Bioavailability and Assessment of Metal Contamination in Surface Sediments of Rades-Hamam Lif Coast, around Meliane River (Gulf of Tunis, Tunisia, Mediterranean Sea)

Table 3

Pollutants indicators: sediment quality indexes.

Sediment quality index
Contamination factor: Cf = C heavy metal/C background [21]
If:	Cf < 1, low factor
	1 ≤ Cf < 3, moderate factor
	3 ≤ Cf < 6, considerable factor
	Cf ≥ 6, very high factor
Geoaccumulation index: Igeo = log 2 (Cn/1.5 Bn) [22]
If:	Igeo ≤ 0, uncontaminated
	0 < Igeo ≤ 1, uncontaminated to moderately contaminated
	1 < Igeo ≤ 2, moderately contaminated
	2 < Igeo ≤ 3, moderately to strongly contaminated
	3 < Igeo ≤ 4, strongly contaminated
	4 < Igeo ≤ 5, strongly to extremely contaminated
	Igeo > 5, extremely contaminated
Pollution load index: PLI = (Cf1  Cf2  Cf3....)1/n [23]
If:	PLI ≤ 1, no pollution
	PLI > 1, pollution