Characterization and Evaluation of Heavy Metals Pollution in River Sediments from South Western Nigeria

Hussein Kehinde Okoro*1, 2, Julius Oluwafunso Ige1, Catherine J. Ngila2

1Material and Environmental-Analytical Research Group, Department of Industrial Chemistry University of Ilorin, P.M.B. 1515. Ilorin 24003, Nigeria.

2Analytical-Environmental and Membrane Nanotechnology Research Group, Department of Applied chemistry, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, Johannesburg, Republic of South Africa

Corresponding Author e-mail : 


Geochemistry, pollution load index (PLI) contamination factor (CF), geoaccumulation index (Igeo) and anthropogenic factors (AF) of sediment samples collected from Olonkoro river, South West, Nigeria has been conducted. Atomic absorption spectrometry (AAS), Xray diffraction (XRD) and Fourier Transform infrared (FTIR) techniques were explored for sample analyses. Metals concentrations were varied therefore, the presences of these metals were entirely from non-crustal materials. The enrichment factor EF values in this site are in the decreasing order Cu > Pb> Mn> Zn >Cd. High Igeo was recorded for most of the metals; Zn belong to strongly contaminated while Pd was predominately extremely contaminated. Igeo values for Cu ranged from 5.44 to 6.98 with a mean value of 6.17 and most of the samples fell into class 6 of very strongly contaminated. This high index is caused mainly by industrial activities and agricultural activities taking place within the area. The PLI values from location P1 to P10 suggest deterioration of site sediment quality. The mineral phases were extracted from the XRD data. All the samples exhibited similar diffractographs, it is confirmed that the most dominant of all the minerals present is quartz. its absorption band appears around 455 to 450, 798 to 800. Pyrites are principally present at locations 1, 5, 7 and 10 its absorption frequency ranges from 700 to 800. This could be connected to the presence of iron (Fe) Thus, an immediate intervention to ameliorate pollution at sites is needed. The average AF of >1 was recorded for Fe, this suggest that it’s enrichment was through anthropogenic source. Fe in the entire ten locations exhibit this characteristic while Mn, Cu, Zn, Pb, Cd reflect geogenic sources of these metals. Thus, the order of degrees of anthropogenic contamination in the sediment samples is: Fe > Cu > Zn > Pb > Mn> Cd. Geomineral analyses confirmed the presence of pyrite, quartz, Felspar, Goethite, chromites, calcite, and Kaolin as part of the sediment compositions.


Geoaccumulation index; pollution index, contamination factor, anthropogenic factors, sediments, pollution

Okoro et al JKCS 11-1 (2018), 18-27

Quantification of all trans-lycopene, cis-lycopene and β-carotene from tomato varieties found in Zanzibar

Haji Khamis1*, Kituyi Lusweti2, Haji Mwevura3

1,2Department of Chemistry and Biochemistry, P.0.Box 1125-30100, University of Eldoret, Chepkoilel, Kenya
3The State University of Zanzibar (SUZA), P. O. Box 146, Zanzibar, Tanzania

Corresponding author: Haji Khamis Email :


Tomatoes contain lycopene and β-carotene which have important health benefits. Different varieties are available in Zanzibar Islands and used in daily meal. However, there is little information in Zanzibar about quantity of all trans-lycopene, cis-lycopene and βcarotene available in those tomato varieties. The objective of this study was to quantify all trans-lycopene, cis-lycopene and βcarotene from tomato varieties. Samples were collected and extracted using hexane/acetone/ethyl acetate (4:2:1 v/v/v). Extracts were filtered and lycopene layer separated, washed, dried, dissolved in hexane and fractionated by silica gel column. Fractions were collected, dried by blowing with a stream of nitrogen gas and measured their masses by electronic balance. Results showed that mass (in g/g) of all trans-lycopene varied from 316 to 827 and from 136 to 931, cis-lycopene from 60 to 528 and from 35 to 845, βcarotene from 41 to 405 and from 44.1 to 573, from Lycopersicon esculentum and Solanum quitoense respectively.Tomatoes contain valuable quantities of lycopene and β-carotene necessary for human nutrients. Best growing conditions which facilitate highest possible quantity of lycopeneand β-carotene should be investigated and used during tomato cultivation.


lycopene, quantify, β-carotene, Lycopersicon esculentum, Solanum quitoense

Khamis et al., JKCS 11-1 (2018), 3-9

Assessment of Levels of Selected Heavy Metals in Soil and Vegetables grown in Eldoret Municipal Dumpsite, Kenya

Choge Phoebe*, Samuel Lutta
Department of Chemistry,University of Eldoret
P.O. Box 1125-30100 Eldoret,Kenya :


Urban agriculture in developing countries is facing major challenges which include limited land spaces and the rising cost of artificial fertilizers. As a result, free land spaces are used to grow food crops and raw sewage sludge is applied to enhance fertility. In Eldoret town; Kenya, the old municipal dumpsite has become an ideal site for growing vegetables and sewage sludge is applied without regards to risks of toxic heavy metals and other contaminants. This research was conducted to determine levels of selected heavy metals in soil and vegetables grown in the dumpsite. A total of 42 samples were analysed using atomic absorption spectroscopy and all data were analysed using SPSS version 20.0 where significance was considered at p < 0.05. Results obtained from soil indicated the following mean concentrations: lead, 1.630 mg/Kg, cadmium, 0.070 mg/Kg, copper, 0.380 mg/Kg, zinc, 2.310 mg/Kg, iron, 101.530 mg/Kg and nickel, 10.370 mg/Kg. In kales mean concentration were as follows: lead, 1.356 mg/Kg; cadmium, 0.110 mg/Kg; copper, 0.095 mg/Kg; iron, 42.070 mg/Kg; zinc, 0.875 mg/Kg and nickel, 9.240 mg/Kg. In spinach the following concentrations were obtained: lead, 1.088 mg/Kg; cadmium, 0.090 mg/Kg; copper, 0.103 mg/Kg; iron, 22.110 mg/Kg; zinc, 0.800 mg/Kg and nickel, 9.190 mg/Kg. In onions mean concentration were as follows: lead, 0.404 mg/Kg; cadmium, 0.345 mg/Kg; copper, 0.109 mg/Kg; iron, 2.650 mg/Kg and zinc, 2.650 mg/Kg. Levels of all the heavy metals in soil were within the acceptable range of WHO/FAO while in vegetables, all the heavy metals were within the acceptable range except lead and cadmium which were above the acceptable limits. It was therefore concluded that the vegetables grown in the dumpsite are not good for human consumption due to high levels of lead and cadmium.

Keywords: Heavy metals, dumpsite wastes, wastewater, vegetables


Choge, P & Lutta, S JKCS 11-1 (2018) 10-17 copy