ICMM
International Council on Mining and Metals

International Workshop
on Life-Cycle Assessment and Metals

THE ISSUES

Life-cycle assessment (LCA) has proven to be a valuable tool to evaluate the potential environmental impact of products and materials. It is increasingly used by industry for guidance in decision-making on products and materials. LCA information also influences environmental policy-making and government regulators.

Recently, the growing global interest in LCA has led a number of government and industry sectors, including the metals industry, to develop life-cycle inventory (LCI) databases. Furthermore, a need has been identified to discuss knowledge that has been obtained with respect to the mining, production, use and disposal of base metals, and to compare it with current LCA methodologies. As well, over the last few years, a major science program has helped better document the environmental and health interactions of metals and can be used to enrich LCA.

From April 15 to 17, 2002, a workshop was held in Montréal to discuss issues related to LCA and metals. Sixty technical experts, from 15 countries with different perspectives (LCA, life-cycle impact assessment (LCIA), risk assessment (RA), economy, geology) and from diverse sectors (industry, academia, consultant, government) attended the workshop. It was sponsored by the United Nations Environment Programme (UNEP), the Society of Environmental Toxicology and Chemistry (SETAC), the Asia Pacific Economic Cooperation (APEC), the International Council on Mining and Minerals (ICMM), and Natural Resources Canada. The workshop was also supported by the International Copper Association, the International Zinc Association and the Nickel Development Institute. The aluminum and steel sectors also sent representatives.

The purposes of the workshop were:

• to build bridges between the LCA community and scientists interested in toxicological and environmental considerations related to metals, and
  
• to support the UNEP/SETAC Life-Cycle Initiative by proposing metal-related areas for future work aimed at improving the quality of LCA results for decision-making.

The discussions were focussed around three themes: life-cycle inventory, metal mining, and human and environmental toxicity.

LIFE-CYCLE INVENTORY

The objectives of Theme 1 were:

• to discuss industry- and government-sponsored LCI databases for metal production and recycling;
• in compliance with ISO 14041, to assess the consistency of data by examining system boundaries, allocation rules and emission criteria; and
• to examine data gaps and how to address those issues.

Recycling is an important feature for the metal sector and it has been a dominant issue with respect to data gaps and how to allocate the environmental burden. Three conclusions were reached for that theme.

Review information on metals recycling

A working group can be established (within the Life-Cycle Initiative or ICMM) to review available information on metals recycling and techniques for its improvement.

For the primary production, good-quality data exist for the LCI of steel and base metals. But the data related to emissions associated with the recycling activities need to be compiled for various commodities. Furthermore, the knowledge of the recycling rate for various products can be improved.

Guidance document on recycling

A guidance document entitled "Inherent properties, loop closure and recycling modeling in LCI in the context of metals" can be developed. This should be done under the Life-Cycle Initiative and within ISO standards. It could be expanded to include other materials.

The ISO International Standard 14041 and the ISO Technical Document 1049 describe allocation procedures for recycling based on the "inherent properties" of the material and how to apply it. The understanding of the "inherent property" is a function of the background of the participants. For some, it was the function that defined the properties and for others it was the atomic structure that determined the properties.

Guidance document on LCI databases

A guidance document can be developed that deals with how LCI databases should be presented and used (i.e., organized for easy access and understanding for practitioners; used in transparent and consistent ways).

This recommendation reflects the tension between practitioners desiring open access to all data all the time, and the generators/owners of that data concerned about how that data will be used. It might be misused out of ignorance or abused for competitive marketing purposes. Put another way, it is easier to see what practitioners get out of open databases, and easier to imagine how the generators of those databases could be affected by the misuse or abuse of those databases. Moreover, a number of national and regional databases are being developed that may or may not resemble each other, let alone databases that are currently found in proprietary software packages. The process of developing a guidance document could assist in bringing the interests of the different stakeholders together.

METAL MINING

The objectives for Theme 2 were to review current information with respect to mining and to compare it to LCA practices in order to evaluate gaps and enhance relevancy. Discussions were structured around the applicability of the concept of resource depletion, the direct impact of mining, and how to improve the collaboration between LCA and mining experts.

Resource depletion/availability

A consensus emerged that, as a result of the availability, recyclability and substitutability of metals, the depletion of resources is not an issue that requires high-priority consideration; it need not be a priority issue in the assessment of metals, particularly when compared to other themes. Since the word "depletion" suggests scarcity in the minds of many, the expression "resource availability" or "access to resources" may be more helpful. The word "access" points to the socio-economic issues that, in practice, are the most likely to place limits on access to resources. It is, however, unclear how this aspect would fit into the life-cycle impact assessment (LCIA) framework, as impact categories with a "positive" meaning are not used in accepted methodologies.

Physical impact and land use

There is a danger to use some oversimplification in modeling the environmental impact of mining. Approaches that propose to quantify the impact of mining strictly as a function of the volume are not appropriate in LCA. Surface use and other impact categories such as acidification (acid mine drainage) and salinization are much more relevant and site specific. Environmental issues related to tailings stability, mine closure and abandoned mines were discussed.

Case studies

As the impact of mining depends on the site and the management practices, it has been concluded that case studies could be used to make generic impact assessment factors for different mining types. That information would be useful information on uncertainty determination. In order to increase the reliability of LCA, it has been recommended: a) to develop a number of case studies that span the range of mining conditions, management practices and age of the mine; b) to develop a set of generic applicable factors for the different archetypal cases and a general average for background databases, and to document uncertainty ranges; and c) to use the case studies to define criteria or indicators to measure mining impacts.

HUMAN AND ENVIRONMENTAL TOXICITY

The objective of Theme 3 was to characterize the methods and technical limitations, for the incorporation into LCA, of ecological and human health impacts of metals.

Exploration of this objective was an exercise in establishing an interface between practitioners of two disciplines: metals life-cycle assessment and risk assessment (RA). Participants searched for common ground, defined terms, explored differences of opinion, and discussed the applications and limitations of each discipline. Since the objective was one of incorporating ecological and health impacts into LCA, the emphasis was squarely on how the biology could inform and comply with the methods and metrics of LCA, and not the reverse. Throughout the presentations and discussion, topics shifted among metals toxicity, health and ecological impacts, and risk assessment. Three major conclusions were reached for that theme.

Definitions on LCA and RA

There is a conflict of jargon as used in LCA and RA. A dictionary of definitions as used by each and a common ground for definitions need to be developed.

Metals-specific research issues

Metals-specific research issues need to be investigated to improve current approaches for addressing toxicological impacts in LCA. These issues include: transformation/speciation, fate and transport, bioavailability, background conditions and effects.

How should the form of the metal and its speciation be considered? For each metal, how many and which species should be considered? How should the bioavailable fractions in different waters (fresh, marine, estuarine and laboratory) be considered? How should metals speciation be considered expressly for terrestrial ecotoxicity separate from aquatic ecotoxicity? Research, similar to that now under way in aquatic environments, is needed for terrestrial ecosystems. In the long term, fate and transport models (e.g., biotic ligand model, speciation models) need to be adapted for use in LCA. Meanwhile, in the short term, appropriate components of models can be used in LCA.

How should uptake from water (including uptake of particulate matter) and food be considered in general, but also specifically for metals? Analyses of sources of metals to biota must consider uptake from food versus uptake from the media (e.g., water, sediment), the type of diet and the specific organisms being considered for impact. Consideration of bioavailability is vital in both risk and life-cycle assessments when insights beyond screening-level assessments are required. In this process it is important to distinguish between bioaccumulation (Bioconcentration Factor, or BCF) and bioavailability.

What are the ranges of media and environments that should be considered in LCAs (e.g., soil types, water types, air compartments)? It would be interesting to study how this could be dealt with in LCA, by considering different classes of generic site information (e.g., three classes of background conditions). Which benchmark of toxicity should be used in a comparative assessment? Dose-response measures that best characterize the dose and shape of the dose-response curve (Benchmark Dose, or BMD) should be used, if available and where background concentrations can be taken into consideration. The most representative species or the median response among species, rather than the most sensitive species, should be used as the indicator species for both risk and life-cycle assessment.

Advance integration between RA and LCA

In order to increase the relevance of life-cycle impact assessment (LCIA), a white paper on the difference and similarities between LCA and RA and workshops in integrating RA and LCA are recommended. An instructive case study that includes: (1) both RA and LCA (separate analyses on the same product, followed by comparison and then an attempt to integrate), (2) both organic chemical(s) and metals to ensure uniformity of methods, and (3) one site-specific and one generalized scenario is suggested.

LCA AND DEVELOPING COUNTRIES

Developing countries are characterized by a large informal economy, including artisan mining and recycling activities. Those activities are having an impact on the environment and human health but are a source of employment. The life-cycle approach has been applied successfully in the Philippines to restructure the secondary lead-acid battery industry, including the informal sector.

Generally, the concept of LCA is new and not well understood by the mining and metallurgical industry and government in developing countries, but one of the Life-Cycle Initiative objectives includes the development and the dissemination of practical tools with the involvement of developing countries.

NEXT STEPS

The proceedings of the workshop will be co-published by UNEP and SETAC. Some of the proposed activities will be discussed by ICMM and by the Life-Cycle Initiative.

CONCLUSIONS

This workshop provided a good opportunity to build bridges among specialists from different disciplines with a common concern regarding metals. It permitted identification of issues in the application of LCA and the proposal of areas for future work in order to increase the reliability of LCA results. Those results will feed into the Life-Cycle Initiative.

Steering Committee:

Co-chairmen
Alain Dubreuil (Natural Resources Canada)
Antoon Franckaerts (International Council on Mining and Metals)

Members
Atsushi Inaba (Agency of Industrial Science and Technology - Japan)
Olivier Jolliet (Swiss Federal Institute of Technology - Lausanne)
Gregory Schiefer (Society of Environmental Toxicology and Chemistry)
Guido Sonnemann (United Nations Environment Programme)

Scientific Committee:

Chairman
Alain Dubreuil (National Resources Canada)

Members
Scott Baker (International Copper Association)
Alain Dubreuil (Natural Resources Canada)
Mark Goedkoop (PRé Consultants)
Atsushi Inaba (Agency of Industrial Science and Technology - Japan)
Olivier Jolliet (Swiss Federal Institute of Technology - Lausanne)
Bruce McKean (Nickel Development Institute)

For more information, contact:

Dr. Alain Dubreuil
Tel.: (613) 995-5844
Fax: (613) 996-9041
E-mail: dubreuil@nrcan.gc.ca

Life-Cycle Inventory

• Abstracts List

• Buxman - Key Features on How to Treat Aluminium in LCAs, With Special Regard to Recycling Issues
• Dove - Zinc Ecoprofile Data: the Results of a Pan-European Study
• Hay - EUROFER Stainless Steel LCI Study
• Jungbluth - Life-Cycle Inventory Modelling in the Swiss National LCI Database ECOINVENT 2000
• Landfield - Comparative Analysis of Several Non-Ferrous Metals LCAs
• Markus - Proposal for New Allocation Procedure for Steel Recycling
• Middleton - Life-Cycle Assessment of Nickel Products
• Narita - Life-Cycle Inventory Analysis of CO₂ Emission From Copper Products Manufacturing System in Japan
• Norris - Avoiding Co-Product Allocation in the Metals Sector
• Peterson - Sustainability - The Ultimate Reality Check: Development of a Science-Based Impact Assessment Methodology
• Russel - Metals, LCA, and ISO 14041 Allocation Procedures for Recycling
• Stewart - Life-Cycle Inventories for Minerals Processing in South Africa and Australia: Uses in Decision-Making for Technology Choice
• Trusty - Metal LCI Databases and Methodological Issues
• Von Blottnitz - Functionality and Allocation in a Multi-Product Metals Refinery
• Zapp - Metallic Raw Material Flows - Inventory Analysis

Metal Mining

Abstracts List

List of Presentations

• C. Bauer - Metallic Raw Material Flows - Impact Assessment - “An Approach for Spatial Differentiation to Address Metal-Specific Issues”
• Bourassa - Material-Based Indicators
• Kramadibrata - The Role of Time-Dependent Analysis to Improve Environmental Management System in Mine Closure Plant in Open-Pit Mine
• Lindeijer - How to Improve Impact Assessment for Metal Mining?; Illustrated With a Land Use Biodiversity IA Method for LCA
• Notten - Inventory and Impact Assessment Uncertainty in Coal-Based Power Generation
• Notten - Salinity and Metals’ Impacts of Solid Waste Management Practice in Mining and Minerals Processing
• Rodenburg - Materials Resources and Depletion Based on the Limits of Supply, Prepared for the Helsinki Symposium on Industrial Ecology, August 2000
• Rogich - Metals Use in Relation to Aggregate Material Flows and Sustainable Development
• Steen - Extraction of Metals From Bedrock
• Tremblay - Sustainable Development in the Mining Industry
• van Zyl - Towards Improved Enviromental Indicators During the Mining Life Cycle

Human and Environmental Toxicity

Abstracts List

List of Presentations

• Adams - Integrating Emerging Metal Risk Assessment Technologies
• Chapman - Issues in Risk Assessment of Metals and Metalloids
• Cook - Key Considerations in Assessing Environmental Impacts of Essential Elements
• Deschênes - Partitioning and Speciation of Metals in Surface Soil: Influence on Ecotoxicity Assessment


• N. Itsubo - Development of Damage Functions Considering Toxic Impacts of Ecosystem in Japan
• McGeer - Environmental Toxicity and Impact Assessment Models for Metals
• P. Paquin - Consideration of Metal Availability and Fate in Life Cycle Assessment (LCA)
• J.M. Skeaff - On the Aquatic Hazard Classification of Metals and Alloys
• A.W. Sleeswijk - Metals in the Ocean: An Adapted LCA Fate and Exposure Model

LCA and Developing Countries

All documents are in PDF format.

Abstract:

Bordia - Abstract - Relevance of Life-Cycle Assessment in Developing Countries

List of Presentations:

• Bordia - Relevance of Life-Cycle Assessment in Developing Countries
• Pena - Life-Cycle Assessment as a Process Comparison Tool in the Chilean Copper Production