Comparative Analysis of Heavy Metals Concentration in Soil and Vegetable (Celosia argentea) Collected from Two Sampling Sites and Their Effect on the Plant’s DNA Stability

Abstract

This study investigated the quantities of heavy metals including cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn)in soil samples and in the organs (leaf, stem and root) of Celosia argentea collected from a dumpsite (at Ojota) and a farmland (at Badagry) in Lagos, Nigeria. Additionally, the macroelement content of the soils and the effect of heavy metal soil contamination on C. argentea DNA stability was analysed. Heavy metals and NPK concentrations in the soil samples and organs of C. argentea were evaluated using standard techniques. The results of this study revealed that the microelement were more abundant in the soil collected from the dumpsite. Likewise, all the heavy metals (Cd,Cr,Cu,Pb and Zn) investigated in this study were detected in higher quantities in the dumpsite soil. Notably, the concentration of the metals was within the WHO/FAO limits in the soils collected from both sampling sites save Zn which was 660.260 mg/kg and 449.180mg/kg in the dumpsite and farmland respectively. The concentration of heavy metals in the C. argentea organs in this research were higher in samples collected from the dumpsite and Zn was the most accumulated on both the dumpsite and farmland. The highest amount (95.987 mg/kg) of Zn was by C. argentea root collected from the dumpsite while the least amount (15.380 mg/kg) was detected in C. argentea stem collected from the farmland. The DNA base pairs were not visibly fragmented in the samples C. argentea collected from the control and dumpsite sites. Although most of the heavy metals detected in C. argentea were in negligible quantities, the soils and the vegetable appear to be Zn-contaminated and unsafe for consumption. Keywords: Heavy Metal, DNA, vegetables, biomagnifications, Bioaccumulation, Dumpsites Farmlands