First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR,

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 259101011, see www.rivm.nl/cce

• Status December 2002: Expert Meeting, 2 – 4 December 2002, in Berlin, Minutes see www.icp.mapping.org

Gudrun SchützeOEKO-DATA

http://www.rivm.nl/cce




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:




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 limitsStatus June 2002: Direct ecotoxicological effects of Pb and Cd

Terrestrial (forest, natural, agricultural ecosystems):

Receptor Pathway Pb Cd

Soil micro-organisms total metal concentration 8 0.8Plants in soil solution [µg l-1]

Soil fauna (invertebrates) reactive metal content in 30 0.9soil [mg kg-1]

Aquatic (freshwater ecosystems):

Receptor Pathway Pb Cd

Algae total dissolved 11 0.3Crustacea metal concentrations [µg l-1]

Fish




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 concentrationeffects data (soil) – total content, added amountsmetal leaching from soil – total concentration in soil solutionavailable 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 suspendedparticles)




Computation methods (Cd and Pb):




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




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 cadmium SSL cadmium

EMEP 50x50 grid cells with Critical Loads (CL) and Stand Still Loads (SSL) for cadmium,

protecting 95% of the ecosystems

PRELIMINARY MAPS

CL lead SSL 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 deposition Using conifer dependent deposition

12th CCE Workshop and 18th 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




Status December 2002 - 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




Critical Load approach for heavy metals – decision tree

Determineminimal 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

Emissions

No consideration if natural input dominates [set high C.Load]

Chemical model

input estimation

Depositionmodel

Present damage but recovery in progressORNo damage at present

Future damage foreseenPresent damage: yes OR no

Release of heavy metals to

atmosphere

Fertilisermodel

Other anthro-pogenic inputs

GeologicalInputs

(weathering)

Annex III

SMB methods

Integrated Assessment, incl. dynamic methods

Critical Load approach for heavy metals – decision tree

Annex III

Future damage foreseenPresent damage: yes OR no

Critical Load approach : Emissions

Present damage but recovery in progressORNo damage at present

Emissions




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:

First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR,

Documents

Transcript of First Meeting of the Expert Group on Heavy Metals under the Convention on LRTAP / WGSR,