Determination Of Levels Of Some Heavy Metals In Water, Soil & Fruit Samples Of Tibila Irrigation Farm, Boset District, East Shoa Zone, Oromia, Ethiopia

Abstract

Food contamination by heavy metals has been a major concern in recent years due to their potential to accumulate in bio-systems via contaminated water, and soil. Fruits are an important part of a healthy diet due to their nutritional values, which help in preventing major diseases. As a result, any form of contamination by heavy metals is of great concern. The main objective of this study was to determine the concentrations of some selected heavy metals in irrigation water, soil, and fruit samples of (Orange, and Pawpaw) collected from the Tibila Farm of the Boset District, Oromia regional state, Ethiopia. The composite samples of soil, water, and fruits were collected randomly from the Farm during the wet season. To decompose organic materials and solubilize metals from the samples, optimal wet digestion techniques were used. The validation was performed by spiking the samples with a standard solution of each metal having a known concentration, and the percentage recovery values for all samples were in the range of (81-110%) with a relative standard deviation of (0.24-14.3%). After wet acid digestion, the collected samples were analyzed for Cd, Pb, Zn, Cr, Cu, Mn, Fe, Co, and Ni, with flame atomic absorption spectrometry (FAAS). The MDL and LOQ values recorded were greater than the IDL, indicating that the instrument used was sensitive. The result of the study showed that the heavy metals concentration in the studied samples was in the decreasing order of: Fe > Mn > Zn >Cu > Cr > Ni > Co; Fe > Cr > Zn > Cu > Ni > Mn > Co; Zn >Cr > Fe > Mn > Cu > Ni > Co; Zn > Fe > Cr > Cu > Co > Ni > Mn in the soil, water, orange and pawpaw samples, respectively. The concentration levels of Mn, Zn, & Cu in the soil; Zn, Cr, Mn, Fe & Ni in orange; Zn, Fe, Cr, & Ni in pawpaw; and Zn, Cr, Cu & Ni in the water sample exceeded the permissible limit set by WHO/FAO. The result of one-way ANOVA revealed that there was a significant difference between the samples (p < 0.005; 95% CL) for all metals in the soil, water & fruits. According to the findings of this study, continuous heavy metal inspection in farm products is required to avoid contamination and ensure human safety