Guidance for Evaluating Human Health Effects in Impact Assessment: Air Quality

Organization: Health Canada

Date published: December 2023

This document provides generic guidance on assessing potential human health risks of air quality in federal impact assessments (IAs) of proposed major resource and infrastructure projects in Canada (such as mines, dams, pipelines and other projects). It presents the principles, current practices and basic information Health Canada looks for when it reviews the impact statement or other documentation submitted by project proponents as part of the IA process.

The guidance is presented to support an efficient and transparent project review process. The foundational information described here should be supplemented appropriately with additional information relevant to proposed projects.

The guidance was prepared for the Impact Assessment Agency of Canada (the Agency) and stakeholders involved in the IA process to communicate Health Canada's standard areas of engagement and priorities to help ensure that sufficient evidence is available to support sound decisions.

As part of its review, Health Canada may suggest that the Agency, review panels or others collect information not specifically described in this document to assess the health effects of proposed projects. As the guidance provided is generic and designed to support the IA process, the scope of Health Canada's review may also be amended to reflect project-specific circumstances.

This document concerns the assessment of human health risks associated with air quality. It contains information on the division of roles and responsibilities for issues related to air quality at various levels of government in Canada; health effects associated with air quality; indicators of these effects; and steps in Health Canada's preferred approach to assessing air quality-related health effects.

Appendix A provides a checklist for verifying that the key elements of an air quality assessment have been completed and where this information appears in the assessment document.

Appendix B lists the Canadian Ambient Air Quality Standards (CAAQS) and National Ambient Air Quality Objectives (NAAQOs) for various ambient air pollutants, current as of the date of publication of this document. The Canadian Council of Ministers of the Environment (CCME)'s State of the Air website also provides key information on air quality across Canada. Definitions and equations for converting units are provided at the end of this appendix.

Appendix C provides a sample calculation of additional lung cancer mortality from fine particulate matter (PM_2.5) recommended for the characterization of health risks of diesel exhaust.