Experimental Investigation of Mercury Distribution in Polluted Soils of Owerri Area, Southeastern Nigeria

J.O Mbe,L.I Chukwu,A.O Ano,I.N Onyekwere,E.U Onweremadu

doi:10.15580/gjas.2013.3.042413584

Abstract

Mercury is a neurotoxic heavy metal, found in some polluted soils. A soil survey of Nekede mechanic village in Owerri area, Southeastern Nigeria polluted with automobile wastes was conducted. A transect was cut from the automobile service station outwards to link soils affected by automobile activities. Two profile pits, representing polluted and non-polluted sites were dug, described and sampled for laboratory analysis. Soil samples were collected based on differences in pedogenic horizons. The soil samples were analyzed in the laboratory for physical and chemical properties. Results of the physical properties showed that the bulk density of the soils ranged from 1.48-1.57 g cm-3, clay fraction ranged from 6-32 %, Silt fraction ranged from 2.0 to 8.0 % while sand fraction ranged from 62-80 %. Soil reaction ranged from 4.7 to 5.8, organic carbon ranged from 2 to 2.5 %, total nitrogen ranged from 2 to 23g/kg, CEC ranged from 2.9 to 6.9 cmol kg-1 and Hg ranged from 0.22 to 1.88 mg kg-1. The soil organic carbon, total nitrogen and mercury content of the soil decreased down the profile, while the bulk density increased down the profile.

Highlights

Environmental pollution involves release of substances in excess of threshold value by human activities into the environment
One of the problems of land degradation is the accumulation of toxic heavy metals such as mercury, whose mercury (11) form is strongly retained by soil (Isirimah et al, 2003)
Soil mercury content and bioavailability may be dependent on the depth, organic matter content of the soil, form of mercury and presence of sesquioxides, seasonal changes and vegetal forms (Roulet et al, 1999)

Summary

Introduction

Environmental pollution involves release of substances in excess of threshold value by human activities into the environment. Many of these pollutants including heavy metals are toxic and are persistent in the environment. Soil mercury can result from long history of accumulation from emission, soil erosion and land clearing (Fostier et al, 2000). The availability of mercury in soil in excess of threshold value affects biodiversity, which affect plant, soil plant interactions; and human health. One of the problems of land degradation is the accumulation of toxic heavy metals such as mercury, whose mercury (11) form is strongly retained by soil (Isirimah et al, 2003).

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