Evaluation of heavy metals deposition on selected agricultural products dried in local kitchens and roadsides, Wukari, Nigeria

Bando Christopher David^ab*; Ikwebe Joseph^b; Imo chinedu^b; Jummai Adamu Tutuwa^c; Jesse Shingu Polly^a; Imbasire Nuhu^a; Rejoice Habila Tadawas^a; Odiba Emmanuel Ogu^a; Tsoken Danji Agbu^a
Page No.1-19

Most agricultural products in Nigeria are often susceptible to environmental pollution due to anthropogenic activities and mode of preservation. As a case study, this work was aimed at evaluating the levels of heavy metals (Pb, Hg, As, Cd, Zn and Fe) depositions on selected agricultural products that are either stored at the rooftop of local Nigerian kitchens, sun-dried by roadsides or sun-dried away from local kitchens and roadsides. The selected agricultural samples (Zea mays, Manihot esculenta, Capsicum annuum, Solanum lycopersicum, Abelmoschus esculentus and Hibiscus sabdariffa) were sourced from Byepyi (Wukari – Jalingo highway), Gindin waya (Wukari – Ibi road) and Kente (Wukari – Kente road). Heavy metal was determined using Atomic Absorption Spectrophotometer (AAS). Generally, heavy metals depositions on the selected agricultural samples showed higher concentrations in samples stored at rooftops of local kitchens, compared to samples sun-dried by the roadsides and samples sun-dried under control conditions in the three locations. In Byepyi, heavy metal such as Pb, Hg, As, Cd, Fe levels were significantly higher (P≤0.05) in samples stored at rooftops of local kitchens. Slight change in the result trends was observed for Cu, which showed higher concentrations for samples sun-dried by roadsides. In Gindin waya, heavy metals such as Pb, As, Fe, Cu analytes levels were significantly higher (P≤0.05) in samples stored at rooftops of local kitchens, while Hg is at same level with samples sun-dried by the roadsides and Cd showed higher concentration in samples sun-dried by the roadsides. In Kente, levels of heavy metals such as Pb, Hg, As, Cd were significantly higher (P≤0.05) in samples stored at rooftop of local kitchens. Slight change in the trends was observed for Fe, Cu, which showed higher concentrations for samples sun-dried. The research showed appreciable levels of metallic contamination in selected agricultural products, although they were found to be below FAO/WHO permissible limits. Bioaccumulation of these food contaminants in humans could result to serious health problems.
Keywords: AAS; Cadmium (Cd); Lead (Pb); Arsenic (As); Mercury (Hg); Chromium (Cr); Kitchens; Roadsides.