Objective To carry out the potential ecological risks assessment of heavy metals in farmland soils, and provide a reference for formaluting of the local soil environmental and health related polices.
Methods Nemerow index and potential ecological index were used for evaluation based on the data of the heavy metals lead (Pd), cadmium (Cd), and chromium (Cr) in farmland soil in Hongta district of Yuxi, China, measured in 2017-2020, and MapGIS was used to perform a spatial interpolation analysis of risk level.
Results The excess rates of heavy metals in farmland soil were 22.5% for Cd, 3.7% for Pb and 0% for Cr. The proportion of soil monitoring points polluted by Cd accounted for 12.5%. There was a gradual increase in the measurement value of Cd over years, with a significant difference from 2017 to 2020. The Nemerow index indicated that Cd and Pb were moderately and slightly polluted. The comprehensive potential ecological index was 1.84-96.45, which result as a slight ecological risk.
Conclusion The risk of three heavy metals such as Pb, Cd and Cr in farmland soil in Hongta District is low; the Cd element in some points exceeds the standard, and the prevention and control of heavy metal Cd pollution should be strengthened.
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