Priority Substances List Assessment Report for Releases from Primary and Secondary Copper Smelters and Copper Refineries - Releases from Primary and Secondary Zinc Smelters and Zinc Refineries

1.0 Introduction

The Canadian Environmental Protection Act, 1999 (CEPA 1999) requires the federal Ministers of the Environment and of Health to prepare and publish a Priority Substances List (PSL) that identifies substances, including chemicals, groups of chemicals, effluents and wastes, that may be harmful to the environment or constitute a danger to human health. The Act also requires both Ministers to assess these substances and determine whether they are "toxic" or capable of becoming "toxic" as defined in Section 64 of the Act, which states:

...a substance is toxic if it is entering or may enter the environment in a quantity or concentration or under conditions that

1. have or may have an immediate or long-term harmful effect on the environment or its biological diversity;
2. constitute or may constitute a danger to the environment on which life depends; or
3. constitute or may constitute a danger in Canada to human life or health.

Substances that are assessed as "toxic" as defined in Section 64 may be placed on Schedule 1 of the Act and considered for possible risk management measures, such as regulations, guidelines, pollution prevention plans or codes of practice to control any aspect of their life cycle, from the research and development stage through manufacture, use, storage, transport and ultimate disposal.

Based on initial screening of readily accessible information, the rationale for assessing "Releases from primary and secondary copper smelters and copper refineries" provided by the Ministers' Expert Advisory Panel on the Second Priority Substances List (Ministers' Expert Advisory Panel, 1995) was as follows:

A wide variety of substances is released into the Canadian environment from primary and secondary copper smelters and refineries. The individual chemical components of releases from these facilities include particulate matter, copper, lead, arsenic and sulphuric acid. The Panel recognizes that assessing the effects of these releases will be difficult from a human health perspective. Releases are often very complex, containing variable mixtures of individual compounds. Often there are no epidemiological studies on populations living near such point sources. For populations at some distance, it may be difficult to attribute effects to the source under examination since other sources can contribute to exposure. Nonetheless, given the large volumes released and the persistent and hazardous nature of some of those substances, an assessment is required to determine the nature and extent of local and long-range ecological and health effects.

The rationale provided by the Panel for assessing "Releases from primary and secondary zinc smelters and zinc refineries" was the same, except that the individual components identified were particulate matter, zinc and sulphuric acid.

Because of their similarities, assessments of whether these two PSL substances are "toxic" under Section 64 of CEPA 1999 were conducted in parallel, and the findings are reported together in this Assessment Report. Since most releases (on a mass basis) are discharged to air and releases to air have the greatest potential for causing widespread effects, these assessments have focused on environmental and human health risks of air emissions. Levels in air were also expected to better reflect current releases than is the case for other environmental media, which can be strongly influenced by high historical emissions. Releases to water from several Canadian copper smelters and refineries and zinc smelters and refineries (more conventionally "zinc plants") will be included in the effluents regulated under the revised Metal Mining Liquid Effluent Regulations (MMLER) and Guidelines of the Fisheries Act.¹ Releases subject to the Fisheries Act² were not examined in these assessments.

Although potential impacts on both the environment and human health are considered in these assessments, the focus of the assessment is on environmental effects. This is due primarily to limitations of available epidemiological studies of human populations near copper smelters and refineries and zinc plants, which are exposed directly to releases from these facilities, and difficulties in assessing the effects of mixtures based on data from mammalian toxicity studies on individual compounds. These limitations were recognized in the rationale for these assessments provided by the Ministers' Expert Advisory Panel.

Since the entries included on the second Priority Substances List relate to "releases" from copper smelters and refineries and zinc plants, the human health assessment was focused on populations in the vicinity of these facilities, which are expected to be most exposed to substances emitted from them, and on evaluating the potential impacts of current releases. Consequently, the health-related sections of this report contain a summary of recent environmental levels of a number of substances near these facilities in Canada, obtained in response to a questionnaire sent to the companies. A review of available epidemiological studies of populations in the vicinity of copper smelters and refineries and zinc plants is also included. Given the number and variety of substances released from copper smelters and refineries and zinc plants, the health assessment builds on previous work for information on health effects and exposure-response for individual substances, relying on other assessments conducted under the PSL assessment program and other programs.

Descriptions of the approaches to assessment of the effects of Priority Substances on the environment and human health are available in published companion documents. The document entitled "Environmental Assessments of Priority Substances under the Canadian Environmental Protection Act. Guidance Manual Version 1.0 - March 1997" (Environment Canada, 1997a) provides guidance for conducting environmental assessments of Priority Substances in Canada. This document may be purchased from:

• Environmental Protection Publications
  Environmental Technology Advancement Directorate
  Environment Canada
  Ottawa, Ontario
  K1A 0H3

It is also available on the  Commercial Chemicals Evaluation Branch web site at www.ec.gc.ca/substances/ese/eng/esehome.cfm under the heading "Guidance Manual." It should be noted that the approach outlined therein has evolved to incorporate recent developments in risk assessment methodology, which will be addressed in future releases of the guidance manual for environmental assessments of Priority Substances.

The approach to assessment of effects on human health is outlined in the following publication of the Environmental Health Directorate of Health Canada: "Canadian Environmental Protection Act - Human Health Risk Assessment for Priority Substances" (Health Canada, 1994), copies of which are available from:

• HECS Publishing
  Healthy Environments and Consumer Safety Branch
  Health Canada
  Tunney's Pasture
  Address Locator: 3100A
  Ottawa, Ontario
  K1A 0L2

or on the Environmental Health Program publications web site (www.hc-sc.gc.ca/ehp/ehd/catalogue/bch.htm). The approach is also described in an article published in the Journal of Environmental Science and Health -Environmental Carcinogenesis & Ecotoxicology Reviews (Meek et al., 1994). It should be noted that the approach outlined therein has evolved to incorporate recent developments in risk assessment methodology, which are described on the Existing Substances Division web site (www.hc-sc.gc.ca/exsd-dse) and which will be addressed in future releases of the approach paper for the assessment of effects on human health.

Informal questionnaires were used to obtain the most recent information available from Canadian industry on releases, environmental concentrations and the ecological effects of their releases. The search strategies employed in the identification of additional data relevant to assessment of potential effects on the environment (prior to fall 1999) and on human health (prior to March 2000 for monitoring and epidemiological data on nearby populations only) are presented in Appendix A. Review articles were consulted where appropriate. However, all original studies that form the basis for determining whether releases from copper and zinc smelters and refineries are "toxic" under CEPA 1999 have been critically evaluated by staff of Environment Canada (entry and environmental exposure and effects) and Health Canada (human exposure and effects on human health). In addition, a number of reports were prepared under contract in support of the environmental component of these assessments; these are also listed in Appendix A.

The environmental components of these assessments were led by P. Doyle and D. Gutzman, with support from D. Caldbick, A. El-Shaarawi, C. Fortin, A. Green, M. Lapointe, D. Morin and J. Sanderson on behalf of Environment Canada. Sections of the Assessment Report and the supporting documentation related to the environmental assessment of copper and zinc smelters and refineries were prepared or reviewed by the members of the Environmental Resource Group (ERG), established by Environment Canada in August 1997 to support the environmental assessment. ERG members were selected based on their expertise in fields of particular significance to these assessments, including releases from the base metal smelting sector, aquatic and terrestrial effects, atmospheric dispersion modelling, metal transport and fate, metal speciation, critical loads, ambient sulphur dioxide (SO₂) and acid deposition. Members include:

• J. Ayres, Environment Canada
• G. Bird, Canadian Nuclear Safety Commission
• U. Borgmann, Environment Canada
• S. Daggupaty, Environment Canada
• W. de Vries, DLO Winand Staring Centre, The Netherlands
• M. Diamond, University of Toronto
  
• G. Dixon, University of Waterloo
• R. Garrett, Natural Resources Canada
• B. Hale, University of Guelph
• D. Hart, Beak International Inc.
• K. Hedley, Environment Canada
• W. Hendershot, McGill University
• R. Hoff, University of Maryland Baltimore County
• D. Hrebenyk, SENES Consultants Ltd.
• T. Jackson, Environment Canada
• P.K. Leung, Environment Canada
• S. Linzon, Phytotoxicology Consultant Services Ltd.
• K. Lloyd, Environment Canada
• M. Sheppard, ECOMatters Inc.
• S. Sheppard, ECOMatters Inc.
• J. Skeaff, Natural Resources Canada
• A. Tessier, University of Quebec
• P. Thompson, Canadian Nuclear Safety Commission

Industry representatives on the ERG who monitored the assessment process include:

• Cominco Ltd. - M. Edwards and G. Kenyon
• Falconbridge Ltd. - R. Telewiak
• Hudson Bay Mining and Smelting (HBM&S) Ltd. - W. Fraser
• Inco Ltd. - T. Burnett, C. Ferguson and W. Szumylo
• Noranda Ltd. - J. Moulin and H. Veldhuizen

In addition to members of the ERG, the following individuals reviewed and provided comments on environmental sections of the supporting documentation:

• H. Allen, University of Delaware
• B. Antcliffe, Department of Fisheries and Oceans
• N. Belzile, Laurentian University
• G. Bonham-Carter, Natural Resources Canada
• T. Burnett, Inco Ltd.
• D. Chambers, SENES Consultants Ltd.
• P. Chapman, EVS Environmental Consultants
• B. Duncan, Cominco Ltd.
• L. Evans, University of Guelph
• D. Gamble, Agriculture and Agri-Food Canada
• A. Germain, Environment Canada
• M. McLaughlin, CSIRO, Australia
• M. Moran, Environment Canada
• M. Power, University of Waterloo
• R. Prairie, Noranda Ltd.
• M. Sadiq, University of Guelph
• R. Stager, SENES Consultants Ltd.
• H. Veldhuizen, Noranda Ltd.

Individuals who reviewed and provided substantive comments on the draft environmental assessment report and who have not been recognized above include:

• Bezak, Manitoba Conservation Department
• P. Campbell, Institut National de la Recherche Scientifique - Eau
• V. Chapados, Noranda Ltd.
• D. Daoust, Noranda Ltd.
• M. Edwards, Cominco Ltd.
• W. Fraser, HBM&S Ltd.
• B. Keller, Laurentian University
• J. Leclerc, Noranda Ltd.
• K. Taylor, Environment Canada
  

Supporting documentation and sections of this Assessment Report related to human health were prepared by the following staff of Health Canada:

• K. Byrne
• H. Hirtle
• M.E. Meek
• R. Newhook

The health-related supporting documentation was circulated for comment to the following representatives of the smelting and refining companies who are members of the ERG for this assessment, primarily to ensure the accuracy of the information contained therein concerning the copper smelters and refineries and zinc plants that their companies operate:

• M. Edwards, Cominco Ltd.
• W. Fraser, HBM&S Ltd.
• R. Prairie, Noranda Ltd.
• W. Szumylo, Inco Ltd.
• R. Telewiak, Falconbridge Ltd.

Due to reliance on measures of exposure-response derived from peer-reviewed sources for comparison with ambient levels of components of releases, external review of the health-related sections of the assessment was less extensive than for other assessments on Priority Substances. The health-related sections in the Assessment Report were reviewed externally by M. Younes, World Health Organization (WHO) International Programme on Chemical Safety and M. Dourson, Toxicology Excellence for Risk Assessment.

The health-related sections of the Assessment Report were reviewed and approved by the Health Protection Branch Risk Management meeting of Health Canada.

The entire Assessment Report was reviewed and approved by the Environment Canada/Health Canada CEPA Management Committee.

A draft of the Assessment Report was made available for a 60-day public comment period (July 1 to August 30, 2000) (EC/HC, 2000b). Following consideration of comments received, the Assessment Report was revised as appropriate. A summary of the comments and responses is available on the Internet at:

 Public Comment on Draft Assessment Reports
www.ec.gc.ca/substances/ese/eng/psap/public/main.cfm

The text of the Assessment Report has been structured to address environmental effects initially (relevant to determination of "toxic" under Paragraphs 64(a) and (b)), followed by effects on human health (relevant to determination of "toxic" under Paragraph 64(c)).

Copies of this Assessment Report are available upon request from:

• Inquiry Centre
  Environment Canada
  Main Floor, Place Vincent Massey
  351 St. Joseph Blvd.
  Hull, Quebec
  K1A 0H3

or on the Internet at:

 Priority Substance Assessment Program Assessment Reports
www.ec.gc.ca/substances/ese/eng/psap/final/main.cfm

Unpublished supporting documentation, which presents additional information, is available upon request from:

• Existing Substances Branch
  Environment Canada
  14th Floor, Place Vincent Massey
  351 St. Joseph Blvd.
  Hull, Quebec
  K1A 0H3

or

• Existing Substances Division
  Health Canada
  Environmental Health Centre
  Tunney's Pasture
  Address Locator: 0801C2
  Ottawa, Ontario
  K1A 0L2

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1. The Metal Mining Liquid Effluent Regulations (MMLER) and Guidelines, which are currently in force, will be replaced by the Metal Mining Effluent Regulations (MMER), which are anticipated to come into force in 2002.
2. Only smelter or refinery effluents that are combined with those from mining operations fall under the Fisheries Act regulations.