Effect of nanohydroxyapatite and its derivates on cadmium reduction in edible lettuce tissues

Abstract Understanding the role of nanohydroxyapatite (nHAP) and its derivatives in mitigating cadmium (Cd) toxicity is essential for enhancing food safety in contaminated regions. This study investigated the effectiveness of nHAP and its modified forms (sheep wool‐modified (nWHAP), rice husk‐modified (nRHAP), and a combination of both (nWRHAP)) in reducing Cd accumulation in lettuce grown under alkaline, acidic, and hydroponic conditions. The structural and functional properties of the synthesized materials were characterized using SEM, XRD, and FTIR. Although Cd exposure did not hinder lettuce growth, it significantly increased Cd concentrations in plant tissues. Under alkaline conditions, the application of Triple Super Phosphate reduced Cd levels from 57.7 to 39.4 mg kg −1 . In acidic soil, treatments with nHAP derivatives lowered Cd concentrations from 64.7 to approximately mg kg −1 . Likewise, in hydroponic systems, nHAP, nWHAP, and nRHAP significantly decreased Cd concentrations from 206 to <190 mg kg −1 . Markedly, these amendments did not adversely affect the uptake of essential nutrients such as K, Ca, Mg, Fe, Zn, Cu, and Mn; in fact, Zn uptake improved under alkaline conditions. Overall, nHAP and its derivatives show promise in reducing Cd accumulation while maintaining plant nutritional balance. Further research on other crops and heavy metals is recommended.