Executive Summary

Introduction

Ground-level Ozone

Particulate Matter in Air

Conclusions

References

National Ambient Air Quality Standards : proposed decisions on particulate matter and ozone

Introduction

The Government of Canada is pleased to respond to the request of U.S. Environmental Protection Agency, in the Federal Register notices of December 13, 1996, for comments on proposed revisions to ozone and particulate matter air quality standards under the U.S. Clean Air Act.

Canada strongly welcomes the EPA effort to tighten ozone and particulate matter standards in the U.S. The Government of Canada and provincial governments have already determined that much stricter ozone and PM standards are needed in Canada. This determination followed a comprehensive review of scientific assessments that show that existing ozone and PM levels are having a significant and adverse impact upon public health.

For ozone, Canada confirmed nationwide objectives in 1989. These objectives require ozone levels to be restricted to 82 parts per billion in any one hour period, a level that is approximately 25% more stringent than the ozone standard that EPA is proposing to adopt. Since 1989, this objective has been enforced at the federal and provincial levels.

For particulate matter, Canadian scientists determined in 1995, that PM objectives could be tightened. A decision to adopt new Canadian federal objectives was made by Canadian governments in November, 1996. The Canadian recommended levels for PM10 and PM2.5 are likely to be at least as stringent as that being proposed by the EPA and are expected within the next few months.

These comments describe Canada's decisions to tighten its domestic ozone and PM objectives including summarizing the scientific assessments upon which these decisions are being based. In fact, on the basis of these assessments, Canada believes that even stronger air pollution controls than EPA has proposed would be warranted. These comments also briefly describe the impact that transboundary flow from the U.S. into Canada have upon Canada's ability to control its own air pollution levels.

Canada and the U.S. have recognized for many years that air quality in each country affects the ability of the other to meet its air quality standards and objectives. More than 20 years ago, the U.S. Congress adopted section 115 of the Clean Air Act, which was specifically aimed at controlling transboundary flows of air emissions from the U.S. into Canada. More recently, in the 1991 Canada-United States Air Quality Agreement, the two countries reaffirmed their conviction that "transboundary air pollution can effectively be reduced through cooperative or coordinated action."

Canada therefore looks forward to working closely with the United States in developing stronger air pollution controls, and in sharing research and scientific assessments that clearly demonstrate the need for such controls. Canada believes that this type of "coordinated action" can achieve mutually beneficial improvements in the two nations' common airsheds, and will provide enormous public health improvements in both Canada and the United States in coming years.