Table 3

Sites	Chemical Parameters
Sites	Hg (0.05)	Cr (0.1-1),[<25a, 25-75b , > 75c]	Zn (1-5), [<90a, 90 -200b , >200c]	Cd (0.01-0.05)	Pb (0.2-2.0) [<40a, 40 -60b , >60c]
S₁	0.00052 ± 0.00009^a	2.05 ± 0.02^a	32.13 ± 06^b	0.027 ± 0.0018^a	0.71 ± 0.05^b
S₂	0.00068 ± 0.00003^c	9.69 ± 0.18^b	61.6 ± 0.35^c	0.032 ± 0.009^b	0.75 ± 0.009^a
S₃	0.00066 ± 0.00004^a	5.69 ± 0.13^e	58.89 ± 0.36^c	0.021 ± 0.0005^a	1.44 ± 0.03^c
S₄	0.00017 ± 0.00004^b	8.10 ± 0.35^d	107.5 ± 4.45e^*	0.035 ± 0.0035^c	1.73 ± 0.04^d
S₅	0.00054 ± 0.00003^a	6.86 ± 0.1^c	71.95 ± 06^d	0.018 ± 0.0007^a	1.32 ± 0.05^c
S₆	0.00011 ± 0.00006^a	1.56 ± 0.02^a	11.4 ± 0.06a	0.012 ± 0.0001^a	0.56 ± 0.03^a

^*Values with different letters showed significant differences (P<0.05, ANOVA), letter “a” indicates the smallest value for a given physico-chemical parameter. Values with bold and ^* indicate those above MAL in sediment and polluted sediment [13,14].

Table 3: Mean value of metal concentration ± SE in mg kg-l of dry weight of sediment samples collected from Lake Hawassa, Values in parentheses () and square bracket [] indicate maximum acceptable levels (MAL) according to international standards for soil/sediment, anon-polluted, bmoderately polluted and cheavily polluted on the basis of numerical sediment quality guidelines (SQGs) [13,14].