Assessment of heavy metals concentrations intropical agroecosystem (Wakwa,Adamawa,Cameroon): An Index Analysis Approach

A study has been conducted to evaluate the degree of Heavy Metals (HM)contamination on farm soils of Wakwa’s, using enrichment factor (EF), geo-accumulation index (Igeo), pollution load index (PLI), Ecological risk factors (Eir), Ecological risk indices(PER) and statistical analysis.In the currentstudy, composite surface agricultural soil samples were collected in 4 sites and analyzed for the concentration of HMs including As, Ba, Co, Cr, Cu, Ni, Mn, Mo, Pb, Sr, V, Y, Zn and Zr.Electric conductivity(EC)and pH were also determined.The concentrations of Cr, Zr, Mo andPb are significantly higher than average shale valuesin all sites. Sites WK3and WK4 recorded high concentrations ofNi and V. obtained EFvary from 0.07 for Sr to 2.35for Mo and indicate zero tomoderateenrichment. Igeo vary from -3.83 for Sr to 1.26 for Mo and indicate zero to moderatecontamination.PLIvary from 0.61 to 0.83with the highest to the lowest polluted site being WK4 >WK3 >WK2 >WK1. All HM present low ecological concern and low potential ecological risk indices. All sites recordedacidic pHexcept site WK1which has neutralpH.WK4which is upstreamthe Lake Piu is the most pollutedand present the lowestpH(5.183) andthehighest EC(563.667μs/cm). Positive and highly significant correlations were observed for several pairs; this could indicate the same source of pollution for most HMs. This study concludes that a regular assessment is needed to estimate the risk level of toxic metal contamination in the ecosystem.The presentstudy is valuable because it is probably the first work on heavy metal levels in Wakwa locality.