Summary of Critical
Air Quality Issues
in the Transboundary Region
Report from the
International Air Quality
Advisory Board
to the
International Joint Commission
ISBN 1-894280-43-1
January 2004
Cover
Illustration Credit:
Geographic Distribution of Contributions to
Atmospheric Deposition of Mercury to Lake Superior,
2001-2003 Priorities Report to the International Joint Commission
(Dr. Mark Cohen, NOAA-ARL)
1.0
MANY ‘DIRTY DOZEN’ PERSISTENT TOXICS
DIMINISHING IN THE
1.1 Story
A number of toxic substances
are capable of intercontinental atmospheric transport; their ability to
ultimately increase contamination of terrestrial and aquatic ecosystems
continues to be of great concern. Among
these substances are some of those identified as Critical Pollutants by the
Water Quality Board of the International Joint Commission in 1985, including
mercury, toxaphene, hexachlorobenzene,
and PCBs.
These pollutants were
designated because of their chronic toxic effects, long lifetimes in the
environment and their bioaccumulation in ecosystems which continues to cause a
variety of deleterious effects, particularly in humans. At certain levels, current
Evidence of the accumulation of persistent toxic
substances (PTSs) in various ecosystems, such as the
Since 1985, the Great Lakes
Water Quality Board, the US-Canada Binational Toxics
Strategy (BTS), the United Nations Economic Commission for Europe (UNECE)
Protocol on Persistent Organic Pollutants (POPs), the
Stockholm Convention (UNEP), and the Commission for Environmental Cooperation
(CEC) Sound Management of Chemicals (SMOC) initiative have all focused
attention on the chemicals summarized in Table 1.
Substantial progress has been
made in management of the ‘dirty dozen’ PTSs,
identified by the Water Quality Board in 1985.
Active use and production of many persistent, bioaccumulating
toxic substances has been banned or sharply curtailed over the past twenty
years. However, even in the case of
banned substances, soil and sediments in water bodies remain contaminated,
leading to significant re-emissions and continued damage to ecosystems.
Table
1: Various Organizational Frameworks and Program
Status: Persistent Toxic Substances
The levels of many of these
persistent toxic substances have been decreasing, not only in the environment
but also in human tissue samples. For
example, the pesticide dieldrin was banned from
almost all uses in the early 1970’s.
Figure 1 shows
the corresponding drop in dieldrin in human breast
milk. This is evidence that the efforts
to reduce environmental levels of PTSs can result in
relatively rapid and noticeable reductions in human exposure levels.
In the
Unfortunately, this story is
not uniformly positive. Unlike many PTSs, mercury levels have increased in the past 20 years in
fish-eating birds and mammals (see section on mercury). It is important to note that although
pathways into and out of the Great Lakes basin are relatively well understood,
this is not the case in areas such as the west coast, the mountain ecosystem,
and the central agricultural region of the United States and Canada.
Further, the transport of
particulate matter from Mongolian dust storms under various meteorological
conditions to
In addition, current-use
pesticides such as atrazine (Figure 2 shows the
geographic distribution of sources contributing to the deposition of atrazine to
For those PTSs
for which significant progress toward remediation has yet to be made, the
knowledge base for future management has developed rapidly on all scales from
local to global. Recent research,
however, has suggested that urban centers are a substantial source of toxic
emissions, including mercury, PCBs and dioxins and the magnitude of these
sources remains largely unquantified. Special attention should be paid to
quantifying the transport of such contaminants from urban cores to adjacent
agricultural crop districts and other non-urban areas. However, evidence is mounting that other
similar pollutants could pose significant threats. Further, a new class of hazardous persistent
compounds, including PBDE’s and phthlates,
is emerging. Some of these are
“estrogenic” compounds which have the capability to disrupt human and animal
reproductive systems.
1.2 What Does It Mean?
While existing international
agreements for further control should be supported, knowledge of the levels and
trends of these pollutants in the environment and ecosystems should be
enhanced, and remediation efforts intensified, there is also an evident need to
move beyond the substances currently addressed by various agreements toward
emerging contaminants such as those noted above. The elements of a regional and global
assessment program, including binational and
multilateral monitoring, modeling and emission inventory initiatives, and
further research on effects on humans and the environment must be put in place
if the significance of these contaminants is to be fully understood and
effective prevention and remediation programs developed.
1.3 Recommendations
1. A scientific assessment of the current state of and gaps in our understanding for PTSs is required. Areas of particular importance are:
a. Mercury, where levels in fish eating birds and mammals in some locales continue to increase as does the number of fish advisories.
b. The role of urban centers as major sources of PTSs. Special attention should be paid to the impact of urban emissions on crops in adjacent agricultural lands.
c. The ubiquitous nature of current-use pesticides and unlisted Persistent Organic Pollutants which are now appearing in foods and sources of drinking water.
2. This assessment should evaluate emerging research on substances thought to be reproductive or endocrine disrupters and recommend specific future activities to assess the extent of this threat.
3. The Commission should continue to reinforce its advocacy of the development and implementation of multilateral programs to reduce emissions of these substances regionally and, where appropriate, globally.
4. As a review of the Great Lakes Water Quality Agreement is under consideration, the Commissioners should encourage the Parties toward inclusion of substances of emerging concern as well as delineation of a process for their continued assessment.
2.0
GLOBAL MERCURY EMISSIONS UNCHANGED: REDUCTIONS IN
2.1 Story
Total annual anthropogenic
mercury emission trends estimated from global emission inventories indicate no
significant change in total emissions between the years 1990 and 1995. However, a shift is apparent in the nature of
the dominant sources, and their respective geographic locations. The 1995 anthropogenic mercury sources
attributed to Asian emissions were estimated at 56.1 percent of the total
global anthropogenic emissions, a 25 percent increase over emissions from this
continent in 1990. The increase was due
largely to additional coal combustion in
Mercury is capable of
intercontinental atmospheric transport and can, through deposition, increase
contamination of aquatic ecosystems.
At current levels, mercury in
the Great Lakes and the Arctic pose the greatest health risk to individuals
whose diet is composed largely of local fish and game, those who have higher
than typical fish consumption habits, or sensitive subpopulations such as young
children and pregnant women. In some of
these locales, mercury levels have increased in the past 20 years in
fish-eating birds and mammals. The
number of North American water bodies subject to fish consumption advisories
due to mercury contamination has also increased.
In seeking a global remedy,
European nations,
Many of the UNECE members also
promoted the development of a global agreement under the auspices of the United
Nations Environment Programme (UNEP) to contend with
the growing global problem of persistent organics. This global agreement is acknowledged as the
UN Stockholm Convention on Persistent Organic Pollutants (a subset of the
PTS). Mercury was not added to the
Stockholm Convention although its organic form, methyl mercury, was considered.
In
2.2 Recommendations
1. Governments from
both countries should continue to support mercury reduction efforts. In addition, the existing mercury measurement
programs in
2. The contribution of urban centers as a fugitive source of mercury emissions should be quantified.
3. The governments should continue to vigorously pursue a global agreement on the reduction of mercury from all of the major source regions.
3.0
MEETING TIGHTENED US AND CANADIAN AMBIENT AIR QUALITY HEALTH BASED STANDARDS FOR OZONE AND PARTICULATE MATTER (PM) WILL CHALLENGE GOVERNMENTS AND THE PUBLIC.
3.1 Story
Since the last IAQAB Special
Report, analyses of the scientific bases for the ozone and particulate matter
(PM) health standards have been completed and new standards were promulgated in
each country. In each case both the form
and numerical value of the standards were made more stringent to reflect new
scientific information on the immediate (acute) and long term negative health
effects experienced by the general population, and most dramatically by
sensitive subgroups or exposure to these pollutants.
The previous standards for
ozone and PM were not adequately protective of public health, and there were
incidences of morbidity and/or mortality experienced by sensitive members of
the general population caused by levels of exposure that were once considered
safe. While the new standards are more
stringent, most recent research indicates that adverse health impacts will
persist at concentration levels equal to or below those in the new standards.
The new
For particulate matter, the
focus was redirected from PM10 to PM2.5 or the finer fraction, to respond more fully to
concerns of excess morbidity and mortality among sensitive or susceptible
members of the general public from this contaminant. In
Recognizing
that the transboundary flow of air pollution has a
significant effect on attainment and maintenance of air quality standards in
the adjacent country, in 2003, the governments of the
3.2 What does it mean?
These new, more stringent
standards will require the development and implementation of new control
strategies in both countries. In the
For ozone, the focus will be
on reduction of the levels of nitrogen oxides as well as specific classes of
hydrocarbons (VOCs) in the atmosphere, to lower the
total burden of ozone in the atmosphere, and not just a reduction in the peak
level observed during any particular day.
Recent modeled estimates of
the contribution of global ozone background concentrations are in the vicinity
of 15 ppb, with an Asian contribution of approximately 4-7 ppb. While these estimates should be considered
preliminary, and global concentrations associated with particular elevated
ozone events are lower, given the tightening of standards in both countries
this external contribution takes on more significance. New opportunities to reduce the anthropogenic
inputs contributing to the increasing global background for ozone should be
identified and pursued.
For particulate matter, new
strategies must be developed and employed to define and reduce the primary
particle emissions of PM2.5 from specific sources, and reduce the emissions of
precursors, including acidic species such as SOx and NOx, which result in the formation of secondary PM2.5. Because of
the complexity of the PM2.5 mass it is not possible to specifically identify
those components associated with the most toxic effects. In future years, research may identify the
specific compounds or components of concern, but at this time control
strategies should be designed to reduce the entire ambient PM2.5 mass.
In the Board’s view, in areas
affected by transboundary air pollution, air quality
management would benefit from a procedure to understand and communicate the
distinctions between the standards of each country and the further development
and refinement of communication tools including forecasting capabilities that
provide citizens of both countries with equitable protection of human health
and the environment. This will be
discussed in further detail later in the report.
Also,
in addition to the steps already in place, including the further regulation of
gasoline and diesel powered vehicles, successful
attainment of these standards will require alterations in individual behaviour patterns and practices. Particularly important in urban settings,
these changes should include the development of alternate transit and flexible
workplace strategies to reduce traffic burden.
Reductions in emissions from off road vehicles and small gasoline
engines such as those used in personal watercraft, lawnmowers, chainsaws, etc.,
and reductions from open burning and wood-burning fireplaces should continue to
be pursued.
FURTHER REDUCTIONS IN EMISSIONS FROM BOATS, SHIPS, PLANES, CONSTRUCTION EQUIPMENT AND SMALL GASOLINE ENGINES NEEDED
While
both federal governments tighten emissions standards for cars and trucks fueled
by gasoline and diesel fuel, other sectors such as off-road and non-road
applications remain largely uncontrolled.
Cleaner diesel fuel entering the market in 2006, and new diesel engine
emission standards in 2007 should reduce PM2.5 and
hazardous air pollutants emissions substantially. However, even with these improvements,
emissions from off-road diesel applications will remain significant largely due
to the increased number of vehicles and increased usage.
Due to
both the volume of emissions and their discharge in the upper atmosphere,
aircraft also contribute significantly to air pollution, as do airport
operations. Ships contribute
approximately seven percent to the global emissions of NOx
while adding to the PM2.5 burden as well. The effects of this are most apparent in areas
near major harbors and confined channels.
Further multilateral action will be required to attain widespread
reductions from these latter sources. A
recent commitment under the Canada-U.S. Border Air Quality Strategy by the
governments to address emissions from marine vessels on the west coast of
Also,
the relative importance of emissions from ski-doos,
sea-doos, outboard motors and lawn maintenance
equipment, chainsaws, small generators and other personal use devices has
increased substantially. The
introduction of 4-stroke technology to many of these
applications has the potential to reduce the negative impacts substantially.
With
the number and types of engines and their applications increasing, the
implementation of technological advancements in every sector must outpace
growth, or substantive emission reductions will not be realized. Further, inadequate attention to maintenance
procedures contribute to the growth of emissions from these devices on a global
basis.
3.3 Recommendations
1. The Board
encourages the Commission to maintain a dialog with the Parties and support the
implementation of effective control strategies to reduce the levels of ozone
and PM transported between the
2. The Board encourages the Commission to request a review including the application of benchmarks (for example, monitoring hospital admissions) that can identify success in reducing the exposure to ozone and PM among sensitive or susceptible members of the general population as part of the demonstration of progress in achieving each standard.
3. The Parties should continue to further define the global ozone background and strategies necessary to address it.
4. The Board is encouraged by the announcement of the pilot airshed management strategies and recommends the International Joint Commission continually review their evolution over the next two years. As governments move forward with the development of these pilot projects, the Board emphasizes that they must be developed in a coordinated manner with the involvement of local communities and stakeholders if they are to be effective in attaining and maintaining air quality standards.
5. Governments must address emissions from all internal combustion engines and aircraft and their associated airport operations if ozone and PM2.5 are to be fully met. Given the continued global growth in all vehicular sectors and the proliferation of the internal combustion engine, proper maintenance must be pursued in a comprehensive manner through inspection programs or other means.
6. All levels of government should focus on the delivery of local programs, including public education emphasizing informed choice, to reduce or eliminate use of personal device sources, particularly small gasoline engine use in recreational, yard maintenance and other applications.
4.0
NITROGEN COMPOUNDS REMAIN PIVOTAL.
4.1 Story
Nitrogen and nitrogen
compounds are essential to all living organisms. Nitrogen can serve as a nutrient, enhancing
growth and productivity, or as a toxin, causing ecological damage (Ref. 2). In cases where nitrogen acts as a toxin, in
addition to the role of NOx in ozone formation, plant
populations and forest growth can be affected with the removal of nutrients
from soil, inhibiting the natural growth and persistence of forest cover. Other nitrogen compounds can also have a
negative effect on the environmental and human health. Emissions of other nitrogen species, in
particular ammonia, appear to have increased; ammonia will be further
considered in the latter portion of this segment of the report.
NOx Emissions
As the Board emphasized in its
first Special Report, while there have been reductions
in emissions of NOx in certain sectors, total
nitrogen oxide emissions in both countries have essentially remained unchanged
over the past two decades. NOx
emission reduction efforts have been countered by economic
growth; activities such as motor vehicle operation and the burning of fossil
fuels now account for more than 90 percent of
NOx and Fine Particulate and Ozone Formation
Various forms of nitrogen,
including nitrogen oxide and ammonia, when in the atmosphere, react with water vapour and other available compounds to form fine
particulate. These
very small particles enter the human respiratory system and, even at
concentrations below current air quality standards, can have deleterious
effects on the health of sensitive individuals.
NOx also reacts in the presence of sunlight with Volatile
Organic Compounds (VOCs) to form ozone, a pollutant
which can compromise the human respiratory system for some individuals even at
levels below the current standards.
While there has been much consideration of which of the two precursors
is the crucial or limiting factor in ozone formation in various locales,
reduction in NOx emissions is a critical part of any
strategy to reduce ozone
formation.
Acid Rain:
Acidic pollutants can be
transported through the atmosphere in both wet and dry forms and subsequently
deposited to the earth’s surface at locations which may be some distance from
the original source. One of the impacts
of the resulting acidification of lakes and streams is
a decline in the sport fish population.
The acidity of rain is
determined by the concentration of hydrogen ions, and this concentration
depends on two things: the presence of acid-forming substances such as sulphates and nitrates, and the availability of
acid-neutralizing substances such as calcium and magnesium salts. Non acidified rain has a pH value in the
vicinity of 5.1. By comparison, vinegar
has a value on the ph logarithmic scale of three.
The readily evident transboundary effects of acid precipitation impelled
jurisdictions in both the US and Canada to reduce acidic sulfur compound
emissions and subsequent transport and deposition of sulfur dioxide and other
sulfate species, resulting in significant decreases
of sulfate in wet and total deposition and in surface waters. Wet sulfate deposition to lakes and streams
declined approximately 40 percent in the 1990’s in regions of the
The Acid Rain Program, created
under the U.S. Clean Air Act and Amendments (CAAA) of 1990, targets both SO2
and NOx emissions.
As is evident in the
illustration (Figure 5) from the 2002 Progress Report under the Canada US Air
Quality Agreement, the lack of significant reduction in nitrate emissions is
evident in the relative stability of wet nitrate deposition in the last decade;
with the exception of lowered inputs in some particular areas of intense
deposition.
Slight declines in nitrate
deposition were demonstrated to some extent in the northeast, where many
sensitive ecosystems are located. On the
contrary, the upper midwest
experienced somewhat elevated nitrate concentrations and areas in the western
Rain in significant portions
of eastern
For example, the pH of rain in
Some
acidified lakes are recovering, but many more are not. Of 202 Canadian lakes studied since the early
1980s, 33 percent have reduced levels of acidity while 56 percent have shown no
change and 11 percent have actually become more acidic. The greatest improvements have been seen in
the
Forestry
Impacts
Acidic
atmospheric deposition can also impact terrestrial environments through
increased nutrient depletion. Forested
areas are susceptible to increased levels of sulfuric and nitric acid
deposition and some eventually become regions of sensitivity. Current or projected acidic deposition
exceeds the level that would sustain forest ecosystem health and productivity.
Continued
deposition of nitric acids, along with sulphuric
acids, accelerates the loss of critical nutrients such as calcium, magnesium
and potassium, all essential minerals, from forest soils. A significant implication of such deposition
is slow forest growth, increasing the time between timber harvests, and the
ultimate decline in forests (Ref. 4).
The species mix of particular forests may be skewed in favour of plant species able to cope with or thrive in
increased nitrogen concentrations.
Preliminary
modeling shows that annual forest growth in eastern
As
one response to these threats, the Eastern Canadian Premiers and New England
Governors have developed a coordinated forest mapping initiative, called The
Forest Mapping Project. Analysis of
these maps is ultimately meant to allow determination of sustainable levels of
acid deposition for forest soils in the
Maps
of sustainable deposition and actual exceedances have
been prepared for
Ammonia
(NH4)
Emissions of ammonia,
particularly from these large scale operations, support the atmospheric
formation of ammonium sulfate and ammonium nitrate, contaminants that
contributes to levels of PM2.5, a threat to human health, and a cause of visibility
impairment. In many locations,
ammonia is the limiting factor for secondary particle production and unchecked
ammonia emissions will likely offset decreases in other PM precursor emissions.
In addition, ammonia is a preferred source of nitrogen to plants and is quickly
metabolized by many organisms, often contributing to algal blooms and other
degradations of estuaries and other sensitive ecosystems, reducing productivity
of coastal waters. The extent of ammonia
deposition in the
Large Scale Animal Husbandry
Operations:
Livestock
and poultry operations are undergoing consolidation; in the
This
source sector often is referred to as confined animal farm operations (CAFOs). While these
operations have emerged as among the chief methods of meat production in
In
consideration of the above, further quantification of the contribution of
emissions from CAFOs to air pollution is necessary,
along with a management strategy and technology options to abate these
emissions.
4.2 What Does It Mean?
The impact of acid deposition
and the amelioration of its effects are among the longest standing
environmental issues considered singly and jointly by federal, state and
provincial governments by, among many others, the Canada US Air Quality
Accord. Reduction in emissions for sulphur dioxide has been the subject of international
agreements and substantial progress has been made and will continue to be made
in both countries. Some of this limited
progress is evident in reduced acidification of particular water bodies in both
countries.
Reduction in the emissions of
nitrogen oxide species has proved less tractable; the burning of fossil fuels
in both large utilities and mobile sources (cars and trucks) is the source of a
great majority of these emissions and they have not decreased substantially
over the last decade.
In addition to the negative
impact of acidification on fisheries in smaller water bodies and the health of
forests, nitrogen oxides are also essential to the formation of ozone and fine
particulate matter, both of which have an immediate and direct negative impact
on human health.
Ammonia (NH4)
is another nitrogen species emerging as a contributor to fine particulate
formation and the excessive nutrification of water
bodies, resulting in algal blooms and other undesirable outcomes in affected
locales. Large animal husbandry
operations (cattle feedlots and intensive hog farming) contribute substantially
to this burden and their impact needs further examination.
The
Board continues to see the delineation of the effects of nitrogen species, and
continued efforts toward a reduction in their emission, as pivotal to
improvement in several aspects of air quality.
4.3 Recommendations
1. Further coordinated approaches, such as those undertaken by the New England Governors and the Eastern Canadian Premiers in addressing the impacts of acidic deposition in both aquatic and terrestrial ecosystems, should be encouraged.
2. In order to reduce the impacts of acid species on the ecosystem and the production of excessive levels of ozone, further reductions in the emissions of nitrogen oxides from stationary and mobile sources must be pursued.
3. The need for further controls on production of other nitrogen species, such as ammonia, must be further investigated.
4. The US and Canadian governments should extend their investigation of the environmental impacts of intensive animal husbandry operations to include a consideration of the effects of emissions of gaseous ammonia compounds from these operations on air quality and appropriate remedial actions.
5.0
CAN DETERIORATION OF AIR QUALITY IN NON URBAN, RELATIVELY CLEAN, DESIGNATED AREAS BE PREVENTED?
5.1 Story
Prevention of significant
deterioration of visibility has been the topic of discussion in a number of the
more recent reports under the Canada US Air Quality Agreement. The two countries have distinctly different
approaches to such prevention, largely as a result of differences in the structure
and distribution of environmental authority in each country.
The visibility protection
commitments (Annex 1, part 4) contained in the Canada US Air Quality Agreement
of 1991 are a reflection of the interest of both parties in the protection and
improvement of air quality in national, international and state or provincial
parks and designated wilderness areas in their respective countries.
Briefly, in that Agreement,
the US extended the provisions of Part C, Title I of the Clean Air Act which
call for both non-deterioration and eventual elimination of visibility
impairment from anthropogenic sources in specific US National Parks and
Wilderness Areas, several of which lie along the US Canada boundary, to further
include consideration of sources that could cause significant transboundary air pollution.
At the time of the Agreement,
these commitments were considered balanced, as neither country had any formal
regulatory requirements specific to visibility protection.
However, in July 1999 the US
EPA issued the Regional Haze rule, requiring states and tribes to work together
via regional transport associations to remediate any existing impairment of
visibility resulting from manmade air pollution in 156 Class I areas, including
national parks and wilderness areas, and to prevent any future impairments.
Particles causing visibility
impairment include ammonium sulfate, ammonium nitrate, secondary organic
aerosols, carbon and soil. A number of
regional air strategies will be needed to improve and preserve visibility in clean
air areas, including further control of combustion sources, windblown dust and
emissions from biological burning.
The US Rule defines visibility
impairment as “reconstructed light extinction” as measured by specific sampling
and analytical methods and requires no deterioration on the cleanest 20 percent
of sampling days (often days with transboundary flows
from Canada), as well as steady progress toward a long-term (year 2064)
national visibility goal of eliminating all anthropogenic haze inputs on the
haziest 20 percent of sampling days. By
2008, Regional Planning Organizations (RPOs) are to
develop interim strategies to make progress toward these goals.
There are five RPOs in the
The success of air management
strategies is to be demonstrated by the ongoing nationwide monitoring of
visibility-reducing particles via the currently operational 110-station
Interagency Monitoring of Protected Visual Environments (IMPROVE) network,
representative of all Class I areas where monitoring proved practical.
CI
would be applied in areas with ambient pollution levels better than required
standards but still above the levels associated with observable health
effects. The KCAC principle recognizes
an interest in preserving relatively clean areas. Jurisdictions are encouraged to take remedial
and preventive actions to reduce emissions from anthropogenic sources to the
extent practicable using a cooperative national guidance document on CI/KCAC
currently under development.
5.2 What does it mean?
Recent consideration of the
commitments to Prevention of Significant Deterioration in the Air Quality
Agreement has focused on visibility. The
promulgation of the Regional Haze Rule in the US and the monitoring and
regional planning that accompany it have resulted in differences in the level
of specificity with which the dialogue is conducted on this issue between the
Parties. In the
Given
the contribution of fine particulate to haze, there may be an opportunity to
more closely align fine particulate (PM2.5) regulations
in the two countries. Current US Primary
PM2.5 standards do not address visibility; the annual
average requirement of 15 µg/m3 is over far too
long a time scale to address what is a short term and frequently transitory
phenomenon, while the 24-hour standard of 65 µg/m3
represents extremely hazy conditions.
However, the value associated with the Canada-Wide 24-hour standard of 30 µg/m3
(although primarily meant to protect human health) would be roughly equivalent
to a visibility of 16 km (10 miles), and its implementation should also provide
some measure of visibility protection.
5.3 Recommendations
1. The Commission should champion keeping clean areas clean in the border region. As a first step, the Commission should convene an expert workshop in one of the transboundary areas currently within a US Regional Planning Organization (RPO) to review prevention of significant deterioration and related visibility programs in both the US and Canada in detail and obtain advice on effective ways and means to preserve and enhance such programs under both national approaches.
2. The Commission
should encourage the
3. As a step toward integration of programs meant to directly or indirectly preserve or enhance visibility, the Commission should encourage the formal inclusion of Canadian federal and provincial agency personnel in those US RPOs whose mandate extends along some portion of the boundary.
6.0
THE AVAILABILITY OF NEW PUBLIC INFORMATION TOOLS INCLUDING AIR QUALITY INDICES AND/OR HEALTH BASED ADVISORIES, IS STIMULATING GREATER PUBLIC INTEREST AND CONCERN REGARDING AIR QUALITY.
6.1 Story
State, provincial and federal
governments continue to develop public communication tools which broadcast the
status of local air quality in real or near-real time. Some of these tools include the
Because of several factors,
among them the fact that calculation of a particular value of the air quality
index (AQI) historically has been based on one dominant pollutant rather than
the cumulative contributions of all the smog-related air pollutants tracked
under a given index, negative effects on human health have been observed in
circumstances when the AQI value has been characterized as ‘good’ or ‘adequate’
and indeed, such effects are evident even when all tracked pollutants are
within attainment. As a
result, modifications to this communication tool are currently under
consideration to allow a more accurate representation of air quality levels at
a given time with health risk.
Some jurisdictions have begun
to incorporate measurement of fine particulate matter (PM) into the AQI. The ability to measure fine PM in real time
is relatively new and technologies to do so are continuing to evolve and
improve. At the moment, the monitoring
network for real-time fine PM in some areas where an AQI exists is significantly
less dense than that for many of the other pollutants traditionally factored in
the index, making inclusion of such PM2.5 measurements
to the AQI challenging. However, this is
gradually improving as measurement capabilities are enhanced in response to the
need to demonstrate the success of emission reductions to address smog
pollutants and precursors. Such enhanced
networks would also support the development of more accurate air quality
forecasting and related health advisories.
The
6.2 What Does It Mean?
Public communications tools,
particularly in weather forecasting, have included the development of several
national and regional programs in the
Additional pollutants, such as
fine particulate (PM2.5) are being added into the Index calculation, and
altering the nature of that calculation.
It is evident that, in attention to sharpening their own determinations,
jurisdictions adjacent to the boundary must strive to improve the coherence and
consistence of air quality indices and advisories across their particular transboundary region.
6.3 Recommendations
1. The Commission should encourage governments to continue to collaborate on air quality information products on the internet and elsewhere, with the objective of providing clear, comparable, coherent, and effective health messages across common airsheds, while reconciling differences associated with current distinct health-based air quality indices and acknowledging differences in national standards.
2. The governments should also be encouraged to continue development of public information tools and services such as air quality forecasts and real time air quality reporting that provide the public with the information they need to make appropriate choices about protecting their health and their environment.
7.0
HOW WELL ARE AIR QUALITY MANAGEMENT PROGRAMS PERFORMING? INVENTORIES, MONITORING AND ANALYSES ALL NEED RENEWAL TO PROVIDE VERIFICATION AND GUIDANCE.
7.1 Story
Monitoring
programs are the basic tools required to maintain vigilance for
known chemicals of concern and serve an alerting function for emerging
environmental concerns. Responsibility
for developing and maintaining these programs is shared among federal,
state/provincial/territorial and local governments and, very occasionally,
industry.
Emissions
inventory programs are typically meant to estimate emissions of
pollutants of concern from specific sectors (stationary and mobile) to the
atmosphere. In the
Emissions
inventory information is a primary input to the modeling of the transport and
deposition of pollutants. Current and
accurate emissions inventories of all important emitter types including
stationary sources (power plants, incinerators, industrial operations), areal sources (drycleaning,
backyard burning, etc.), and mobile sources, are crucial to a successful
monitoring effort. The sharing of
responsibility for monitoring, inventory management and data analysis, among
agencies, with each portion of the program responding to different needs and
drivers, makes achieving a high quality inventory input most difficult.
Concentration and
deposition monitoring programs
fall into two main categories: regulatory
monitoring, meant to demonstrate compliance with standards protective of human
health, and research monitoring, used to study the transport, fate, and
trends of various pollutants of immediate or emerging concern. Both types require continual scrutiny to
maintain peak usefulness. Typically,
federally mandated air quality programs require widespread monitoring - in some
cases, at thousands of locations nationwide.
It appears that routine monitoring programs for substances that are
currently relatively well controlled, for example lead or sulfur dioxide, could
now be diminished and resources moved to support emerging regulatory programs
(e.g. support for new fine particulate and ozone air quality standards) and
several agencies are currently attempting to do so.
Research monitoring, particularly for hazardous and persistent
air toxins, is a distinctly different challenge. Concentrations of pollutants of concern tend
to be at levels typically well below those associated with regulatory
monitoring, when appropriate regulations exist.
In addition, the universe of contaminants is much larger, and the
release of new compounds into the environment continues to expand this number.
To be of best use as an aid to
the computer modeling and other elements of the environmental policy and
management community, measurements must be made continuously over very long
periods of time (often decades) and at a sufficient number of locations across
the continent to allow reasonable estimates of concentration and deposition
trends. Simply put, strong research
monitoring programs require stable funding, carefully selected and
well-established analytical laboratories, and sufficient resources to analyze,
archive, disseminate, interpret and verify the resulting data.
Recognizing that it is
impossible to monitor all chemicals at all desired locations, computer models
are frequently applied to fill the gaps.
However, such models are only as good as the data used to drive them and
the understanding scientists have of the underlying physics and chemistry. Comprehensive fate and transport models used
to determine sources of pollutants of concern affecting receptors of interest
such as the
7.2 What does it mean?
The
To do this effectively, while
maintaining the program continuity necessary to allow evaluation of progress
and the design of new control programs, a more collaborative and coordinated
approach to managing and integrating emissions inventory development,
monitoring, and analysis (modeling) is needed.
As there is further recognition of the extent to which many persistent
toxic substances (mercury) and criteria pollutants (ozone) are subject to
global transport, this collaborative approach must cross national and
continental boundaries. Without such an
approach, as governments struggle to respond to emerging issues, duplication of
efforts, erosion of baseline monitoring and failure to address significant
knowledge gaps will continue.
7.3 Recommendations
1. The Commission should encourage the governments, as an activity under the Air Quality Accord, to assess monitoring programs, particularly those adjacent to the boundary, and identify those most productive in the monitoring of transboundary air quality and supporting related science. The Board will track progress toward such a review as an effort to identify the core monitoring networks in the boundary region.
2. While recognizing that most monitoring programs have already been subjected to extensive examination and review, the Board believes that new ways of managing existing resources must be developed to allow reapportionment of existing funds. In some cases, new sources of funds may also be required.
3. As an outcome of the review recommended about, and other such considerations, support for programs that have outlived their usefulness should be redirected to address emerging pollutants of concern.
4. In cases where new programs must be continuous to be of greatest value, the availability of funds on a multi-year basis must be ensured at initiation to prevent critical lapses or gaps in the monitoring report subsequently derived from such programs.
5. Initiatives to secure support from industry and other major pollutant sources for monitoring efforts adjacent to their facilities, including appropriate quality control and public accessibility to the data, should be considered.
ACRONYMS
ANC acid
neutralizing capacity
CAAA Clean
Air Act and Amendments
CAFOs confined
animal farm operations
CEC Commission
for environmental Cooperation
CI continuous improvement
EPA Environmental Protection Agency
GLWQA
HAPs hazardous
air pollutants
HCH hexachlorocyclohexane
IAQAB International
Air Quality Advisory Board
IJC International
Joint Commission
IMPROVE Interagency
Monitoring of Protected Visual Environments
KCAC keeping
clean areas clean
LRTAP Long-Range
Transport of Air Pollution
NOAA National
Oceanic and Atmospheric Administration
PAHs polyaromatic hydrocarbons
PBDE polybrominated diphenol ethers
PCBs polychlorinated
biphenyls
PM Particulate
Matter
POPs persistent
organic pollutants
PTSs persistent
toxic substances
RPOs Regional
Planning Organizations
SIPs State
Implementation Plans
SMOC Sound
Management of Chemicals
UNECE United
Nations Economic Commission for
UNEP United
Nations Environmental Program
US United
States
VOCs Volatile
Organic Compounds
REFERENCES
1. United Nations
Environment Program. 2002. North American Regional Report -
Regionally Based Assessment of Persistent Toxic Substances,
pg 79. Global Environment Facility.
2. National Atmospheric Deposition Program, Nitrogen in the Nation’s Rain. p.5, 2000
3. U.S. Environmental
Protection Agency, Response of Surface Water Chemistry to the Clean Air Act
Amendments of 1990 p. iii January 2003 Available at
http://www.epa.gov/ord/htm/CAAA-2002-report-2col-rev-4.pdf
4. Valentinetti,
R., NEC/ECP Acid Rain Action Plan.
Presentation accessed on
http://www.sso.org/otc/meetings/presentations/2002/NEG_ECP_020226.pdf