Air Quality, Surface
Transportation Impacts on
Paul Boulter
PAEHolmes, Sydney, Australia
Article Outline
Glossary
Definition of the Subject
Introduction
Historical Trends
Air Pollution Pathways
Emission Processes
Modelling Transport Emissions
Pollutant Dispersion and Transformation
Modelling Air Pollution from Transport
Reducing Air Pollution from Transport
Future Directions
Bibliography
Glossary
DPF Diesel particulate filter, the preferred and
most effective technology for removing particulate matter from diesel exhaust. DPFs can be
broadly divided into two types: “full flow” and
“partial flow.” The latter are more permeable
and are less effective, but need no maintenance.
DPFs physically capture particles and can fill up
rapidly. They must therefore be periodically
“regenerated,” and several passive and active
systems have been developed for this purpose.
Emission standard A value that specifies the
maximum amount of a pollutant that can be
released into the environment per unit activity
(e.g., g/km or g/kWh).
NO 2 Nitrogen dioxide, a gaseous air pollutant
produced as a result of combustion. NO 2 is
also a precursor for a number of harmful secondary air pollutants such as ozone, and plays a
role in the formation of acid rain. Long-term
exposure to high concentrations of NO 2 causes
adverse health effects, and levels regularly
exceed air quality standards.
O 3 Ground-level ozone, a secondary pollutant
produced by reactions between NO 2 , hydrocarbons, and sunlight. High levels of ozone are
generally observed during hot, sunny weather,
and concentrations tend to be higher in rural
areas than in urban areas.
PM 10 Mass concentration of particles with an aerodynamic diameter of less than 10 mm. Particles
smaller than 10 mm (also known as “thoracic”
particles) can settle in the bronchi and lungs.
PM 2.5 Mass concentration of particles with an
aerodynamic diameter of less than 2.5 mm,
sometimes referred to as “fine” or “respirable”
particles. Particles in this size range can penetrate deep into the lungs.
Primary particles Particles emitted directly to
the atmosphere, typically as a result of combustion or abrasion processes.
SCR Selective catalytic reduction, an exhaust
aftertreatment method that is used to reduce
emissions of nitrogen oxides. It will be the
main technology for enabling compliance
with future emission standards.
Secondary particles Particles formed within the
atmosphere from gas-phase precursors. These
include particles originating from atmospheric
oxidation of sulfur and nitrogen oxides, and
their reaction products with ammonia, and
from the oxidation of organic compounds.
Ultrafine particles Particles with a diameter of
less than 0.1 mm. These can pass through cell
membranes and migrate from the lungs into
other organs. There is evidence to indicate
that they may be more damaging to the cardiovascular system than PM 10 and PM 2.5 .
Definition of the Subject
Until the middle of the twentieth century poor air
quality in populated areas was usually associated
© Springer Science+Business Media, LLC 2012
M. E. Goodsite et al. (eds.), Air Pollution Sources, Statistics and Health Effects,
https://doi.org/10.1007/978-1-0716-0596-7_554
Originally published in
R. A. Meyers (ed.), Encyclopedia of Sustainability Science and Technology, © Springer Science+Business Media LLC, 2012
https://doi.org/10.1007/978-1-4419-0851-3_554
47
Transportation Impacts on
Paul Boulter
PAEHolmes, Sydney, Australia
Article Outline
Glossary
Definition of the Subject
Introduction
Historical Trends
Air Pollution Pathways
Emission Processes
Modelling Transport Emissions
Pollutant Dispersion and Transformation
Modelling Air Pollution from Transport
Reducing Air Pollution from Transport
Future Directions
Bibliography
Glossary
DPF Diesel particulate filter, the preferred and
most effective technology for removing particulate matter from diesel exhaust. DPFs can be
broadly divided into two types: “full flow” and
“partial flow.” The latter are more permeable
and are less effective, but need no maintenance.
DPFs physically capture particles and can fill up
rapidly. They must therefore be periodically
“regenerated,” and several passive and active
systems have been developed for this purpose.
Emission standard A value that specifies the
maximum amount of a pollutant that can be
released into the environment per unit activity
(e.g., g/km or g/kWh).
NO 2 Nitrogen dioxide, a gaseous air pollutant
produced as a result of combustion. NO 2 is
also a precursor for a number of harmful secondary air pollutants such as ozone, and plays a
role in the formation of acid rain. Long-term
exposure to high concentrations of NO 2 causes
adverse health effects, and levels regularly
exceed air quality standards.
O 3 Ground-level ozone, a secondary pollutant
produced by reactions between NO 2 , hydrocarbons, and sunlight. High levels of ozone are
generally observed during hot, sunny weather,
and concentrations tend to be higher in rural
areas than in urban areas.
PM 10 Mass concentration of particles with an aerodynamic diameter of less than 10 mm. Particles
smaller than 10 mm (also known as “thoracic”
particles) can settle in the bronchi and lungs.
PM 2.5 Mass concentration of particles with an
aerodynamic diameter of less than 2.5 mm,
sometimes referred to as “fine” or “respirable”
particles. Particles in this size range can penetrate deep into the lungs.
Primary particles Particles emitted directly to
the atmosphere, typically as a result of combustion or abrasion processes.
SCR Selective catalytic reduction, an exhaust
aftertreatment method that is used to reduce
emissions of nitrogen oxides. It will be the
main technology for enabling compliance
with future emission standards.
Secondary particles Particles formed within the
atmosphere from gas-phase precursors. These
include particles originating from atmospheric
oxidation of sulfur and nitrogen oxides, and
their reaction products with ammonia, and
from the oxidation of organic compounds.
Ultrafine particles Particles with a diameter of
less than 0.1 mm. These can pass through cell
membranes and migrate from the lungs into
other organs. There is evidence to indicate
that they may be more damaging to the cardiovascular system than PM 10 and PM 2.5 .
Definition of the Subject
Until the middle of the twentieth century poor air
quality in populated areas was usually associated
© Springer Science+Business Media, LLC 2012
M. E. Goodsite et al. (eds.), Air Pollution Sources, Statistics and Health Effects,
https://doi.org/10.1007/978-1-0716-0596-7_554
Originally published in
R. A. Meyers (ed.), Encyclopedia of Sustainability Science and Technology, © Springer Science+Business Media LLC, 2012
https://doi.org/10.1007/978-1-4419-0851-3_554
47