Fig. 2. Concentration ratios (CR_{fractional,slag}) of As, Cu, Pb, Tl, and Zn (in mg kg^-1 dry plant per mg kg^-1 slag in mixture) for various vegetables grown on a red slag–soil mixture 1:1 (filled gray bars) and a black slag–soil mixture 1:1 (filled black bars) as compared with the CR_{control soil} of the metals in the control soil (hatched bars). Error bars are standard deviation (n = 2).