Table 4.

Comparative heavy metal concentrations (mg/kg) in the sediments of some coastal lakes

	Sand + gravel (%)	Silt (%)	Clay (%)	TOC (%)	Al (mg/kg)	Cr (mg/kg)	Ni (mg/kg)	Cu (mg/kg)	Zn (mg/kg)	As (mg/kg)	V (mg/kg)	Pb (mg/kg)	Hg (mg/kg)
Sand + gravel	1
Silt	− 0.978	1
Clay	− 0.801	0.657	1
TOC	− 0.443	0.443	0.327	1
Al	− 0.388	0.310	0.506	− 0.308	1
Cr	− 0.359	0.268	0.526	− 0.188	0.752	1
Ni	− 0.304	0.187	0.558	0.327	0.400	0.481	1
Cu	− 0.016	− 0.006	0.073	0.430	− 0.011	− 0.133	0.442	1
Zn	− 0.137	0.081	0.262	0.447	0.035	− 0.020	0.606	0.892	1
As	0.072	− 0.134	0.124	0.592	− 0.317	− 0.032	0.641	0.446	0.583	1
V	− 0.312	0.182	0.602	0.365	0.470	0.500	0.953	0.445	0.591	0.558	1
Pb	− 0.088	0.035	0.217	0.498	− 0.118	− 0.042	0.653	0.810	0.905	0.770	0.605	1
Hg	− 0.270	0.255	0.243	0.615	− 0.272	− 0.089	0.272	0.314	0.406	0.599	0.229	0.537	1

Values in italics are significant at a confidence level α = 0.05