Presentation is loading. Please wait.

Presentation is loading. Please wait.

Lipids Water. Cwater GILL UPTAKE GILL ELIMINATION Fish-Water Two Compartment Model dC F / dt = k 1.C W – k 2.C F C F : Concentration in Fish C W : Concentration.

Similar presentations


Presentation on theme: "Lipids Water. Cwater GILL UPTAKE GILL ELIMINATION Fish-Water Two Compartment Model dC F / dt = k 1.C W – k 2.C F C F : Concentration in Fish C W : Concentration."— Presentation transcript:

1 Lipids Water

2

3 Cwater GILL UPTAKE GILL ELIMINATION Fish-Water Two Compartment Model dC F / dt = k 1.C W – k 2.C F C F : Concentration in Fish C W : Concentration in Water k 1 : Uptake clearance rate k 2 : Elimination rate constant C F = C W (k 1 /k 2 ).(1 - exp(- k 2.t))

4 Slope = - k 2

5

6 Bioconcentration : Equilibrium Partitioning f biota  f water

7

8 Woodwell, (1967) Sci Amer.

9

10

11 Biomagnification : f biota  f water f predator  f prey

12

13

14 Criteria for Bioaccumulation * Parameter Value Bioaccumulation FactorBAF > 5,000 Bioconcentration FactorBCF > 5,000 Octanol - Water Partition log K OW > 5 Coefficient * - BAF is better than BCF is better than K OW

15

16

17 Calves are born in June and weaned after 130 days Grazing: Lichen Diet (C. rangiferina, and C. nivalis)

18 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 (G D ) =1.5 kg/day: 5 calves, 2 yearlings and 16 adults)

19 Field Study Results: Spatial distribution of PCB 153 InuvikCambridg e Bay Bathurst Inlet Lichen Caribo u Wolf

20 Observed biomagnification in Bathurst Inlet food-chain logK OW 4.0 4.55.56.9 Chemica l

21 BMF - K OW relationshipBMF - K OA relationship

22

23 L G Diet (m ol d -1 ) Growth Lactation (mol d -1 ) Metabolism (k M ) Fecal Excretion (mol d -1 ) Urine (mol d -1 ) GI T Air (m ol d -1 )

24 Canada’s Domestic Substance List

25 PCBs (PNVs)(NPNVs) (PVs)(NPVs)

26 United Nations LRTAP POPs Protocol (1998) Targets chemicals that are: P ersistent B ioaccumulative T oxic

27 Canadian Environmental Protection Act: Framework for Evaluating DSL Chemicals Inherently Toxic Persistent or Bioaccumulative Screening Assessment List of Toxic Substances No Further Action at this Time Substances on the DSL and No Yes PHASE 1: Categorization PHASE 2: Screening level risk assessment Outcomes Priority Substances List no further action under this program

28 Bioconcentration Factor: BCF = C F / C W Biota-Sediment Accumulation Factor : BSAF = C F / C S Bioaccumulation Factor : BAF = C F / C W Measures of Bioaccumulation Octanol-Water Partition Coefficient: Kow = C O / C W Biomagnification Factor: BMF = C F / C Diet

29 BCF or BAF = C Fish / C Water C Fish = g substance/ kg wet weight organism C Water = g substance / L water BCF WW = L/kg wet weight C Fish = g substance/ kg lipid C Water = g substance / L BCF L = L/kg lipid Units of Bioaccumulation BCF WW = L.BCF L BCF WW : Wet weight based BCF BCF L : Lipid weight based BCF L : Lipid content organism (kg lipid/kg wet weight organism)

30 BSAF = C Biota / C Sediment C Biota = g substance / kg wet weight biota C Sediment = g substance / kg dry sediment BSAF = kg dry sediment/kg wet weight biota C Fish = g substance / kg lipid C Sediment = g substance / kg organic carbon BSAF L = kg organic carbon L/kg lipid Units of Bioaccumulation

31 BSAF WW = (L/  OC ).BSAF L BSAF WW : Wet weight based BSAF (kg dry sediment/kg wet weight biota) BSAF L : 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)

32 BMF = C F / C D C F = g / kg wet weight C W = g / L BCF W = L/kg wet weight C F = g / kg lipid C W = g / L BCF L = L/kg lipid Units of Bioaccumulation BCF W = L.BCF L BCF W : Wet weight based BCF BCF L : Lipid weight based BCF L : Lipid content organism (kg lipid/kg wet weight organism)

33

34

35

36

37

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

39

40

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

42 Trophic Dilution

43

44

45

46

47 Criteria for Bioaccumulation UNEP & CEPA * Parameter Value Bioaccumulation FactorBAF > 5,000 Bioconcentration FactorBCF > 5,000 Octanol - Water Partition log K OW > 5 Coefficient * - BAF is better than BCF is better than K OW

48 Aquatic organismsAir-breathing animals GIT Lipid-Air partitioningLipid-Water partitioning (K OW ) GIT (K OA ) may better assess bioaccumulation potential in air- breathing animals

49

50 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

51 Chemicals on the DSL

52

53

54

55

56

57 Algae Suspended Sediments Bottom Sediments C water C sediment

58

59 Chemical Equilibrium K d = C A /C W f A = f W f : Fugacity (Pa) C : Concentration (mol/m3) Z : Fugacity Capacity (mol/Pa.m3) C = f.Z

60 Algae Suspended Sediments Bottom Sediments f WATER f ALGAE f SUSP-SED f SEDIMENT = = =

61 K d = C A /C W K d = C SS /C W K d = C BS /C W

62 f = C/Z Z water = 1/H Z algae = OC.0.41.K ow.d a /H Z ssed = OC.0.41.K ow.d ss /H Z bsed = OC.0.41.K ow.d bs /H

63 Lake Ontario

64

65

66 Lake Erie

67 Lake Superior

68 Lake St. Clair

69 Observations: 1. There is no equilibrium 2. f BS > f SS > f A > f W 3. f BS /f w, f SS /f W, f A /f W increase when Kow decreases

70 26% 4% 1.5% 1 0.15 0.058 1 6.5 17.3 Mineralization OCZf

71 fafa f bs f ss f W3 f W2 f W1 DpDp DsDs D bs D wp D pw D sw D bsw D wbs D ws

72 fafa f bs f ss f W3 f W2 f W1 DpDp DsDs D bs D wp D pw D sw D bsw D wbs D ws f a / f w = D pw / (D pw + D p ) f ss / f a = G p. Z p / G s. Z s f bs / f s = G ss. Z ss / G bs. Z bs

73 fafa f ss f W2 DpDp DsDs D sw D ws f ss / f a = (D p + D sw ) / (D s + D sw ) f ss / f a = D p / D s = G p. Z p / G s. Z s

74 f bs f ss f W3 DsDs D bs f bs / f s = (D s + D ssw ) / (D ss + D ssw ) f bs / f s = D s / D ss = G s. Z s / G ss. Z ss

75 100 2000 490 1900 110 100 1 20 5 100 Log Kow =4Log Kow =7

76 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


Download ppt "Lipids Water. Cwater GILL UPTAKE GILL ELIMINATION Fish-Water Two Compartment Model dC F / dt = k 1.C W – k 2.C F C F : Concentration in Fish C W : Concentration."

Similar presentations


Ads by Google