Pollution Characteristics and Risk Assessment of Heavy Metals in Soil of Alisma orientale in Sichuan

• • Mean soil Cd concentration was 1.77 mg·kg−1, exceeding the agricultural land risk screening value (0.3 mg·kg−1 for pH≤7.5), driving Pi and Pn to confirm Cd contamination; this necessitates targeted Cd remediation in Sichuan Alisma fields. • • Cu, Cd, Pb, and Ni exhibited highly significant positive correlations (p<0.01) in soil, indicating a common anthropogenic source; this enables source-specific mitigation strategies rather than blanket soil treatment. • • Alisma orientale showed a strong bioaccumulation factor for Zn (mean 1.85) but weak for Cu, Cd, Pb (BAF<0.5) and negligible for Ni (BAF<0.1), confirming species-specific uptake patterns that inform safe cultivation site selection. • • THQ and HI values for all metals were below 1 (max HI=0.42), indicating no non-carcinogenic health risk from current Alisma consumption; however, continuous monitoring is warranted given Cd's ecological risk.