destruction of the ozone layer and climate change,
are a problem for all life on Earth.
Ozone Layer Destruction While tropospheric
ozone can be harmful, the stratospheric ozone
layer prevents much of the sun’s ultraviolet radiation from reaching the Earth’s surface. Anthropogenic chlorofluorocarbons (CFCs) emitted to the
atmosphere can act to convert stratospheric ozone
into oxygen through a series of reactions. Once the
reactions are complete, the destructive capacity of
the CFCs is left intact. The reaction series is able
to begin again, destroying more ozone through a
catalytic process [72]. In the mid- 1980s, a large
hole in the ozone layer above the Antarctic was
documented, as was the general depletion of
stratospheric ozone. The damage to the ozone
layer led to the Montreal Protocol, which legislated reductions in the production of ozonedepleting substances such as CFCs [73]. While
existing ozone-depleting substances will, over
decades, be removed from the atmosphere [72],
other factors affecting stratospheric ozone chemistry, many of which are anthropogenic, make for
some uncertainty about whether the ozone layer
will ever return to the pre-1980s levels [73].
Climate Change Air pollutants such as methane
and nitrous oxide are greenhouse gases and, as
such, act to increase the Earth’s trapping of electromagnetic radiation, leading to the increase in
global average temperatures often referred to as
global warming or climate change. Some Greenhouse Gases (GHGs) are affected by air pollution
through chemical reactions [74], and GHGs such
as CO 2 are co-emitted with primary pollutants,
especially during fossil fuel combustion. Ozone
in particular affects the lifetime of GHGs
[74]. Other effects of climate change include such
global problems as rising sea levels, likely extinction of 15–30% of species (with a 2 °C increase in
global average temperatures), reduced agricultural
productivity, and fresh-water shortages [75].
Summary of Air Pollution Problems
The motivating factors behind air pollution monitoring include understanding air pollution’s
impacts on human health, regional problems
including economic costs, and global problems.
Effects on health and the global economy are far
from negligible, and the urgency of regional and
global environmental problems is apparent. None
of these problems at their current magnitude are
compatible with sustainability. If the Earth’s
growing civilization is to be sustainable, understanding air pollution in an effort to minimize its
direct and indirect impacts must be a priority.
Motivations Behind Monitoring Air
Pollution
Immediate benefits of air pollution monitoring
include knowledge of when and where standards
are violated and the ability to communicate health
risks. Communication of health risk can be
accompanied by warnings that can guide behavior
of individuals, populations, and industry and
reduce human exposure to air pollution.
While minimizing health problems and ensuring that standards are adhered to are important,
there are deeper motivations for the monitoring of
air pollution. Establishing and quantifying connections between air pollution and the related
impacts depends on measurements such as those
made through monitoring and related air pollution
research. For example, epidemiological studies of
associations between air pollution and related
hospital admissions could not occur without air
pollution monitoring. By proving connections
between air pollution and problems, monitoring
and the related research influence air pollution
policy. It is anticipated, but not guaranteed, that
continued improvement of policy will drive
improved mitigation efforts and hence avoidance
of the problems associated with air pollution.
Air Quality Warnings
Monitoring of air pollution yields data on present
air quality conditions that can be used to provide
health warnings. For example, Canada’s Air
Quality Health Index (AQHI) combines data on
ozone, PM, and NO 2 to produce an AQHI value
ranging from 1 to 10+. Advice associated with
the AQHI is given in Table 5 and ranges from
Air Pollution Monitoring and Sustainability
395
are a problem for all life on Earth.
Ozone Layer Destruction While tropospheric
ozone can be harmful, the stratospheric ozone
layer prevents much of the sun’s ultraviolet radiation from reaching the Earth’s surface. Anthropogenic chlorofluorocarbons (CFCs) emitted to the
atmosphere can act to convert stratospheric ozone
into oxygen through a series of reactions. Once the
reactions are complete, the destructive capacity of
the CFCs is left intact. The reaction series is able
to begin again, destroying more ozone through a
catalytic process [72]. In the mid- 1980s, a large
hole in the ozone layer above the Antarctic was
documented, as was the general depletion of
stratospheric ozone. The damage to the ozone
layer led to the Montreal Protocol, which legislated reductions in the production of ozonedepleting substances such as CFCs [73]. While
existing ozone-depleting substances will, over
decades, be removed from the atmosphere [72],
other factors affecting stratospheric ozone chemistry, many of which are anthropogenic, make for
some uncertainty about whether the ozone layer
will ever return to the pre-1980s levels [73].
Climate Change Air pollutants such as methane
and nitrous oxide are greenhouse gases and, as
such, act to increase the Earth’s trapping of electromagnetic radiation, leading to the increase in
global average temperatures often referred to as
global warming or climate change. Some Greenhouse Gases (GHGs) are affected by air pollution
through chemical reactions [74], and GHGs such
as CO 2 are co-emitted with primary pollutants,
especially during fossil fuel combustion. Ozone
in particular affects the lifetime of GHGs
[74]. Other effects of climate change include such
global problems as rising sea levels, likely extinction of 15–30% of species (with a 2 °C increase in
global average temperatures), reduced agricultural
productivity, and fresh-water shortages [75].
Summary of Air Pollution Problems
The motivating factors behind air pollution monitoring include understanding air pollution’s
impacts on human health, regional problems
including economic costs, and global problems.
Effects on health and the global economy are far
from negligible, and the urgency of regional and
global environmental problems is apparent. None
of these problems at their current magnitude are
compatible with sustainability. If the Earth’s
growing civilization is to be sustainable, understanding air pollution in an effort to minimize its
direct and indirect impacts must be a priority.
Motivations Behind Monitoring Air
Pollution
Immediate benefits of air pollution monitoring
include knowledge of when and where standards
are violated and the ability to communicate health
risks. Communication of health risk can be
accompanied by warnings that can guide behavior
of individuals, populations, and industry and
reduce human exposure to air pollution.
While minimizing health problems and ensuring that standards are adhered to are important,
there are deeper motivations for the monitoring of
air pollution. Establishing and quantifying connections between air pollution and the related
impacts depends on measurements such as those
made through monitoring and related air pollution
research. For example, epidemiological studies of
associations between air pollution and related
hospital admissions could not occur without air
pollution monitoring. By proving connections
between air pollution and problems, monitoring
and the related research influence air pollution
policy. It is anticipated, but not guaranteed, that
continued improvement of policy will drive
improved mitigation efforts and hence avoidance
of the problems associated with air pollution.
Air Quality Warnings
Monitoring of air pollution yields data on present
air quality conditions that can be used to provide
health warnings. For example, Canada’s Air
Quality Health Index (AQHI) combines data on
ozone, PM, and NO 2 to produce an AQHI value
ranging from 1 to 10+. Advice associated with
the AQHI is given in Table 5 and ranges from
Air Pollution Monitoring and Sustainability
395