Background: The growing use of treated wastewater in farming has raised concerns about the potential impacts on public health.
Methods: This study assessed the levels of the heavy metals lead (Pb), cadmium (Cd), and arsenic (As) in plants watered in greenhouse settings using both well water and synthetic wastewater. Synthetic wastewater with As at concentrations of 0.1, 0.2, and 0.4 mg/L, Pb at 1, 3, and 5 mg/L, and Cd at 0.01, 0.03, and 0.05 mg/L, as well as well water were used to irrigate radish, coriander, and grass. In the end, 144 vegetable samples were gathered, and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to determine the heavy metal concentrations in the samples. Risk assessment for consumers was determined based on the measured levels of heavy metals in the vegetables.
Results: Even though the concentrations of heavy metals in the wastewater were within the limits for irrigation, the risk assessment showed that consumption of vegetables irrigated with treatment wastewater could pose risks to individuals’ health. The maximum concentration of Pb in radish leaves was observed at the Pb concentration of 5 mg/L, and the maximum concentration of As in cress irrigated with As effluent at the As concentration of 0.02 mg/L.
Conclusion: The consumption of vegetables containing Pb can pose a significant non-carcinogenic risk to consumers. However, well water may also be dangerous in the long run. Therefore, it is important to ensure about food safety when using treated wastewater for irrigation.