Bioaccumulation of trace elements by different plant species grown on potentially contaminated soils of NWFP, Pakistan.

摘要

This study was conducted during summer and winter seasons of the years 2000 and 2001 to assess the bioaccumulation of trace elements (viz., Zn, Cu, Fe, Mn, Cd, Cr, Ni and Pb) by different plant species grown on potentially contaminated soils of Amangarh Industrial Area and Pirsabak, Nowshehra (NWFP), Pakistan. A total of 40 effluent irrigated plant samples were collected from NWFP. The plant samples include bottle gourd (Cucurbita maxima), aubergine (Solanum melongena), coriander (Coriandrum sativum), hot pepper (Capsicum frutescens), maize, okra, spinach, sponge gourd (Luffa acutangula), radish, turnip and wheat. For comparison four tubewell irrigated plant samples were also collected as background samples. The highest values of 75.0, 137.9, 982.0, 286.9, 8.3, 15.0, 73.0, 72.0 mg kg-1 were observed in effluents irrigated plant tissue and 34.2, 18.6, 120.9, 34.0, 2.6, 4.2, 16.0 and 20.0 mg kg-1 in tube well irrigated plant tissue for Zn, Cu, Fe, Mn, Cd, Cr, Ni and Pb, respectively. The values observed were also compared with the toxic and excessive levels. The comparison showed that 90, 28, 43, 98 and 30% of samples contained toxic or excessive levels of Cu, Cd, Cr, Ni and Pb, respectively. The concentrations of these elements in effluent irrigated plants were higher than those in tubewell irrigated plants and also higher than those generally reported in the literature..