Abstract:
A human health-based soil risk assessment system and technical standard for contaminated sites has initially formed in our country, while the technical methods and standard system for soil pollution risk assessment based on the protection of ecological receptors have not yet been established. The current situation of soil composite pollution in key industries are firstly introduced, then the ecological effects of composite pollution of characteristics pollutants are summarized, and the mechanism of different combined effects are analyzed. The current commonly used ecological risk assessment methods are classified and expounded, and the research progress of ecological risk characterization of compound pollution is introduced. Pollution characteristics such as heavy metal-heavy metal complex, heavy metal-polycyclic aromatic hydrocarbon complex usually appear in key industries sites such as smelting and coking. When such pollutants coexist, they can form synergistic, additive, antagonistic and other combined effects by affecting each other's biological absorption, transport, degradation, transformation, and finally toxicity. Currently commonly used ecological risk assessment methods include index method, quotient value method, and probability method. The index method constructs a comprehensive assessment index based on different indicators of pollution sources, exposure pathways and biological receptors to quantify the relative risk of pollutants. The quotient method quantifies the absolute risk of pollutants based on pollutant exposure and toxicity reference values. The probability method obtains the absolute risk considering the variability of pollution distribution and toxic effects through the probability density function and cumulative distribution probability function of pollutant and toxicity data. In the case of compound pollution, concentration addition, effect addition, and a combination of the two can be used for comprehensive characterization of risk.