STATE OF THE GREAT LAKES 2005
ARE WE MAKING PROGRESS TO IMPROVE AIR QUALITY?
Yes, significant progress has been made over the past 20 years to improve air quality in the Great Lakes region,
however, serious impacts due to air pollution remain. There are opportunities to build on the progress made and
The Issues
• Air quality is a local and regional issue affected
by human activities, weather, and topography
• Many Great Lakes cities experience
unacceptable air quality, especially in the
summer.
• Levels of ozone and microscopic airborne
particles remain a concern in the Great Lakes
region, especially in the Detroit-Windsor-
Ottawa corridor (extending northward to Sault
St. Marie), the Lake Michigan region and the
Buffalo-Niagara region. These pollutants
continue to exceed air quality criteria and
standards at a number of monitoring stations in
southern Ontario and the lower Great Lakes
region of the United States. Ozone and
microscopic airborne particles (particulate
matter) combine with other air pollutants to
produce a condition known as smog.
• Continued economic growth, population
growth, and associated urban sprawl threaten
to offset emission reductions through both
increased energy consumption and vehicle
miles travelled.
Photo: Microsoft Office.
The Indicator
A suite of local and regional pollutants is measured
by the governments of the United States and
Canada to monitor air quality in the Great Lakes
ecosystem and to infer the potential impact of
degraded air quality on human health and the
environment in the Great Lakes region. Key
pollutants of concern are carbon monoxide,
nitrogen dioxide, sulfur dioxide, lead, particulate
matter, ground level ozone and toxic contaminants
in the atmosphere (also known as air toxics.)
© Chad Boyko, 2005
A clear day (left) and a smog day (above) over Hamilton
Harbour, Ontario. Photos: Chad Boyko.
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ARE WE MAKING PROGRESS TO
IMPROVE AIR QUALITY?
Pollutant
Carbon Monoxide
(CO)
Nitrogen Dioxide
(N02)
Nitrogen Oxides
(NOX)
Sulfur Dioxide
(S02)
Lead
PM *
1 1V110
(Direct Emissions)
PM *
1 1V12.5
(Direct Emissions)
Benzene
(Air Toxics)
Ozone (O3)
1-hour maximum
Ozone (O3)
(8-hour mean)
Ozone (O3)
(seasonal means)
Region
United States
Canada
Ontario
U.S. Great Lakes Region
Ontario
United States
United States
Ontario
U.S. Great Lakes Region
Ontario
U.S. Great Lakes Region
United States
United States
United States
Ontario
United States
Ontario
U.S. Great Lakes Region
Ontario
Timeline
1993 - 2002
1980 - 2000
1991 - 2000
1982 - 2001
1975 - 2002
1993 - 2002
1993 - 2002
1993 - 2002
1993 - 2002
1971 - 2001
1982 - 2001
1984 - 2000
1992 - 2001
1993 - 2002
1999 - 2002
1993 - 2002
1994 - 2002
1993 - 2002
1993-2003
1980-2003
1990 - 2003
1980 - 2003 summer
1980 - 2003 winter
rr-r i
Trend
Concentration i 42%
Emissions 1 21%
Concentration 1 60%
Emissions -I 4%
Concentration 1 19%
Concentration -I 23%
Emissions -I- 12%
Concentration -I 39%
Emissions i- 31%
Concentration ^ 20%
Emissions -i- 82%
Concentration i 95%
Concentration -I 95%
Concentration •!• 12%
Emissions i 22%
Concentration 1 8%
Emissions -I 17%
Concentration -I 47%
Concentration i 56%
Concentration -I 2%
Concentration i 1 0%
Concentration 1 6%
Concentration T 2 1 %
Concentration T 29%
Table 1. Ambient concentration and emissions trends tor air pollutants in both the United States and Canada over
the various time periods. * No Canadian data for particulate matter (PM10 and PM25)
^ Indicates concentrations decreased over indicated timeline.
Indicates concentrations increased over indicated timeline.
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ARE WE MAKING PROGRESS TO
IMPROVE AIR QUALITY?
The Assessment
There has been significant progress in reducing both
the ambient concentration and emissions of many of
the key air pollutants in the Great Lakes basin. Six
criteria pollutants of concern for human health and
the environment are listed in the U.S. Clean Air Act
(also listed in The Indicator section) and progress has
been made in reducing ambient concentrations of all
six, however, ambient concentrations of ozone and
particulate matter are of particular concern in both
the United States and Canada. In general, air
pollution levels still continue to have significant
human health and environmental effects.
Table 1 summarizes trends of ambient
concentrations and emissions for pollutants of
concern. Sources or reductions for these pollutants
include:
• Carbon Monoxide (CO): CO levels in the Great
Lakes region have decreased, mainly as a result
of more stringent transportation emissions
standards.
• Nitrogen Dioxide (No2): The combustion of fuel
in motor vehicles is the most common source of
NOX emissions. Significant reductions of both
NO2 and NOX, the family of nitrogen oxides,
have occurred in the transportation sector.
• Sulfur Dioxide (SO2): Emissions of this pollutant
are from a variety of sources including industrial
processes and electrical utilities. Significant
reductions have occurred mainly as a result of
regulations imposed on coal and fossil fuel
burning power plants and some smelters.
• Lead: Regulatory efforts to reduce the content of
lead in gasoline have led to significant
reductions in both the United States and
Canada.
• Particulate Matter (PM): The fraction of particles
in the atmosphere with a diameter of 10 microns
or less (PM10) or 2.5 microns or less (PM2S) is
monitored. PM2S is of particular concern to
human health because it can penetrate deeply
into the lungs. Particulate matter is produced by
many sources, including cars, trucks, and buses
burning diesel and other fossil fuels; the
preparation and application of fertilizers and
pesticides; road construction; industrial
processes; mining; agricultural burning; and the
operation of fireplaces and wood stoves.
• Ground-Level Ozone (O3): O3 forms during the
reaction of sunlight or heat with pollutants
already present in the environment, making it a
secondary pollutant. O3 is a problem throughout
the Great Lakes region, with the exception of
Lake Superior. In 2003, O3 levels (measured as
hourly values) in the United States were the
lowest recorded in 20 years. The improved air
quality mainly resulted from favourable weather
conditions. In Ontario, the maximum recorded
hourly O3 concentrations decreased from 1980 to
2002, while the trend in average seasonal values
appears to be increasing over the past 10 years.
At their current levels,
one-hour O3
concentrations continue
to exceed Ontario's
Ambient Air Quality
Criterion (AAQC).
Wood stove. Photo:
Environment Canada.
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ARE WE MAKING PROGRESS TO
IMPROVE AIR QUALITY?
• Air Toxics: Various pollutants with the potential
to harm human health or cause adverse
environmental and ecological effects are
grouped into this category. Example pollutants
include benzene, chromium, and carbon
tetrachloride.
Current Actions
Major pollution reduction efforts are underway in
both the United States and Canada, which focus on
better characterization of ambient pollution levels
and minimization of pollution emissions.
Under the Border Air Quality Strategy, the Great
Lakes Basin Airshed Management Framework pilot
project is conducting a joint investigation of local
and sub-regional airshed management in a
contiguous urban area that crosses the border. The
project will focus on the ground level ozone and
fine particle (PM) pollution problems that impact
the southeast Michigan/southwest Ontario border
region.
Monitoring for specific pollutants continues. In the
United States, the National Air Toxics Trend Site
network detects trends in high risk air toxics such as
benzene and chromium. Regulatory agencies in the
province of Ontario and the eight Great Lakes states
have developed the Great Lakes Regional Air Toxics
Emissions Inventory in an effort to reduce airborne
deposition of persistent
toxic chemicals to the Great
Lakes. In 2000, Canada and
the United states signed the
Ozone Annex to the Air
Quality Agreement,
committing both countries
to reducing emissions of
nitrogen oxides and
volatile organic
compounds, the precursor
pollutants to ground-level
ozone.
Photo: Microsoft Office.
Additional actions in the United States include a
rule known as the "NOX SIP Call" that requires
eastern states to improve air quality by reducing
emissions of NOX; the Clean Air Interstate Rule,
which, when fully implemented, will reduce SO2
emissions in these states by over 70% and NOX
emissions by over 60% from 2003 levels; and the
2007 Clean Diesel Trucks/and Buses and Low Sulfur
Diesel Rule and the Clean Air Non-road Diesel Rule,
which impose more stringent standards for new
diesel engines and fuels beginning in 2006.
Photo: Microsoft Office.
Actions Needed
Improving air quality in areas where it is degraded
is a continuing challenge. Although there have been
significant improvements in the levels of air
pollutants in the Great Lakes region, parts of the
region continue to experience poor air quality.
Continuing human health research is needed to
better characterize the harmful effects of air toxics.
To Learn More
For further information about Great Lakes air
quality, refer to the State of the Great Lakes 2005
report, which, along with other Great Lakes
references, can be accessed at
www.epa.gov/glnpo/solec.
02/06
EPA905-F-05-005
IISG-05-11
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