Fig. 4From: Toxic metal concentrations and Cu–Zn–Pb isotopic compositions in tiresPlots of Cu versus Zn concentrations (a), δ65CuAE647 versus δ66ZnIRMM370 (b), 206Pb/207Pb versus δ65CuAE647 (c), and 206Pb/207Pb versus δ66ZnIRMM3702 (d) for the tire samples in this study, background soil, and brake dust as potential sources of road dustBack to article page