Effect of vanadium on Lactuca sativa L. growth and associated health risk for human due to consumption of the vegetable.

Elevated vanadium in the environment adversely affects organisms, including plants, animals, and humans. Plants act as the main conduit for environmental vanadium to enter the food chain, and simultaneously their growth response characteristics reflect vanadium toxicity efficacy for plants. The aim of the present study is to investigate lettuce (Lactuca sativa L.) growth involving morphological change, physiological adjustment, vanadium accumulation under vanadium stress, and the potential health risk (expressed as health risk index (HRI)) of adults and children who consume it. Lettuce was grown in nutrient solution with 0, 0.1, 0.5, 2.0, and 4.0 mg L of pentavalent vanadium [V(V)]. Results showed that 0.1 mg L V did not significantly affect lettuce growth versus control, and marked depression arose at ≥ 0.5 mg L V. Foliar proline increased rapidly at ≥ 0.5 mg L V. No striking change emerged in leaf cell membrane permeability at all treatments. V(V) and total vanadium concentration in plant tissues were ordered as root > stem > leaf, while tetravalent vanadium [V(IV)] was leaf > root > stem. No health risk (HRI < 1) exists for adults and children who consume lettuce at control treatment. However, the health risk occurs (HRI ˃ 1) when they both ingest the seedlings exposed to ≥ 0.1 mg L V, and the risk overall markedly increases with increasing vanadium. Therefore, enough attention needs to be paid to the human health associated with the ingestion of vegetables like lettuce grown in substrata contaminated by vanadium.