Trace metal levels in castor plants growing on refuse dumpsites in wukari metropolis, Nigeria

Abstract

A preliminary survey of the risk assessment of selected trace metal (Cd, Cr, Cu, Pb and Zn) levels of castor (Ricinus communis L.) plant growing on refuse dumpsites in Wukari Metropolis, Taraba State was investigated. Duplicate samples each of whole castor plants and decomposed remains of the refuse dumpsites were collected from three locations namely Kwararafa 1(Abo prisoners), G.R.A (Barikr) and Marmara 1(Abattior) based on population density and out of the 10 locations surveyed. Triplicates pH readings of the decomposed refuses at the three locations were recorded. Trace metal levels and pH were determined by the flame AAS using acetylene/air and pH meter respectively. Selected risk assessment techniques such as soil-plant transfer coefficient (TC), plant uptake factor (PUF) and translocation factor (TF) were worked out for the castor plants. Results revealed a high TC value (1.405) for whole castor plant above the permissible limits (value >1) than PUF and TF with less than unity value revealing the potential possible transfer of metals into the plant body. Higher levels of Zn and Cd were evident, followed by Cu according to the Joint FAO/WHO Food standards 2006. Health risk assessment of metals from refuse dumpsites is a good technique for predicting potential threat to life.