Elements *Target value of soil
(mg/kg)
***Permissible value of plant
(mg/kg)
Cd 0.8 0.02
Zn 50 0.60
Cu 36 10
Cr 100 1.30
Pb 85 2
Ni 35 10
*Target values are specified to indicate desirable maximum levels of elements in unpolluted soils
Source: Denneman and Robberse 1990; Ministry of Housing, Netherlands 1994
***Source: WHO (1996)
Table 11: WHO permissible limits for heavy metals in plant and soil.