Evaluation of the bioindicator suitability of Polygonum aviculare in urban areas

► Polygonum aviculare showed greater accumulation of Cd, Cu, Fe, Ni, Pb and Zn due to vehicle traffic. ► Highway exhausts only were related with the highest Ni and Fe concentrations in shoots. ► Street and industrial emissions were related to the highest Cd, Cu, Pb, Zn concentrations in shoots. ► Cd, Ni, Pb sequestration in roots is probably the mechanism of metal tolerance. ► P. aviculare allocates essential Cu, Mn and Zn in photosynthetic tissues.