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K. Kupiainen et al.
and PM 2.5 emission factors separately for different climatic zones, road and street
categories, and road maintenance practices in Finland. The non-exhaust emissions
are influenced by climatic and weather factors, especially the road surface moisture,
and have seasonal peaks particularly in winter and spring, due to enhanced formation
of layers of street dust and their suspension to the air. The results demonstrated that
changes in the selection of the types of winter tyres and their use, as well as road
maintenance interventions could substantially reduce the non-exhaust emissions,
especially in spring. Data gaps were identified in collecting the relevant inputs for
the model. The methods presented in this study could be used at least in the whole
Northern part of the world, i.e., the Nordic countries and Northern Central Europe,
Northern Russia, North America, and parts of China and Japan.
33.1 Introduction
Modern emission abatement technologies are reducing the particle emissions from
vehicular exhaust sources, but the non-exhaust sources remain a challenge. Studies
and inventories of road traffic emissions should accurately characterize the nonexhaust sources to support efficient emission mitigation to the benefit of air quality
and human health. In the Nordic countries key sources of non-exhaust PM emissions
are wear products from pavements, tyres and brakes as well as sand and salt used
for traction control [3, 4]. Additionally climatic and weather factors, especially the
road surface moisture, influence the ambient emissions and result in seasonal peaks
particularly in spring, due to enhanced formation of layers of street dust and their
suspension to the air. With all these influencing factors the system guiding the nonexhaust PM emissions is complex and it is often difficult to identify the main sources
or formulate recommendations on how to most efficiently reduce emissions in different locations. Our thinking is that a method to overcome these challenges is to use
generalized, process based models for estimating non-exhaust PM emission factors
that would better represent emission characteristics in broader weather, traffic, road
and street conditions. However, there are not that many models available for the time
being. In this work we utilized the recently developed and published non-exhaust
emission model NOn-exhaust Road TRaffic Induced Particle emissions (NORTRIP)
[1, 2, 4] to estimate the PM 10 and PM 2.5 emission factors for different climatic zones,
road and street categories, and road maintenance policies in Finland.
33.2 Methods
The non-exhaust emission model NORTRIP [1, 2, 4] includes a range of key processes governing road dust surface loading, PM emissions and surface moisture
conditions. It uses the mass balance approach to estimate street surface moisture
and dust loading and calculates the emissions of both dust and salt. The NORTRIP
K. Kupiainen et al.
and PM 2.5 emission factors separately for different climatic zones, road and street
categories, and road maintenance practices in Finland. The non-exhaust emissions
are influenced by climatic and weather factors, especially the road surface moisture,
and have seasonal peaks particularly in winter and spring, due to enhanced formation
of layers of street dust and their suspension to the air. The results demonstrated that
changes in the selection of the types of winter tyres and their use, as well as road
maintenance interventions could substantially reduce the non-exhaust emissions,
especially in spring. Data gaps were identified in collecting the relevant inputs for
the model. The methods presented in this study could be used at least in the whole
Northern part of the world, i.e., the Nordic countries and Northern Central Europe,
Northern Russia, North America, and parts of China and Japan.
33.1 Introduction
Modern emission abatement technologies are reducing the particle emissions from
vehicular exhaust sources, but the non-exhaust sources remain a challenge. Studies
and inventories of road traffic emissions should accurately characterize the nonexhaust sources to support efficient emission mitigation to the benefit of air quality
and human health. In the Nordic countries key sources of non-exhaust PM emissions
are wear products from pavements, tyres and brakes as well as sand and salt used
for traction control [3, 4]. Additionally climatic and weather factors, especially the
road surface moisture, influence the ambient emissions and result in seasonal peaks
particularly in spring, due to enhanced formation of layers of street dust and their
suspension to the air. With all these influencing factors the system guiding the nonexhaust PM emissions is complex and it is often difficult to identify the main sources
or formulate recommendations on how to most efficiently reduce emissions in different locations. Our thinking is that a method to overcome these challenges is to use
generalized, process based models for estimating non-exhaust PM emission factors
that would better represent emission characteristics in broader weather, traffic, road
and street conditions. However, there are not that many models available for the time
being. In this work we utilized the recently developed and published non-exhaust
emission model NOn-exhaust Road TRaffic Induced Particle emissions (NORTRIP)
[1, 2, 4] to estimate the PM 10 and PM 2.5 emission factors for different climatic zones,
road and street categories, and road maintenance policies in Finland.
33.2 Methods
The non-exhaust emission model NORTRIP [1, 2, 4] includes a range of key processes governing road dust surface loading, PM emissions and surface moisture
conditions. It uses the mass balance approach to estimate street surface moisture
and dust loading and calculates the emissions of both dust and salt. The NORTRIP