November/December 1998
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November/December 1998 |
Air pollution knows no political boundaries. To counter transboundary air pollution, a "seamless border" approach is promoted
by John McDonald
Much closer coordination of research, measurement efforts and management strategies by the United States and Canada is necessary to effectively improve air quality along their common border. This is the major thrust of a Special Report on Transboundary Air Quality Issues prepared by the IJCs International Air Quality Advisory Board.
The report presents an overview of the main air quality issues along the entire length of the U.S./Canadian border and makes a number of recommendations for action by the IJC and governments. The IJC fully supports the board's findings, endorses the recommendations and has urged governments to take appropriate action on these issues that affect human and ecosystem health.
Air pollution knows no political boundaries and neither should pollution management. To counter transboundary air pollution, a "seamless border" approach is promoted by the board with the identification of Transboundary Air Pollution Transport Regions as a basis for joint effort by the governments to control and reduce the impact of common pollutants on a regional basis. This concept would enable a more fully integrated and cooperative approach to the management of air quality issues.
Ambient Air Quality Standards/Objectives
The board notes that the long-term goal for both countries should be to achieve the same numerical standards and targets for pollutants such as ozone and fine particulate.
As this goal is not likely to be achieved in the near future, the board advocates:
Applying this approach is particularly important as the United States begins a concerted effort to measure and manage fine particle (PM2.5) concentrations at more than 1,000 sites nationwide.
Regional Issues
In New England and the Atlantic provinces, the board emphasized the impact of fine particles, acid rain and ozone. Acid rain remains a threat to sensitive areas and ozone concentrations continue to reach unhealthy levels during the summer causing breathing difficulties in humans.
High ozone levels and fine particulates are also a concern in the U.S. Midwest and Ontario-Michigan border region. This area also is bombarded by and emits, particularly from large urban centers, persistent toxic substances that are finding their way to the arctic. As confirmed by recent studies in the Chicago area, the toxic content of urban air plumes must be more closely measured, so their contribution to the overall air toxics burden is better known.
In the mountain and prairie region, sulfur dioxide and related compounds continue to reduce visibility and affect forests. In the Pacific region, ozone and fine particulate levels are occasionally unhealthy in the large centers, such as Vancouver and Seattle, and additional measurements are needed to better track these pollutants.
Nitrogen Oxides
The board states that nitrogen oxides will be the most important major air pollutant over the next decade. This class of pollutants is implicated in continental and global air quality issues such as acid rain, global warming, and ozone and fine particle formation often perceived as haze. Emissions are projected to increase in the next few years. Two major contributors are autos and power plants; further reductions in emissions from these sectors will be a significant challenge.
Sulfur in Gasoline
Increased energy consumption and related emissions from cars and trucks in both Canada and the U.S. are of concern. To allow auto emission control systems to work better and lower sulfur dioxide production, the board and the IJC both strongly support the reduction of sulfur content in gasoline. Gasoline in Canada contains about 350 parts per million (ppm) of sulfur -- over 500 ppm in Ontario -- and parts of the U.S. sell gas with several hundred ppm. The board and Commission believe that the current California annual average standard of 30 ppm, with a maximum level of 80 ppm, should be put in effect nationwide in both countries by at least the year 2005 and preferably by 2001. The board will closely track U.S. and Canada decisions on this issue during the next few months.
Power Generation
Coal-fired electrical power generation is of great interest because of its emissions of nitrogen oxides as well as mercury, a persistent toxic substance that has resulted in fish advisories in several locations in the U.S. and Canada. The board continues to review NOx emissions from this sector and, in the next several months, will consider its contribution to the environmental mercury burden. Working with the Commission for Environmental Cooperation, the board co-sponsored a Science Experts Workshop on Mercury in October 1998. The output from this workshop, coupled with other research, will contribute to the development of specific recommendations regarding possible further mercury emission reductions from this source sector.
The International Air Quality Advisory Board
The 10-member board of air quality experts includes individuals from the two federal governments, state and provincial governments, and academic experts. In the past several years, the board has reported on emissions from municipal and hazardous waste incinerators; atmospheric input of toxic substances to the Gulf of Maine and to Lake Superior; the need for an integrated monitoring approach to measuring environmental quality; air quality in the Detroit-Windsor area; and protection and enhancement of visibility, particularly in remote areas.
The text of the full report and additional information on the board can be found on the IJCs web site at www.ijc.org or by contacting the Great Lakes Regional Office.
John McDonald is secretary to the International Air Quality Advisory Board.
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Publication d'un aperçu de la pollution atmosphérique transfrontièr, d'un océan à l'autre, par la Commission mixte internationale (CMI)
Telle est l'idée principale d'un rapport spécial sur la qualité de l'air transfrontalier du Conseil consultatif international sur la qualité de l'air de la CMI.
Puisque, comme le souligne le Conseil, la pollution atmosphérique ne connaît pas de frontières, il devrait en être de même pour la lutte contre cette pollution. Le Conseil a réclamé de nouveau que la gestion de qualité de l'air soit uniforme dans les régions frontalières et il encourage les gouvernements à désigner comme zones de lutte conjointe des zones transfrontalières spéciales. On pourrait ainsi combattre la pollution due aux fortes concentrations d'ozone et de fines particules dans le centre et l'est de la zone frontalière.
Objectifs
Parvenir, dans les deux pays, aux mêmes normes et objectifs numériques, en ce qui concerne les polluants tels que l'ozone et les fines particules est un objectif à long terme. Cependant, le Conseil préconise :
Les questions de pollution atmosphérique transfrontière les plus préoccupantes comprennent les émissions d'oxydes d'azote, le soufre dans l'essence à moteur et les émissions de mercure des centrales électriques à charbon. Dans son rapport, le Conseil mentionne aussi les questions et activités parallèles ailleurs dans le monde, plus particulièrement en Europe, et il encourage la CMI à s'intéresser vivement aux efforts de ces pays pour surveiller, gérer et améliorer la qualité de l'air.
Le Conseil recrute ses dix membres chez les représentants des deux administrations fédérales, des États et des provinces ainsi que chez les spécialistes des établissements d'éducation supérieure. On peut trouver le texte intégral du rapport et des renseignements supplémentaires sur le Conseil en accédant au site Web de la Commission (www.ijc.org) ou en s'adressant au Bureau régional des Grands Lacs.