May 2016 Vol.4 No.4

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Original Research Article

Heavy metal pollution in burnt brick-producing wetland areas of Benue State

¹Agera S. I. N., ^*2Ogwuche J. A. and ³Ayuba S. A.

¹Dept of Forest Production and Products, University of Agriculture, Makurdi, Benue State
²Department of Soil Science, University of Agriculture, Makurdi, Benue State, Nigeria
³Department of Geography, Benue State University, Makurdi, Nigeria

*Corresponding Author’s E-mail: ogwuche.jonathan@yahoo.com

Accepted April 19, 2016

Abstract

Burnt brick production involves soil excavation and utilises a large volume of fuel wood and takes place mainly along river banks. This study assessed heavy metal pollution (Cadmium, Lead, Chromium, Iron, Manganese and Zinc) resulting from wood-based brick-producing activities in wetland brick-producing areas of Benue State. Eight (8) out of 23 Local Governments Areas (LGAs) were purposively selected for the study. The selected Local Governments are Buruku, Gboko, Gwer West, Konshisha, Kwande, Makurdi, Ushongo and Vandeikya. From each of the selected LGAs, two burnt brick sites were chosen for investigation. Two soil pits were dug at each of the sixteen brick sites selected and samples taken at intervals of 10-15cm, 60-65cm, and 90-95cm. Thus, a total of 96 soil samples were collected from thirty-two soil pits located in sixteen brick sites within the study area. Also four composite soil samples were taken (two each at burnt and unburnt areas of brick sites) that served as control. Collected data were chemically analysed and subjected to descriptive and inferential statistical analyses (means, standard error of the mean, percentages, co-efficient of variation, student T-test, and correlation). The statistical package Genstat Discovery Edition 4 was used for analysis of variance (ANOVA). Results showed that burning of bricks with fuelwood significantly increases the concentrations of heavy metals such as Cd, Pb, Cr, Fe, Mn and Zn, with significant lower concentrations in unburnt soils than ash-rich burnt soils, as well as decreased concentrations with increasing depth. These have very serious environmental (social, economic and physical) implications. The study therefore recommends proper land-use planning in allocation of brick sites, deliberate afforestation and incorporation of appropriate technology in brick making so as to save bodies and rich agricultural lands in the State.

Keywords: Burnt bricks, Burnt and Unburnt soils, Heavy Metals, Mean Concentration, Pollution