2010 Progress Report - International Joint Commission

Figure 40. Lake and Stream
Exceedances of Estimated Critical Loads
(Sulphur + Nitrogen) for Total Nitrogen
and Sulphur Deposition, 1989–1991
Figure 41. Lake and Stream
Exceedances of Estimated Critical Loads
(Sulphur + Nitrogen) for Total Nitrogen
and Sulphur Deposition, 2006–2008
Scientific and Technical Cooperation and Research
Source: US EPA 2010
Source: US EPA 2010
Other Related Canadian and
U.S. Atmospheric Research
Ammonia Emissions
Ammonia (NH 3
) is listed by the United Nations
Economic Commission for Europe (UNECE) Protocol to
Abate Acidifi cation, Eutrophication and Ground-level
Ozone (Gothenburg Protocol) as a chemical whose
emissions have a more severe environmental or health
impact. NH 3
is a precursor chemical in the formation
of fi ne particulate matter (PM 2.5
), a component of the
mixture known as smog. As NH 3
emissions worldwide
are expected to increase in response to agricultural
intensifi cation (with agricultural activity accounting
for 90% of Canadian NH 3
emissions in 2007 in
the form of livestock and fertilizer application: see
Figure 42), the role of ammonia in PM 2.5
formation
may proportionally become more important as
emissions of other precursor gases level off or
decrease due to emissions control policies.
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