Need for Specific approaches for Environmental Hazard and Exposure assessments for metals and inorganics

Transcription

1 Need for Specific approaches for Environmental Hazard and Exposure assessments for metals and inorganics H. Waeterschoot (Eurometaux-ICMM) (with contributions from C. Schlekat (NIPERA)) Paris, September

2 The Holy Grail Question? Are metals different or do they believe they are different? 2

3 Question? For Chemicals management programs like OECD HPV? What are those properties or aspects requiring different Hazard and Exposure assessment approaches for Metals and inorganics, compared to typical organic contaminants? 3

4 Basic aspects/challenges of metals (discussed at the workshop) Chemicals of natural origin and in use for a long time How to deal with Natural background How to deal with Historical regional pollution Data sets can be (very) data-rich : Are classical approaches used relevant? BUT Metals can also be data-poor too! Requiring TIERED approaches Speciation and Bioavailability are important to understand effects How to deal with in effects assessment schemes? Metals can be toxic and equally being an essential element What to do when AF s are larger than this margin? 4

5 Basic aspects/challenges of metals (beyond the scope of the workshop) Some metals are very difficult to test (Fe, Al, Sn, ) So assessment of hazard properties can be a real challenge Metals are used in complex materials like alloys that (may) change their hazard properties How to account for in Hazard assessment schemes? Diffuse releases may contribute extensively to the exposure balance How to distinct between chemicals related emissions and others? Some metals have good monitoring data sets How can we make best use of this? 5

6 ENV-Hazard and Risk Assessment aspects for metals : Focus of the workshop 1 Classification & ranking Acute/ chronic aquatic toxicity, Transformation / dissolution, Particle sizes, Ranking systems, etc 0 Risk concepts tiered approach Effects assessment soil sediment water sec. Data selection, poisoning Data handling, bioavailability 2 Effects analysis, Uncertainty management, etc Data selection, Data handling, Local scenario, Regional scenario, Waste scenario, etc 3 soil sediment Eco regions- Geographical scale water sec. poisoning Exposure assessment General concepts essentiality soil sediment etc water sec. poisoning Risk characterisation Probabilistic, Local scenario, Regional scenario, Waste scenario, etc 4 6 6

7 Metal effects assessment Are metals data rich? The example of Ni (water) # of entries Scientific literature, databases, reports, NiPERA research Metals are often data rich thereby covering a broad ecological and taxonomic spread individual high quality data entries 27 species (more than any other substance) 16 families primary producers, primary consumers, omnivores, predators grazers, filter feeders, surface deposit feeders algae/plants invertebrates fish/amphibians 7

8 Data rich and data poor... But many data poor files exist also for metals! Often metal and poorly soluble files are lacking data Read across methodology possible on a soluble ion basis Me, alloys,... : No data Sparingly soluble (MeO) No or few data Soluble - MeCl 2 8 Soluble - MeSO4

9 Cumulative probability Large effects data sets Require specific concepts and statistical approaches 100% Species Sensitivity Distribution (SSD) Microcystis 80% 60% 40% TRV = HC5 (SSD) 20% 0% Concentration ( m g/l) Derivation by statistical Species Sensitivity Distribution (SSD) approach Pimephales Daphnia 9

10 Importance of natural background Highly variable Natural background can vary extensively Impact on effects assessment?

11 Importance of natural background for effects assessment? Optimal [Zn]-range reported for Thalassiosira weissflogii Optimal [Zn]-range reported for Ephydatia fluviatilis Optimal [Zn]-range reported for Daphnia magna 0,0001 0,001 0,01 0, Total Zinc Concentration, µg/l 11

12 Bio-availability correction for metals Do we understand the role and importance of Bioavailability for the metal? Does it apply to all relevant environmental compartments (water-sediment-soils)? Can we quantify it? Is it applicable to all organisms in the same way? Can it be applied for Chemicals management systems? LOTS of questions BUT do we also have appropriate answers? 12

13 Generic Environmental Effects Assessment scheme 13

14 predicted 21d-ECx (µg Ni/L) NOEC (µg/l) Bioavailability incorporation: does it reduce variability? no BLM BLM 1386 µg/l 2551 µg/l µg/l 299 µg/l 281 µg/l 218 µg/l 325 µg/l Daphnia magna µg/l Artificial EC50 Artificial EC10 artificial EC10 Natural EC50 Natural EC20 Natural EC µg/l 37 µg/l 9 µg/l 17 µg/l R. sub capitata D. magna O. mykiss observed 21d-ECx (µg Ni/L) BLMs reduces variability and allow for toxicity predictions within a factor 2-3!!! 14 14

15 AQUATIC Bioavailability correction When and under which conditions? Bioavailability correction strategy as applied for metal RA s Total metal levels Physico-chemical speciation modelling (WHAM 5 or WHAM 6) Bioavailability Assessment Modelling BLMs 15

16 Read across for bioavailability: How predictable are the models for other non-tested species? BLM model fish (rainbow trout) Read across? BLM model algae (Raphidocelis) Read across? BLM model water flea (Daphnids) Read across? 16 16

17 ENV-Hazard and Risk Assessment aspects for metals : a stepwise approach of refinement Effects data set Effects data set after Quality screening No, Partial or Full Normalisation for Bioavailability HC5 or PNEC Derivation for normalised data set Refinement level HC 5 for Ecoregion 1 HC 5 for Ecoregion 2 HC 5 for Ecoregion 3 HC 5 for Ecoregion 4 HC 5 for Ecoregion 5 17

18 Diffuse sources: a challenge for metals Often highly dominating RA outcomes Copper Molybdenum Brake pads 18

19 Diffuse sources Chemicals release contributions can vary extensively Product releases Other diffuse sources for Ni Product releases Other diffuse sources for Pb 100% 100% 75% 75% 50% 25% 50% 25% 0% Water (kg Pb/year) Air (kg Pb/year) Soil (kg Pb/year) Total (kg Pb/year) Product releases Industry processes Other diffuse sources 0% Water (kg Pb/year) Product releases Air (kg Pb/year) Other diffuse sources Soil (kg Pb/year) Total (kg Pb/year) Contribution of diffuse sources can be dominant in the exposure assessment. A correct and comprehensive assessment is consequently required for a correct metals Risk Assessment or Risk Characterisation 19

20 Metal specific Guidance : build on experience Methodologies described in Guidance Documents are often inappropriate or inadequate for metals and inorganic metal compounds Development of metal specific tools and methodologies Consolidation of experience and learning lessons in risk assessment of metals in two projects: MERAG : Metals environmental Risk Assessment Guidance HERAG : Metals Health Risk Assessment Guidance Recognition in Regulatory Guidance (e.g. REACH, WFD,...) 20

21 Hoping having provided you an helicopter view on challenges in respect to metals and metal compounds effects assessment? Thank You 21

22 For further information please contact: