New scientific article by Aerosol
Black carbon emissions of individual cars measured under real traffic conditions
The latest study of Aerosol scientists determined black carbon (BC), particle number concentration (PN) and nitrogen oxides (NOx) emission factors (EFs) of different vehicles in real driving conditions. It is the first study where EFs of individual passenger cars were determined with the on-road chasing method and the first on-road study to report BC EFs of diesel cars. EFs are usually measured in laboratories, where only a limited number of vehicles can be measured on a prescribed driving cycles, thus the diversity of real driving conditions is not reflected. The chasing method used in this study measures emissions of individual vehicles by following them on roads and thus including the variety of in-use vehicles and traffic situations. Results showed that new diesel and petrol-fueled cars produce less BC per unit of fuel than old cars; while new goods vehicles (diesel trucks and buses) produce more BC per unit of fuel than older goods vehicles. The contrary was true for NOx EFs, these decreased from older to newer vehicle age groups. NOx EFs of diesel cars showed similar values over all investigated age groups. The span of PN EFs petrol-fueled cars increased in the newest age group, reflecting the high PN emissions of the newly introduced direct injection engines.
Air intake tubes hanging from a window of the car funneled exhaust gases into separate instruments for measuring black carbon, nitrogen oxide and particulates.
Original article can be read in an open access journal Atmospheric Chemistry and Physics:
I. Ježek, T. Katrašnik, D. Westerdahl, G. Močnik, »Black carbon, particle number concentration and nitrogen oxide emission factors of random in-use vehicles measured with the on-road chasing method«, Atmos. Chem. Phys., 15, 11011-11026, (2015)
The article has already received attention in EOS Earth & Space Science News: https://eos.org/articles/tailpipe-study-newer-trucks-emit-more-black-carbon and in Science for Environment Policy (Issue 441, 7 January 2016) - Black carbon emissions of individual cars measured under real conditions: http://ec.europa.eu/environment/integration/research/newsalert/archive/air-pollution.htm