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