EXPLORING POSSIBLE PREDICTORS OF ADOLESCENT PREGNANCY BY LOGISTIC REGRESSION

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4.8.4 Bimonthly variations of trace and heavy of groundwater samples close to

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manganese contents of the well close to the Oremeji dumpsite was significantly different from those of all the other samples (Appendix 53).

4.8.4.3 Copper

In April 2008, copper was not detected in all groundwater samples except the one before the Ojokondo dumpsite and the one close to the Idi Ope dumpsite with values of 0.099 mg/L and 0.062 mg/L respectively. In June 2008 it was not detected in the groundwater samples before and after the Ojokondo dumpsite and also the well close to the Olodo dumpsite. In August 2008, it was not detected in the samples from the well close to the Idi Ope dumpsite and the well close to the Oremeji dumpsite. In October 2008, it was not detected in the sample from the control well (Balewa) and the well close to the Oremeji dumpsite. In December 2008, it was not detected in the samples from the well after the Ojokondo dumpsite, the well close to the Moniya dumpsite and the well close to the Idi Ope dumpsite (Figure 4.44c; Appendices 54 to 60).

In February 2009, copper was detected in all groundwater samples except from the control site (Balewa). However, in April 2009, it was not detected in all groundwater samples. In June 2009, it was detected only in the samples from the well before the Ojokondo dumpsite and the one close to the Oremeji dumpsite with values of 0.026 mg/L and 0.097 mg/L respectively. In August 2009, it was detected only in the samples from the Moniya well and the Oremeji well with values of 0.002 mg/L and 0.007 mg/L respectively. In October 2009, it was only detected in the sample from the well before the Ojokondo dumpsite with a value of 0.019 mg/L. In December, it was detected at the Moniya well with a value of 0.075 mg/L and lastly, in February 2010, it was detected at the Olodo well with a value of 0.009 mg/L (Figure 4.44c;

Appendices 54 to 60).

One way analysis of variance showed that the copper content in the samples from the various dumpsites were not significantly different from one another at P<0.05 (Appendix 52).

4.8.4.4 Zinc

Zinc was not detected in all groundwater samples in the month of April 2008. In June 2008 it was not also detected in all samples except at the well after the Ojokondo

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dumpsite and the well close to the Moniya dumpsite with the values of 0.0002 mg/L and 0.0475 mg/L respectively. In October 2008, February 2009, August 2009 and October 2009, zinc was not detected at the Idi Ope well, the well after the Ojokondo dumpsite, the well before the Ojokondo dumpsite and the well at the control site (Balewa) respectively. In December 2009, it was not detected in all samples except that from the control site (Balewa) and the well close to the Moniya dumpsite with values of 0.0020 mg/L and 3.246 mg/L respectively. In addition, in February 2010, zinc was not detected in all samples except from the wells close to the Oremeji and Olodo dumpsites with the values of 0.0960 mg/L and 0.2920 mg/L respectively (Figure 4.44d; Appendices 54 to 60).

One way analysis of variance showed that the zinc contents of the samples from the various wells were significantly different from one another at P<0.05 (Appendix 52).

Duncan’s multiple range tests also showed that zinc contents of the well after the Ojokondo dumpsite and the well at the Idi Ope dumpsite were significantly different from the zinc contents of all the other samples but not significantly different from each other (Appendix 53).

4.8.4.5 Lead

Lead was not detected in all groundwater samples in April and June 2008 except at the ones close to the Olodo and Moniya dumpsites respectively with values of 0.1960 mg/L and 0.2625 mg/L respectively. In October 2008, it was only in the sample from the well close to the Idi Ope dumpsites that lead was not detected (Appendices 56 to 58).

In April 2009, lead was not detected in all groundwater samples except those close to the Oremeji and Moniya dumpsites with values of 0.2100 mg/L and 0.2010 mg/L respectively. Furthermore, in June 2009, lead was detected in the well after the Ojokondo dumpsite, and the wells close to Idi Ope and Oremeji dumpsites with values of 0.0590 mg/L, 0.0200 mg/L and 0.2480 mg/L respectively. In addition, in August 2009, lead was discovered in the well after the Ojokondo dumpsite – 0.0340 mg/L; the well close to the Moniya dumpsite – 0.1990 mg/L; and the well close to the Oremeji dumpsite – 0.0950 mg/L. In October 2009, it was detected in the well before the Ojokondo dumpsite – 0.0030 mg/L, the well after the Ojokondo dumpsite – 0.0010 mg/L and the well close to the Oremeji dumpsite – 0.0930 mg/L. In December

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NOTE: Blank spaces indicated that the control site (Tafawa Balewa Hall) was not sampled in the months of April and June, 2008. Other blank spaces indicated that Fe, Mn, Cu and Zn were not detected in the samples.

Figure 4.44: Bimonthly variation of some trace and heavy metals of groundwater samples close to dumpsites (a) Fe (b) Mn (c) Cu (d) Zn

-5 0 5 10 15

Fe (mg/L)

A

MPL HDL - Highest desirable level (0.1 mg/L)

MPL - Maximum permissible level (1.0 mg/L)

HDL

-5 0 5 10 15

Mn (mg/L)

HDL - Highest desirable level - 0.05 mg/L MPL - Maximum permissible level - 0.5 mg/L

-0.5 0 0.5 1 1.5

Cu (mg/L)

A HDL -Highest desirable level - 0.05 mg/L MPL - Maximum permissible level - 1.5

HDL MPL

-5 0 5 10 15 20

Zn (mg/L)

Sampling Year/Month

Ojokondo (Before Dump) Ojokondo (After Dump) Olodo

Moniya Idi Ope Oremeji

Balewa

A

MPL HDL HDL -Highest desirable level - 5 mg/L

MPL - Maximum permissible level - 15 mg/L

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2008 and February 2010, lead was detected in the groundwater samples from the control site (Balewa) and Olodo dumpsite respectively with values of 0.1490 mg/L and 0.1990 mg/L respectively (Figure 4.45a; Appendices 54 to 60).

One way analysis of variance showed that the lead contents in the wells close to the various dumpsites were not significantly different from one another at P<0.05 (Appendix 52).

4.8.4.6 Cadmium

Cadmium was not detected in the sample from the well close to the Idi Ope dumpsite in April 2008. In June 2008, it was not detected in the groundwater samples close to the Olodo, Moniya and Oremeji dumpsites. In August 2008, it was detected in the groundwater sample from the Oremeji dumpsite with a value of 0.0147 mg/L. In October 2008, December 2008 and February 2009, cadmium was not detected in all groundwater samples (Figure 4.45b; Appendices 54 to 60).

In April 2009, cadmium was not detected in the sample from the well before the Ojokondo dumpsite and the well close to the Olodo dumpsite. In December 2009 and February 2010, it was not detected in the well close to the Idi Ope dumpsite and the well after the Ojokondo dumpsite respectively (Figure 4.45b; Appendices 54 to 60).

The bimonthly values of cadmium contents of groundwater samples close to the dumpsites ranged from 0.002 to 0.04 mg/L (0.02±0.01 mg/L) at the well before the Ojokondo dumpsite, 0.006 to 0.07 mg/L (0.04±0.01 mg/L) at the well after the Ojokondo dumpsite, 0.002 to 0.07 mg/L (0.04±0.01 mg/L) at the well close to the Olodo dumpsite, 0.004 to 0.04 mg/L (0.02±0.01 mg/L) at the well close to the Moniya dumpsite, 0.001 to 0.07 mg/L (0.03±0.01 mg/L) at the well close to the Idi-Ope dumpsite, 0.002 to 0.06 mg/L (0.02±0.01 mg/L) at the well close to the Oremeji dumpsite and 0.004 to 0.07 mg/L (0.03±0.01 mg/L) at the well at the control site (Balewa) (Figure 4.45b; Appendices 54 to 60).

One way analysis of variance showed that the cadmium contents in the samples from the various dumpsites were not significantly different from one another at P<0.05 (Appendix 52).

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4.8.4.7 Nickel

Nickel was not detected in all groundwater samples in June 2008. In August 2008, it was not detected in the sample from the control site (Balewa). In October 2008, it was not detected in the samples from the well after the Ojokondo dumpsite and the well close to the Oremeji dumpsite. Furthermore, in April 2009, it was not detected in the samples from the wells close to the Olodo and at the control site. In June 2009, it was not detected in the samples from the Moniya and control site wells. In addition, in August 2009, it was not detected in samples from the well before the Ojokondo dumpsite, Idi Ope well and the control site (Figure 4.45c; Appendices 54 to 60).

In October 2009, nickel was detected in the sample from the well after the Ojokondo dumpsite and the Oremeji well with values of 0.0590 mg/L and 0.0420 mg/L respectively. In December 2009, it was not detected in samples from the well before the Ojokondo dumpsite, the well at the Olodo dumpsite and the Idi Ope well.

However, nickel was detected in February 2010 in the samples from the Idi Ope well and the control site with values of 0.0550 mg/L and 0.0590 mg/L respectively (Figure 4.45c; Appendices 54 to 60).

One way analysis of variance showed that the nickel contents in the wells close to the various dumpsites were not significantly different from one another at P<0.05 (Appendix 52).

4.8.4.8 Chromium

Chromium was not detected in all samples in the months of October 2008, October 2009, December 2009 and February 2010 (Figure 4.45d; Appendices 54 to 60).

In June 2008, chromium was not detected in the samples from the Olodo, Moniya and Oremeji wells. In December 2008, it was detected in the sample from the control site with a value of 0.1292 mg/L. Furthermore, in February 2009, it was still detected in the sample from the well before the Ojokondo dumpsite and also the control site with values of 0.1369 mg/L and 0.1445 mg/L respectively. In addition, in April 2009, June 2009 and August 2009, chromium was detected in the samples from Moniya well – 0.0320 mg/L, Oremeji well – 0.0190 mg/L and Moniya well – 0.1100 mg/L respectively (Figure 4.45d; Appendices 54 to 60).

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One way analysis of variance showed that the chromium contents in the samples from wells close to the various dumpsites were not significantly different from one another at P<0.05 (Appendix 52).