First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals Calculation and Mapping of Critical Loads of Heavy Metals (Pb, Cd, Hg) in Terrestrial and Aquatic Ecosystems Status June 2002: Results of the first European mapping exercise (CCE/EMEP MSC-East) RIVM Report , see Status December 2002: Expert Meeting, 2 – 4 December 2002, in Berlin, Minutes see Gudrun Schütze OEKO-DATA

First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals Critical Limits: Mike Ashmore, University of Bradford, West Yorkshire (UK) Wim de Vries, ALTERRA Wageningen (NL) Régis Farret, INERIS, Verneuil en Halatte (F) Gudrun Schuetze, OEKO-DATA Strausberg (D) (organiser) David Spurgeon, CEH, Huntingdon (UK) and other contributors Transfer functions: Bert Jan Groenenberg, ALTERRA, Wageningen (NL) (organiser) Tatiana Pampura, Russ. Academy of Science, Inst. Pushchino (RU) Paul Roemkens, ALTERRA, Wageningen (NL) Edward Tipping, CEH, Cumbria, (UK) and other contributors Mercury Limits and Models have been provided also by: Markus Meili (SE) Harald Sverdrup (SE)

Flowchart for the Critical Loads approach: First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals Select a receptor Determine the critical limit Select a computation method Collect input data Calculate the critical load Compare with the actual load

Receptors and critical limits Status June 2002: Direct ecotoxicological effects of Pb and Cd Terrestrial (forest, natural, agricultural ecosystems): Receptor PathwayPbCd Soil micro-organismstotal metal concentration80.8 Plantsin soil solution [µg l -1 ] Soil fauna (invertebrates)reactive metal content in soil [mg kg -1 ] Aquatic (freshwater ecosystems): Receptor PathwayPbCd Algaetotal dissolved Crustaceametal concentrations [µg l -1 ] Fish First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals

Transfer functions are needed to transform metal contents/concentrations related to different extraction methods, e.g. best description of most effects – free ion activity effects data (waters) – total dissolved concentration effects data (soil) – total content, added amounts metal leaching from soil – total concentration in soil solution available soil data – total content, aqua regia, reactive content Status June 2002: Terrestrial ecosystems: Set of transfer functions, based on data of the almost entire spectrum of soils from The Netherlands Aquatic ecosystems:Transfer functions to distinguish total concentration from total dissolved concentration (considering suspended particles) First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals

Computation methods (Cd and Pb): First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals Critical load models, based on critical limits Stand-still model, based on present metal contents/concentrations Steady state mass balance models

Status June 2002 – Pb and Cd: Critical Limits, Transfer functions, Computation methods, How to gather input data Limitations Results of preliminary European mapping: Critical loads (Do not quote!) Emissions / total deposition Exceedance (Do not quote!) Recommendations for work First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals Guidance for the calculation of critical coads for cadmium and lead in terrestrial and aquatic ecosystems (De Vries et al. 2001) CCE / EMEP MSC-E: Preliminary modelling and mapping of critical loads for cadmium and lead in Europe (Hettelingh et al. 2002)

The following pages are an extract from the presentation of J.-P. Hettelingh (Chair of CCE) to the WGSR in September 2002 Please note that according to the agreements of the Meeting in Berlin, Dec. 2002, the Stand-still Loads (SSL) are not distinguished anymore within Critical Loads mapping, but can become part of a next stage, involving dynamic modelling

11 countries submitted preliminary data Bulgaria (CL and SSL) Belarus (CL) Czech Republic (CL and SSL) Germany (CLs and SSL) Italy (SSL based on a ‘semi-dynamic’ approach ) The Netherlands (CL and SSL) Russia (CL) Slovakia (CL and SSL) Switzerland ( CL) Ukraine (CL) United Kingdom (CL and SSL)

6 countries expressed need for further work Austria Belgium (Flanders) Finland France Sweden Norway

CL cadmiumSSL cadmium EMEP 50x50 grid cells with Critical Loads (CL) and Stand Still Loads (SSL) for cadmium, protecting 95% of the ecosystems PRELIMINARY MAPS

CL leadSSL lead EMEP 50x50 grid cells with Critical Loads (CL) and Stand Still Loads (SSL) for lead, protecting 95% of the ecosystems PRELIMINARY MAPS

Average deposition minus critical critical loads for Cd and Pb in 2010

Deposition minus forest critical loads for Pb in 2010 Using average depositionUsing conifer dependent deposition

12 th CCE Workshop and 18 th Task Force on Modelling and Mapping: Selected recommendations for further work: Review total metal inputs, Identify, where the stand-still approach might be more appropriate than an effects-based approach Analyse uncertainties, inconsistencies (e.g. cross border) Review critical limits and transfer functions including, as far as possible, humus layers Include human health aspects (and, as far as possible, food chains) Explore effects based approaches for mercury First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals

Status December Receptors, critical limits, transfer functions: Pb/Cd/(Hg): Direct ecotoxicological effects of Pb and Cd + Check indirect ecotoxicological effects (food chains) + Check of human health effects (e.g. Cd in wheat, Hg in fish) Current and future work to be finished by end of 2003: Sophistication of critical limits related direct ecotoxicological effects (relating effects to free metal ion activities) Sophistication of critical limits for human health (relating exposure limits to food quality criteria) Fitting transfer functions (TF) to the broad spectrum of European soils, TF for consideration of free metal ion activities First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals

Critical Load approach for heavy metals – decision tree Determine minimal critical limits Critical Loads for heavy metals Evaluation according to knowledge of the site (esp. Comparison of Natural C and Clim, ) Exceedance of Critical Load > 0 Exceedance of Critical Load <= 0 Critical Load approach : Emissions No consideration if natural input dominates [set high C.Load] Chemical model input estimation Deposition model Present damage but recovery in progress OR No damage at present Future damage foreseen Present damage: yes OR no Release of heavy metals to atmosphere Fertiliser model Other anthro- pogenic inputs Geological Inputs (weathering) Annex III SMB methods Integrated Assessment, incl. dynamic methods

Critical Load approach for heavy metals – decision tree Annex III Future damage foreseen Present damage: yes OR no Critical Load approach : Emissions Present damage but recovery in progress OR No damage at present Emissions

First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR, 20 – 21 March 2003, Geneva International Working Groups on Critical Limits and Transfer Functions for Heavy Metals Work plan 2003/4 to be confirmed by the Task Force on ICP M & M 2003:Finish work on critical limits and transfer functions (Pb, Cd, Hg), circulate results, draft chapter on HM of Mapping Manual; Conduct new national mapping exercises including Pb, Cd, Hg, circulate results, update the HM draft chapter of Mapping Manual; Methods to quantify non-atmospheric inputs are required 2004:Spring: Workshop on Critical Loads for Heavy Metals: Recommend(preliminarily) final methods, edit Manual chapter on HM to be proved by the Task Force on ICP Modelling and Mapping and WGE Autumn: Call for data on CL of Pb, Cd (Hg?) Output: Critical load maps, related to ecotox. effects Critical load maps, related to human health effects 2005: