Chemical industrial park groundwater health risk grading early warning method and system based on double-threshold determination

Abstract

The invention discloses a chemical industry park groundwater health risk grading early warning method and system based on double threshold determination. The method focuses on an inhalation exposure approach, and preliminary screening is carried out by comparing the pollutant concentration with a standard limit value. And for excessive pollutants, checking the integrity of toxicity parameters of the excessive pollutants, if the toxicity parameters are effective, calculating a carcinogenic risk index CR and a non-carcinogenic hazard index HI, and if the toxicity parameters are ineffective, marking. The core of the method is that a refined risk judgment threshold is adopted: a high risk threshold of CR is set as 1E-6, and a medium risk threshold of CR is set as 1E-7; the high risk threshold value of the HI is set to be 1, and the medium risk threshold value of the HI is set to be 0.1. During comprehensive judgment, if both CR and HI have values, respectively judging and then taking the grade with higher risk as the final grade; and if all the parameters are invalid, judging that the toxic parameters are not available. The results are visualized in different colors. According to the method, risk fine grading early warning is realized, the fault-tolerant capability for toxicity parameter deficiency is realized, the database is extensible, and the accuracy, practicability and operability of chemical industry park groundwater risk assessment are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of environmental health risk assessment technology, specifically to a method and system for classifying and warning of health risks of groundwater pollutants in chemical industrial parks and focusing on inhalation exposure pathways, and particularly to an intelligent assessment scheme that uses specific risk thresholds and combines toxicity parameter error tolerance processing. Background Technology

[0002] Currently, China's health risk assessment of groundwater pollutants mainly refers to the risk assessment models and parameter systems recommended in the "Technical Guidelines for Risk Assessment of Soil Pollution in Construction Land (HJ 25.3-2019)". These guidelines essentially borrow from and localize the risk assessment framework of the U.S. Environmental Protection Agency (USEPA), calculating the carcinogenic risk index (CR) and non-carcinogenic hazard quotient (HI) of a single pollutant through multiple exposure pathways (such as oral ingestion, skin contact, and inhalation of outdoor / indoor air).

[0003] However, when applying this general model to groundwater risk assessment in a specific type of site such as a chemical industrial park, the following limitations exist: First, the exposure scenarios in chemical industrial parks are unique in terms of the applicability of exposure pathways. The drinking water for workers in these parks is typically supplied centrally, resulting in a low risk of direct ingestion of contaminated groundwater. Furthermore, their occupational activities limit long-term skin contact with groundwater. Therefore, the most dominant and concerning health risk exposure pathway in this scenario is the inhalation of pollutants through groundwater volatilization and penetration into building interiors (i.e., "vapor intrusion"). While current general models include inhalation pathways, they lack optimization and parameter focus specifically for this dominant pathway in chemical industrial parks, leading to a relatively complex and inefficient assessment process.

[0004] Secondly, regarding the refinement of risk levels and the determination thresholds, the current guidelines mainly focus on whether the risk exceeds an acceptable level (usually using CR=1×10⁻). 6 (HI=1 as a reference threshold) lacks a standardized threshold system for finely classifying risk levels into high, medium, and low. This binary "pass / fail" judgment model is insufficient to support the risk classification and priority governance decisions required for environmental management in chemical industrial parks.

[0005] A more prominent issue is the ability to handle missing toxicity parameters. Chemical industrial parks often involve a large number of characteristic pollutants (such as specific intermediates and byproducts), whose key toxicity parameters (such as the carcinogenicity slope factor SF and reference dose RfD for inhalation) may be missing from existing databases. Current technical systems typically address such omissions by directly skipping them or using parameters from irrelevant pathways as default values. These methods have significant drawbacks: skipping them can lead to the complete neglect of potential risks; and using inappropriate default values ​​(such as using oral toxicity data instead of inhalation data) can introduce serious errors and distort risk assessment results.

[0006] Furthermore, existing assessment tools or systems are mostly based on static, closed databases. When new toxicological research findings are published, standard limits are updated, or new characteristic pollutants are discovered, the system struggles to integrate this latest data in a timely and convenient manner, causing assessment results to lag behind scientific and cognitive advancements.

[0007] Therefore, there is an urgent need for a dedicated groundwater health risk assessment method and system that can closely integrate with the actual exposure characteristics of chemical industrial parks, establish refined risk classification thresholds, intelligently handle missing toxicity parameters, and have good scalability. This would compensate for the shortcomings of existing general methods in this specific application scenario, improve the pertinence, accuracy, completeness, and timeliness of risk assessment, and provide effective technical support for precise environmental risk management in chemical industrial parks. Summary of the Invention

[0008] The technical problem to be solved by this invention is to overcome the shortcomings of existing technologies, such as coarse risk level classification, sensitivity to missing toxicity parameters, and lagging database updates, and to provide a hierarchical early warning method and system based on clear dual risk thresholds and with fault tolerance and scalability. A method for classifying and early warning of groundwater health risks in chemical industrial parks, characterized by comprising the following steps:

[0009] S1: Build and maintain at least three core databases: a "standard database" containing standard limits for pollutants, a "calculation parameter database" containing calculation parameters of pollutant inhalation pathways (including but not limited to carcinogenic slope factor SF and reference dose RfD), and an "interactive database" for receiving user input and displaying results.

[0010] S2: Obtain the measured concentration data of each pollutant in the groundwater of the target area from the "interactive database".

[0011] S3: For each pollutant, first query the "Standard Database" to obtain its standard limit, and then compare the measured concentration with the standard limit: If the measured concentration is ≤ the standard limit, the risk level of the pollutant is directly determined to be "low risk (below the standard limit)", and the subsequent calculation for the pollutant ends. If the measured concentration is greater than the standard limit or there is no standard limit, proceed to step S4.

[0012] S4: Query the calculated parameters for this pollutant from the "Calculated Parameter Database" and perform a parameter integrity check: S4.1: Check the validity of the carcinogenic slope factor SF parameter. If the SF parameter is valid (non-empty and greater than 0), calculate the carcinogenic risk values ​​CRiov3, CRiiv2, and CR total according to the preset carcinogenic risk model; if the SF parameter is invalid (empty or equal to 0), mark the calculation results of the carcinogenic risk values ​​CRiov3, CRiiv2, and CR total as "lacking toxicity parameters".

[0013] S4.2: Check the validity of the reference dose RfD parameter. If the RfD parameter is valid (not empty and greater than 0), calculate the non-carcinogenic hazard indices HQiov3, HQiiv2, and HI total according to the preset non-carcinogenic risk model; if the RfD parameter is invalid (empty or equal to 0), mark the calculation results of the non-carcinogenic hazard indices HQiov3, HQiiv2, and HI total as "lacking toxicity parameters".

[0014] S5: Based on the calculation or labeling results of step S4, determine the comprehensive risk level: If both the total CR and the total HI have valid numerical results, then risk classification is performed according to the preset CR and HI risk thresholds, and the higher risk level is taken as the final level. If only the total risk (CR) has a valid numerical result, then the risk level is determined based on the total risk threshold of the CR. If only HI has a valid numerical result, then the risk level is classified according to the risk threshold of HI. If both CR and HI are marked as "lacking toxicity parameters", the final risk level will be determined as "lacking toxicity parameters".

[0015] S6: The concentration data of each pollutant, the calculation results (CRiov3, CRiiv2, CRtotal, HQiov3, HQiiv2, HItotal) and the final risk level are structured and output to the "interactive database" for visualization, and different color labels are applied to the results of different risk levels.

[0016] Further, the carcinogenic risk model in step S4.1 is: CRiov3 = IOVERca3 × Cgw ×SF; CRiiv2 = IIVERca2 × Cgw × SF; CRtotal = CRiov3 + CRiiv2; where Cgw is the pollutant concentration after unit conversion.

[0017] The non-carcinogenic risk model in step S4.2 is: HQiov3 = IOVERnc3 × Cgw / RfD / k; HQiiv2 = IIVERnc2 × Cgw / RfD / k; HItotal = HQiov3 + HQiiv2; where k is the allocation coefficient, preferably 0.5.

[0018] The "standard database" and "calculation parameter database" are open databases that allow users to dynamically expand the types of pollutants based on the latest research or standards, and to supplement or update the toxicity parameters and standard limits of existing pollutants without modifying the core logic of the system.

[0019] The present invention also provides a system for implementing the above method, characterized in that it comprises: The data management module is used to maintain the "standard database", "calculation parameter database" and "interactive database", wherein the standard database and the calculation parameter database adopt an open and editable structure; The input processing module is used to receive and verify the pollutant concentration data entered by the user in the "interactive database"; The standard comparison module is used to perform step S3 to realize automatic comparison and primary screening of pollutant concentration with standard limits; The core calculation module is used to execute the step S4, including a parameter checking submodule, a carcinogenic risk calculation submodule, and a non-carcinogenic risk calculation submodule, and implements the function of marking the missing toxicity parameters; The risk assessment module is used to execute step S5, and to make a comprehensive level determination based on the output of the calculation module and the application of preset risk threshold logic. The result output module is used to execute step S6, fill the calculation results and judgment level back into the "interactive database", and control the color rendering of the visualization interface.

[0020] Fault tolerance and practicality: By introducing an intelligent tagging mechanism for missing toxicity parameters ("missing toxicity parameters"), the system can still run even when the database is incomplete, and clearly prompts users to identify the problem. This avoids the evaluation process being interrupted due to a single point of data loss, and greatly improves the system's availability in real-world complex scenarios.

[0021] Comprehensive risk assessment and rigorous logic: A two-tiered evaluation process is employed, involving first comparing the pollutant to standards and then performing item-by-item calculations. Even if subsequent calculations cannot be performed due to missing parameters, the pollutant will still be a key focus as long as its concentration exceeds the standard limit. The judgment logic follows the principles of "judging if there is a result, partially judging if there is a partial result, and explicitly warning if there are no results" and "taking the highest risk," ensuring safe and reliable conclusions.

[0022] Highly targeted to specific scenarios: The method focuses on the most important "inhalation" exposure pathways in chemical industrial parks, simplifies the model, makes the required parameters clearer, and makes the assessment more targeted and efficient.

[0023] The results are clear and intuitive: the results are visualized through differentiated colors (such as red, yellow, green, and gray) and clear text labels, making high-risk objects and problem data clear at a glance, which facilitates quick decision-making.

[0024] Excellent scalability and forward-looking capabilities: The system's database adopts an open design, allowing users to easily add new pollutants or update parameters based on the latest scientific research findings, achieving "add and use immediately." This ensures that the system can keep pace with the times, continuously absorb the latest scientific data, significantly enhance its ability to address the risks of emerging pollutants, and extend the system's technological lifecycle.

[0025] Integrated and easy to use: It integrates database management, intelligent comparison, dual-path fault-tolerant calculation and result visualization into one system (such as based on Excel VBA and other platforms), which lowers the professional threshold and is particularly suitable for grassroots environmental protection departments and park management agencies to carry out rapid, batch and sustainable risk assessment work. Attached Figure Description

[0026] Fig. 1 This is an overall flowchart of the method described in this invention.

[0027] Fig. 2 This is a logical diagram of the core calculation and judgment module in the system described in this invention.

[0028] Fig. 3 This is a schematic diagram of the interface of a specific implementation of the system described in this invention on the Excel platform, showing the data table, button controls, and result color indicators. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0030] like Figs. 1-3 As shown, this embodiment implements the system on the Microsoft Excel platform using the VBA (Visual Basic for Applications) programming language.

[0031] Database construction and extension: Create three editable worksheets in the Excel workbook, named "Existing Standards Database," "Risk Calculation Database," and "Input and Calculation Results," respectively. The "Risk Calculation Database" column structure includes pollutant ID, name, CAS number, IOVERca3, IIVERca2, IOVERnc3, IIVERnc2, SF, RfD, etc. The "Standards Database" contains pollutant names and standard limits. Users can directly add new pollutant rows or modify existing data in these worksheets based on the latest documents or research literature, such as the "Technical Guidelines for Risk Assessment of Contaminated Sites," to expand and update the system's knowledge base.

[0032] Method and process implementation: a) Users enter the measured concentration (μg / L) of each pollutant in column D of the “Input and Calculation Results” worksheet.

[0033] b) When a user triggers a calculation command (such as clicking a dedicated button), the system starts the evaluation process.

[0034] c) For each pollutant in the list, the system automatically matches and compares its standard limit from the "Existing Standard Database". If the standard is met, "Low Risk (below the standard limit)" is filled in directly, and the background of that row is set to green.

[0035] d) For pollutants that fail to meet the standards, the system reads their calculation parameters from the "Risk Calculation Database". If SF=0 or is empty, "Missing toxicity parameter" is entered in the CR-related result cells (columns E, F, G); if RfD=0 or is empty, "Missing toxicity parameter" is entered in the HI-related result cells (columns H, I, J); if the parameter is valid, the corresponding calculation is performed and the value is entered.

[0036] e) Based on the results of c) and d), the system determines the risk level according to preset thresholds (e.g., CR>1E-6 is high risk, HI>1 is high risk, etc.) and fills the results into the "Risk Level" column (column K). The results for "Missing toxicity parameters" will also be filled into this column.

[0037] f) The system automatically sets the background color for each row of data based on the text content of the "Risk Level" column: red represents "high risk", yellow represents "medium risk", green represents "low risk", and gray represents "lacking toxicity parameters". Simultaneously, the system automatically counts the number of entries for each level and displays a statistical summary in a pop-up window.

[0038] Example of dynamic expansion operation: When adding a new substance named "Example Pollutant X", the administrator simply adds a new row at the end of the "Risk Calculation Database" worksheet, fills in its parameters (fill in 0 for missing parameters), and enters its standard limit in the "Existing Standards Database" (leave blank if none exists). Then, clicking the "Refresh List" button on the "Input and Calculation Results" interface will add the pollutant to the evaluation list for assessment. This process requires no modification to any VBA code.

Claims

1. A method and system for classifying and early warning of groundwater health risks in chemical industrial parks based on dual threshold determination, characterized in that, Includes the following steps: Steps for obtaining pollutant concentration data; Standard limit comparison steps; Parameter checking and grading calculation steps; The comprehensive risk level determination process is based on preset refined risk assessment thresholds, which include: Cancer risk (CR) assessment threshold: Set the first threshold T_CR_high = 1×10⁻ 6 The second threshold T_CR_mid = 1×10⁻ 7 When CR > T_CR_high, it is judged as high risk; when T_CR_mid < CR ≤ T_CR_high, it is judged as medium risk; when CR ≤ T_CR_mid, it is judged as low risk. Non-carcinogenic hazard index (HI) determination thresholds: set the first threshold T_HI_high = 1, and the second threshold T_HI_mid = 0.1; when HI > T_HI_high, it is determined to be high risk; when T_HI_mid < HI ≤ T_HI_high, it is determined to be medium risk; when HI ≤ T_HI_mid, it is determined to be low risk. When making a comprehensive judgment, if both CR and HI have valid values, the higher risk level will be selected as the final risk level after each judgment.

2. The method according to claim 1, characterized in that, In the standard limit comparison step, if the measured concentration is lower than or equal to the standard limit, it is directly determined to be of low risk level.

3. The method according to claim 1, characterized in that, In the parameter checking and grading calculation steps, if the carcinogenic slope factor SF is invalid, the carcinogenic risk-related results are marked as missing; if the reference dose RfD is invalid, the non-carcinogenic hazard index-related results are marked as missing.

4. The method according to claim 1, characterized in that, The comprehensive risk level determination step further includes: if both CR and HI are marked as missing, the final risk level is determined as the level of missing characterization parameters.

5. The method according to claim 1, characterized in that, It also includes a results visualization step, which uses different colors to identify different final risk levels.

6. A system for implementing the method as described in any one of claims 1-5, characterized in that, include: The module includes a data management module, a standard comparison module, a core calculation module, a risk assessment module, and a result output module.

7. The system according to claim 6, characterized in that, The system is built on a spreadsheet software platform.

8. The system according to claim 6, characterized in that, The result output module is configured to use different colors to indicate different risk levels.

9. The system according to claim 6, characterized in that, The database maintained by the data management module has an open structure, which allows for dynamic expansion of pollutant types and updating of parameters.

10. A medium storing a computer program, which, when executed by a processor, implements the method as described in any one of claims 1-5.

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