Bioaccumulation of trace metals concentration in some vegetables grown near refuse and effluent dumpsites along Rumude-Doubeli bye-pass in Yola North, Adamawa State

M.H. Shagal¹*, H.M Maina¹_, R.B. Donatus¹ and K. Tadzabia²

*Corresponding Author E-mail: shagal2006@yahoo.com; Tel: +2348052284456

¹Department of Chemistry, Modibbo Adama University of Technology, P.M.B. 2076, Yola, Nigeria.

²Department of Chemistry, Umar Suleiman College of Education, P.M.B. 2 Gashua, Yobe State, Nigeria.

Accepted 09 May, 2012

Amaranthus spp, Hibiscus sabdariffa and Lactuca sativa grown around refuse and effluent site were analysed for five (5) heavy metals viz: cadmium (Cd), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn) by atomic absorption spectrophotometric method. Analysis of the results showed that the concentration of the analysed metals ranged from 10.00 – 16.67 mg/kg cadmium, 30.02 – 43.33 mg/kg copper, 40.82 – 70.50mg/kg manganese, 5.02 – 8.80 mg/kg lead and 29.16 – 30.00 mg/kg zinc. Data showed that metal uptake differences by the vegetables are attributed to plant differences in tolerance to heavy metals and vegetable species. The cadmium and lead concentrations in all the vegetable samples were more than the maximum permitted concentrations proposed by FAO/WHO while manganese, copper and zinc concentrations were below the maximum permitted concentrations. But with increase in vegetable consumption by the community, the situation could worsen in the future due to the high level of cadmium and lead accumulation which have damaging effect on both plants and animals. However, the regular monitoring of concentration levels of these metals from refuse and effluents, in vegetables and in other food materials is essential to prevent excessive build-up of these metals in the food chain.

Keywords: Heavy metals, effluents, concentration, lead, vegetables, bioaccumulation.