Trace metal contamination from water and soil to vegetables and associated human health risks.

Vegetables represent potential pathways for increased heavy metal exposure in humans. Inductively coupled plasma mass spectrometry (ICP-MS) was applied to estimate 19 trace metals in various parts of beetroot, onion, rice, spinach, parsley, rhubarb, dill, basil, and radish plants as well as in the irrigation water and corresponding cultivated soils. Parsley, rhubarb, and basil showed the same distribution pattern for most elements as follows: leaf > stem > root. Likewise, onion, spinach, and radish demonstrated similar trends for most metals as follows: root > stem > leaf. The fraction of metals present in the plant and the soil-to-plant transfer factor (TF) indicated that the absorption and movement of metals were significantly influenced by both the specific element and the plant compartment, with the majority of metals exhibiting low transfer rates, although certain metals demonstrated greater accumulation in particular organs, as the TF for most metals was less than 1. The HQ values of the consumable different organs of vegetables/plans of this study revealed distinct variations in the compartmentalization of metals across the examined vegetables/plants. As and Cr were the predominant contributors to non-carcinogenic risks across all consumable parts exceeding the established USEPA threshold for the majority of compartments of vegetables/plants, with the highest HQ values recorded in the edible parts of rice grain (54 for adults and 62 for children) for As and onion leaf (9.4 for adults and 10.7 for children) for Cr. The hazard index (HI) values for heavy metals in different parts of the selected vegetables and plants, except for the stems and leaves of rhubarb, were higher than the USEPA-established threshold of 1, indicating potential health risks for adults and children. The carcinogenic risk (CR) was very diverse among plant species and tissues. The CR values for As in all analysed vegetables, Cr (except the edible parts of beetroot) and Ni (skin, core, and leaf of beetroot and rice grain) exceeded the probable carcinogenic threshold (>1.0 × 10-4). The findings regarding Pb and Cd indicate that most levels are within tolerable or negligible risk limits for both adults and children. This implies a potential carcinogenic risk, though it is accompanied by some uncertainty.