Assessment of Some Chemical Pollutants in Soil and Watermelon Samples Cultivated in Benisheikh, Borno State, Nigeria

Abstract

The study was conducted to determine the concentration of heavy metals (Cd, Pb, Cu, Ni, Mn, Fe, Zn and Co); ions (NO3 – , NO2 – , PO4 3- , SO4 -2 , K+ , Na+ , Ca2+ and Mg2+); in seed, pulp, leaves, stem and root of watermelon (sugar baby and crimson sweet) and physical parameters (pH, Electrical Conductivity, Organic Carbon and Organic Matter) in soil at different depth (0-10cm, 10-20cm and 20-30cm from Benisheikh, Kaga LGA, Borno State, for the period of three months. Atomic Absorption and UV visible smart spectrophotometer were used to analyse the samples obtained for this study. The results of this study showed that the pH of the soil samples ranges from 4.30 ± 0.15 to 6.40 ± 0.56, revealing that the soils were slightly acidic. Organic carbon values ranges between 0.23 ±0.11-1.55 ±0.10 % and organic matter values ranges between 16.30 ±2.45-4.15 ± 0.25 %. Organic carbon and organic matter showed the lowest. The concentration 0.86 ± 0.12 µg/g of iron is the highest in the leaves and least in the stem (0.13±0.02 µg/g). Lead showed the least concentration of 0.02±0.01 µg/g in pulp. The levels of Heavy metals increased significantly (p <0.05) based on depth. The ions, calcium and potassium showed the highest concentration in leaves with values 57.14±0.02 µg/g and 52.22±0.04 µg/g while nitrite, phosphate and sulphate showed the lowest concentration in pulp and seed samples analyzed. The concentration of all the parameters analyzed was below the threshold limits set by World Health Organization. Thus, watermelon samples from Benisheikh may not constitute possible health hazard.