Determination Of Concentration Levels Of Selected Heavy Metals In Tomato (Lycopersicon Esculentum) Samples Prodcued Using Irrigation Water In Hidabu Abote District, North Showa Zone Of Oromia Regional State, Ethiopia

Abstract

Vegetables are vital to the human diet, and in particular provide the well-known nutrients to maintain normal physiological functions. The prolonged application of large amount of fertilizers and pesticides has resulted in heavy metal accumulation in agricultural crops including vegetables. Exposure to heavy metals by the consumption of contaminated vegetables and its toxicity is a serious concern globally. The present study investigated the level of heavy metals such as Fe, Zn, Cu, Mn, Cr, Ni, Pb, Cd, and Co in tomato fruit samples irrigated around Hidabu Abote North Showa of Oromia, Ethiopia. Three sampling villages (i.e., Debela Bokolo, Sire Morose and Haro Calenko villages) having high production compared to other villages of the district would be included for the sample collection. The three samples would be taken at Hidabu Abote tomato irrigation farm and composited sampling methods would be followed for sample collection(zigzag sample) The mean concentration levels of heavy metals in tomato fruit samples were 14 ± 0.76, 8.47 ± 0.72, 4.76 ± 1.68,3.88 ± 0.67, 0.67 ± 0.33, 22.22 ± 0.05, 3.56 ± 0.00, 1.9 ± 0.004 and ND in mg/kg in Haro Calenko site, 17.28 ± 0.2, 10.56 ± 0.32, 7.39 ± 0.02, 0.97 ± 0.336, ND, 10 ± 0.03, 3.45 ± 0.00, 0.2 ± 0.001, and ND in mg/kg in Debela Bokolo site and 15.79 ± 1.32, 0.82 ± 0.27, 4.4 ± 1.10, 2.79 ± 0.42, ND, ND, 0.00 ± 0, 1.9 ± 0.01 and ND in mg/kg in Sire Morose site for Fe, Zn, Cu, Mn, Cr, Ni, Pb, Cd and Co, respectively. The concentrations of Cobalt (Co) in the studied tomato were below the detection limit. The concentration levels of lead and cadmium exceeded the standards set by the world Health Organization (WHO/FAO).The study showed hazard quotient (HQ) to be less than 1 suggesting acceptable level of non-carcinogenic adverse health risk except for Cd, Pb and Cu. The hazard index (HI) values of the heavy metals studied ranged were above 1, indicating non-carcinogenic adverse health effect. This indicates that the metals possibly cause human health risks to the consumers. Consequently, we recommend a strict regulatory control on the safety of vegetables originated from the study area