Correlation matrix between heavy metals in groundwater and soil of residential area at 1-150 m and 151-300 m radii around Awotan landfill, Ibadan, Southwest-Nigeria.

Table 4: Correlation matrix between heavy metals in groundwater and soil of residential area at 1-150 m and 151-300 m radii around Awotan landfill, Ibadan, Southwest-Nigeria.

Variables	Pb	Cd	Cr	Ni	Cu	Fe	Zn
Pb	1	0.987^*	0.956^*	0.932^*	0.958^*	1^*	0.990^*
Cd		1	0.991^*	0.978^*	0.992^*	0.990^*	0.955^*
Cr			1	0.997^*	1^*	0.962^*	0.907^*
Ni				1	0.997^*	0.940^*	0.844^*
Cu					1	0.904^*	0.910^*
Fe						1	0.987^*
Zn							1

*correlation is significant at the 0.05 level (2-tailed). Correlation rating: ≥ 0.91 = very strong; 0.81-0.90 = strong; 0.51-0.80 = moderate and ≤ 0.50 = no correlation.