Article: Zheng, X; Wu, Y; Zhang, SJ; Hu, JN; Zhang, KM; Li, ZH; He, LQ; Hao, JM; “Characterizing Particulate Polycyclic Aromatic Hydrocarbon Emissions from Diesel Vehicles using a Portable Emissions Measurement System”, Scientific Reports, 7
Abstract: Particulate polycyclic aromatic hydrocarbons (p-PAHs) emitted from diesel vehicles are of concern because of their significant health impacts. Laboratory tests, road tunnel and roadside experiments have been conducted to measure p-PAH emissions. While providing valuable information, these methods have limited capabilities of characterizing p-PAH emissions either from individual vehicles or under real-world conditions. We employed a portable emissions measurement (PEMS) to measure real-world emission factors of priority p-PAHs for diesel vehicles representative of an array of emission control technologies.
The results indicated over 80% reduction in p-PAH emission factors comparing the China V and China II emission standard groups (113 mu g kg(-1) vs. 733 mu g kg(-1)). The toxicity abatement in terms of Benzo[a] pyrene equivalent emissions was substantial because of the large reductions in highly toxic components. By assessing real traffic conditions, the p-PAH emission factors on freeways were lower than on local roads by 52% +/- 24%. A significant correlation (R-2=0.85) between the p-PAH and black carbon emissions was identified with a mass ratio of approximately 1/2000. A literature review indicated that diesel p-PAH emission factors varied widely by engine technology, measurement methods and conditions, and the molecular diagnostic ratio method for source apportionment should be used with great caution.
Funding Acknowledgement: National Key Research and Development Program of China [2017YFC0212100]; National Natural Science Foundation of China (NSFC) [91544222]; Ministry of Science and Technology (MOST)’s International Science and Technology Cooperation Program [2016YFE0106300]; China Postdoctoral Science Foundation [2017M610092]; Cornell University’s David R Atkinson Center for a Sustainable Future (ACSF); Cornell University’s Jeffrey Sean Lehman Fund
Funding Text: Y.W. acknowledges support from the National Key Research and Development Program of China (2017YFC0212100) and the National Natural Science Foundation of China (NSFC) (No. 91544222). X.Z. acknowledges the support from Ministry of Science and Technology (MOST)’s International Science and Technology Cooperation Program (No. 2016YFE0106300) and the support from China Postdoctoral Science Foundation (No. 2017M610092). S.Z. is in part supported by Cornell University’s David R Atkinson Center for a Sustainable Future (ACSF). K.M.Z. would like to acknowledge the support from Cornell University’s Jeffrey Sean Lehman Fund for Scholarly Exchange with China. The contents of this paper are solely the responsibility of the authors and do not necessarily represent official views of the sponsors.