Emission factors from road dust resuspension in a Mediterranean freeway

Abstract

Particulate matter emissions from paved roads are currently one of the main challenges for a sustainable transport in Europe. Emissions are scarcely estimated due to the lack of knowledge about the resuspension process severely hampering a reliable simulation of PM and heavy metals concentrations in large cities and evaluation of population exposure. In this study the Emission Factors from road dust resuspension on a Mediterranean freeway were estimated per single vehicle category and PM component (OC, EC, mineral dust and metals) by means of the deployment of vertical profiles of passive samplers and terminal concentration estimate. The estimated PMio emission factors varied from 12 to 47 mg VKT -1 (VICT: Vehicle Kilometer Traveled) with an average value of 22.7 ± 14.2 mg VKT -1 . Emission Factors for heavy and light duty vehicles, passenger cars and motorbikes were estimated, based on average fleet composition and EPA ratios, in 187-733 mg VKT -1 , 33-131 VKT -1 , 9.4-36.9 VKT" 1 and 0.8-3.3 VKT -1 , respectively. These range of values are lower than previous estimates in Mediterranean urban roads, probably due to the lower dust reservoir on freeways. PM emitted material was dominated by mineral dust (9-10 mg VKT -1 ), but also OC and EC were found to be major components and approximately 14 -25% and 2-9% of average PM exhaust emissions from diesel passenger cars on highways respectively.

Characterization of Road Dust Emissions in Milan: Impact of Vehicle Fleet Speed

“…For the second and third campaigns, deposited PM loadings were investigated as a function of height, using the samplers utilized by Amato et al (2012aAmato et al ( , 2016 for estimating emission factors from vertical profiles of dust deposition (below 10 µm) in the cities of Barcelona (Spain) and Paris (France). Sampler design details can be found in our previous publications (Amato et al, 2012a; briefly, it consists of 15 cylindrical canisters of 6 cm height each and 7 cm of inner diameter. The canisters were installed in three vertical arrays, with canisters being separated by 1 cm from each other.…”

“…The theoretical basis on which Eq. (3) is based can be found in Amato et al (2012a), which assumes that the dry deposition of particulate matter is governed by diffusionand gravitational-like mechanisms (Pasquill, 1962). Once the net deposition flux is obtained for particles with diameter below 10 µm, this can be converted to emission rate (Escrig et al, 2011).…”

Characteristics of trace metals in traffic-derived particles in Hsuehshan Tunnel, Taiwan: size distribution, potential source, and fingerprinting metal ratio

“…1c), with the exception of a number of crustal elements such as Al, K, Mg, and Rb. This suggests that a lower road dust reservoir is present inside the freeway tunnel (Amato et al, 2012). Considerably high outlet-to-inlet ratios (ranging from 2.2 for Sr to 4.3 for Zn) were found for trafficderived elements, including Zn, Cu, Ba, Mn, Sb, Sn, Pb, Ga, Sr, and Cd.…”

Re-entrained road dust PM10 emission from selected streets of Krakow and its impact on air quality

“…Many studies conducted worldwide indicate that the resuspended dust emission constitutes a significant share in the PM10 concentrations in the air near the transport routes [6,8,[14][15][16][17][18][19][20]. Research carried out in the US city of Tucson (Arizona) in the winter showed that the fraction of particulate matter from the fuel combustion in car engines and the share of re-entrained road dust ranged from 4-40 % and 30-50 % of the total PM10 concentration in the air, respectively [21].…”