Abstract:
Vegetables are important components of human diet. As a result of environmental pollution the
food safety of vegetables including tomato has become one of the concern of researchers.
Globally, heavy metal contamination of vegetables is one of the most important aspects of food
quality assurance.The study evaluates concentration levels of some heavy metals in tomato
(Solanumspp.) vegetable sample by Atomic Absorption Spectroscopy cultivated in East Shoa
Zone, Oromia Region, Ethiopia by the digestion procedures of 0.5 g of homogenized and
powdered tomato sample was placed in microwave digestion vessel to which 9 ml of 10M HNO3
and 3 ml 10 M HCl were added. The vessels were tightly capped and placed in the microwave
digestion system and digestion take place at 180˚C for 45 min`s until a clear solution were
obtained. In this study, tomato samples from three villages (kebeles), namely Kona Dagaga,
Bato, and Ulaga villages of Adama area were collected and analyzed for cadmium (Cd), lead
(Pb), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), iron (Fe),manganese (Mn) and zinc
(Zn). The results revealed that the mean heavy metal concentrations in tomato sample for Cd,
Pb, Cr, Co, Ni, Cu, Mn, and Zn were in the range of 3.2–3.46, 2.02-12.7, ND - 5.8, ND- 29.6,
28.89-34.4, 7.11-23.55, 20.6-26.73, 6.91-18.9 and 25.42-35.3 mg/kg, respectively. In general, the
level of metals in tomato collected from the sampling sites are found to be in the decreasing
order of Zn>Ni> Co>Fe>Cu>Mn>Pb>Cr>Cd. When compared to the WHO/FAO thresholds
values for the metals, the concentration levels of Pb, Cd, Cr and Ni were exceeded (Dagaga >
Ulaga > Bato) the threshold values for tomato vegetable for human consumption. This indicated
that these metals (i.e., Pb, Cd, Cr and Ni) can cause unintended health effects to the consumers.
The health index (HI) owing to tomato in Dagaga, Bato and Ulaga ingesting were 48.9%, 21.7%
and 29,4% respectively, signifying likely adversative health implication to the population from
the ingestion of the tomatoes. The Total Cancer Risk (TCR) analyses have uncovered the
possible cancer hazard persuaded by Cd, Cr, and Ni from the ingestion of all area tomatoes.
From the outcomes this study, it can be concluded that the water and vegetables from Dagaga
areas are possibly contaminated with toxic metals and hence demand strict monitoring to
safeguard the public around the study area and beyond
