From emission to immission: the way to pertinent evaluation of transport-related health and environmental impacts

This contribution focusses on emission/immission contribution assessment of road transport to global pollution source apportionment. The recent evolution in this domain show the impressive reduction of tailpipe emissions when brake and tyre wear PM emissions become the major source of recent powertrains. Inside vehicle immissions have been assessed using a vehicle inserted in the traffic as a ‘mobile laboratory’. These immissions may represent the major part of the daily personal space-time exposure budget to air pollution. As an example, each hour spent in a car cabin may represent to a 1 hour exposure above the WHO recommendation limits for both PM and NO2. Time course evolution of car cabin immissions shows an important reduction of PM exposure thanks to the Euro5 regulation which made mandatory the use of particulate filters on light duty diesel-powered vehicles. In the meantime, recent toxicological studies demonstrate the impressive reduction of genotoxity, carcino-genicity, and pro-inflammatory potentials of post Euro5 diesel-vehicle emissions. As a conclusion, the impressive reduction of post Euro5 diesel-vehicle tailpipe emissions leads to a reduction of traffic-related pollutant immissions which will further improve with the expected growing of Euro6 complying vehicles in the forthcoming years.