Levels of some toxic heavy metals (Cr, Cd and Pb) in selected vegetables and soil around eastern industry zone, central Ethiopia

Abstract

The purpose of this study was to determine the concentration of heavy metals (Cr, Cd and Pb) in vegetables and the soil contaminating levels as a result of irrigation using Flame Atomic Absorption Spectrophotometer (FAAS). The wet digestion and sequential fractionation extraction procedures were employed to solubilize the metals from the collected samples. The results obtained from this study showed overall concentration of heavy metals Cr, Cd and Pb respectively, in the range of (2.90-3.77), (2.20-3.68) and (4.60-5.50) (mg/Kg) in the edible parts of sampled vegetables. Whereas, concentrations (mg/Kg) of the metals in the soil samples were found to be in the ranges of 22.37-66.30, 27.93-45.33 and 18.82-64.87 for Cr, Cd and Pb, respectively. The modified Tessier sequential extraction procedure was used to fractionate the above three metals from the soil samples into five fractions. In this study the heavy metals were predominantly concentrated in residual fraction (F5); since lead was mainly associated with the organic matter bounded fraction (F4) (34.33-43.45%), it was found to be more bioavailable and mobile than the other investigated heavy metals. The concentrations of heavy metals (Cr, Cd and Pb) in the soil and vegetable samples were above the recommended limit of both WHO and FAO. But Pb for the soil samples was smaller than WHO and FAO recommended limit. Based on facts obtained from this study we suggests concerned official body (ies) to take the necessary precaution measures for cleaning the polluted area.

Health risk assessment of heavy metals in selected Ethiopian spices

“…Cadmium is highly toxic metal even at low concentration and accumulates in the kidneys and liver and it can cause many severe diseases [ 25 , 26 , 27 ]. The concentration of Cd in all spices was under the limit of detection of the applied method.…”

“…Chromium is a toxic heavy metal which plays important role for physiological and biological functions of the human body when it is below tolerable limits [28]. However, its deficiency causes hyperglycemia and elevated body fat; and high Cr concentration damages kidneys, liver, and blood cells through oxidation reactions [26]. Copper is also essential element which is important in variety of biochemical processes.…”

Public health implications of heavy metals in foods and drinking water in Ethiopia (2016 to 2020): systematic review

“…Of 21 articles included in this systematic review, 6(28.57%) studies conducted in Oromia region [20][21][22][23][24][25], 5(23.8%) in Amhara region [25][26][27][28][29], 3 (14.29%) in Tigray [30][31][32], 2(9.5) %) in Southern Nations, Nationalities, and Peoples' (SNNP) [33,34], 1(4.76%) in Addis Ababa [35], 1(4.76%) in Harari [36], and 3 (14.29%) studies conducted in unspecific area (one in and around Addis Ababa [37]; one in Oromia and Addis Ababa [38] and one unspecified; conducted in Ethiopia) [39].…”

“…On the other hand, 5 (23.8%) studies conducted on vegetables alone [20,21,23,36,37], while one study included both fruit and vegetables [22]. Three (14.29%) and 3 (14.29%) studies were conducted to determine the concentration of heavy metals in drinking water [31,32,34] and fruit [26,33,39], respectively.…”

“…Seven (33.3%) articles (one article on each of edible mushrooms [24]; milk [40]; honey [38]; barley [27]; popcorn and cornflakes [35]; sesame seeds [30]; and raw and roasted seeds and bread [28]) were conducted to determine the concentration of heavy metals in raw and processed foods. Furthermore, among the included articles , 7 (33.3%) and 5 (23.8%) were published in 2020 [21,26,27,29,31,33,36] and in 2019 [20,23,25,30,32] respectively. (See Table 1 for details).…”