Bioavailability and bioaccumulation: keys for quality ecosystem

Transcription

1 Bioavailability and bioaccumulation: keys for quality ecosystem European Joint Master in Water and Coastal Management University of Cadiz (May 2016) 1

2 Today s lecture Basic concepts Monitoring contamination: Advantages and disadvantages of the environmental compartments Interaction between trace metal and aquatic organism (FIAM model) Case study: Aznalcollar mining accident. Estuary biomonitoring 2

3 Basic concepts Bioconcentration factor (BCF) at equilibrium BCF= Corganism/Cwater Units= ml/g Unitless 1mL=1 g Bioaccumulation factor (BAF) at equlibrium BAF= C organism/c sediment Wet weight or dry weight Unitless BAF/BSAF are employed in ERA Biomagnification BF=Cc/Cf 3

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5 Biological indicators (bioindicators). Organisms their own absence or presence indicate la existence or abundance of a particular critical factor (Capitella capitata) 5

6 Environmental monitoring Repetitive data collection for the purpose to determining trends in environmental parameters a priori and posteriori Which is the objective? - To screen effluents, receiving waters or biota for potentially harmful toxicants - To investigate the effects of environmental quality on human health - To study the sources, transport pathways and sinks for contaminants - To provide historical records - To investigate specific environmental impacts of individual or multiple developments 6

7 Biological monitors The means for regular surveillance They can be used to quantify the amount of a pollutant present in a particular environment Goldberg et al sentinel Hellawell, 1986 bioaccumulative Indicator Biomonitor 7

8 Trace metal? Heavy metal? Nieboer and Richardson 1980 Lewis acid properties metal 8

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10 Environmental compartments Water (ng/l to mg/l) Nutrients Pb (10-50 ng/l) Sample contamination Clean lab (at least for open ocean sites) Estuaries (flow intensity, intermittency of contaminated discharges, tidal, current,..) Lack correlation between the contaminant concentrations and their biological availability Sediment Contaminant tend to associate preferentially with suspended matter Al, Fe, Pb, Mn particulate matter As, Cd, Se present in solution in natural waters Short-term variations problem tend to be reduced Concentrations in sediment are also several orders of magnitude greater than in natural waters Concentrations do no reflect the absolute magnitude in sampling site. Complex function of the relative fluxes of contaminant and suspended particles in the system Grain size and organic content affect to contaminant concentration 10

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13 Organisms Accumulate significant quantities of contaminant in their tissues Trace metals is a complex phenomenon Take up and retain are different between phyla and also between individual species within phyla. Evolutionary strategies for detoxifyng trace metals 13

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16 Iberian Peninsula Zn (µg/g dw) Squilla mantis (Linnaeus, 1758) 6º 44 W 36º 50 N A 6º 42 W 36º 48 N Region 2 B 6º 43 W 36º 49 N 6º 41 W 36º 48 N F 6º 36 W 36º 49 N C D N 6º 40 W 36º 45 N E 6º 39 W 36º 47 N 6º 37 W 36º 43 N G Region 3 H I 6º 35 W 36º 45 N 6º 34 W 36º 46 N Region 1 J 6º 32 W 36º 49 N Guadalquivir River Chipiona 37º 45 N 6º 34 W 36º 40 N L K 6º 33 W 36º 40 N Region 4 M 6º 39 W 36º 38 N 10 km 6º 35 W 16

17 R. philippinarum -sessile or sedentary C. angulata -abundant and easy to identify -tolerating wide ranges of contaminants and variables as salinity -strong accumulators of the relevant trace metals 17

18 Scrobicularia plana Problems of biomonitor organisms -capacity regulation -Sex, size -Seasonal variability -Local variability 18

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20 Biomonitoring - metal concentrations in organisms are ten or hundred fold the concentrations in water - concentration reflects the bioavailabity of metal for biota Biomonitoring programs Mussel Watch, Monitoring of Temporal Trends in Chemical Contamination (NOAA), ICES, MAFF, RNO, MEDPOL, OSPAR 20

21 Interaction trace metal aquatic biota 1. Metal speciation in the external environment 2. Metal interactions with the biological membrane 3. Metal partitioning with the organism and the attendant biological effects 21

22 Factors affecting metal permeation Routes Hydrophobic solution in the membrane Attachment to the membrane proteins (and carbohydrates) Attachement to the membrane lipids Endocytosis of membrane components Permeation through water channels Permeation through nonspecific channels Permeation through specific channels Permeation by general active processes (e.g. electrochemical potentials) Permeation by specific active processes (eg. ATPase) Forms of metals Metal ions (e.g. M 2+ ) Hydrated ions (e.g. M(H2O) 6 2+ ) Charged metal complexes (e.g. MCl(H2O) 5+ ) Uncharged ionic complexes (e.g. MCl 20 ) Organometallic complexes (e.g. CH 3 M +n ) 22

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24 Qualitative evidence exists to the effect that the total aqueous concentration of a metal is not a good predictor of its bioavailability Does FIAM (free ion activity model) explain the available data? - Only applicable for dissolved cations (e.g. Al, Cd, Cu, Fe, Mn, Ni, Pb, Zn) - No applicable to organic metallic species nor particulate metals 24

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26 1. Advection or diffusion of the metal from bulk solution to the biological surface 2. Diffusion of the metal through the outer protective layer 3. Sorption/surface complexation of the metal at passive binding sites within the protective layer, or at sites on the outer surface of the plasma membrane 4. Uptake or internalization of the metal 26

27 Historical Development Early (pre 1975) metal-organism interaction. Influence biological variables Computing facilities, Chemical equilibrium programs (limitations stability constant database). Unicellular algae (small size, access to large populations, ease of culture, rapid growth,..) 27

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35 Apparent exceptions to the FIAM Organic ligands forming lipohilic complexes with metal Inorganic anions Low molecular weight organic ligands forming hydrophilic complexes with the metal 35

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37 Ag(I) Inorganic ligands 37

38 Low molecular weight organic ligands 38

39 FIAM IN SYSTEMS CONTAINING DOM Laboratory bioassay experiments (isolated natural organic matter) [M z+ ] Dilution experiments in which DOM-rich natural waters is diluted with synthetic media in order to vary DOM and metal bioavailability as function of [M z+ ] Biological monitoring of natural ecosystems (surface water samples are collected over an annual cycle and tested in lab with the same assay organism, test protocol and same metal) 39

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45 Case study: Aznalcóllar mining accident 45

46 Aznalcóllar óllarbalsa minera Dirección del vertido Aznalcázar El Rocío Matalascañas Parque Nacional de Doñana Río Guadalquivir Sampling strategy Biweekly Monthly La Esparraguera (F) Caladero (A) La Salina (E) La Pantoca (D) Las Piletas (C) Montijo (B) 46

47 C. angulata Melicertus kerathurus Uca tangeri Palaemon longirostris 47

48 Liza ramada Other species Nereis diversicolor Pomatoschistus minutus 48

49 ppm (dry weight) Zn Cu Year 49

50 12000 ug/g dry weight T= 3 meses 2000 T= 2 meses 0 T=1 mes Cu Zn T=0 Mn Fe C. angulata 6 ug/g dry weight T= 3 meses 1 T= 2 meses 0 Co T=1 mes Tl Ag Ni T=0 Pb Cd 50

51 Zn (ug/g dry weight) /1/1998 1/7/1998 1/1/1999 1/7/1999 1/1/2000 1/7/2000 1/1/2001 1/7/ Cu (ug/g dry weight) /1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/02 12 C. angulata Zn: 9134 ug/g dw Cu: 1460 ug/g dw. 10 Cd: 5.45 ug/g dw Cd (ug/g dry weight)

52 Zn (ug/g dry weight) /1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/ Cu (ug/g dry weight) Scrobicularia plana /1/98 1/7/98 1/1/99 1/7/99 1/1/00 1/7/00 1/1/01 1/7/01 1/1/02 52

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54 Final work (Individual) Objective To design a monitoring program to establish the impact of chronic or acute contamination To select a coastal or estuary area To present its physical and chemical characteristics Environmental compartment? How do you implement bioavailability? Extension (3 pages) Send the report (tentative project) to the following address: julian.blasco@csic.es To include a report of the practice work In the message cc to aguas.mundus@uca.es Deadline: 15th July

55 References Paquin PR, Farley K, Santore RC, Kavvadas CD, Mooney KG, Winfield RP, Wu K-B, DiToro DM. (2003) Metals in aquatic systems. A review of exposure, bioaccumulation and toxicity models. Pensacola, FL.,USA. SETAC, 168 p. Campbell PGC. (1995). Interaction between trace metals and aquatic organisms: a critique of the free ion actiity model. In Metal Speciation and Bioavailability in Aquatic Systems (Tessier A & Turner DR,editors). John Wiley and Sons, West Sussex, England, pp. Phillips DJH, Rainbow PS. (1994) Biomonitoring of trace aquatic contaminants. Chapman & Hall, Oxford (UK) 371 p. 55