Method for testing and evaluating the level of microbial contamination of the environment of a residential area based on a spatiotemporal interface

Abstract

The method for testing and evaluating the microorganism pollution level of residential environment based on space-time interface belongs to the technical field of residential environment, microorganism testing and microorganism pollution level evaluation. The method plans the three-dimensional scale of residential environment in units of buildings, clearly defines five space-time interfaces of the residential environment, stipulates the data collection method of different interfaces, and the collected data accurately reflects the microorganism pollution level of the environment. The method for testing and evaluating the microorganism pollution level of residential environment based on space-time interface is proposed, and the correlation between each data and the calculation principle of the correlation coefficient are clearly defined. The method can be applied to residential areas with similar space-time interfaces, and the size of the evaluation result reflects the level of health risk of the residential area, and has strong universality. The method is a systematic evaluation of the microorganism pollution level under the space-time scale of the residential building, and is a key supplement to the evaluation system of the residential environment.

Description

Technical Field

[0001] This invention relates to a method for testing and evaluating the level of microbial pollution in residential environments based on a spatiotemporal interface, which belongs to the technical field of residential environmental assessment. Background Technology

[0002] Currently, with improved living standards and increased knowledge, residents are paying more attention to their residential environment. Microorganisms pose a significant challenge to human health due to their sudden onset and pathogenicity, making real-time monitoring, similar to that for particulate matter pollution, impossible. Apartments, as primary locations for the gathering and dispersal of people, face a high risk of microbial (bacteria, fungi, and viruses) infection. Therefore, developing a testing system and assessment methods for residential microbial environmental pollution levels is of great practical significance. Current industry attention to residential environmental pollutants mainly focuses on indoor (CN109902972A) and outdoor (CN115600789A) environments, or a combination of both (indoor / outdoor: CN114708968A). These existing technologies have been extensively discussed and studied for both indoor and outdoor conditions, proposing related pre-evaluation and evaluation methods. Compared to particulate or VOCs pollutants, microbial pollution poses a higher potential threat to human health. Apartments, as residents' long-term living environments, currently lack a comprehensive testing and evaluation system for overall microbial pollution levels, which is a necessary component for assessing microbial risks. Summary of the Invention

[0003] Currently, detection technologies or evaluation methods in the field of residential pollution mainly focus on cities, towns, and streets, or conduct independent detection or evaluation with indoor and outdoor environments as reference objects. There is a lack of a detection and evaluation method that takes a relatively complete residential environment as the object.

[0004] This invention provides a testing system and evaluation method for the level of microbial contamination in residential areas based on spatiotemporal interfaces, aiming to solve the problems of unscientific and incomplete testing and evaluation of microbial contamination levels in apartments. This invention determines the microbial testing system using methods of population density and spatial probability, and determines the evaluation method for the level of microbial contamination in apartment environments based on data from five spatiotemporal interfaces. This invention will provide a relatively accurate and reliable assessment of the level of microbial contamination in apartments.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for testing and evaluating the level of microbial pollution in residential environments based on a spatiotemporal interface, the method comprising:

[0006] (1) Determine the testing system. The testing system includes the spatiotemporal interface and its corresponding data acquisition method. Based on the intuitiveness of the data, it is divided into explicit data that directly shows the level of microbial contamination and implicit data that is related to the level of microbial contamination.

[0007] (2) The spatiotemporal interface includes: apartment entrance, elevator entrance, elevator exit, residential entrance, and residential exit; (3) Collection method: the arrangement method of airborne bacteria sampling points is determined based on the spatial probability of pedestrian flow, the location of sedimentation bacteria sampling points is determined according to the spatial structure characteristics of the spatiotemporal interface, and the sampling duration and sampling frequency are determined according to the characteristics of pedestrian flow.

[0008] (4) Determine the assessment method: Based on the microbial pollution data of the residential environment using the spatiotemporal interface, obtain the weight coefficients of each data item. Based on the obtained weight coefficients of each item and the scores of the microbial pollution data, obtain the comprehensive assessment result of the microbial pollution level of the residential environment based on the spatiotemporal interface.

[0009] The method for arranging the airborne bacteria sampling points involves analyzing monitoring images to determine the space (excluding residential exits) through which more than 80% of people pass at the corresponding spatiotemporal interface. Using the midpoint of this space horizontally and 0.8m vertically as reference points, the airborne bacteria sampling points at the apartment entrance are located 0.5–1.5m after the reference point, the airborne bacteria sampling points at the elevator entrance are located 0.5–1.5m before the reference point, the airborne bacteria sampling points at the elevator exit are located 0.5–1.5m before the reference point, and the airborne bacteria sampling points at the residential entrance are located at the center of the space. The space at the residential exit is its actual size, and the airborne bacteria sampling point at the exit is located at the center of the exit.

[0010] The sampling points for sedimentation bacteria are located at the lower edge of the spatiotemporal interface on both sides of the interface, in the same plane as the spatiotemporal interface. The number of culture dishes on each side should be greater than 2. During static testing, the exposure time of the culture dishes should be more than 30 minutes. During dynamic testing, the exposure time of the culture dishes should not exceed 4 hours.

[0011] Furthermore, in the arrangement of airborne bacteria sampling points, if the width L of the space is greater than 1m, the number of airborne bacteria sampling points in the width direction is increased, and the number N of sampling points is:

[0012]

[0013] Where L is the width of the space in the horizontal direction. This is the floor function of the width of the space in the horizontal direction;

[0014] The sampling point width direction position distribution is located at respectively At this location, the average value of the airborne bacteria data from all sampling points is the average concentration of airborne bacteria.

[0015] Furthermore, the assessment method in step (4) is as follows: assess the level of microbial contamination in the residential area according to formula (2).

[0016]

[0017] Where W1 is the pollution assessment result at the apartment entrance, W2 is the pollution assessment result at the elevator entrance, W3 is the pollution assessment result at the elevator exit, W4 is the pollution assessment result at the residential entrance, and W5 is the pollution assessment result at the residential exit.

[0018] Z n-1 The average transit time from the (n-1)th spacetime interface to the nth spacetime interface, where n is a positive integer from 2 to 5;

[0019] T represents the complete contact time, which is the infection time of one pathogenic microorganism or the shortest infection time of multiple pathogenic microorganisms in the apartment. The coefficients of W1-W4 in the equation are determined by the ratio of the average transit time Z to the complete contact time T. Since people spend a lot of time indoors, the coefficient of W5 is determined based on the residents' living habits. K is the average value of the coefficients of W1-W4. G represents the assessment result of the microbial contamination level of the apartment area.

[0020] Furthermore, W i It is the total concentration of airborne bacteria and settled bacteria obtained by correcting the natural sedimentation method of the Auerbach formula in a certain spatiotemporal interface, where i is a positive integer from 1 to 5; that is, the pollution assessment result at a certain spatiotemporal interface.

[0021]

[0022] Where A is the correction factor for airborne bacteria at the sampling point, F is the concentration of airborne bacteria at the sampling point, N is the number of airborne bacteria samples, B is the correction factor for settling bacteria at the sampling point, C is the concentration of settling bacteria at the sampling point, M is the number of settling bacteria samples, and R is the risk factor for settling bacteria.

[0023] The explicit data is the microbial concentration; the implicit data includes temperature, humidity, and wind speed.

[0024] When there are multiple spatiotemporal interfaces with the same function, the coefficients are determined according to the proportion of people flow density, and the sum of all coefficients is 1.

[0025] The sampling duration and frequency were determined based on the periodicity and density of pedestrian traffic. The sampling duration was determined based on the periodicity to ensure the integrity of the sampling results; the sampling frequency was determined based on the pedestrian traffic density to analyze the correlation between microbial contamination levels and individual individuals, and to identify the factors influencing data changes.

[0026] The beneficial effects of this invention are: it proposes a standardized testing system and evaluation method for microbial contamination in apartment-style residential areas, which is beneficial for the quantitative assessment of microbial contamination in these areas. This transforms laboratory test results into assessable, quantifiable, and scientifically valuable reference results. These results can be used to assess the microbial safety level of apartment-style residential buildings, and also to effectively assess the microbial safety level of spaces between two spatiotemporal interfaces.

[0027] From a social value perspective, the results measured at each spatiotemporal interface of this invention can be compared horizontally, and property management companies or relevant practitioners can conduct targeted optimization based on the level of microbial pollution in the residential area to ensure a healthy living environment for residents.

[0028] From an economic perspective, this invention can effectively assess the health level of a residential area and allow for horizontal comparison with similar residential areas. The assessment results provide an index-based representation of the health level of the residential area, which can be: the basic pollution assessment results for each floor after the elevator exit, the basic pollution assessment results for each household after entering the residence, or the basic pollution assessment results for the entire process of an individual residence after exiting the residence. This provides a new, important, and scientific reference for real estate sales and customization.

[0029] In summary, assessing the level of microbial contamination in apartments helps quantify the risk of microbial infection in residential areas, enabling residents and community managers to take appropriate measures to improve the environment, and facilitating the enhancement of residents' biosafety awareness and reduction of the risk of microbial infection. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 This is a flowchart for assessing environmental microbial contamination in apartment residential areas. Detailed Implementation

[0032] Before conducting the assessment, it is necessary to confirm whether the assessment object is a residential environment and whether its spatiotemporal interface is complete. If it is a residential environment and its spatiotemporal interface is complete, this method can be used for assessment; otherwise, this method is not suitable for assessment.

[0033] Then, the information of the apartment to be evaluated is determined, including the spatial location and size of the five spatiotemporal interfaces, as well as the corresponding pedestrian flow characteristics at each location, and then a series of related data collection and microbial contamination level assessments are conducted:

[0034] Spatial location information includes the geometric dimensions and spatial distances of each spatiotemporal interface, while the characteristics of pedestrian flow are the periodicity of passage through each spatiotemporal interface and the density of pedestrian flow.

[0035] The method for determining the data collection location is based on the probability of a person passing through the spatiotemporal interface, which is correlated with the type of apartment opening (e.g., double doors, sliding doors, single doors). To ensure scientific data collection, the space through which more than 80% of people pass (excluding residential exits) at the corresponding spatiotemporal interface is determined based on monitoring image analysis. The actual dimensions of the space through the residential exits are used as the reference point. The risk coefficient R of settling bacteria for people passing through the spatiotemporal interface is determined by the distance from this reference point to the edge of the spatiotemporal interface.

[0036] The airborne bacteria measurement point at the apartment entrance is located 0.5–1.5 m after passing the spatial reference point; the airborne bacteria measurement point at the elevator entrance is located 0.5–1.5 m before passing the spatial reference point; the airborne bacteria measurement point at the elevator exit is located 0.5–1.5 m before passing the spatial reference point; the airborne bacteria measurement point at the residential entrance is located at the spatial reference point; and the airborne bacteria measurement point at the residential exit is located at the exit reference point. The sampling flow rate should be greater than 100 L / sample (GB / T16293-2010). During static testing, if the airborne bacteria concentration at a certain sampling point cannot be observed, two resamplings should be performed. Only if both test results are qualified can the test be considered compliant.

[0037] If the horizontal width (L) of the space is greater than 1m, the number of sampling locations in the width direction of the planktonic bacteria should be appropriately increased, and the number of sampling locations (N) should conform to Equation 1. The locations are distributed as follows: At this location, the mean value of the airborne bacteria data from all sampling points is the average concentration of airborne bacteria. The risk factor for airborne bacteria sampling is 1.

[0038]

[0039] Where L is the width of the space in the horizontal direction. The width of the space in the horizontal direction is rounded up, and N is the number of sampling positions.

[0040] The sampling location for sedimentation bacteria is the lower edge of the corresponding spatiotemporal interface on both sides of the joint wall, preferably in the same plane as the spatiotemporal interface. The number of culture dishes on each side should be more than 2 (GB / T 16294-2010). During static testing, the exposure time of the culture dishes should be more than 30 minutes; during dynamic testing, the exposure time of the culture dishes should not exceed 4 hours. The mean of all sedimentation bacteria data is the average concentration of sedimentation bacteria. Since sedimentation bacteria and airborne bacteria are correlated to a certain extent, and airborne bacteria are the main source of entering the human respiratory tract and affecting human health, the risk coefficient of sedimentation bacteria can be determined according to the flow characteristics in the scene. The risk coefficient should be between 0 and 1. The actual meaning of this value is the probability that sedimentation bacteria brought by personnel or air flow will float back into the air. Thus, the test methods for each spatiotemporal interface of the residential area microbial pollution assessment have been clarified. Based on the sampling data, the level of microbial pollution in the residential area is assessed according to formula (2).

[0041]

[0042] Where W1 represents the pollution assessment results at the apartment entrance, W2 represents the pollution assessment results at the elevator entrance, W3 represents the pollution assessment results at the elevator exit, W4 represents the pollution assessment results at the residential entrance, and W5 represents the pollution assessment results at the residential exit. n-1 This is the average transit time from the (n-1)th spatiotemporal interface to the nth spatiotemporal interface, where n is an integer greater than 1. This value was obtained through data survey.

[0043] Based on the infectivity of microorganisms, the risk of infection is correlated with contact time and distance. Taking COVID-19 as an example, according to the World Health Organization (WHO), close contact is defined as being in the same indoor space as a virus carrier for more than 15 minutes and at a distance of less than 2 meters. In this case, the risk of infection is high. Due to factors such as the space and population density in apartment buildings, the distance between people is usually less than 2 meters. Therefore, 15 minutes is defined as the complete contact time T (the infection time of one pathogen or the shortest infection time of multiple pathogens). The coefficients of W1-W4 in the equation are determined by the ratio of the average transit time Z to the complete contact time T. Since people spend a long time indoors, the coefficient of W5 can be determined based on residents' living habits. K is the average of the coefficients of W1-W4. G represents the assessment result of the microbial contamination level in the apartment residential area.

[0044] Equation (3) is the calculation method for each term in Equation (2). The first term in Equation (3) is the calculation process for the concentration of airborne bacteria; the second term obtains the concentration of settling bacteria by correcting the natural settling method of the Auerbach formula, and then converts it to the air microbial content, converting its unit from CFU / plate to CFU / m³. 3 :

[0045]

[0046] The calculation methods for W2, W3, W4, and W5 are similar.

[0047] Where A is the correction coefficient for airborne bacteria at each sampling point, F is the concentration of airborne bacteria at each sampling point, N is the number of airborne bacteria samples, B is the correction coefficient for settling bacteria at each sampling point, C is the concentration of settling bacteria at each sampling point, M is the number of settling bacteria samples, and R is the risk coefficient for settling bacteria. For a horizontally opening spatiotemporal interface, A and B can be 1. For some spatiotemporal interfaces with other functions (such as spatiotemporal interfaces with rotation functions, spatiotemporal interfaces with air curtains, etc.), A and B need to be appropriately corrected. Due to the diversity of scenarios, this invention does not specify the correction rules for A and B. The R value is determined based on factors such as the size of the spatiotemporal interface, the internal and external working conditions of the interface, and the density of people. This value can be measured in a microbial background control experiment without airborne bacteria to simulate real working conditions. A is the plate area in cm². 2 t is the sampling time in min.

[0048] Example 1:

[0049] Taking an apartment building as an example, the building has 14 floors, with 23 units per floor and 2 people per unit. The test unit is located in the innermost room on the 14th floor. Settling bacteria were sampled using φ90mm×15mm petri dishes. The study aimed to assess the risk of COVID-19 infection (complete contact time T = 15 min). The five spatiotemporal interface data are as follows: the average concentration of airborne bacteria at the apartment entrance was 583 cfu / m³. 3 The average concentration of settling bacteria was 20.75 CFU / plate, the risk factor (R) for settling bacteria was 0.15, and the average concentration of airborne bacteria at the elevator entrance was 721.5 CFU / m³. 3 The average concentration of settling bacteria was 24.5 CFU / plate, the risk factor (R) for settling bacteria was 0.17, and the average concentration of airborne bacteria at the elevator exit was 417.5 CFU / m³. 3 The average concentration of settling bacteria was 19 CFU / plate, with a risk factor (R) of 0.13. The average concentration of airborne bacteria at the residential entrance was 423 CFU / m³. 3 The average concentration of settling bacteria was 12.5 CFU / plate, the risk factor (R) for settling bacteria was 0.19, and the average concentration of airborne bacteria at the residential outlet was 356 CFU / m³. 3 The average concentration of settling bacteria was 14.75 CFU / plate, the risk factor (R) of settling bacteria was 0.05, Z1 was 0.5 min, Z2 was 2.8 min, Z3 was 0.5 min, and Z4 was 0.5 min.

[0050] The result can be obtained by calculation using equation (3).

[0051] Similarly, W2 = 830.1715, W3 = 482.2427, W4 = 485.2526, and W5 = 375.3311.

[0052] We obtain the result from equation (2).

[0053] The resulting assessment of the contaminant (COVID-19) levels in the apartment's test residents was 294.4841.

[0054] Example 2

[0055] Similarly, if you want to calculate the pollutant level assessment results for all residents on the 14th floor (i.e., after leaving the elevator on the 14th floor), you only need to calculate the first four items.

[0056]

[0057] Similarly, with W2 = 830.1715, W3 = 482.2427, and W4 = 485.2526, the result G is 257.2638.

Claims

1. A method for testing and evaluating the level of microbial contamination in residential environments based on a spatiotemporal interface, characterized in that: The method includes: (1) Determine the testing system. The testing system includes the spatiotemporal interface and its corresponding data acquisition method. Based on the intuitiveness of the data, it is divided into explicit data that directly shows the level of microbial contamination and implicit data that is related to the level of microbial contamination. The explicit data is the microbial concentration; the implicit data includes temperature, humidity, and wind speed. (2) The spatiotemporal interface includes: apartment entrance, elevator entrance, elevator exit, residential entrance, and residential exit; (3) Collection method: The arrangement method of airborne bacteria sampling points is determined based on the spatial probability of pedestrian flow, the location of sedimentation bacteria sampling points is determined according to the spatial structure characteristics of the spatiotemporal interface, and the sampling duration and sampling frequency are determined according to the characteristics of pedestrian flow; (4) Determine the assessment method: Based on the microbial pollution data of the residential environment using the spatiotemporal interface, obtain the weight coefficients of each data item. Based on the obtained weight coefficients of each item and the scores of the microbial pollution data, obtain the comprehensive assessment result of the microbial pollution level of the residential environment based on the spatiotemporal interface. The method for arranging the airborne bacteria sampling points involves analyzing monitoring images to determine the space (excluding residential exits) through which more than 80% of people pass at the corresponding spatiotemporal interface. Using the midpoint of this space horizontally and 0.8m vertically as reference points, the airborne bacteria sampling points at the apartment entrance are located 0.5–1.5m after the reference point, the airborne bacteria sampling points at the elevator entrance are located 0.5–1.5m before the reference point, the airborne bacteria sampling points at the elevator exit are located 0.5–1.5m before the reference point, and the airborne bacteria sampling points at the residential entrance are located at the center of the space. The space at the residential exit is its actual size, and the airborne bacteria sampling point at the exit is located at the center of the exit. The sampling points for sedimentation bacteria are located at the lower edge of the spatiotemporal interface on both sides, within the same plane as the spatiotemporal interface. The number of culture dishes on each side should be greater than 2. During static testing, the exposure time of the culture dishes should be more than 30 minutes. During dynamic testing, the exposure time of the culture dishes should not exceed 4 hours. The specific assessment method in step (4) is as follows: assess the level of microbial contamination in the residential area according to formula (2): （2） in The pollution assessment results at the apartment entrance. The pollution assessment results at the elevator entrance. The pollution assessment results at the elevator exit. The results of the pollution assessment at the entrance of the residence. The pollution assessment results at the residential exit; The average transit time from the (n-1)th spacetime interface to the nth spacetime interface, where n is a positive integer from 2 to 5; Complete exposure time is the time it takes for an individual pathogen to infect a particular apartment, or the shortest time for multiple pathogens to infect the same apartment; mean transit time is used instead. With full contact time The ratio is determined in the equation The coefficient is determined based on residents' living habits, since people spend a lot of time indoors. coefficient for The average value of the coefficients; The results of the assessment of microbial contamination levels in the apartment complex.

2. The method for testing and evaluating the level of microbial contamination in residential environments based on a spatiotemporal interface according to claim 1, characterized in that: In the arrangement of airborne bacteria sampling points, if the width of the space is considered... When the width is greater than 1m, increase the number of sampling points for airborne bacteria in the width direction. for: （1） in, The width of the space in the horizontal direction. This is the floor function of the width of the space in the horizontal direction; The sampling point width direction position distribution is located at respectively , … At this location, the average value of the airborne bacteria data from all sampling points is the average concentration of airborne bacteria.

3. The method for testing and evaluating the level of microbial contamination in residential environments based on a spatiotemporal interface according to claim 2, characterized in that: It is the total concentration of planktonic bacteria and sedimented bacteria obtained by correcting the natural sedimentation method of the Auerbach formula in a certain spatiotemporal interface, where i is a positive integer from 1 to 5; （3） in, The correction factor for airborne bacteria at the sampling point. The concentration of airborne bacteria at the sampling point. The number of airborne bacteria sampled. The correction factor for sedimentation bacteria at the sampling point. The concentration of sedimenting bacteria at the sampling point. This refers to the number of sedimentation bacteria sampled. This represents the risk factor for settling bacteria.

4. The method for testing and evaluating the level of microbial contamination in residential environments based on a spatiotemporal interface according to claim 1, characterized in that: When there are multiple spatiotemporal interfaces with the same function, the coefficients are determined according to the proportion of people flow density, and the sum of all coefficients is 1.

5. The method for testing and evaluating the level of microbial contamination in residential environments based on a spatiotemporal interface according to claim 1, characterized in that: The sampling duration and sampling frequency are determined by the periodicity and density of the crowd flow; the sampling duration is determined based on the periodicity to ensure the integrity of the sampling results; the sampling frequency is determined based on the crowd flow density to analyze the correlation between microbial contamination levels and individual individuals, and to determine the influencing factors of data changes.

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