Trace element pollution indices
Formulae
Reference
Degree of contamination
DC = ∑ i = 1 n C f i
(Edet & Offiong, 2002)
Enrichment factor
ER= ( Ci/ Cie )sample ( Ci/ Cie )background
(Zhang et al., 2007)
Ecological risk factor
E r i = T r i × C f i
Hakanson (1980)
Ecological risk index
RI i = ∑ i=1 n E r i
pollution load index
PLI= C f1 × C f2 ×⋯× C fn n
(Harikumar et al., 2009)
Geo-accumulation index
I geo = log 2 [ C i / ( 1.5 C ri ) ]
(Ji et al., 2012)