Tree Leaves as Bioindicator of Heavy Metal Pollution in Mechanic Village, Ogun State

Metal contamination issues are becoming increasingly common in automobile workshop and elsewhere, Heavy metals, such as cadmium, copper, lead, are major environmental pollutants. Heavy metal accumulation in soils is of concern in agricultural production due to the adverse effects on food safety and marketability, crop growth due to phytotoxicity, and environmental health of soil organisms. Soil and plant samples were collected from mechanic village in Odeda local Government of Ogun State. The soil samples were collect at depth of 0- 15cm and 15-30 cm, which are top soil and sub soil. The physiochemical parameters for soil were determined through the standard method and the heavy metal concentrations were determined using AAS. (Atomic Absorption Spectrometer). The EC range of the control farmland is 25 μS/cm- 195 μS/cm at 25℃ while that of mechanic village ranges from 70 μS/cm-276 μS/cm at 25℃, the temperature of the farmland ranges from 27.8℃-28.0℃ while that of the mechanic village ranges from 27.7℃-28.1℃. The pH of the farmland and mechanic village ranges from 6.47-7.67 and 6.48-7.79 respectively. The mean concentrations of the heavy metals in the soil of the farmland are in order of magnitude Cd>Cu>Pb, (0.62>0.018>0) while the mean concentration of the heavy metals in the soil of the mechanic village are in order of magnitude Pb>Cu>Cd (2.96>0.67>0.14) The mean concentration in leaf of farmland are Cu>Cd>Pb. (0.105>0.03>0.0001), while the mean concentration in mechanic village are Cu>Pb> Cd. (0.13>0.11> 0.02) the sudden rise of lead in mechanic village is understandable giving the various activities such as painting, welding, soldering and fueling which contain lead. Though the result indicate that they are not significant as they that are within the acceptable standard of FAO and WHO, 2010.

Keywords
Bioindicator; Contamination; Environmental Health; Heavy Metal; Phytotoxicity