GROWTH, BIOACCUMULATION POTENTIAL AND HEALTH ASSESSMENT OF MAIZE (Zea mays Linn) GROWN ON SOIL COLLECTED AROUND FRANCISCA QUARRY SITE IN AKURE METROPOLIS

Abstract

Anthropogenic activities such as mining, smelting, chemical and metallurgical industries, indiscriminate waste disposal and open burning of refuse are major sources of heavy metals in the environment. Growth and bioaccumulation potential of two maize varieties (Zea mays Linn.) grown on soil collected around Franscisca Quarry Company, Ikota Ijare, site in Akure metropolis were investigated. This was aimed at determining the level of heavy metals content in each sample of soil and to assess the bioaccumulation and transfer factor of maize grown on the contaminated soil and also to investigate the health risk assessment associated with the Maize samples when consumed. The study was conducted in a screen house. Soil samples were collected at 50 m, 150 m, and 250 m from the quarry site at a sowing depth of 0 - 10 cm using a calibrated soil auger. Representative soil samples from the site were taken and transported to the laboratory for analysis. The following heavy metals contents were determined Iron (Fe), lead (Pb), Nickel (Ni), Chromium (Cr) and Cadmium (Cd) using Atomic Absorption Spectrophotometer (AAS). Two varieties of maize seeds (SWAN 1 and SAMMAZ 52) were sourced from the Seed Bank of the Ondo State Ministry of Agriculture and authenticated at the Herbarium Unit of Federal University of Technology, Akure. The seeds were sown into experimental pot containing 10 kg of soil collected from varying distance from the quarry and a control soil. The experimented was replicated thrice and was completely randomised. The following growth parameters were determined; shoot height, shoot biomass, root biomass and leaf area. Health risk assessment using various parameters were also investigated, also transfer and bioaccumulation factor were also determined. The data collected were subjected to one way analysis of variance (ANOVA) and significant means were separated using Duncan new multiple range test (DNMRT). Result metals detected in the samples were all below the WHO permissible limits. Also, mean translocation factor for Iron and lead were lower than the permissible limit. Target Hazard Quotient for Iron and Lead were reported to be 0.75 and 1.18for SAMMAZ 52 and 0.7 and 1.2 for SWAN 1 respectivelyobtained from this study show that shoot height, leaf area, chlorophylls a and b were higher in the control plants of both maize varieties when compared to the treatments. All heavy