International Air Quality Advisory Board
SPECIAL REPORT ON
TRANSBOUNDARY AIR QUALITY ISSUES
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- SEAMLESS BORDER
Recognizing the need to manage the transboundary region in as seamless a manner as possible,
the Board recommends the following:
- The Commission propose to governments that the CanadaUnited States
border region (extending far enough on either side to capture transport
distances for at least the common air pollutants) be segmented into
Transboundary Air Pollution Transport Regions (TAPTRs) as a focus of
further joint effort by the governments. The Board commits itself to
provide continual advice and guidance to the Commission as the
governments consider this approach and attempt its implementation.
- Within each of the TAPTRs, the Commission should advocate the
generation of common harmonized data sets, including emission
inventories and monitoring data. Monitoring networks and methodologies
and transport models should be continually examined to determine the
comparability of their outputs. These data resources should be used to
develop truly borderless air quality representations for the transboundary
- For pollutants transported over great distances, such as mercury and POPs
(Persistent Organic Pollutants), the Board should continue to identify
source regions that contribute significantly to CanadaUnited States
transboundary pollution and review the effectiveness of the governments'
control programs in reducing emissions in these regions. This will support
a broader continental effort led by the Commission for Economic
Cooperation (CEC) in North America. Source regions of these PTSs may
in some instances be subsets of the TAPTRs or may be located beyond the
boundaries of the TAPTR border zone.
- NITROGEN OXIDES -THE PIVOTAL POLLUTANT
While many complex factors influence their production, it is likely that NOX emissions will
change substantially in eastern North America. Given this, the Board recommends the following:
- Current monitoring of NOX emissions, ambient air concentrations, and
deposition should continue. At the same time, further monitoring and
process research should be carried out to better understand transformation
mechanisms leading to ozone and particulate formation, as well as
deposition of nitrogen species in acid rain and as excess nutrient loadings.
In addition, resources should be devoted to further research and monitoring
of sensitive endpoints affected by NOX.
- Caution should be used in implementing programs that would result in
seasonal control of NOX as a response to ozone formation which occurs
principally in the summer. Such a strategy would not address the formation
of other nitrogen pollutants that are believed to have year-round adverse
effects on the environment and human health.
- CONTINENTAL ISSUES - PERSISTENT TOXIC SUBSTANCES
The Board recommends that the Commission closely track implementation of the Great Lakes
Binational Toxics Strategy at regular intervals and review the progress in completing specific
elements of the strategy as identified by the Board under the strategy.
- MONITORING and MODELING
Based on the its review of monitoring and modeling activities for both common pollutants and
PTSs, the Board recommends the following:
- The United States and Canada should address and eliminate gaps in
available data on levels of fine particulate matter and ozone in the
transboundary region through a coordinated binational strategy for
monitoring within the region.
- Both countries should collaborate in developing a number of sites where
co-located instrumentation can be operated to assure that data generated by
each country can be directly compared. The DetroitWindsor
transboundary region should be the location of one such site for monitoring
- Both countries should work together to place Canadian and U.S. chemical
and meteorological modules on the Models-3 system/platform so that
modelers from both countries can compare and develop the best modeling
tool to address air pollution issues.
- Both countries should expand routine monitoring capabilities for trace
quantities of substances, such as those measured by the IADN, to include
measurements immediately downwind of urban areas.
- Both countries should develop comparable and compatible high-quality and
publicly accessible binational emissions inventories. These inventories
would have a variety of uses, including abatement planning, policy
development and implementation, modeling analyses, and public education.
- REGIONAL ISSUES
The Board recommends that any regional control strategies to limit transboundary air pollution be
based on source transport and receptor regions as defined by the pollutant, meteorology and
- HARMONIZATION AND STANDARD SETTING PROCESSES
While the merit and possibility of harmonized standards continues to be considered by both
governments, the Board recommends that, in addition to establishing the TAPTRs, the
Commission advocate appropriate inclusion of experts from both countries in the development of
air quality standards and criteria by each country, including joint involvement in elements (e.g.
monitoring and emission inventory development) that contribute to such processes.
- COLLABORATION WITH OTHER ORGANIZATIONS
The Board recommends that the Commission maintain a dialogue with the CEC and consider
opportunities for interaction with the UNECE to ensure that their work reflects North American
practices and to consider which European approaches to determining and managing air quality
might be applicable in North America.
- SURVEILLANCE ISSUES
In conjunction with efforts to assess the release and transport of PM2.5, the Commission should
ensure that any monitoring network established by the United States over the next five years is at
least compatible with, or can be compared to, PM2.5 monitoring done in Canada.
The Commission should urge governments to determine appropriate endpoints and indicators of
air quality (such as hospital admissions and alterations in fisheries) and to conduct periodic
surveys of air pollution receptors (such as sensitive vegetative species) to determine the effects of
cleaner air in the border region. This indicator monitoring should include a research component
to ensure that all the significant health and ecosystem linkages (e.g. air quality effects on forests)
are determined and understood.
- EMERGING AND ANTICIPATORY ISSUES
The Board has recommended to the Commission the development of a uniform standard
throughout both countries for sulfur content in gasoline of 30 ppm annual average, with a
maximum level of 80 ppm, optimally by the year 2001 but certainly no later than 2005.
Subsequently, the Commission made largely the same recommendation to the governments of the
United States and Canada. The Board also considered the need for further reductions in mercury
and NOX emissions from the coal-fired electrical generation sector. It will be considering possible
recommended actions involving this sector in the next several months.