期刊名称：African Journal of Environmental Science and Technology
电子版ISSN：1996-0786
出版年度：2008
卷号：2
期号：5
页码：89-96
语种：English
出版社：Academic Journals
摘要：In this study, the seasonal variations in concentrations of the heavy metals - As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn - in soil and crops from a farm near the refuse dump site of Obafemi Awolowo University, Ile-Ife, Nigeria were investigated during the two major seasons of Nigeria. This was done to assess the pollution status of the farm and hence the safety levels of the crops produced. Soil and crop samples collected during the 2005/2006 rainy and dry seasons were treated and digested using standard wet digestion methods. Heavy metals were determined with Atomic Absorption Spectrophotometer (AAS). Analytical results of soil from landfill indicated that in the wet and dry seasons, values for Cd, Cu, Fe, Ni, Cr, Zn, Co and Pb were higher than normal levels of a typical agricultural soil, but As (3.20 and 4.13 mg/kg) was found to be within the acceptable range while Mn values of 597.00 - 828.37 mgkg-1were slightly above the usual background levels. The study showed highest concentrations of As (8.31 mg/kg), Cr (9.00 mg/kg) and Ni (40.00 mg/kg) inManihot esculentaleaves; Cu (25.0 0 mg/kg) and Fe (176.00 mg/kg) inXantosoma mafaffatuber; Cd (14.50 mg/kg), Co (22.50 mg/kg), Mn (189.50 mg/kg), Pb (680.00 mg/kg) and Zn (440.59 mg/kg) inTalinum triangulare. In general, the levels of heavy metals in soil and crops were higher in the dry season than in the wet season, but this difference is not statistically significant. Particularly, the levels of As, Cd, Cr, Ni, and Pb were above the critical toxic level in plant leaves in both dry and wet seasons while Zn and Cu occurred at toxic levels only in the dry season.
关键词：Contamination; heavy metals; landfill; refuse dump; transfer factor
