Trace Metal Contamination of Selected Vegetables Grown Around Owerri Municipality, Nigeria
C. O. Nwoko *
Department of Environmental Technology, Federal University of Technology, P.M.B. 1526, Owerri, Nigeria.
E. N. Emenyonu
Department of Environmental Technology, Federal University of Technology, P.M.B. 1526, Owerri, Nigeria.
C. E. Umejuru
Department of Environmental Technology, Federal University of Technology, P.M.B. 1526, Owerri, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Trace metal contamination of vegetables grown around urban city of Owerri southeastern Nigeria was assessed. Vegetables: Fluted pumpkin – Telfairia occidentalis, Waterleaf – Talinum triangulare, Green – Amaranthus hybridus) were sampled along major locations of the metropolis based on the traffic intensity to achieve very high, high and low urban activities. Shoot of washed and unwashed samples were sub sampled and analyzed for Pb, Cd, Cr and Cu. Results showed that washing significantly reduced trace metal contamination of vegetables. Trace metal pollution index (TPI) was maximum for Douglas (1.72), followed by Aladinma (0.66), Orji (0.61) and Umunjam (0.57). The percentage reductions in trace metal concentrations due to washing were found highest for Pb, Cd, Cr in T. triangulare, A. hybridus and A. hybridus, respectively in Umunjam, Aladinma and Orji. There is need for continuous monitoring of trace metal contamination of vegetables grown in urban and suburban cities to reduce risk associated with trace metal contamination.
Keywords: Trace metal, metal-uptake, vegetables, urban activity