How VOC Emissions by Asphalt Pavements under Service Conditions Impact Air Quality in Cities?
Authors: Romanias Manolis N. , Lasne Jerome , Lostier Anais , Vassaux Sabine , Lesueur Didier , Gaudion Vincent , Jamar Marina , Derwent Richard , Dusanter Sebastian , Salameh Therese 
Published: February 2023

Outdoor air pollution is the fourth cause of death worldwide, linked to around 4.2 million deaths per year. Air pollution is more severe in urban environments of cities/megacities, due to the high population density and intense anthropogenic activities. More than 50% of global population lives currently in urban areas,1 and a projected 70% is anticipated by 2050,2 even reaching 84% of the population in the EU.3Around 40% of urban areas are covered by asphalt pavements, a fraction that keeps increasing with urbanization.4,5 Asphalt is a petroleum byproduct composed of a large number of organic species 6-8 capable of emitting a wide variety of organic compounds. Although emission of pollutants by asphalt mixtures have been investigated at deposition temperatures (120-160&#176;C), data at service temperatures (i.e., atmospheric relevant conditions) are lacking.Among atmospheric pollutants, Volatile Organic Compounds (VOCs) play a key role in urban atmospheres, as efficient ozone (O3) and Secondary Organic Aerosol (SOA) precursors. In the present work, we characterize and quantify VOC emissions by fresh and aged asphalt surfaces as a function of temperature. Experiments were performed inside a Teflon atmospheric simulation chamber coupled with PTR-ToF-MS, and GC-MS/FID for VOC speciation and quantification. We observe that at atmospheric relevant temperatures, asphalt surfaces significantly contribute to urban pollution, and therefore urgently need to be included in emission inventories, and in air quality models. Emissions are shown to be key in terms of ozone and SOA formation potential in urban areas to account for observations of urban air pollution.&#160;References(1)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Ritchie, H.; Roser, M. Urbanization. Our World in Data 2018.(2)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; United Nations &#8220;World Urbanization Prospects: The 2018 revision &#8221;, 2018.(3)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; EuropeanCommission; Eurostat. Urban Europe : statistics on cities, towns and suburbs : 2016 edition; Publications Office, 2016.(4)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Akbari, H.; Shea Rose, L.; Taha, H. Analyzing the land cover of an urban environment using high-resolution orthophotos. Landsc. Urban Plan. 2003, 63 (1), 1.(5)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Pacheco-Torgal, F.; Labrincha, J.; Cabeza, L. Eco-efficient Materials for Mitigating Building Cooling Needs; 1st Edition ed., 2015.(6)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Lesueur, D. The colloidal structure of bitumen: Consequences on the rheology and on the mechanisms of bitumen modification. Advances in Colloid and Interface Science 2009, 145 (1), 42.(7)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Hung, A. M.; Goodwin, A.; Fini, E. H. Effects of water exposure on bitumen surface microstructure. Construction and Building Materials 2017, 135, 682.(8)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Mirwald, J.; Nura, D.; Eberhardsteiner, L.; Hofko, B. Impact of UV&#8211;Vis light on the oxidation of bitumen in correlation to solar spectral irradiance data. Construction and Building Materials 2022, 316, 125816.