Heavy Metals in Soils and Plants around Industries in Agbara Industrial Estate, Ogun State, Nigeria

摘要

Indiscriminate handling and disposal of industrial effluents into the environment represents one of the major sources of environmental pollution which invariably affect plants, animals and humans. This study assessed heavy metal concentration in soils and plants around industries in Agbara industrial estate, Ogun State, Nigeria. Soil and plant samples were collected from four industries and analyzed for lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr) and nickel (Ni). The pH, organic matter content and cation exchange capacity of the soil samples, as well as bioaccumulation factor (BAF) and translocation factor (TF) of the plant samples were examined. The heavy metal concentration order of the soil and plant samples was Pb < Cu < Cd < Cr < Ni. Pb, Cu, Cr, and Ni in all soil samples were below WHO tolerance limit (300 mg kg~( ~(?1) ), 50 mg kg~( ~(?1) ), 10 mg kg~( ~(?1) ) and 50 mg kg~( ~(?1) ) respectively) while Cd was above WHO tolerance limit (3 mg kg ~(?1) ). Also, Pb, Cd, Cu, and Cr in most plant samples were above WHO tolerance limits (10 mg kg~( ~(?1) ), 0.30 mg kg~( ~(?1) ), 10 mg kg~( ~(?1) ) and 1.5 mg kg~( ~(?1) ) respectively). Statistical differences (P < 0.01) were observed between heavy metals in soil and some plants. Furthermore, there was no correlation between heavy metals in soil and plants. The BAF and TF results showed that Cyperus iria , Alternanthera sessilis , C. esculentus , A. brasiliana , and Megathyrsus maximus are probable accumulators of heavy metals.