Elemental characterization of PM2.5 at an urban traffic site in Central Europe

<p>Metal content in traffic emissions is often overlooked during regulation and policy making. Exhaust and non-exhaust traffic emissions, including tire, brake wear and re-suspended dust, contribute greatly to particulate matter and pose significant health effects to humans in urban areas (Johansson et al., 2009). The current lack of strict regulations on these metal emissions draws attention to the need for controls and monitoring, as reflected in the recent Euro 7 standards proposal for research on traffic emissions. This work aims to quantify metal emissions from traffic at an urban traffic site in Prague, Czech Republic, identify key tracers of emissions, and investigate exhaust and non-exhaust emissions observable in fine particulate matter (PM_2.5). This project signifies the first high-time resolution metal analysis in Prague.</p> <p>Two one-month long measurement campaigns were conducted from February to March and November to December 2020 at an urban traffic site in Prague. Elemental data were obtained from the Xact625i Ambient Metals Monitor (analytical method nondestructive energy dispersive X-ray fluorescence &#8211; EDXRF) equipped with a PM_2.5head at a two-hour time resolution. Enrichment factors were calculated, and correlations of key tracers (e.g. Cu, Ba, Zn, Mn) were identified. Source apportionment will be carried out using Positive Matrix Factorization (US EPA PMF 5.0) as well as a human risk assessment for potentially carcinogenic elements. Metallic elemental concentrations were observed in decreasing order: Fe > Zn > Cu > Ti > Mn > Ba > Cr > As > Cd > Ni. The most abundant metal, Fe, was found in the range of 10 &#8211; 2933 ng/m³, followed by Zn (1 &#8211; 144 ng/m³), Cu (1 &#8211; 104 ng/m³), Ba (0.1 &#8211; 41 ng/m³) and Cr (0.2 &#8211; 16 ng/m³). Enrichment factors of Cr, Mn, Cu and Zn were found to be up to 113, 71, 1937 and 1066, respectively.</p> <p>Acknowledgement:</p> <p>This conference contribution was supported by the Ministry of Education, Youth and Sports of the Czech Republic under grants ACTRIS-CZ LM2018122,&#160; ACTRIS-CZ RI (CZ.02.1 .01 / 0.0 / 0.0 / 16_013 / 0001315) and LTAUSA19006.</p> <p>References:</p> <p>JOHANSSON, C., NORMAN, M. & BURMAN, L. 2009. Road traffic emission factors for heavy metals. <em>Atmospheric Environment - ATMOS ENVIRON,</em> 43<strong>,</strong> 4681-4688.</p> <p>&#160;</p>