Abstract: To compare the applicability of regression model method (RM) and species sensitivity distribution method
(SSD) in deducing the available concentration safety threshold of Pb and Cd in a slag farm in Gejiu,Yunnan Province. The response
of heavy metal content of Chinese cabbage to Pb and Cd content in polluted soil was investigated by pot experiment. The
available concentration safety thresholds of Cd and Pb in soil of agricultural land were derived by RM method and SSD method
for analysis and comparison. The results showed that the total and available contents of Cd and Pb in soil were positively correlated
with the contents of Cd and Pb in Chinese cabbage,and the available contents of Cd and Pb in soil and Chinese cabbage
were negatively correlated with pH,and positively correlated with organic matter and cation exchange capacity. The available
concentration safety thresholds of Cd and Pb in soil were derived by RM method as 0. 68 and 204. 8 mg/ kg,respectively,while
the available concentration safety thresholds of Cd and Pb in soil were derived by SSD method as 2. 02 and 388. 60 mg/ kg,respectively.
According to the available concentration safety threshold derived by RM method,the available concentration safety
thresholds of Cd and Pb in agricultural soil are all located in regions A,D and F,that is,the regions where the soil does not exceed
the standard and the cabbage does not exceed the standard and the soil exceeds the standard and the cabbage exceeds the standard,and the accuracy is higher. SSD method was used to calculate the available concentration safety threshold judgment,
and the available concentration safety threshold of Cd and Pb in soil was located in the D and F regions,that is,the regions
where the soil did not exceed the standard and the cabbage exceeded the standard and the soil exceeded the standard and the
cabbage exceeded the standard,the accuracy was low. Therefore,the available concentration safety threshold derived by RM
method can better reflect the actual situation of the available concentration safety thresholds of Cd and Pb in soil of agricultural
land around a slag farm in Gejiu,Yunnan Province,and can provide reference and guidance for soil remediation evaluation of
agricultural land polluted by Cd and Pb in this region.