Contamination of Roadside Soil and Bush Mint (Hyptis suaveolens) with Trace Metals along Major Roads of Abuja

  •  Ahmed Usman    
  •  Umar Gaya    


There has been a growing concern over environmental pollution by trace metals from automobile source. Abuja, like most urban cities has a high road traffic density. The present study investigates the levels of trace metals in roadside plant and soils along some major roads in Abuja. Thirty samples, consisting of equal number of plants and soils from Airport, Kubwa and Nyanya road were analyzed for Pb, Fe, Cu, Zn, and Cr levels using atomic absorption spectroscopy. The findings reveal trace metal contamination gradient, with the maximum levels closer to the road. Copper is prevalent in the study area with concentrations standing at 76.66 ± 12.02 µg g-1 and 300.00 ± 50.00 µg g-1 in the plant and soil respectively. There is a significant correlation in the concentration of the metals studied regardless of sample class. The average distribution of the metals in the samples decreased in the order Cu > Zn > Fe > Pb > Cr with the exception of Nyanya soil and the plant samples from Kubwa road. Evidence for Pb transfer from soil to Hyptis suaveolens was established and accumulation of Pb, Cu and Fe has reached alarming levels. Chromium traces were as low as 11.91 ± 1.38 µg g-1 in the plant but reached up to 39.68 ± 6.87 µg g-1 in the soil. Concentration of the metals investigated in the soil except for Cu, are within the safety limit recommended by FAO/WHO.

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