X-ray Fluorescence (XRF)-based Assessment of Element in Leafy Vegetables from Phu Tho Province

This study employed X-ray fluorescence (XRF) to analyze the concentrations of essential and potentially toxic elements in leafy vegetables (mustard greens, cabbage, and lettuce), with nutritional element levels determined and the target hazard quotient (THQ) as well as the hazard index (HI) calculated. The results showed that K was the most abundant, reflecting a typical nutritional characteristic of leafy vegetables. Comparative analysis with United States Department of Agriculture (USDA) and Ministry of Health of Vietnam (MHV) data revealed that the studied vegetables contained generally higher levels of Ca and Fe, particularly in lettuce, and higher K, Ca, and Mg in mustard greens and cabbage, suggesting significant nutritional potential. Chromium was identified as the major contributor to non-carcinogenic risk, accounting for 66–93% of the HI values. These findings highlight both the nutritional value and potential health risk associated with leafy vegetable consumption, emphasizing the importance of monitoring Cr contamination in agricultural soils and irrigation water.