dssw)
fbs / fs = Ds / Dss = Gs . Zs / Gss . Zss
Log Kow =4
Log Kow =7
100
100
100
1
110
490
100
5
1900
2000
20
20
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