Relating field bioaccumulation metrics for chemicals in a benthic and pelagic food web with existing bioconcentration data H. Leslie, S.

Transcription

1 Relating field bioaccumulation metrics for chemicals in a benthic and pelagic food web with existing bioconcentration data H. Leslie, S. van Leeuwen, B. van Hattum, F. Gobas, P. Leonards

2 Bioaccumulation assessment criteria Table 1. An overview of regulatory bioaccumulation assessment endpoints and criteria. Regulatory agency Bioaccumulation endpoint Criteria (log values) Program Environment Canada K OW 100,000 (5) CEPA 1999 * Environment Canada BCF 5,000 (3.7) CEPA 1999 Environment Canada BAF 5,000 (3.7) CEPA 1999 European Union bioaccumulative BCF 2,000 (3.3) REACh European Union very bioaccumulative BCF 5,000 (3.7) REACh United States bioaccumulative BCF 1,000 (3) 5,000 (3.7) TSCA, TRI United States very bioaccumulative BCF 5,000 (3.7) TSCA, TRI United Nations Environment Programme K OW 100,000 (5) Stockholm Convention United Nations Environment Programme BCF 5,000 (3.7) Stockholm Convention * CEPA - Canadian Environmental Protection Act, 1999 (Government of Canada 1999; Government of Canada 2000) Registration, Evaluation and Authorisation of Chemicals (REACh) Annex XII (European Commission 2001) Currently being used by the US Environmental Protection Agency in its Toxic Substances Control Act (TSCA) and Toxic Release Inventory (TRI) programs (U.S. EPA 1976) Stockholom Convention on Persistent Organic Pollutants (UNEP 2001)

3 How reliable is the prediction of bioaccumulation in food webs in the field based on lab-derived BCF values? Understand the important factors impacting BCF and BAF measurements

4 Our approach A. Existing BCF data B. Generate bioaccumulation data for real food web C. Which factors influence bioaccumulation? D. Model mechanisms/processes that control bioaccumulation E. Explore relationship between BCF and TMF (trophic magnification factor) Does BCF from lab tests predict/underpredict/overpredict the field bioaccumulation we observe?

5 Study area: Western Scheldt estuary Large land-based pollution input Western Scheldt discharges into the North Sea Various industries at Terneuzen Textile industry Antwerp Sediment Food chain collection Food chain collection Tern colony Tern colony Western Scheldt Terneuzen Saeftinge Common tern food web

6 Pelagic and benthic food chains Piscivoreous bird Common tern Algae Pelagic phytoplankton Mysids Zooplankton Herring Sandeel Fish SPM Seabass Whiting Fish Piscivorous fish Sediment Sculpin Benthic fish Sole Flounder Plaice Goby Cockles Worms Crabs Shrimps Bottom invertebrates Benthic algae Benthic microalgae Primary producers Grazers and filter feeders First level predators Second level predators

7 Chemical substances 16 TBEP BDE209 TEHP OC pesticides PAHs organo-bromine PCBs Organophoshate PFCs TDCPP a-endosulfan TCPP TCEP logkow<2 γ-hch β- α HCH TPP TiBP HBCD BDE99 BDE47 TCP PCB180 BaP PCB153 BDE153 o-terphenyl PCB28 EHDP Pyrene HCB Diisopropyl naphthalene PFOS PFOA PFDA logkow2-5, Koa>5-12 logkow5-9, Koa>5 logkow> LogKow

8 How similar are our BAFs field to BCFs lab? BAF BCF HCH BDE99 BDE47 HBCD PFOS PFDA PFOA Pyrene HCB PCB153 PCB52

9 BCF vs. BAF total and dissolved BCF BAF Pyrene Pyrene PCB153 PCB52 HCB PCB153 PCB52 BAFs based on total concentrations in water phase BAFs based on dissolved concentrations in water phase 9

10 What are the links between BCF, BAF and TMF?

11 Trophic Magnification Factor approach log conc. log conc. TMF>1 TL TMF<1 TMF: Factor by which concentrations in biota change per trophic level in a food web TL Biotransformation

12 Log Concentrations PCB 153 (ng/g lw) PCB 153 as reference compound TMF Trophic level Pelagic Benthic

13 Log concentrations pyrene (ng/g lw) Trophic dilution pyrene and BDE Pyrene TMF 0.2 Pelagic Benthic 05 Pelagic 04 Benthic BDE209 TMF Trophic level Biotransformation and bioavailability important factors

14 log concentrations PFOA (ng/g ww) Trophic magnification PFOA Pelagic Bird Benthic TMF SPM plankton Invert Fish Trophic level High bioaccumulation in birds probably due to high gastrointestinal uptake and slow respiratory elimination

15 Biotransformation impacts bioaccumulation TMF Non-persistent Persistent Non-persistent Persistent TMF Predicted biotransformation T1/2 (days) Episuite, Arnot and Gobas 0, Measured biotransformation S9 rat liver Concentration dependence of rates Induction by other chemicals in the field

16 BAF (L/kg wet weight) BAF vs. TMF BAF = 5,000 TMF = TMF PFOA PFDA PFOS PFOSA PCB 28 PCB 52 PCB 101 PCB 118 PCB 138 PCB 153 PCB 180 HCB Pyrene Benzo-a-pyrene BDE 28 BDE 49 BDE 47 BDE 100 BDE 99 BDE BB 153 BDE 153 BDE 209 a-hbcd y-hbcd BAF Criteria TMF Criteria Error bars are 95% confidence intervals

17 BAF (L/kg wet weight) BAF vs. TMF Type I Error (false positives) BAF = 5,000 TMF = 1 Type II Error (false negatives) TMF PFOA PFDA PFOS PFOSA PCB 28 PCB 52 PCB 101 PCB 118 PCB 138 PCB 153 PCB 180 HCB Pyrene Benzo-a-pyrene BDE 28 BDE 49 BDE 47 BDE 100 BDE 99 BDE BB 153 BDE 153 BDE 209 a-hbcd y-hbcd BAF Criteria TMF Criteria Error bars are 95% confidence intervals

18 BCF (L/lg wet weight) BCF vs. TMF Type I Error (false positives) BCF = 5,000 TMF = 1 Type II Error (false negatives) TMF Error bars are 95% confidence intervals PCB 52 PCB 101 PCB 118 PCB 138 PCB 153 PCB 180 HCB Pyrene Benzo-a-pyrene BDE 209 BCF Criteria TMF Criteria PFOA PFDA PFOS BDE 47 a-hbcd y-hbcd

19 Narrow Kow range of test compounds TBEP BDE209 TEHP OC pesticides PAHs organo-bromine PCBs Organophoshate PFCs TDCPP a-endosulfan TCPP TCEP γ-hch β- α HCH TPP TiBP HBCD BDE99 BDE47 TCP PCB180 BaP PCB153 BDE153 o-terphenyl PCB28 EHDP Pyrene HCB Diisopropyl naphthalene PFOS PFOA PFDA Koa<2 logkow2-5, Koa>5-12 logkow5-9, Koa>5 logkow> LogKow

20 0.5 logkow window logkow logbcf TMF PCB HCB a-hbcd y-hbcd BDE Pyrene PFOS EHDP

21 Bioaccumulation assessment logbcf logbaf BMF TMF PCB PCB HCB Pyrene BDE BDE BDE a-hbcd y-hbcd PFOA PFDA PFOS PFOSA TCPP TPP TBEP Above threshold Below threshold

22 Main conclusions BCF values are subject to variability General relationship exists for BCF-BAF-TMF for water breathers, but NOT air breathers BCF and BAF have less predictive value for the TMF in an aquatic food web that includes air breathing organisms. Reliance on BCF or BAF sometimes gives rise to false positives and false negatives in B assessments BCF more uncertain than BAF in predicting TMF TMF is more information rich than BCF Properties such as biotransformation rates can have a major impact on TMF B-assessments that make use of all available bioaccumulation metrics can avoid potential biases due to applying only BCF (or Kow)

23 Recommendations If possible, rely on or determine the TMF rather than the BCF because the TMF is the real thing while the BCF is a surrogate. TMF > BAF > BCF Classify chemicals in groups with chemical-class appropriate B testing and evaluation methodologies. Bioaccumulation models can be used to do this. Include provisions in the B evaluation to identify substances that can biomagnify in organisms other than fish, i.e. humans, mammals, birds, insects. The TMF or BMF is a useful descriptor.

24 Acknowledgements Cefic & Ecetoc Deltares RWS Waterdienst 24