Changes in the Heavy Metal Levels in Highway Landscaping and Protective Effect of Vegetative Materials

Table 4

Heavy metal limits in Turkey soil [9].

Elements	pH 5-6 (mg/kg dried soil)	pH > 6 (mg/kg dried soil)
Pb	50	300
Cd	1	3
Ni	30	75
Cr	100	100
Co	80	80
Cu	50	140
Zn	150	300