Priority Substances List Assessment Report for Respirable Particulate Matter

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 are 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 an initial screening of readily accessible information, the rationale for assessing "respirable particulate matter less than or equal to 10 microns&" provided by the Ministers' Expert Advisory Panel on the Second Priority Substances List (Ministers' Expert Advisory Panel, 1995) was as follows:

Exposure to respirable particulate matter in the Canadian environment is widespread. Sources include vehicle exhaust, construction, industrial air pollution and the bulk shipping of minerals. Small particles, irrespective of their origins, are trapped in the lungs. Effects associated with ambient exposure to respirable particulate matter include respiratory and pulmonary health dysfunction, which can lead to school absenteeism and increased hospital admissions. An assessment is needed to evaluate health risks.

The potential impacts of ambient exposure to respirable particulate matter on the environment and on human health have recently been evaluated by the Federal¨CProvincial Working Group on Air Quality Objectives and Guidelines as part of the development of National Ambient Air Quality Objectives (NAAQO) for Particulate Matter. The relevant background material was reviewed and the potential risks from ambient PM10 and PM2.5 were assessed in the Science Assessment Document produced in support of the NAAQO (WGAQOG, 1998). This Assessment Report simply summarizes the critical information from that document in the context of the PSL program. Only the risks posed by ambient particulate matter to human health (i.e., whether respirable particulate matter ≤10 µm [as PM10 and PM2.5] is "toxic" as defined in Paragraph 64(c) of CEPA 1999) are addressed in this Assessment Report, since these were the critical effects identified in the NAAQO Science Assessment Document.

The Science Assessment Document on which this Assessment Report is based was prepared by the following individuals:

• R. Bailey, Environment Canada
• M. Bourgeau, Health Canada
• E. Bush, Environment Canada
• T. Dann, Environment Canada
• L. Liu, Health Canada
• S. MacDonald, Health Canada
• S. Pryor, Indiana University
• M. Shepherd, Environment Canada
• N. Suzuki, British Columbia Environment
• K. Timoffee, Health Canada
• G. Wood, Health Canada

Selected sections of the NAAQO Science Assessment Document were prepared based on background contract reports by G. Oberdörster, University of Rochester (toxicokinetics, animal studies) and by M. Utell and J. Samet, University of Rochester and Johns Hopkins University, respectively (controlled human studies).

In January 1997, the draft NAAQO Science Assessment Document, incorporating information on fine particles, was submitted to the Federal-Provincial Working Group on Air Quality Objectives and Guidelines for technical review. In March 1997, the draft document was sent to the following external peer reviewers, who provided written comments with respect to the accuracy of reporting, adequacy of coverage and defensibility of conclusions:

• G. Pengelly, McMaster University
• J. Samet, Johns Hopkins University
• C. Shy, University of North Carolina at Chapel Hill
• M. Williams, U.K. Department of Environment, Transport and the Regions
• W. Wilson, U.S. Environmental Protection Agency

Information acquired up to the end of the period of peer review (i.e., April/May 1997) was considered in revising the NAAQO Science Assessment Document. Following revisions, technical editing and translation, the final Science Assessment Document was released in 1999. Staff of the Priority Substances Section of Health Canada (R. Newhook and M.E. Meek) assisted in the preparation of this Assessment Report, primarily to provide context for presentation to meet the needs of the Priority Substances program.

For additional information on the preparation process for or the content of the NAAQO Science Assessment Document, please contact B. Jessiman of the Air and Waste Section of Health Canada (health-related sections) or M. Shepherd of the Atmospheric Environment Service of Environment Canada (environmental sections).

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 from May 15 to July 14, 1999 (Environment Canada and Health Canada, 1999). Following consideration of comments received, the Assessment Report was revised as appropriate. A summary of the comments and their responses is available on the Internet at:

 www.ec.gc.ca/cceb1/en g/final/index_e.html

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:

 www.ec.gc.ca/cceb1/en g/final/index_e.html

The NAAQO Science Assessment Document on which this Assessment Report is based is available upon request from:

• Environmental Health Centre
  Room 104
  Health Canada
  Tunney's Pasture
  Ottawa, Ontario
  K1A 0L2