Non-exhaust traffic emissions: Sources, characterization, and mitigation measures

Insight into PM<sub>2.5</sub> Sources by Applying Positive Matrix Factorization (PMF) at an Urban and Rural Site of Beijing

“…This factor makes a major contribution to crustal species, such as Na + , Al and Fe (60%, 48% and 34% of species in this factor respectively) suggesting this factor may represent the characteristics of a dust related source as reported previously (Kim and Koh, 2020). In addition, the given factor also included significant contributions to Mn, Pb and Zn (26%, 23% and 20% of species in this factor respectively), which are associated with brake and tyre wear as mentioned above (Pant and Harrison, 2012;Pant and Harrison, 2013;Grigoratos and Martini, 2015;Piscitello et al, 2021).…”

“…Zn is a major additive to lubricant oil. Zn and Fe can also originate from tyre abrasion, brake linings, lubricants and corrosion of vehicular parts and tailpipe emission (Pant and Harrison, 2012;Pant and Harrison, 2013;Grigoratos and Martini, 2015;Piscitello et al, 2021). As the use of Pb additives in gasoline has been banned since 1997 in Beijing, the observed Pb emissions may be associated with wear (tyre/brake) rather than fuel combustion (Smichowski et al, 2007).…”

Insight into PM<sub>2.5</sub> sources by applying positive matrix factorization (PMF) at urban and rural sites of Beijing

“…It is also notable that a high proportion of Na + was attributed to road dust in a previous study conducted at the same urban site (Tian et al, 2016), and a crustal source seems likely but has not been confirmed. In addition, the given factor also included significant contributions to Mn, Pb, and Zn (26 %, 23 %, and 20 % of species in this factor, respectively), which are associated with brake and tyre wear as mentioned above Harrison, 2012, 2013;Grigoratos and Martini, 2015;Piscitello et al, 2021). High concentrations of Zn and Pb have also been reported for particles emitted from asphalt pavement (Canepari et al, 2008;Sörme et al, 2001).…”

“…The general principle is to smooth the data over a fine grid, so that a weighted concentration could be estimated by any wind direction (φ)/wind speed (v) couple, where the weighing coefficients are determined through Gaussian-like functions. CWT and cluster analysis assess the potential transport of pollution over a large geographical scale (Polissar et al, 2001). These approaches combine atmospheric concentrations measured at the receptor site with back trajectories and residence time information and help to geographically evaluate air parcels responsible for high concentrations.…”

“…Zn is a major additive to lubricant oil. Zn and Fe can also originate from tyre abrasion, brake linings, lubricants, and corrosion of vehicular parts and tailpipe emission Harrison, 2012, 2013;Grigoratos and Martini, 2015;Piscitello et al, 2021). As the use of Pb additives in gasoline has been banned since 1997 in Beijing, the observed Pb emissions may be associated with wear (tyre/brake) rather than fuel combustion (Smichowski et al, 2007).…”