ABSTRACT

This study investigated the current state and pollution loads of heavy metals in soils developed on diverse parent materials in southeastern Nigeria. Cu, Mn, Zn, Fe and Al were analyzed to estimate pollution loads and ecological risk of the area. The result showed soils developed on granite gneiss to have a higher concentration (measured in mg kg⁻¹) of Cu (1.79), Mn (78.39) and Zn (28.53), while soils developed on Biotite hornblende gneiss and quartz-mica-schist had a higher concentration of Fe (≥18) compared with other parent materials. The contamination factor for Fe, Zn, Mn and Cu was low, whereas Al was moderately to considerably contaminated except for soils in S2 (0.362), S3 (0.662), S6 (0.142), S9 (0.661), S11 (0.803) and S15 (0.499). The result of the pollution load index indicated an unpolluted condition (PLI < 1). Excluding Al, the soils were practically uncontaminated with Zn, Cu, Fe and Mn, based on the Geo-accumulation index and Quartz-mica-schist was enriched by Zn in S6 (1.325) and showed low ecological risk (Er < 40) and (IR < 150). Hence, the soils in the studied communities are still in a safe state to be used for crop cultivation without any fear of metal contamination.

摘要

本研究调查了尼日利亚东南部在不同母材上发育的土壤中重金属的现状和污染负荷。分析了铜、锰、锌、铁和铝，以估计该地区的污染负荷和生态风险。结果表明，在花岗岩片麻岩上发育的土壤具有较高的浓度（以 mg kg ^-1) 的 Cu (1.79)、Mn (78.39) 和 Zn (28.53)，而在黑云母角闪片麻岩和石英云母片岩上发育的土壤与其他母体材料相比具有更高的 Fe 浓度 (≥18)。Fe、Zn、Mn 和 Cu 的污染因子较低，而 Al 的污染因子为中度至重度污染，除了 S2 (0.362)、S3 (0.662)、S6 (0.142)、S9 (0.661)、S11 (0.803) 和S15 (0.499)。污染负荷指数的结果表明未受污染（PLI < 1）。除 Al 外，土壤几乎未受 Zn、Cu、Fe 和 Mn 污染，基于地积累指数和石英云母片岩在 S6 中富集 Zn (1.325) 并显示低生态风险 (Er < 40) 和(IR < 150)。因此，