Health risks associated with exposure to arsenic, lead, and mercury in tomato fruits grown near Lake Hawassa, Ethiopia

This study examined the potential health risks associated with exposure to arsenic (As), lead (Pb), and mercury (Hg) from tomato samples collected from irrigated vegetable farms near Lake Hawassa in the Ethiopian Rift Valley (ERV). A total of 225 tomato fruit samples and 45 soil samples were collected from three agricultural sites for analysis. The samples were analyzed at the Horticoop Soil and Water Laboratory in Bishoftu, Ethiopia, using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The evaluation of non-carcinogenic health risks and Incremental Lifetime Cancer Risk (ILCR) was based on the consumption of the tomato samples, utilizing metrics such as Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Hazard Index (HI). The results indicated that all soil and tomato samples tested were contaminated with As, Pb, and Hg. The average concentrations in soil samples, ranked from highest to lowest (mg/kg), were Pb (14.21) > As (3.43) > Hg (1.44), with Hg levels exceeding the EU's Maximum Permissible Limit (MPL) at all sites. Similarly, the concentrations in tomato samples followed the same order (mg/kg): Pb (26.72) > As (0.54) > Hg (0.45), surpassing the FAO/WHO limits in all the three sites. The high levels of Pb in the tomato samples indicate significant non-carcinogenic health risks, particularly for children, with a THQ of 1.2 and an HI of 1.73. The data suggest that children face more than double the non-carcinogenic risk compared to adults. The total ILCR for adults ranged from 8.11E-05 to 9.57E-05, averaging 8.82E-05, which exceeds acceptable risk limits primarily due to the concentrations of Pb and As in the tomatoes. This study highlights the urgent need for further research on the health risks of As, Pb, Hg, and other heavy metals in the environment, particularly concerning tomato cultivation and other crops.