The Policy Relevance of WearEmissions from Road Transport,Nowand in the Future-An InternationalWorkshop Report and Consensus Statement

Research output: Contribution to journalArticlepeer-review


  • H.A.C. Denier van der Gon
  • M.E. Gerlofs-Nijland
  • R. Gehrig
  • M. Gustafsson
  • N. Janssen
  • J. Hulskotte
  • C. Johansson
  • M. Jozwicka
  • M. Keuken
  • K. Krijgsheld
  • L. Ntziachristos
  • M. Riediker
  • F.R. Cassee

Colleges, School and Institutes

External organisations

  • National Institute for Public Health and the Environment (RIVM)
  • Netherlands Organisation for Applied Scientific Research, TNO
  • Institute for Risk Assessment Sciences
  • Empa, Swiss Federal Laboratories for Materials Science and Technology
  • Swedish National Road and Transport Research Institute
  • Stockholm University
  • Environment and Health Administration
  • Netherlands Organisation for Applied Scientific Research
  • Ministry of Infrastructure and Environment Directorate Climate and Air Quality
  • Laboratory of Applied Thermodynamics
  • Institute for Work and Health
  • Department of Environmental Sciences / Center of Excellence in Environmental Studies, King Abdulaziz University, PO Box 80203, Jeddah, 21589, Saudi Arabia


Road transport emissions are a major contributor to ambient particulate matter concentrations and have been associated with adverse health effects. Therefore, these emissions are targeted through increasingly stringent European emission standards. These policies succeed in reducing exhaust emissions, but do not address "nonexhaust" emissions from brake wear, tire wear, road wear, and suspension in air of road dust.Is this a problem? To what extent do nonexhaust emissions contribute to ambient concentrations of PM or PM? In the near future, wear emissions may dominate the remaining traffic-related PM emissions in Europe, mostly due to the steep decrease in PM exhaust emissions. This underlines the need to determine the relevance of the wear emissions as a contribution to the existing ambient PM concentrations, and the need to assess the health risks related to wear particles, which has not yet received much attention. During a workshop in 2011, available knowledge was reported and evaluated so as to draw conclusions on the relevance of traffic-related wear emissions for air quality policy development. On the basis of available evidence, which is briefly presented in this paper, it was concluded that nonexhaust emissions and in particular suspension in air of road dust are major contributors to exceedances at street locations of the PM air quality standards in various European cities. Furthermore, wear-related PM emissions that contain high concentrations of metals may (despite their limited contribution to the mass of nonexhaust emissions) cause significant health risks for the population, especially those living near intensely trafficked locations. To quantify the existing health risks, targeted research is required on wear emissions, their dispersion in urban areas, population exposure, and its effects on health. Such information will be crucial for environmental policymakers as an input for discussions on the need to develop control strategies.Road transport particulate matter (PM) emissions are associated with adverse health effects. Stringent policies succeed in reducing the exhaust PM emissions, but do not address "nonexhaust" emissions from brake wear, tire wear, road wear, and suspension in air of road dust. In the near future the nonexhaust emissions will dominate the road transport PM emissions. Based on the limited available evidence, it is argued that dedicated research is required on nonexhaust emissions and dispersion to urban areas from both an air quality and a public health perspective. The implicated message to regulators and policy makers is that road transport emissions continue to be an issue for health and air quality, despite the encouraging rapid decrease of tailpipe exhaust emissions.Supplemental Materials: Supplemental materials are available for this paper. Go to the publisher's online edition of the Journal of the Air & Waste Management Association.

Bibliographic note

Copyright 2013 Elsevier B.V., All rights reserved.


Original languageEnglish
Pages (from-to)136-149
Number of pages14
JournalJournal of the Air & Waste Management Association
Issue number2
Publication statusPublished - 1 Feb 2013