Table 3 Pearson correlation coefficients between TPHs/HMs, and TPHs/HMs and environmental parameters in the Niger Delta coastal systems (lower left diagonal) and associated p-values (upper right diagonal).

From: Pollution of the Niger Delta with total petroleum hydrocarbons, heavy metals and nutrients in relation to seasonal dynamics

 

TPHs

Mn

Zn

Al

B

Cd

Ba

Cr

Co

Cu

Fe

Pb

Hg

Mo

Ni

Temp

DO

Cond

TDS

pH

Turb

Sal

PO43−

NO3

NH4+

SO42−

a—River

 TPHs

0.03

0.64

0.52

0.56

0.07

0.25

0.28

0.31

0.48

0.75

0.34

0.32

0.69

0.52

0.49

0.74

0.72

0.83

0.57

0.37

0.52

0.27

0.12

0.02

0.09

 Mn

0.37

0.00

0.90

0.00

0.00

0.00

0.03

0.00

0.01

0.00

0.08

0.00

0.02

8.02

0.04

0.02

0.65

0.78

0.07

0.91

0.19

0.01

0.51

0.53

0.07

 Zn

0.08

0.59

0.88

6.57

0.08

0.00

0.00

0.01

0.00

0.32

0.17

0.00

0.07

0.01

0.01

0.09

0.53

0.55

0.09

0.01

0.06

0.01

0.58

0.56

0.00

 Al

 − 0.11

 − 0.02

 − 0.03

 

0.60

0.92

0.67

0.61

0.84

0.55

0.51

0.03

0.74

0.66

0.62

0.08

0.45

0.44

0.46

0.30

0.63

0.83

0.58

0.66

0.88

0.49

 B

0.10

0.60

0.62

 − 0.09

0.00

5.03

0.03

0.00

8.10

0.00

0.05

0.18

0.00

0.00

0.01

0.02

0.81

0.63

0.22

0.00

0.18

0.00

0.08

0.10

0.00

 Cd

0.30

0.55

0.29

0.02

0.53

0.00

0.00

0.01

2.49

0.02

0.21

0.03

0.10

0.04

0.20

0.22

0.28

0.36

0.68

0.01

0.12

0.00

0.48

0.21

0.01

 Ba

0.20

0.82

0.59

 − 0.07

0.62

0.51

0.00

0.00

0.00

1.39

0.16

0.00

0.08

0.00

0.02

0.00

0.60

0.69

0.00

0.00

0.07

0.00

0.16

0.10

0.00

 Cr

0.19

0.69

0.85

 − 0.09

0.74

0.54

0.77

0.00

0.00

0.01

0.09

0.01

0.01

0.00

0.00

0.03

0.20

0.21

0.02

0.00

0.03

5.32

0.54

0.29

0.26

 Co

0.18

0.68

0.43

 − 0.04

0.60

0.45

0.50

0.54

6.91

0.00

0.03

0.01

0.01

0.04

0.08

0.01

0.63

0.86

0.50

0.02

0.66

0.01

0.49

0.24

0.02

 Cu

0.12

0.76

0.47

0.1

0.61

0.64

0.53

0.54

0.61

0.00

0.17

2.70

6.44

0.04

0.33

0.31

0.21

0.32

0.88

0.02

0.42

0.00

0.08

0.08

0.02

 Fe

0.06

0.60

0.69

 − 0.11

0.84

0.40

0.66

0.77

0.58

0.56

0.01

9.69

0.01

0.00

0.00

0.00

0.63

0.77

0.16

0.00

0.12

0.00

0.28

0.30

0.00

 Pb

 − 0.16

 − 0.29

 − 0.23

0.36

 − 0.32

 − 0.21

 − 0.24

 − 0.29

 − 0.37

 − 0.24

 − 0.41

0.05

0.18

0.18

0.26

0.01

0.38

0.38

0.08

0.21

0.44

0.10

0.89

0.96

0.17

 Hg

0.17

0.55

0.58

 − 0.06

0.70

0.74

0.53

0.75

0.42

0.64

0.60

 − 0.33

0.15

0.12

0.01

0.04

0.20

0.21

0.35

0.05

0.01

0.00

0.37

0.33

0.01

 Mo

0.07

0.38

0.31

0.08

0.51

0.72

0.30

0.41

0.42

0.62

0.45

 − 0.23

0.71

0.63

0.90

0.17

0.43

0.57

0.35

0.86

0.01

0.23

0.71

0.64

0.37

 Ni

0.11

0.61

0.42

 − 0.09

0.49

0.35

0.82

0.56

0.34

0.34

0.55

 − 0.23

0.27

0.08

0.02

0.00

0.65

0.74

0.00

0.00

0.68

0.89

0.11

0.07

0.00

 Temp

 − 0.12

 − 0.35

 − 0.43

0.30

 − 0.44

 − 0.22

 − 0.38

 − 0.48

 − 0.29

 − 0.17

 − 0.52

0.2

 − 0.43

 − 0.02

 − 0.37

0.00

0.65

0.65

0.03

0.04

0.43

0.04

0.19

0.20

0.02

 DO

 − 0.06

 − 0.40

 − 0.29

0.13

 − 0.39

 − 0.21

 − 0.48

 − 0.37

 − 0.42

 − 0.17

 − 0.59

0.45

 − 0.34

 − 0.24

 − 0.48

0.48

0.90

0.95

0.07

583.0

0.38

0.01

0.09

0.10

0.00

 Cond

 − 0.06

 − 0.08

 − 0.11

 − 0.13

0.04

 − 0.19

 − 0.09

 − 0.22

 − 0.08

 − 0.21

 − 0.08

 − 0.15

 − 0.22

 − 0.13

 − 0.08

0.08

0.02

0.00

0.77

0.85

0.65

0.39

0.74

0.86

0.61

 TDS

 − 0.04

 − 0.05

 − 0.10

 − 0.13

0.08

 − 0.16

 − 0.07

 − 0.21

 − 0.03

 − 0.17

 − 0.05

 − 0.15

 − 0.22

 − 0.10

 − 0.06

0.08

0.01

0.99

0.69

0.91

0.65

0.47

0.69

0.81

0.66

 pH

0.10

0.30

0.29

 − 0.18

0.21

0.07

0.47

0.38

0.12

0.03

0.24

 − 0.30

0.16

 − 0.16

0.5

 − 0.36

 − 0.3

 − 0.05

 − 0.07

0.00

0.44

0.00

0.66

0.46

0.00

 Turb

0.16

0.67

0.42

 − 0.08

0.54

0.40

0.81

0.59

0.39

0.39

0.49

 − 0.22

0.33

0.03

0.86

 − 0.35

 − 0.45

 − 0.03

 − 0.02

0.51

0.87

0.00

0.17

0.05

0.00

 Sal

0.11

0.23

0.31

 − 0.04

0.23

0.27

0.31

0.37

0.08

0.14

0.26

 − 0.13

0.41

0.42

 − 0.07

 − 0.14

 − 0.15

0.08

0.08

0.13

 − 0.03

0.04

0.97

0.83

0.10

 PO43 − 

0.19

0.75

0.45

 − 0.1

0.48

0.47

0.84

0.62

0.43

0.54

0.50

 − 0.28

0.46

0.21

0.67

 − 0.35

 − 0.44

 − 0.15

 − 0.13

0.55

0.81

0.35

0.22

0.09

0.00

 NO3 − 

0.26

 − 0.11

 − 0.1

0.08

 − 0.29

 − 0.12

 − 0.24

 − 0.11

 − 0.12

 − 0.30

 − 0.19

0.03

 − 0.15

 − 0.07

 − 0.27

0.22

0.28

 − 0.06

 − 0.07

 − 0.08

 − 0.23

 − 0.01

 − 0.21

0.00

0.37

 NH4+

0.38

 − 0.11

 − 0.10

0.03

 − 0.28

 − 0.21

 − 0.28

 − 0.18

 − 0.20

 − 0.30

 − 0.18

0.01

 − 0.17

 − 0.08

 − 0.31

0.22

0.28

 − 0.03

 − 0.04

 − 0.13

 − 0.32

 − 0.04

 − 0.28

0.92

0.19

 SO42

0.29

0.72

0.53

 − 0.12

0.49

0.46

0.90

0.69

0.39

0.40

0.52

 − 0.23

0.44

0.16

0.79

 − 0.39

 − 0.47

 − 0.09

 − 0.08

0.58

0.88

0.28

0.92

 − 0.16

 − 0.22

b—Estuary

 TPHs

0.14

0.16

0.24

0.05

0.36

0.14

0.11

0.79

0.58

0.09

0.56

0.36

0.37

0.25

0.90

0.89

0.22

0.21

0.59

0.91

0.14

0.29

0.68

0.78

0.27

 Mn

 − 0.25

0.66

0.99

0.90

0.10

0.40

0.71

0.37

0.38

0.01

0.16

0.78

0.85

0.71

0.89

0.77

0.02

0.02

0.14

0.21

0.67

0.54

0.06

0.04

0.88

 Zn

0.24

 − 0.08

0.20

0.00

0.03

0.00

0.00

0.01

0.70

0.03

0.14

0.00

0.09

0.07

0.01

0.51

0.35

0.32

0.05

0.05

0.04

0.00

0.11

0.05

0.00

 Al

0.2

0.00

0.22

0.33

0.02

0.56

0.08

0.21

0.41

0.27

0.73

0.04

0.78

0.24

0.28

0.78

0.20

0.14

0.26

0.69

0.22

0.49

0.89

0.85

0.85

 B

0.33

 − 0.02

0.51

0.17

0.38

0.00

0.02

0.44

0.51

0.12

0.23

0.29

0.97

0.00

0.00

0.15

0.00

0.00

0.26

0.00

0.30

0.00

0.26

0.11

0.00

 Cd

0.16

0.28

0.36

0.38

0.15

0.68

0.05

0.00

0.00

0.15

0.94

0.11

0.04

0.00

0.08

0.25

0.40

0.47

0.45

0.96

0.58

0.37

0.05

0.03

0.32

 Ba

0.25

 − 0.15

0.5

 − 0.10

0.60

0.07

0.02

0.03

0.21

0.26

0.55

0.05

0.00

0.09

0.00

0.23

0.44

0.49

0.02

0.01

0.45

0.00

0.24

0.12

0.02

 Cr

0.27

 − 0.06

0.58

0.29

0.40

0.34

0.39

0.70

0.90

0.78

0.34

0.42

0.38

0.08

0.17

0.63

0.35

0.33

0.52

0.07

0.03

0.00

0.14

0.08

0.16

 Co

0.05

0.16

0.42

 − 0.21

0.13

0.46

0.36

0.07

0.00

0.00

0.10

0.27

0.00

0.15

0.00

0.59

0.58

0.52

0.00

0.38

0.32

0.02

0.04

0.02

0.10

 Cu

0.09

0.15

0.07

 − 0.14

 − 0.11

0.54

0.21

 − 0.02

0.64

0.91

0.28

0.32

0.00

0.22

0.13

0.07

0.51

0.52

0.11

0.64

0.96

0.12

0.39

0.39

0.63

 Fe

 − 0.28

0.43

0.36

 − 0.19

0.27

0.24

0.19

0.05

0.55

0.02

0.00

0.40

0.97

0.26

0.03

0.31

0.00

0.00

0.25

0.06

0.14

0.49

0.16

0.11

0.16

 Pb

 − 0.10

0.24

0.25

 − 0.06

0.21

 − 0.01

0.1

 − 0.17

0.28

 − 0.19

0.73

0.98

0.21

0.80

0.68

0.64

0.16

0.19

0.24

0.29

0.24

0.53

0.69

0.77

0.47

 Hg

0.16

0.05

0.46

0.34

0.18

0.27

0.32

0.14

0.19

0.17

0.15

 − 0.01

0.01

0.53

0.88

0.27

0.36

0.31

0.89

0.87

0.36

0.55

0.23

0.49

0.48

 Mo

0.16

 − 0.03

0.28

 − 0.05

0.01

0.35

0.47

0.15

0.67

0.77

 − 0.01

 − 0.21

0.42

0.41

0.11

0.61

0.08

0.09

0.01

0.93

0.67

0.03

0.68

0.44

0.45

 Ni

0.20

0.06

0.30

0.20

0.72

0.50

0.29

0.30

0.25

0.21

0.19

 − 0.04

0.11

0.14

0.00

0.79

0.00

0.01

0.96

0.00

0.30

0.00

0.17

0.05

0.00

 Temp

0.02

 − 0.02

 − 0.41

0.18

 − 0.53

 − 0.30

 − 0.47

 − 0.23

 − 0.49

 − 0.26

 − 0.36

 − 0.07

 − 0.03

 − 0.27

 − 0.54

0.11

0.00

0.00

0.42

0.00

0.01

0.00

0.03

0.00

0.00

 DO

 − 0.02

0.05

 − 0.11

0.05

 − 0.25

0.20

 − 0.20

 − 0.08

0.09

0.30

 − 0.17

 − 0.08

 − 0.19

0.09

0.05

0.27

0.27

0.28

0.81

0.34

0.18

0.40

0.73

1.00

0.38

 Cond

0.21

 − 0.40

 − 0.16

0.22

 − 0.48

 − 0.14

 − 0.13

 − 0.16

 − 0.1

0.11

 − 0.50

 − 0.24

0.16

0.30

 − 0.47

0.68

0.19

0.00

0.73

0.00

0.01

0.01

0.36

0.14

0.00

 TDS

0.22

 − 0.39

 − 0.17

0.25

 − 0.46

 − 0.13

 − 0.12

 − 0.17

 − 0.11

0.11

 − 0.48

 − 0.22

0.17

0.29

 − 0.45

0.70

0.19

0.99

0.82

0.00

0.01

0.00

0.40

0.16

0.00

 pH

 − 0.09

 − 0.25

 − 0.33

0.19

 − 0.19

 − 0.13

 − 0.40

 − 0.11

 − 0.50

 − 0.27

 − 0.20

 − 0.20

 − 0.03

 − 0.45

0.01

0.14

0.04

 − 0.06

 − 0.04

0.64

0.90

0.73

0.30

0.55

0.65

 Turb

0.02

0.22

0.34

 − 0.07

0.58

0.01

0.43

0.31

0.15

 − 0.08

0.32

0.18

 − 0.03

 − 0.02

0.55

 − 0.49

 − 0.16

 − 0.53

 − 0.53

 − 0.08

0.28

0.01

0.59

0.60

0.00

 Sal

0.25

 − 0.07

 − 0.35

0.21

 − 0.18

 − 0.10

 − 0.13

 − 0.36

 − 0.17

0.01

 − 0.25

0.2

 −  − 0.16

 −  − 0.07

 − 0.18

0.45

0.23

0.41

0.44

0.02

 − 0.19

0.00

0.32

0.08

0.12

 PO43−

0.18

 − 0.11

0.49

 − 0.12

0.53

0.16

0.49

0.53

0.39

0.27

0.12

 − 0.11

0.10

0.36

0.48

 − 0.76

 − 0.14

 − 0.45

 − 0.47

 − 0.06

0.43

 − 0.50

0.14

0.02

0.00

 NO3

0.07

0.32

 − 0.27

0.02

 − 0.19

 − 0.32

 − 0.2

 − 0.25

 − 0.35

 − 0.15

 − 0.24

 − 0.07

0.20

 − 0.07

 − 0.23

0.37

 − 0.06

0.16

0.14

0.18

0.09

0.17

 − 0.25

0.00

0.49

 NH4+

0.05

0.34

 − 0.33

0.03

 − 0.27

 − 0.36

 − 0.27

 − 0.29

 − 0.39

 − 0.15

 − 0.27

 − 0.05

0.12

 − 0.13

 − 0.32

0.51

0.00

0.25

0.24

0.10

0.09

0.30

 − 0.38

0.94

0.16

 SO42

0.19

0.03

0.48

0.03

0.79

0.17

0.37

0.24

0.28

0.08

0.24

0.12

0.12

0.13

0.77

 − 0.60

 − 0.15

 − 0.52

 − 0.51

 − 0.08

0.56

 − 0.26

0.68

 − 0.12

 − 0.24

c—Lagoon

 TPHs

0.00

0.01

0.11

0.00

0.02

0.00

0.00

0.00

0.01

0.00

0.29

0.02

0.65

0.00

0.20

0.11

0.09

0.35

0.00

0.00

0.00

0.00

0.15

0.09

0.00

 Mn

 − 0.46

0.01

0.32

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.93

0.00

0.82

0.00

0.76

0.06

0.06

0.73

0.55

0.00

0.00

0.00

0.03

0.09

0.00

 Zn

 − 0.35

0.35

0.22

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.92

0.00

0.12

0.00

0.00

0.88

0.32

0.01

0.04

0.00

0.00

0.00

0.10

0.09

0.02

 Al

0.23

 − 0.15

 − 0.18

0.31

0.27

0.17

0.42

0.21

0.17

0.27

0.77

0.73

0.88

0.65

0.13

0.65

0.24

0.53

0.35

0.56

0.01

0.56

0.43

0.58

0.45

 B

 − 0.54

0.56

0.54

 − 0.15

0.00

0.00

0.00

0.00

0.00

0.00

0.68

0.00

0.20

0.00

0.00

0.36

0.14

0.01

0.03

0.00

0.00

0.00

0.07

0.02

0.00

 Cd

 − 0.34

0.48

0.60

 − 0.16

0.60

0.00

0.00

0.00

0.00

0.00

0.60

0.00

0.00

0.00

0.08

0.81

0.00

0.76

0.20

0.00

0.00

0.00

0.01

0.01

0.00

 Ba

 − 0.60

0.62

0.52

 − 0.2

0.70

0.61

0.00

0.00

0.00

0.00

0.71

0.00

0.18

0.00

0.24

0.23

0.07

0.34

0.00

0.00

0.00

0.00

0.09

0.04

0.00

 Cr

 − 0.52

0.66

0.52

 − 0.12

0.69

0.68

0.86

0.00

0.01

0.00

0.81

0.00

0.63

0.00

0.33

0.23

0.03

0.70

0.04

0.00

0.00

0.00

0.04

0.01

0.00

 Co

 − 0.42

0.54

0.51

 − 0.19

0.59

0.82

0.6

0.58

0.00

0.00

0.81

0.00

0.03

0.00

0.22

0.74

0.01

0.67

0.02

0.00

0.00

0.00

0.02

0.01

0.00

 Cu

 − 0.38

0.45

0.45

 − 0.2

0.51

0.63

0.43

0.36

0.57

0.00

0.65

0.02

0.14

0.01

0.01

0.01

0.05

0.46

0.06

0.01

0.00

0.03

0.01

0.01

0.04

 Fe

 − 0.65

0.55

0.43

 − 0.16

0.67

0.46

0.53

0.51

0.59

0.46

0.60

0.00

0.30

0.00

0.13

0.07

0.48

0.12

0.03

0.00

0.00

0.00

0.02

0.01

0.00

 Pb

 − 0.16

 − 0.01

 − 0.01

 − 0.04

 − 0.06

 − 0.08

0.05

 − 0.04

0.04

 − 0.07

0.08

0.82

0.43

0.97

0.46

0.04

0.11

0.22

0.16

0.79

0.99

0.85

0.71

0.84

0.97

 Hg

 − 0.33

0.48

0.49

 − 0.05

0.63

0.55

0.77

0.62

0.58

0.34

0.48

 − 0.03

0.31

0.00

0.18

0.68

0.70

0.04

0.09

0.00

0.00

0.00

0.53

0.44

0.00

 Mo

0.07

 − 0.03

0.23

 − 0.02

0.19

0.43

 − 0.2

0.07

0.31

0.21

0.15

 − 0.12

 − 0.15

0.57

0.01

0.99

0.10

0.46

0.21

0.31

0.04

0.41

0.10

0.16

0.27

 Ni

 − 0.60

0.72

0.46

 − 0.07

0.78

0.63

0.87

0.87

0.66

0.39

0.66

0.01

0.79

 − 0.08

0.56

0.28

0.11

0.38

0.02

0.00

0.00

0.00

0.07

0.03

0.00

 Temp

0.19

 − 0.05

 − 0.47

0.22

 − 0.47

 − 0.25

 − 0.17

 − 0.14

 − 0.18

 − 0.36

 − 0.22

0.11

 − 0.20

 − 0.40

 − 0.09

0.92

0.35

0.00

0.08

0.82

0.00

0.50

0.64

0.43

0.87

 DO

 − 0.23

0.28

0.02

 − 0.07

0.14

0.04

0.18

0.18

0.05

0.37

0.27

 − 0.30

 − 0.06

0.00

0.16

0.02

0.61

0.45

0.49

0.16

0.71

0.10

0.45

0.22

0.07

 Cond

0.25

 − 0.27

 − 0.15

0.17

 − 0.22

 − 0.41

 − 0.26

 − 0.31

 − 0.39

 − 0.29

 − 0.11

 − 0.23

 − 0.06

 − 0.24

 − 0.23

 − 0.14

 − 0.08

0.00

0.51

0.17

0.03

0.21

0.57

0.78

0.14

 TDS

 − 0.14

 − 0.05

0.39

0.09

0.36

0.05

0.14

0.06

0.06

0.11

0.23

 − 0.18

0.30

0.11

0.13

 − 0.67

 − 0.11

0.43

0.21

0.56

0.00

0.61

0.24

0.41

0.89

 pH

0.42

 − 0.09

 − 0.30

0.14

 − 0.32

 − 0.19

 − 0.43

 − 0.30

 − 0.33

 − 0.28

 − 0.31

 − 0.21

 − 0.25

0.18

 − 0.34

0.25

 − 0.10

0.10

 − 0.19

0.02

0.01

0.00

0.16

0.00

0.02

 Turb

 − 0.65

0.70

0.42

 − 0.09

0.72

0.58

0.89

0.89

0.59

0.36

0.66

0.04

0.72

 − 0.15

0.95

 − 0.03

0.21

 − 0.20

0.09

 − 0.33

0.00

0.00

0.05

0.02

0.00

 Sal

0.58

 − 0.43

 − 0.66

0.34

 − 0.82

 − 0.63

 − 0.66

 − 0.66

 − 0.58

 − 0.56

 − 0.61

0.00

 − 0.57

 − 0.29

 − 0.66

0.64

 − 0.06

0.30

 − 0.37

0.35

 − 0.59

0.00

0.26

0.09

0.00

 PO43−

 − 0.48

0.69

0.40

 − 0.09

0.69

0.50

0.83

0.86

0.54

0.30

0.54

 − 0.03

0.70

 − 0.12

0.92

 − 0.1

0.24

 − 0.18

0.08

 − 0.38

0.90

 − 0.58

0.07

0.02

0.00

 NO3

0.21

 − 0.31

 − 0.24

0.12

 − 0.27

 − 0.38

 − 0.25

 − 0.29

 − 0.34

 − 0.39

 − 0.33

0.06

 − 0.09

 − 0.24

 − 0.27

0.07

 − 0.11

 − 0.08

 − 0.17

0.20

 − 0.28

0.17

 − 0.27

0.00

0.14

 NH4+

0.24

 − 0.25

 − 0.25

0.08

 − 0.33

 − 0.39

 − 0.29

 − 0.35

 − 0.35

 − 0.39

 − 0.35

0.03

 − 0.12

 − 0.21

 − 0.32

0.12

 − 0.18

 − 0.04

 − 0.12

0.41

 − 0.34

0.25

 − 0.33

0.89

 

0.05

 SO42

 − 0.52

0.72

0.35

 − 0.11

0.64

0.53

0.86

0.87

0.59

0.30

0.46

 − 0.01

0.64

 − 0.16

0.90

 − 0.02

0.26

 − 0.21

0.02

 − 0.33

0.91

 − 0.52

0.89

 − 0.22

 − 0.29

  1. Correlation values = 0.00–0.10 (negligible correlation), 0.10–0.39 (weak correlation), 0.40–0.69 (moderate correlation), 0.70–0.89 (strong correlation), 0.90–1.00 (very strong correlation).
  2. p < 0.0001, p < 0.01, p < 0.05.
  3. Significant Pearson's r values are indicated in bold.