HEAVY METAL CONCENTRATION OF PLANTS (Zea mays, Potato, Green leaf, Water leaf) GROWN AROUND WASTE DUMPSITES IN OZORO, DELTA STATE, NIGERIA

Ojebah, C. K & Uwague, A.

Department of Science Laboratory Technology

Delta State Polytechnic, Ozoro.

Email: ckojebah@gmail.com

ABSTRACT

This study was conducted to determine the heavy metal concentration of plant/food crops grown around waste dumpsites in Ozoro, Delta State, Nigeria. Four different plants (Zea may, Potato, Green leaf and Water leaf) were used for this study. The plant samples were air dried for three days and there after ashed in an electric furnace at 450˚C. 2g of the ashed plant was weighed and put in a beaker. 10ml of nitric/perchloric acid, ratio 2:1 was added to the sample and digested at 105˚C for 1hour. Atomic Absorption Spectrophotometer (AAS) (Varian spectra 200 AA model) was used to determine the total metal concentration in the various plant samples. Iron was the predominant metal in all the samples and its concentration though low ranged from 1.84 – 4.24mg/kg. The concentration of Manganese and Zinc was equally low and ranged from 0.83 – 1.67mg/kg and 0.01 – 2.12mg/kg respectively. Similarly copper, cadmium and lead concentrations were also relatively low. The mean concentration of all the metals in the four plants is in the order of Fe>Mn>Zn>Cu>Cd>Pb. There was significant variation in metals from plant to plant (P<0.05). The results obtained were still within the permissible level set by FAO/WHO. This situation is a threat to our life, therefore planting of vegetables within or around dumpsites should be discontinued with.