Trace Metals Charaterisation of Soils in the Vicinity of a Major Active Dumpsite in Lagos: An Integrative Multivariate Indices Approach

The use of non-sanitary landfill facilities in refuse disposal process put much burden on the soils around the dumpsite, thereby portending health risk to man (soil-plant-man). However, the paucity of data on quality of soils around dumpsite necessitates this study using multivariate indices approach to assess the quality status of soils in and around dumpsite area. Forty (40) top and subsoil samples were collected around Olusosun dumpsite in Lagos, and analysed for heavy metals and organic carbon using standard methods. The pH and particle size distribution of the soils were also investigated. The data obtained were analysed using descriptive statistics, correlation coefficient and multivariate indices: enrichment factor (EF), contamination factor (CF), geo accumulation index (Igeo) and pollution load index (PLI). The order of Igeo of metal pollution was Zn > Cd > Ni > Fe > Cu > Pb. The CF revealed low index for Pb, considerable index for Ni and very high index for Fe, Cu, Zn and Cd. The PLI confirmed deterioration of the soil in and around the dumpsite. Measures are urgently necessary to mitigate further accumulation of heavy metals which should include upgrading existing dumpsites to landfill and employing global refuse disposal standards of 3-Rs (Reduce-Recycle-Reuse).