Distribution (%) of enrichment factor values (based on eqn (1)) for 1528 soil samples across five-category enrichment factor index^a.

	Pb	As	Mn	Cr	Ni	Cu	Cd	Zn
No or minimal enrichment	50.2	71.2	99.8	99.1	99.8	92.2	99.7	34.6
Moderate enrichment	38.2	25.7	0.1	0.9	0.2	6.8	0.3	56.5
Significant enrichment	10.2	3.0	0.1			0.9		8.8
Very high enrichment	1.1	0.1				0.1		0.1
Extremely high enrichment	0.3

^aFe was used as reference element.