Biological Evidence 2018, Vol.8, No.3, 21-31
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Table 2 Level of heavy metals in sediment along Nun River at Gbarantoru and Tombia towns in Bayelsa state, Nigeria
Parameters Around oil and gas
installations (Location A)
Gbarantoru (Location B) Tombia (Location C)
Median mean
Geometric mean
Cd, mg/kg 0.012±0.000b
0.011±0.000b
0.005±0.002a
0.011
0.008
Cr, mg/kg
0.003±0.001c
0.002±0.000b
0.001±0.000a
0.002
0.002
Co, mg/kg 0.002±0.000b
0.001±0.000a
0.001±0.000a
0.001
0.001
Ni, mg/kg 0.032±0.000c
0.012±0.000b
0.001±0.000a
0.012
0.008
Pb, mg/kg 0.017±0.000c
0.013±0.000b
0.007±0.000a
0.013
0.012
Zn, mg/kg 0.126±0.001c
0.110±0.001b
0.082±0.001a
0.110
0.104
Fe, mg/kg 0.314±0.001c
0.247±0.001b
0.138±0.001a
0.247
0.220
Note: Data is expressed as mean ± standard error (n=3); Different letters across the row indicate significant difference (P<0.05)
according to Tukey Honestly Significance difference statistics
Table 3 Spearman's rho of the sediment quality studied parameters
Parameters
Cd
Cr
Co
Ni
Pb
Zn
Fe
Cd
1.000
Cr
0.983
**
1.000
Co
0.845
**
0.887
**
1.000
Ni
0.933
**
0.950
**
0.803
**
1.000
Pb
0.917
**
0.900
**
0.678
*
0.950
**
1.000
Zn
0.950
**
0.967
**
0.837
**
0.967
**
0.933
**
1.000
Fe
0.867
**
0.883
**
0.912
**
0.883
**
0.817
**
0.883
**
1.000
Note: **. Correlation is significant at the 0.01 level (2-tailed); *. Correlation is significant at the 0.05 level (2-tailed); N=9; n=3
Lead concentration in the sediment ranged from 0.007-0.017 mg/kg. There was significant variation (P<0.05)
among the various locations (Table 2). Lead showed positive significant correlation with zinc (r=0.933) and iron
(r=0.817) at P<0.01 (Table 3).
Zinc concentration in the sediment ranged from 0.082-0.126 mg/kg. There was significant variation (P<0.05)
among the various locations (Table 2). Zinc showed positive significant relationship iron (r=0.883, P<0.01) (Table
3). The level of iron in the sediment samples ranged from 0.138-0.314 mg/kg. There was significant variation
(P<0.05) among the various locations (Table 2).
The sediment showed that there was significant variation (P<0.05) among most of the locations for each of the
heavy metals. Furthermore, the results also showed that location A has higher heavy metal concentration
compared to Location B and C. This suggests possible human impacts in the areas. Furthermore, all the heavy
metals showed positive significant relationship (P<0.05) suggesting that the source of the heavy metals in the
sediment is of similar origin. The concentration of the respective heavy metals in sediment had some similarity
with the values previously reported in Warri river (Aghoghovwia et al., 2015) and Kolo creek (Ogamba et al.,
2017b). This suggests that surface water is a major recipient of anthropogenic activities from both water and land.
Typically, surface water has relationship with water quality (Seiyaboh et al., 2016a; 2017c; Kigigha et al., 2018).
As such water contaminants tend to sink in the bottom of the water often called sediment. The values of heavy
metals of the water quality tend to be lower compared to the sediment heavy metals concentrations. These trends
have been reported by Aghoghovwia et al. (2015) on their study on water and sediment quality of Warri River.
Table 4 presents contamination factor, degree of contamination and pollution load index of the heavy metals
concentration in sediment of Nun River at Gbarantoru and Tombia towns in Bayelsa state, Nigeria. The results
showed that heavy metals pollution level ranged from low contamination (CF < 1) to moderate contamination (1 ≤
CF <3) for all the heavy metals in the different location under both background scenarios except for Nickel in
Location A under geometric mean background scenario. The results also showed that locations A were most
contaminated.
