Air pollution and air quality

Air quality research at VTI focuses on emissions of air pollutants from the transport sector. Field and laboratory measurements are used within national and international research projects. One important field concerns wear particles from road and railroad traffic. The emission process and the characteristics of the aerosol particles emitted are thoroughly investigated with respect to health standards and toxicity. The aim of the research is to understand why and how the particulate matter is hazardous to human health and which abatement strategies which are efficient for lowering the emission.

Within the aerosol research a unique laboratory setup with controlled emissions of particles from of road and wheel interaction is used, the VTI road simulator. In the emission chamber pure wear particles, with no interference from combustion particles, can be produced, measured and collected for further analysis. The isolation of particles from one source or process is an important premise when doing toxicological analyses of the collected sample. The studies in the road simulator primarily concerns questions about how different combinations of wheels and pavements influences the particle generation. The results can be used when designing roads and choosing wheels, so that the emission of inhalable particles and their toxic effects can be minimized.

The road simulator is also used for evaluation of dust binding agents. VTI have developed a method where the relative efficiency and durability of the dust binders can be compared. The method is used within the EU-project CMA+ and in projects by manufacturers of chemicals.

Field investigations of particulate matter in road and railroad environments are also done within the air quality research at VTI. Railroad related particles are often found in high concentrations in tunnel environments; they are relatively small in size and contain high concentrations of metals. This has implied an increased attention to their health effects, and they have been studied within several project.

Aerosol research requires broad competence as well as expensive and technically advanced equipment for analyses why VTI cooperates with several universities and research institutes.

VTI's particle instruments are:

  • RP TEOM (Tapered element oscillating microbalance) – measurements of PM10 or PM2,5
  • TSI DustTrak (2 st) – fast, small och battery supplied, measures PM10, PM4, PM2,5 or PM1.
  • TSI APS (aerodynamic particle sizer) – aerosol size distribution between ca 0,5–18 µm.
  • TSI SMPS (scanning mobility particle sizer) – aerosol size distribution between ca 10 nm–0,5 µm
  • TSI NAS (nanometer aerosol sampler) – sampling of nanosized particles for analyses
  • Fidas AQguard (2 pcs) optical instruments that provide PM1, PM2.5, PM4, PM10 and size distributions with 1 s time resolution.
  • Ecotech Microvol (2 pcs) programmable samplers for PM10 or PM2.5 on 47 mm filters.
  • Ecotech high volume sampler – sampling of large amounts of PM10 for e.g. toxicology

The instruments and the road simulator are available for research cooperation and, depending on availability, for rent.

VTI also has an own-developed equipment for road dust sampling called the Wet Dust Sampler (WDS), which is used in Sweden, Norway and Finland.

VTI Road Simulator described in more detail

The Wet Dust Sampler, WDS described in more detail

Mätutrustning och laptop med grafer
Some VTI equipment during a running test at KTH.
VTI's Road Simulator with two DustTrak up front.

Ongoing and recent projects, examples:


EU project in collaboration with IDIADA, Ford, Audi, JRC, RIVM, TNO to investigate particulate and noise emissions from tires, propose test method for tire wear and develop low-noise truck tires.


In collaboration with IVL, and financed by the Swedish Transport Administration, a new method is being developed for measuring the emissions of wear particles from passing vehicles. WDS is used to define the amount of road dust on the test surfaces used in the development.

NorDust II

The project is a Nordic collaboration to improve the knowledge situation on how emissions of road dust can be reduced and modeled in a better way. Field studies provide the basis for improved parametrization and further development of the Nordic emission model NORTRIP. The project is funded by NordFoU and is a collaboration with MetNorway (Norway), NILU (Norway), Metropolia (Finland), SYKE (Finland), SLB-analys (Sweden) and the University of Iceland (Iceland).

The project follows up on the NorDust project:

The NorDust´s report External link.

The tyre/road interaction PhD project

In a PhD project funded by the Swedish Transport Administration and VTI, two PhD students, affiliated with KTH, are working on emissions linked to the interaction between tyres and road pavement. One of the doctoral students focuses on particle emissions and one on noise and rolling resistance. In the project, among other things, an evaluation of a porous pavement was carried out on Industrigatan in Linköping.

Licentiate thesis: Non-Exhaust PM10 and Road Dust (2018, DiVA portal) External link.


uCARe is a Horizon 2020 project funded by the EU and deals with how car owners themselves can reduce their emissions through increased knowledge of the importance of driving modes and choices and maintenance of vehicles and components. The project is ongoing between 2019-2022. VTI works in the project with emissions of wear particles and with research on behavior and psychology.

The uCARe project website External link.

Intersection project

The project is funded by BVFF and aims to investigate the extent to which the air quality at intersections differs on road links. Measurements of air quality and traffic flows have been made in Stockholm.

Indicative method for assessing PM10 emission of pavements
The project is funded by the BVFF and aims to investigate whether laboratory methods developed to test double-tire wear of coating samples can also be developed to make initial assessments of their PM10-emitted properties.

Wear Tox II

In the project WearTox II, funded by the Swedish Transport Administration, the toxic properties of wear particles from road surfaces with different stone materials are studied. Lund University of Technology, Linköping University and the CBI (Cement and Concrete Institute) participate in the study with expertise in aerosolization, toxicology and geology respectively. A smaller project, financed by the Dutch RIVM, has been linked to the project, where particles from brakes are tested at KTH and used in the same toxicological experiments. The study is a follow-up to the WearTox project that was reported in 2005.

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