Metal bioavailability in sediments: scientific fact vs. regulatory reality

Transcription

1 Metl biovilbility in sediments: scientific fct vs. regultory relity Dt: Burton et l., 2005, ET&C Colin Jnssen, Krel De Schmphelere, Yblin Román nd Lien Nguyen Lbortory of Environmentl Toxicology nd Aqutic Ecology Deprtment of Applied Ecology nd Environmentl Biology

2 Fcts relity Environmentl qulity criteri for chemicl substnces re needed For metls: Sediment nd soil criteri re bsed on totl metl concentrtions Possible importnce of biovilbility is negted Are we doing the best we cn? Wht s scientific evidence?

3 Risk ssessment: scientific bsis for estblising EQC Hzrd identifiction Dt compiltion Exposure ssessment PEC Effect ssessment PNEC Risk chrcteristion PEC/PNEC Environmentl qulity criteri

4 Effects ssessment estblishing EQC Ecotoxicologicl dt Dt Extrpoltion fctors Assessment fctor L(E)C50 short-term toxicity tests 1000 NOEC for 1 long-term toxicity test 100 NOEC for dditionl long-term toxicity tests of 2 trophic levels NOEC for dditionl long-term toxicity tests of 3 species of 3 trophic levels cumultive distribution function Species sensitivity distribution (SSD) N. brblutus H. ztec P. nottus P. prtenog. P. fluvitilis O. reinhrdtii O. kisuth S. fontnilis P. promels C. riprius C. dubi D. pulex I. puncttus D. mgn O. mykiss G. pulex C. mgnific C. decisum Protection level: 95% [C] HC5 = 95% protection level dissolved copper (µg/l) Hzen plotting Loglogistic fitting PNEC or EQC

5 Wht we re ignoring Tests which re used for deriving SQC re performed: in sediments with different physicochemicl chrcteristics different species with different: life histories ecologicl niches

6 Relity Me Kd Me-diss Me-specition Species 1 Species 2 Species 3 O 2 Me AVS Me-diss Me-specition

7 Biovilbility in sediments SEM-AVS concept Me 2+ Wter oxic lyer Me 2+ Minerl bound noxic lyer MeS Sediment metl 1M HCl extrction SEM (Simultneously Extrcted Metls) + AVS (Acid Voltile Sulfide) ΣSEM = SEM Cu + SEM Pb +SEM Cd + SEM Zn + SEM Ni (AVS ffinity Cu >Pb>Cd>Zn>Ni) Excess SEM Cu = SEM Cu (AVStotl) potentilly biovilble

8 SEM, AVS, OC does mtter Survivl (%) % OC 5% OC 10% OC Totl Ni (mg/kg dry wt.) Dt: Krsten Liber, 2002

9 Dt: Krsten Liber, 2002 SEM, AVS, OC does mtter Survivl (%) % OC 5% OC 10% OC Avg. LC50: mg/l Pore Wter Ni (mg/l)

10 However Reluctnce to incorporte SEM/AVS nd/or OC normlistion into regultory schemes (e.g. EU), becuse: Evidence bsed on cute tox results Only tested for few species No field dt Nturl vribility of AVS

11 Reserch lbortory testing Long-term testing with different benthic orgnisms Artificil sediment mnipultion:model development Nturl sediments: vlidtion Surfce deposit feeders Sub-surfce feeders Burrowing & surfce/ subsurfce feeding Hyllel ztec Tubifex tubifex Chironomus riprius Gmmrus pulex Lumbriculus vriegtus Ephoron vigro

12 Dt: Lb Environmentl Toxicology, Ghent University NOT TO BE CITED/USED WITHOUT PRIOR WRITTENPERMISSION Tubifex Hylell Chironomus Survivl Growth Lumbriculus Biomss Gmmrus Survivl Growth Lbortory testing Survivl Reproduction Growth Survivl Growth Emergence NOEC (mg Cu/ kg dry wt) 54 - > Fctor difference > EC50 (mg Cu/ kg dry wt) > > ~ 4503 Fctor difference > ~ 41

13 Lbortory testing Artificil sediments: AVS nd OC mnipultion EC50 totl (mg Cu/kg) Tubifex - survivl low OC high OC EC50 totl (mg Cu/kg) Tubifex - growth low OC high OC mmol AVS / kg dry wt mmol AVS/ kg dry wt Dt: Lb Environmentl Toxicology, Ghent University NOT TO BE CITED/USED WITHOUT PRIOR WRITTENPERMISSION

14 Lbortory testing Artificil sediments: AVS nd OC mnipultion EC50 totl (mg Cu/kg) Hylell - survivl mmol AVS / kg dry wt low OC high OC EC50 totl (mg Cu/kg) Hylell - growth mmol AVS/ kg dry wt low OC high OC Dt: Lb Environmentl Toxicology, Ghent University NOT TO BE CITED/USED WITHOUT PRIOR WRITTENPERMISSION

15 Tubifex tubifex Nturl sediments - Chironomus survivl reproduction growth emergence biomss Brkel Krenepoel 1 Krenepoel 2 Leuven Ijzer NOT TO BE CITED/USED WITHOUT PRIOR WRITTENPERMISSION EC50 (mg Cu / kg dry wt) Dt: Lb Environmentl Toxicology, Ghent University Lbortory testing AVS < 1 mmol/kg; OC < 3% AVS mmol/kg; OC 7-25%

16 Lbortory testing Nturl Nturl sediments Hylell ztec - Hyllel survivl reproduction growth emergence biomss Brkel Krenepoel 1 Krenepoel 2 Leuven Ijzer NOT TO BE CITED/USED WITHOUT PRIOR WRITTENPERMISSION EC50 (mg Cu / kg dry wt) Dt: Lb Environmentl Toxicology, Ghent University AVS < 1 mmol/kg; OC < 3% AVS mmol/kg; OC 7-25%

17 Field testing Long term field vlidtion of Zn concentrtions tolerted by benthic mcroinvertebrte communities Field dt on the reltionship mong SEM/AVS, seson nd Zn toxicity University of Ghent, Belgium Wright Stte University, USA Itlin Institute of Hydrobiology, Itly Dt: Burton et l., 2005, ET&C

18 Field testing Site sediments spiked with Zn: 1) High zinc (1,200 mg/kg finl concentrtion) 2) Low zinc (400 mg/kg finl concentrtion) 3) Reference Sediment nlyses: AVS, SEM, Totl Metls, Orgnic Crbon, Dry Weight, Benthos. Sediments in coloniztion trys: 4 replictes/tretment 3 exposure periods: 3 to 9 months Dt: Burton et l., 2005, ET&C

19 Field testing Replicte trys picked for benthic invertebrtes nd subsmpled for chemistry. Benthic indices recommended by EU s AQEM project: Bry-Curtis Dissimilrity Index Abundnce (individuls/smple) Number of Tx Shnnon-Weiner Diversity Index Txonomic Evenness % Gstropod, % EPT/% Oligochet Dominnt Txon (%) Biotic Sediment Index (BSI) BMWP (Biologicl Monitoring Working Prty) ASPT (Averge Score Per Txon, bsed on BMWP). Dt: Burton et l., 2005, ET&C

20 Field testing Dt: Burton et l., 2005, ET&C

21 Field testing: sites < /2002 1/2003 Pllnz (St.2) /2002 Ankeveen / / /2002 Biesbosch / / /2002 Schmllenberg High Low Ref High Low Ref High Low Ref. SEM/AVS AVS SEM Site Dt: Burton et l., 2005, ET&C

22 Field testing Species Evenness, Diversity nd Richness Evenness Reference Low-Zn High-Zn Shnnon's Diversity Reference Low-Zn High-Zn Schmllenberg Ankeveen Biesbosch 0 Schmllenberg Ankeveen Biesbosch b Ankeveen Schmllenberg Biesbosch Reference Low-Zn High-Zn Dt: Burton et l., 2005, ET&C

23 Field testing Density nd Species Richness (The Netherlnds) Orgnisms/smple b b b Reference Low-Zn High-Zn Tx/smple b b b b Reference Low-Zn High-Zn 0 June September December 0 June September December Smpling dte Smpling dte SEM/AVS Low-Zn High-Zn June: September: December: Dt: Burton et l., 2005, ET&C

24 Field testing Density nd Species Richness (Itly) Number smple b b Tx smple b b 0 Reference Low-Zn High-Zn 0 Reference Low-Zn High-Zn Smple Smple SEM/AVS Low-Zn High-Zn Dt: Burton et l., 2005, ET&C

25 Field testing: summry June Sep Dec Sch. Bies. Ank. Sch. Bies. Pl.St2 Sch. Bies. Abundnce L&H L&H Tx H L&H L&H Shnnon s Index H H Evenness H Bry-Curtis Index (%) Gstropod L&H L&H EPT/ Oligochet H L&H L&H Dominnt txon L&H H H H BSI H H Dt: Burton et l., 2005, ET&C

26 Field testing: Benthic Mcroinvertebrte Indice Effects vs. Totl Zn Dt: Burton et l., 2005, ET&C % Benthic Mcoinvertebrte Indice Effects 37.5% % 62.5% 75.0% Totl Zn

27 Field testing: Benthic Mcroinvertebrte Indice Effects vs. SEM/AVS Dt: Burton et l., 2005, ET&C % Benthic Mcoinvertebrte Indice Effects % % % 75.0% SEM/AVS

28 Field testing: Benthic Mcroinvertebrte Indice Effects vs. SEM AVS/ƒoc Dt: Burton et l., 2005, ET&C % Bnethic Mcroinvertebrte Indice Effects % % % % SEM-AVS/foc

29 Conclusions Sediment nd soil criteri re bsed on totl metl concentrtions Are we protecting the environment the environment from the risks of dverse effects of metls when using SQC bsed on totl metl concentrtions? NO Are we doing the best we cn? NO Wht s scientific evidence? The effects of metls on long-term toxicity to benthic community cn be predicted if pproprite biovilbility fctors re tken into ccount