“…Factor 5 was characterized by high loads of Cr, Co, Ni, Cu, Sr, Ba, and Pb, indicating non-combustion related industrial emission (Cai et al, 2017;Chang et al, 2018;Liu et al, 2019;Rai et al, 2020). High loads of Cr, Mn, Cu, Zn, Se, Pb in factor 6 suggested traffic emission (Alias et al, 2020;Lin et al, 2015).…”