Conclusion

The United States and Canada have continued to fulfill the obligations set forth in the Air Quality Agreement successfully. Implementation of each country's acid rain control program is a notable achievement of the Agreement; however, both countries recognize that additional efforts are necessary to address ongoing human health and environmental problems, particularly in highly sensitive areas and within the United States-Canada transboundary region.

The United States and Canada successfully negotiated an Ozone Annex in 2000, and the 2004 Progress Report is the first biennial report to incorporate information on the progress being made to address transboundary ozone pollution in the eastern border regions of each country. To assist in completing this first review of progress, the United States and Canada met in Quebec City in June 2004 and, with stakeholders, outlined the programs that have been implemented in each country, discussed the emission reductions expected, and charted the ozone air quality levels that will serve as benchmarks for future reviews of progress to meet the ozone air quality standards in each country.

Efforts to address PM levels in the air are important in both the United States and Canada. Within the context of the Air Quality Agreement, transboundary PM transport has become an issue of interest. The conclusions of a joint scientific report on transboundary PM were issued in 2004 and are summarized in the 2004 Progress Report. The first joint effort of this kind to be undertaken by the two countries, these conclusions and those of other joint analyses, such as that in the Georgia Basin-Puget Sound of British Columbia and Washington State, provide the basis for moving forward in a bilateral context. In particular, these conclusions guide the countries in addressing PM and other air-related matters with priority given to the eastern half of the two countries and with due consideration given to the issues identified in the shared airshed in the Georgia Basin-Puget Sound and the Rocky Mountain region.

Human health and the environment have benefited greatly from progress made under the U.S.-Canada Air Quality Agreement. Both countries look forward to assessing the results of implementing the Ozone Annex and to addressing additional transboundary air pollution problems.