A soil cadmium environmental ecological toxicity data screening processing method and application
By screening and processing soil cadmium ecotoxicity data, a species sensitivity distribution model was established, which solved the problems of data lack and inconsistency in soil ecological risk assessment, achieved data unification and accuracy of risk assessment, and provided reasonable recommended values for soil environmental standards.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING INST OF ENVIRONMENTAL SCI MINIST OF ECOLOGY & ENVIRONMENT OF THE PEOPLES REPUBLIC OF CHINA
- Filing Date
- 2023-06-05
- Publication Date
- 2026-05-15
AI Technical Summary
Soil ecological risk assessment in my country is challenging due to a lack of ecotoxicity data, insufficient coverage of pollutants, limited range of biological species, inconsistent endpoint indicators and testing methods, and uneven data quality. Existing models are also difficult to expand upon with ecotoxicity data.
By screening ecotoxicity data, including terrestrial species and soil ecological process data, data that does not meet international standards are removed. The processed data are extrapolated and fitted based on ECx values to establish a species sensitivity distribution model, draw a sensitivity distribution map, extrapolate the recommended values of soil environmental standards, and conduct a rationality analysis.
High-quality ecotoxicity data were selected to expand the data scope, a unified data analysis model was established, and applicable soil environmental standard recommendations were extrapolated to improve the accuracy of risk assessment. Rationality analysis ensured the effectiveness of the recommendations.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of soil cadmium data processing technology, specifically to a method and application for screening and processing soil cadmium environmental ecotoxicity data. Background Technology
[0002] Because my country's soil pollution problems involve many regions, are complex in type, and have a wide variety of pollutants, the overall situation is not optimistic. This not only increases the difficulty of soil ecological risk assessment in my country, but also leads to the relatively slow development of soil environmental benchmark research in my country.
[0003] Therefore, it is necessary to explore key technologies for soil ecological risk assessment and environmental benchmarks in my country. Ecotoxicity data is a fundamental and important component, but existing ecotoxicity data is relatively scarce and suffers from problems such as insufficient pollutant coverage, limited range of biological species involved, and inconsistent endpoint indicators and testing methods. Furthermore, the storage of soil ecotoxicity data is limited, and the quality of the data varies, resulting in limited applications and species toxicity studies. Current research has found that soil ecotoxicity models can further expand ecotoxicity data. Summary of the Invention
[0004] To address the above problems, this invention provides a method for screening and processing soil cadmium environmental ecotoxicity data.
[0005] The technical solution of this invention is: a method for screening and processing soil cadmium environmental ecotoxicity data, comprising the following steps:
[0006] S1. Obtain ecotoxicity data
[0007] Ecotoxicity data are obtained through ecotoxicological tests or by searching existing literature. The ecotoxicity data includes data on terrestrial ecological species and data on soil ecological processes.
[0008] The terrestrial ecological species data include: toxicological endpoint data on mortality / stasis, growth, maturity, and reproduction of terrestrial ecological species; the soil ecological process data include: toxicological endpoint data on mortality / stasis and enzyme activity inhibition of soil microorganisms.
[0009] The effect data includes the effect concentration ECx, where x represents the percentage of impact; the terrestrial ecological species include terrestrial plants and invertebrates;
[0010] S2, Filter Data
[0011] Ecotoxicity data on terrestrial plants, invertebrates, soil microorganisms, and enzyme activity were screened and categorized into multiple groups for separate evaluation.
[0012] In step S1, determine whether the ecotoxicity data obtained through ecotoxicological testing meets internationally recognized method standards. If yes, select the data; otherwise, discard it.
[0013] In step S1, an assessment is made based on the ecotoxicity data obtained by searching existing literature.
[0014] The first judgment method is as follows: determine whether the ecotoxicity data can determine the exposure time and toxicological endpoint of the soil pollutant, whether the corresponding toxic effect data ECx can be estimated based on the dose-response relationship, whether the condition parameters for conducting the toxicological test are recorded, and whether the toxicological effect of the tested pollutant is attributed to the pollutant of concern; among which, the condition parameters are soil pH, organic matter and clay content, and temperature;
[0015] Ecotoxicity data that are all "yes" in the first screening test are filtered out; the rest are removed.
[0016] Take the baseline extrapolated ecotoxicity data from the first screening of ecotoxicity data, determine whether they use the same analytical testing methods, and specify the actual exposure concentration; if yes, retain them; otherwise, remove them.
[0017] S3, Data Processing
[0018] S3-1. Determine whether the ecotoxicity data obtained from step S2 is an ECx value and whether it falls within the range of 25% < ECx value ≤ 90%; if both are true, it is selected; otherwise, it is not adopted.
[0019] S3-2. In the ecotoxicity data selected in step S3-1, data with ECx values ranging from 40% to 60% are used directly; data with ECx values ranging from 25% to 40% are used after multiplying by an extrapolation factor; data with ECx values ranging from 60% to 90% are used after dividing by an extrapolation factor; the extrapolation factor is 2.
[0020] Note: By using the above data screening and processing methods, we can select better ecotoxicity data and process the data to a uniform level, making it easier to analyze and calculate.
[0021] Furthermore, field ecotoxicological test data may be used if the following conditions are met: the effect data must come from the same region and the same research period, and the physicochemical properties of the tested soil must be available; sample collection, processing, and storage should follow existing benchmark methods.
[0022] Note: By screening and using field data, the scope of ecotoxicity data collection can be expanded, providing a reference for data research.
[0023] An application of a method for screening and processing soil cadmium environmental ecotoxicity data was demonstrated, which was then applied to studies of species with varying proportions.
[0024] Furthermore, the application method is to establish a species sensitivity distribution model to enable the study of species in multiple proportions;
[0025] The method for establishing the species sensitivity distribution model is as follows: the toxicity data obtained in step S3 are grouped according to the physicochemical properties of the soil, and then the ecotoxicity data of each group are fitted with the logistic stike model to establish the species sensitivity distribution model. The species sensitivity distribution model is as follows (1):
[0026]
[0027] In the formula: x is the EC obtained in step S3-2 50 The value is y, which is the cumulative probability value corresponding to the value of x. a, b, and x0 are all fitting parameters. The fitting parameter values are obtained based on the above model.
[0028] The research method for species with multiple proportions is as follows: using the obtained fitting parameter values, the x values of species with multiple proportions in the ecological environment are derived, as shown in the following formula (2):
[0029]
[0030] Explanation: By using the selected data to simulate the species sensitivity distribution model, fitting parameters can be obtained, which facilitates understanding the sensitivity distribution of ecological species to pollutants based on limited ecotoxicity data. The establishment of the above grouping model makes it easier to analyze the sensitivity distribution of ecological species to pollutants under soils with various physicochemical properties; the x-values of multiple proportional species can be derived using formulas, providing reference values for the study of multiple species, and further expanding the ecotoxicity data.
[0031] Furthermore, the recommended values for soil environmental standards in ecological conservation were determined using the established species sensitivity distribution model. The application method is as follows:
[0032] S1. Draw a species sensitivity distribution map according to the species sensitivity distribution model. In the map, the X-axis is the soil pollutant concentration and the Y-axis is the cumulative distribution probability of ecotoxicity data, that is, the proportion of species affected.
[0033] S2. Using the species sensitivity distribution map obtained in step S1, extrapolate the recommended values of soil environmental standards for ecological protection. The extrapolation method is as follows: set an acceptable ecological risk (PAF) value. The PAF value is determined according to local management standards and policies. Then, based on the PAF value as the cumulative probability value, the critical value x of the corresponding soil pollutant is obtained using the cumulative probability value y of the species sensitivity distribution model. x is then used as the recommended value of the soil environmental standard.
[0034] Note: By applying the above methods, we can extrapolate recommended values for soil environmental standards to protect the ecology based on species sensitivity distribution maps. This can serve as a reference for revising the cadmium baseline environmental pollution baseline values, making the recommended values for soil environmental standards more applicable to actual conditions.
[0035] Furthermore, the application also includes step S3, which involves performing a rationality analysis on the recommended values of the soil environmental standards obtained in step S2. The analysis method is as follows:
[0036] S3-1, Reasonable setting of cadmium standard value
[0037] The evaluation was conducted using a combination of criteria: soil "exceeding standards" and "meeting standards," and plant "exceeding standards" and "meeting standards."
[0038] When both soil and plants meet the standards, it is recorded as A1, which means it is correct; that is, the cadmium content in both soil and plants does not exceed the corresponding evaluation standards, and no abnormalities are found in the cadmium content in the soil. It can be considered that the cadmium in the soil has not affected the quality of crops.
[0039] When both soil and plant cadmium levels exceed the standard, it is recorded as A2, indicating that it is correct. When both soil and plant cadmium levels exceed the corresponding evaluation standards, it can be considered that the abnormal soil cadmium content may have led to excessive plant cadmium levels, affecting plant quality.
[0040] When the soil exceeds the standard but the plants meet the standard, it is recorded as B, which represents a misdiagnosis; that is, the cadmium content in the soil exceeds the evaluation standard, but the cadmium content in the plants does not exceed the standard, the cadmium content in the soil is abnormal, but it can still be considered that the cadmium in the soil has not affected the quality of the plants.
[0041] When the soil meets the standard but the plants exceed the standard, it is marked as C, which represents an error; that is, the soil cadmium content does not exceed the corresponding evaluation standard, but the plant cadmium content exceeds the standard. It can be considered that soil cadmium may affect plant quality, but the soil cadmium pollution evaluation based on cadmium element standards fails to reflect this.
[0042] S3-2. Obtain multiple sets of soil cadmium content values and plant cadmium content values through ecotoxicological tests, and plot a planar graph with soil cadmium content value on the X-axis and plant cadmium content value on the Y-axis.
[0043] Draw two straight lines x = k1 and y = k2. With the intersection of the two lines as the center of a circle, the first quadrant represents A2, the second quadrant represents C, the third quadrant represents A1, and the fourth quadrant represents B.
[0044] Where k1 is the recommended value of soil environmental standard obtained in step S2 or the soil environmental quality standard value obtained from standard literature, and k2 is the standard value of plant cadmium content obtained from standard literature.
[0045] Then, the rationality of the soil environmental standard recommendation value obtained in step S2 is judged based on the percentage of error rate C in the plan view.
[0046] If the error rate C of the recommended value of the soil environmental standard is less than the error rate C of the value of the soil environmental quality standard, then the recommended value of the soil environmental standard is considered reasonable; otherwise, it is considered unreasonable.
[0047] Explanation: Through the above rationality analysis, we can verify the recommended values of soil environmental standards by checking whether the cadmium content in the soil and the plants growing on it exceeds the standard and its impact on plant quality. This allows us to effectively judge the rationality of the recommended values of soil environmental standards.
[0048] Furthermore, the application also includes monitoring the X-axis value of soil pollutant concentration, using the species sensitivity distribution model obtained in step S1 to obtain the corresponding Y-axis value, and then obtaining the proportion of risk-affected species based on the Y-axis value to conduct soil ecological risk assessment.
[0049] Note: By determining the above application method, the proportion of endangered species in risk assessment can be obtained based on the Y-axis value, which facilitates research and the formulation of relevant policies.
[0050] The beneficial effects of this invention are:
[0051] (1) The present invention can screen out better ecotoxicity data through data screening and processing methods, and process the data to a uniform level to make it easier to analyze and calculate; by using the screened data to simulate the species sensitivity distribution model, fitting parameters can be obtained, which makes it easier to grasp the sensitivity distribution of ecological species to pollutants to a greater extent based on limited ecotoxicity data.
[0052] (2) Through the setting of multiple application methods, this invention can derive the x-values of multiple proportional species using formulas, and can further expand the ecotoxicity data; it can also derive the recommended values of soil environmental standards for ecological protection, which can serve as a reference for the revision of the cadmium benchmark environmental pollution benchmark values, making the recommended values of soil environmental standards more applicable to actual conditions; it can also obtain the proportion of risk-affected species based on the Y-axis value, which facilitates research and the formulation of relevant policies; through rationality analysis, it can verify the recommended values of soil environmental standards by whether the cadmium content in the soil and the plants growing on it exceeds the standard and its impact on plant quality, and can effectively judge the rationality of the recommended values of soil environmental standards. Attached Figure Description
[0053] Figure 1 This is a flowchart of the method of the present invention;
[0054] Figure 2 This is a distribution map of species sensitivity in this invention;
[0055] Figure 3 This invention includes a species sensitivity distribution map of extrapolated recommended values for soil environmental standards for ecological protection.
[0056] Figure 4 This is a schematic diagram illustrating the variation of the soil-plant pollution diagnosis scenario with standard values according to the present invention. Detailed Implementation
[0057] The present invention will now be described in more detail with reference to specific embodiments, so as to better demonstrate the advantages of the present invention.
[0058] Soil environmental baselines refer to the maximum limits or critical contents of physical and chemical elements in soil that do not have adverse or harmful effects on soil organisms, crops, health, or use functions; including but not limited to soil environmental baselines for protecting plant safety, human health, ecological receptors, and groundwater; the biotoxicity data collected from the literature includes: biotoxicity data from literature obtained from the ECOTOX toxicity database, biotoxicity data from literature obtained from the CNKI China Journal Full-text Database, and experimental biotoxicity data obtained from laboratory tests. These data are derived from the results of toxicity tests using native Chinese terrestrial organisms. After obtaining the experimental biotoxicity data from the laboratory, the experimental biotoxicity data from soils with different characteristics are converted into standard soil experimental biotoxicity data.
[0059] Example 1
[0060] A method for screening and processing soil cadmium environmental ecotoxicity data includes the following steps:
[0061] S1. Obtain ecotoxicity data
[0062] Ecotoxicity data are obtained through ecotoxicological tests or by searching existing literature. The ecotoxicity data includes data on terrestrial ecological species and data on soil ecological processes.
[0063] The terrestrial ecological species data include: toxicological endpoint data on mortality / stasis, growth, maturation, and reproduction of terrestrial ecological species; the soil ecological process data include: toxicological endpoint data on mortality / stasis and enzyme activity inhibition of soil microorganisms.
[0064] The effect data includes the effect concentration ECx, where x represents the percentage of impact; the terrestrial ecological species include terrestrial plants and invertebrates;
[0065] Field ecotoxicological test data may be used if the following conditions are met: the effect data must be from the same region and the same study period, and the physicochemical properties of the tested soil must be available; sample collection, processing and storage should follow existing benchmark methods.
[0066] S2, Filter Data
[0067] Ecotoxicity data on terrestrial plants, invertebrates, soil microorganisms, and enzyme activity were screened and categorized into multiple groups for separate evaluation.
[0068] In step S1, determine whether the ecotoxicity data obtained through ecotoxicological testing meets internationally recognized method standards. If yes, select the data; otherwise, discard it.
[0069] In step S1, an assessment is made based on the ecotoxicity data obtained by searching existing literature.
[0070] The first judgment method is as follows: determine whether the ecotoxicity data can determine the exposure time and toxicological endpoint of the soil pollutant, whether the corresponding toxic effect data ECx can be estimated based on the dose-response relationship, whether the condition parameters for conducting the toxicological test are recorded, and whether the toxicological effect of the tested pollutant is attributed to the pollutant of concern; among which, the condition parameters are soil pH, organic matter and clay content, and temperature;
[0071] Ecotoxicity data that are all "yes" in the first screening test are filtered out; the rest are removed.
[0072] Take the baseline extrapolated ecotoxicity data from the first screening of ecotoxicity data, determine whether they use the same analytical testing methods, and specify the actual exposure concentration; if yes, retain them; otherwise, remove them.
[0073] S3, Data Processing
[0074] S3-1. Determine whether the ecotoxicity data obtained from step S2 is an ECx value and whether it falls within the range of 25% < ECx value ≤ 90%; if both are true, it is selected; otherwise, it is not adopted.
[0075] S3-2. In the ecotoxicity data selected in step S3-1, data with ECx values ranging from 40% to 60% are used directly; data with ECx values ranging from 25% to 40% are used after multiplying by an extrapolation factor; data with ECx values ranging from 60% to 90% are used after dividing by an extrapolation factor; the extrapolation factor is 2.
[0076] It is applied to the study of species in multiple proportions; by establishing a species sensitivity distribution model, the study of species in multiple proportions can be realized.
[0077] The method for establishing the species sensitivity distribution model is as follows: the toxicity data obtained in step S3 are grouped according to the physicochemical properties of the soil, and then the ecotoxicity data of each group are fitted with the logistic stike model to establish the species sensitivity distribution model. The species sensitivity distribution model is as follows (1):
[0078]
[0079] In the formula: x is the EC obtained in step S3-2 50 The value is y, which is the cumulative probability value corresponding to the value of x. a, b, and x0 are all fitting parameters; the fitting parameter values are obtained according to the above model; for example... Figure 2 As shown;
[0080] Based on the physicochemical properties of the soil, the toxicity data obtained in step S3 are grouped, and then species sensitivity distribution models applicable to soils with various physicochemical properties are established in step S4.
[0081] The application method is as follows: using the values of the fitting parameters obtained in step S4, the x values of multiple proportional species in the ecological environment are derived, as shown in the following formula (2):
[0082]
[0083] Example 2
[0084] The difference between this embodiment and Embodiment 1 is that the species sensitivity distribution model established in Embodiment 1 is further used to determine the recommended values of soil environmental standards for ecological protection. The determination method is as follows:
[0085] S1. Draw a species sensitivity distribution map according to the species sensitivity distribution model. In the map, the X-axis is the soil pollutant concentration and the Y-axis is the cumulative distribution probability of ecotoxicity data, that is, the proportion of species affected.
[0086] S2. Using the species sensitivity distribution map obtained in step S1, extrapolate the recommended values of soil environmental standards for ecological protection. The extrapolation method is as follows: set an acceptable ecological risk (PAF) value. The PAF value is determined based on local management standards and policies; then, using the PAF value as a cumulative probability value, the corresponding critical value x for soil pollutants is obtained using the cumulative probability value y from the species sensitivity distribution model, and x is used as the recommended value for soil environmental standards; for example... Figure 3 As shown, the species sensitivity distribution model obtained in Example 1 is applied to soil ecological risk assessment. By monitoring the value of the soil pollutant concentration on the X-axis, the corresponding value on the Y-axis is obtained using the species sensitivity distribution model obtained in step S1. Then, based on the value of the Y-axis, the proportion of species affected by the risk assessment is obtained.
[0087] Example 3
[0088] The difference between this embodiment and Embodiment 2 is that:
[0089] It also includes step S3, which analyzes the rationality of the recommended values of soil environmental standards obtained in step S2. The analysis method is as follows:
[0090] S3-1, Reasonable setting of cadmium standard value
[0091] The evaluation was conducted using a combination of soil "exceeding standards" and "meeting standards," and plant "exceeding standards" and "meeting standards," with rice being the plant.
[0092] When both soil and plant cadmium meet the standards, it is recorded as A1, which means that the soil and plant cadmium content do not exceed the corresponding evaluation standards and no abnormalities are found in the soil cadmium content. It can be considered that soil cadmium has not affected crop quality.
[0093] When both soil and plant cadmium levels exceed the standard, it is recorded as A2, indicating that it is correct. When both soil and plant cadmium content exceed the corresponding evaluation standards, it can be considered that the abnormal soil cadmium content may have led to excessive plant cadmium levels, affecting plant quality.
[0094] When the soil exceeds the standard but the plants meet the standard, it is recorded as B, which represents a misdiagnosis; that is, the cadmium content in the soil exceeds the evaluation standard, but the cadmium content in the plants does not exceed the standard, the cadmium content in the soil is abnormal, but it can still be considered that the cadmium in the soil has not affected the quality of the plants.
[0095] When the soil meets the standard but the plants exceed the standard, it is marked as C, which represents an error; that is, the soil cadmium content does not exceed the corresponding evaluation standard, but the plant cadmium content exceeds the standard. It can be considered that soil cadmium may affect plant quality, but the soil cadmium pollution evaluation based on cadmium element standards fails to reflect this.
[0096] S3-2. Obtain multiple sets of soil cadmium content values and plant cadmium content values through ecotoxicological tests, and plot a planar graph with soil cadmium content value on the X-axis and plant cadmium content value on the Y-axis.
[0097] Draw two straight lines x = k1 and y = k2. With the intersection of the two lines as the center of a circle, the first quadrant represents A2, the second quadrant represents C, the third quadrant represents A1, and the fourth quadrant represents B.
[0098] Where k1 is the recommended value of soil environmental standard obtained in step S2 or the soil environmental quality standard value obtained from standard literature, and k2 is the standard value of plant cadmium content obtained from standard literature.
[0099] Then, the rationality of the soil environmental standard recommendation value obtained in step S2 is judged based on the percentage of error rate C in the plan view.
[0100] If the error rate C of the recommended value of the soil environmental standard is less than the error rate C of the soil environmental quality standard value, then the recommended value of the soil environmental standard is considered reasonable; otherwise, it is considered unreasonable. Figure 4 As shown.
[0101] Experimental Example
[0102] The species sensitivity distribution model in Example 1 is as follows: Figure 2 As shown, the X-axis represents the soil pollutant concentration, and the Y-axis represents the cumulative distribution probability of ecotoxicity data, i.e., the proportion of affected species (PAF). Each point on the curve represents the correspondence between a certain soil pollutant concentration and the proportion of ecological species that may be affected at that concentration.
[0103] Example 2: Species Sensitivity Distribution Model Figure 3 As shown in the figure, the different arrow directions indicate different application processes of SSB; for agricultural land that is expected to protect 90% of ecological species from the harm of soil pollution, the PAF is set to 0.1, that is, the cut-off point of the Y-axis in the figure is 0.1. The critical x value of soil pollutants can be deduced from the cumulative probability distribution function in the figure.
[0104] Example 3 Figure 4 The diagram shows the variation of soil-rice pollution diagnostic scenarios with standard values. In the diagram, x = 0.3 and y = 0.2 represent soil cadmium content of 0.3 mg / kg and rice cadmium content of 0.2 mg / kg, respectively. Assuming x = 0.3 is the soil environmental quality standard, the sample quantity will change in the four scenarios ("Correct (A1)", "Correct (A2)", "Misdiagnosed (B)", and "Incorrect (C)") as x moves.
[0105] Following the analytical method of Example 3, and using GB3762-2017 as the reference rice standard, and based on the soil standard values of GB15618-1995 and the recommended soil environmental standard values obtained in Example 2, cadmium pollution was diagnosed in actual soil-rice samples. The cadmium pollution diagnosis scenarios are shown in Table 1.
[0106] Table 1. Diagnostic results of different cadmium standard values for soil-rice contamination.
[0107] Standard types GB15618-1995 Recommended Standards Accuracy (A1) 24.25％ 30.84％ Accuracy (A2) 44.01％ 38.32％ Misdiagnosis rate (B) 6.29％ 11.98％ Error rate (C) 25.45％ 18.86％
[0108] According to GB15618-1995, the standard values for soil with pH ≤ 7.5 and pH > 7.5 are 0.3 and 0.6 mg / kg, respectively; the recommended standards are 0.3, 0.4, 0.6, and 0.8 mg / kg for soil with pH ≤ 5.5, 5.5 < pH ≤ 6.5, 6.5 < pH ≤ 7.5, and pH > 7.5, respectively.
[0109] Based on the results of exceeding the standards in Table 1, the accuracy rate (A1+A2) of the recommended soil environmental standard values in Example 2 is 69.16%, which is higher than the 68.26% of the standard value diagnosis result in GB15618-1995, and the error rate (C) is lower than that in GB15618-1995. Considering the protection of rice quality and safety as the main factor, the recommended standard in Example 2 is better than GB15618-1995. Therefore, the recommended soil environmental standard values in Example 2 are considered reasonable.
Claims
1. A method for screening and processing soil cadmium environmental ecotoxicity data, characterized in that, Includes the following steps: S1. Obtain ecotoxicity data Ecotoxicity data are obtained through ecotoxicological tests or by searching existing literature. The ecotoxicity data includes data on terrestrial ecological species and data on soil ecological processes. The terrestrial ecological species data include: toxicological endpoint data on mortality / stasis, growth, maturation, and reproduction of terrestrial ecological species; the soil ecological process data include: toxicological endpoint data on mortality / stasis and enzyme activity inhibition of soil microorganisms. The effect data includes the effect concentration ECx, where x represents the percentage of impact; the terrestrial ecological species include terrestrial plants and invertebrates; S2, Filter Data Ecotoxicity data on terrestrial plants, invertebrates, soil microorganisms, and enzyme activity were screened and categorized into multiple groups for separate evaluation. In step S1, determine whether the ecotoxicity data obtained through ecotoxicological testing meets internationally recognized method standards. If yes, select the data; otherwise, discard it. In step S1, an assessment is made based on the ecotoxicity data obtained by searching existing literature. The first judgment method is as follows: determine whether the ecotoxicity data can determine the exposure time and toxicological endpoint of the soil pollutant, whether the corresponding toxic effect data ECx can be estimated based on the dose-response relationship, whether the condition parameters for conducting the toxicological test are recorded, and whether the toxicological effect of the tested pollutant is attributed to the pollutant of concern; among which, the condition parameters are soil pH, organic matter and clay content, and temperature; Ecotoxicity data that are all "yes" in the first screening test are filtered out; the rest are removed. Take the baseline extrapolated ecotoxicity data from the first screening of ecotoxicity data, determine whether they use the same analytical testing methods, and specify the actual exposure concentration; if yes, retain them; otherwise, remove them. S3, Data Processing S3-1. Determine whether the ecotoxicity data obtained from step S2 is an ECx value and whether it falls within the range of 25% < ECx value ≤ 90%; if both are true, it is selected; otherwise, it is not adopted. S3-2. In the ecotoxicity data selected in step S3-1, data with ECx values ranging from 40% to 60% are used directly; data with ECx values ranging from 25% to 40% are used after multiplying by an extrapolation factor; data with ECx values ranging from 60% to 90% are used after dividing by an extrapolation factor; the extrapolation factor is 2. S4. By establishing a species sensitivity distribution model, research on species in multiple proportions can be achieved; The method for establishing the species sensitivity distribution model is as follows: the toxicity data obtained in step S3 are grouped according to the physicochemical properties of the soil, and then the ecotoxicity data of each group are fitted with the logistic stike model to establish the species sensitivity distribution model. The species sensitivity distribution model is as follows (1): In the formula: x is the EC obtained in step S3-2 50 The value is y, which is the cumulative probability value corresponding to the value of x. a, b, and x0 are all fitting parameters. The fitting parameter values are obtained based on the above model. The method for studying species in multiple proportions is as follows: using the obtained fitting parameter values, the x values of species in multiple proportions in the ecological environment are derived, as shown in the following formula (2):
2. The method for screening and processing soil cadmium environmental ecotoxicity data as described in claim 1, characterized in that, Ecotoxicological data from field trials may be used if the following conditions are met: the effect data must be from the same region and the same research period, and the physicochemical properties of the tested soil must be available; sample collection, processing, and storage should follow existing benchmark methods.
3. The application of the soil cadmium environmental ecotoxicity data screening and processing method as described in claim 1, characterized in that, It was applied to studies of species in multiple proportions.
4. The application of the soil cadmium environmental ecotoxicity data screening and processing method according to claim 3, characterized in that, The recommended values for soil environmental standards in ecological conservation were further determined using the established species sensitivity distribution model. The determination method was as follows: S1. Draw a species sensitivity distribution map according to the species sensitivity distribution model. In the map, the X-axis is the soil pollutant concentration and the Y-axis is the cumulative distribution probability of ecotoxicity data, that is, the proportion of species affected. S2. Using the species sensitivity distribution map obtained in step S1, extrapolate the recommended values of soil environmental standards for ecological protection. The extrapolation method is as follows: set an acceptable ecological risk (PAF) value. The PAF value is determined according to local management standards and policies. Then, based on the PAF value as the cumulative probability value, the critical value x of the corresponding soil pollutant is obtained using the cumulative probability value y of the species sensitivity distribution model. x is then used as the recommended value of the soil environmental standard.
5. The application of the soil cadmium environmental ecotoxicity data screening and processing method as described in claim 4, characterized in that, Also includes: S3. Conduct a rationality analysis on the recommended values of soil environmental standards obtained in step S2. The analysis method is as follows: S3-1, Reasonable setting of cadmium standard value The evaluation was conducted using a combination of criteria: soil "exceeding standards" and "meeting standards," and plant "exceeding standards" and "meeting standards." When both soil and plants meet the standards, it is recorded as A1, which means it is correct; that is, the cadmium content in both soil and plants does not exceed the corresponding evaluation standards, and no abnormalities are found in the cadmium content in the soil. It can be considered that the cadmium in the soil has not affected the quality of crops. When both soil and plant cadmium levels exceed the standard, it is recorded as A2, indicating that it is correct. When both soil and plant cadmium levels exceed the corresponding evaluation standards, it can be considered that the abnormal soil cadmium content may have led to excessive plant cadmium levels, affecting plant quality. When the soil exceeds the standard but the plants meet the standard, it is recorded as B, which represents a misdiagnosis; that is, the cadmium content in the soil exceeds the evaluation standard, but the cadmium content in the plants does not exceed the standard, the cadmium content in the soil is abnormal, but it can still be considered that the cadmium in the soil has not affected the quality of the plants. When the soil meets the standard but the plants exceed the standard, it is marked as C, which represents an error; that is, the soil cadmium content does not exceed the corresponding evaluation standard, but the plant cadmium content exceeds the standard. It can be considered that soil cadmium may affect plant quality, but the soil cadmium pollution evaluation based on cadmium element standards fails to reflect this. S3-2. Obtain multiple sets of soil cadmium content values and plant cadmium content values through ecotoxicological tests, and plot a planar graph with soil cadmium content value on the X-axis and plant cadmium content value on the Y-axis. Draw two straight lines x = k1 and y = k2. With the intersection of the two lines as the center of the circle, the first quadrant represents A2, the second quadrant represents C, the third quadrant represents A1, and the fourth quadrant represents B. Among them, the value of k1 is the recommended value of soil environmental standard obtained in step S2 or the soil environmental quality standard value obtained from standard literature, and the value of k2 is the standard value of plant cadmium content obtained from standard literature. Then, the rationality of the recommended soil environmental standard value obtained in step S2 is judged based on the percentage of error rate C in the plan view; if the error rate C of the recommended soil environmental standard value is less than the error rate C of the soil environmental quality standard value, the recommended soil environmental standard value is considered reasonable, otherwise it is considered unreasonable.
6. The application of the soil cadmium environmental ecotoxicity data screening and processing method as described in claim 5, characterized in that, Also includes: S4. By monitoring the X-axis value of soil pollutant concentration, the corresponding Y-axis value is obtained using the species sensitivity distribution model obtained in step S1. Then, based on the Y-axis value, the proportion of species affected by risk assessment is obtained to conduct soil ecological risk assessment.