A microscopic imaging wind tunnel for environmental precipitation and its application in health risk assessment

Abstract

This invention proposes a microscopic imaging wind tunnel for environmental precipitation and its application in health risk assessment. The wind tunnel simulates precipitation through a precipitation generation module connected to the air. Through meteorological data acquisition, regional gridding, and output of simulated precipitation generation data, the air quality response to precipitation is observed. Following the steps of precipitation simulation, mixing and diffusion, and microscopic observation, the three-dimensional migration behavior of bioaerosols is observed to conduct health risk assessment, solving the challenges of in-situ observation and tracing microscopic imaging of the enrichment of diffused aerosols in ambient air and the apoptosis and proliferation of live cells. The wind tunnel application described in this invention for health risk assessment is simple, easy to implement, and widely applicable. It facilitates the dynamic monitoring of biological pollutants moving with the atmosphere under conditions such as rainfall, snowfall, hail, and typhoons. It is suitable for providing scientific data on the spread of conditionally pathogenic bacteria in residential areas, landfills, and other areas, and has strong relevance and practicality.

Description

Technical Field

[0001] This invention relates to the field of atmospheric environment monitoring technology, specifically to an environmental precipitation wind tunnel for live cell microscopy imaging and its application in health risk assessment. Background Technology

[0002] A wind tunnel is a ground-based aerodynamic simulation device that generates and controls airflow based on similarity criteria to measure the gas flow patterns around a real object or model. Wind tunnels are often designed as tubular structures, with parameters such as airflow velocity, pressure, and temperature uniformly distributed across all cross-sections of the wind tunnel test section, making them one of the important research tools for observing flow phenomena in aerospace, mechanical, and other engineering fields.

[0003] Microorganisms, as an important component of aerosols, can be dispersed through the atmosphere. German scientists, using microscopic techniques to observe a 602μm × 505μm field of view, discovered that the flow-directed eddies of ciliate movement significantly increase the mixing effect, increasing the likelihood of microorganisms acquiring nutrients from the surrounding flow field. Under certain high-humidity natural environmental conditions, the fluid patterns around microorganisms are diverse, such as vortex rings, which significantly increase mass transfer and biofilm nutrition, making it an important aspect of aerosol risk research.

[0004] With the exacerbation of global climate and air pollution, environmental wind tunnels are playing a crucial role in researching the environmental hazards and health effects of aerosols, such as wet deposition and dynamic detection of leaks. Traditional closed-loop wind tunnels offer advantages such as wide measurement range, flow field visualization, and low construction and operating costs, enabling the observation of air pollutant flow characteristics. However, the limited length of wind tunnel test sections makes it difficult to replicate the actual conditions of microbial diffusion. This means that traditional wind tunnels struggle to simulate the long-distance diffusion characteristics of aerosols in real flow fields, particularly the diffusion distance, concentration distribution, trajectory, activity, and infection risk of pathogenic aerosols in precipitation environments. Furthermore, existing wind tunnel technology and equipment pay limited attention to the chemical and biochemical information of local microbial flow fields, restricting our understanding of the mechanisms of microbial diffusion in the air.

[0005] Therefore, it is urgent to design an environmental wind tunnel for live cell microscopy imaging, establish a three-dimensional visualization measurement method that is similar to the air microbial movement environment of key environmental factors such as precipitation and wind, and solve the flow field diagnosis of air bioaerosol diffusion and its application in population health risk assessment. Summary of the Invention

[0006] The purpose of this invention is to solve the existing technical problems, propose an environmental precipitation wind tunnel suitable for live cell microscopic imaging of airborne bioaerosols, and apply it to population health risk assessment.

[0007] To achieve the above objectives, the technical solution adopted in this invention is as follows: An environmental precipitation wind tunnel for live-cell microscopy imaging is proposed, characterized by comprising a precipitation section I, a mixing and stabilization section II, a diffusion and propagation section III, a test section IV, and a power section V. Precipitation in precipitation section I is simulated via a precipitation generation module, a snow-throwing wheel, a chamber, and a water supply and drainage system. Air passes through the mixing and stabilization section II, where a rectifier mesh is arranged, improving the flow field quality. It then passes through the diffusion pipe and nozzle of the diffusion and propagation section III, promoting the uniform diffusion and propagation of airborne bioaerosols. Air is then introduced into the test section IV, which specifically includes a stage, a live-cell microscopic observation lens, and a temperature control system. The test section has a drainage structure at the bottom and a temperature control plate at the top, facilitating the observation of various physical, chemical, and biological interactions between live cells. The air then enters the power section V, which includes an airlock chamber, a heat exchange system, an air-cooled fan system, and an online sealing device, ensuring the supply and return of cold sources during the precipitation and snowfall simulation process in the precipitation section, cooling the diffusion and propagation section III and the test section IV, and finally safely discharged through the outlet.

[0008] The precipitation section I of the precipitation wind tunnel consists of a precipitation generation module, a snow thrower, a box, and a water supply and drainage system.

[0009] Furthermore, the precipitation generation module of precipitation segment I specifically includes the following steps:

[0010] ① Meteorological data acquisition, used to realize the dataset based on the reanalysis of field surface meteorological data, and to provide input meteorological data for the gridded regional precipitation simulation module to dynamically drive the numerical simulation platform;

[0011] ② Regional gridding is used to discretize the computational region in the temporal and spatial dimensions by using the ground meteorological dataset as the initial and boundary conditions of the numerical simulation platform, and obtains precipitation spatial distribution data that meets the measurement accuracy through iterative calculation.

[0012] ③ Output of precipitation occurrence simulation data, used to realize the output of precipitation spatial distribution simulation data, including gridded precipitation intensity, rain and snow flow, precipitation duration and rainfall time, and other important simulation data for urban area precipitation occurrence schemes.

[0013] Furthermore, the environmental precipitation (snow) device of the precipitation section I includes a temperature control system, a rotatable snow scraper, a snow scraper blade, and a precipitation distribution plate, wherein the temperature control system has a temperature adjustment range of -20 to 50°C.

[0014] Furthermore, the water supply and drainage system of the precipitation section I includes a sprinkler microporous screen plate, a flow guide pipe and a control mechanism. The porous screen plate is coated with a capillary diffusion layer, the inner diameter of the capillary is 0.1mm to 5mm, the local friction resistance factor is greater than 0.01, and the shape is circular, rhomboid, or rectangular, but not limited to these. After the environmental rainfall (snow) passes through the screen holes of the precipitation distribution plate, it enters the mixing and stabilization section II.

[0015] The mixing and stabilizing section II of the precipitation wind tunnel includes a honeycomb grid, a rectifier component, and a Venturi mixing chamber, which are used to improve the flow field quality.

[0016] Furthermore, the rectification components of the mixing stabilization section II include a tracer particle inlet, a plug flow mixer, and a swirl chamber. The tracer particle inlet is connected to the tangential inlet of the swirl chamber, and the plug flow mixer is located at the bottom of the swirl chamber to form a liquid storage and drainage space, thereby driving precipitation (snowfall) to rotate in the high humidity air.

[0017] Furthermore, the Venturi mixing chamber of the mixing stabilization section II can release the bioaerosols formed and inject them into the diffusion propagation section III.

[0018] The diffusion propagation section III of the precipitation wind tunnel includes a diffuser and a nozzle; the diffuser can be assembled and installed in the form of a sleeve on the outer wall of the test section IV; the nozzle consists of a bioaerosol releaser, a capillary network matrix interlayer, a connecting pipe and a pump, and can be trapezoidal, triangular, or rectangular, but is not limited to these shapes.

[0019] Furthermore, the bioaerosol releaser of the diffusion propagation section III nozzle is wrapped around the outer wall of the test section IV, and the released bioaerosol enters the test section IV through the pores of the capillary network matrix interlayer.

[0020] Furthermore, the capillary network matrix interlayer of the diffusion propagation section III nozzle has a diffusion convection structure, including hollow fiber type, microcapsule type, and microvascular type. The preferred materials are organosilicon and isocyanate, but not limited to these.

[0021] The test section IV of the precipitation wind tunnel includes a stage, a live cell microscopic observation lens, a microbial aerosol flow tube, and a temperature control system. The microbial aerosol flow tube is equipped with a drainage system.

[0022] Furthermore, one side of the stage of the test section IV is connected to the inner wall of the microbial aerosol flow tube, which is used to observe parameters such as the activity and concentration of microorganisms moving with the air.

[0023] Furthermore, bioaerosol diffusion holes are arranged on the stage of the test section IV. A portion of the aerosol flows into the exposure model along the diffusion holes. Data such as the concentration, flow field structure, and community structure of the diffused bioaerosol are observed and measured using a laser particle size analyzer, Anderson bioaerosol sampler, and live cell imaging culture dish, but not limited to these.

[0024] Furthermore, the live-cell microscopic observation lens of test section IV is used for observing the bioaerosols flowing within the wind tunnel.

[0025] Furthermore, the live cell microscopic observation lens of the test section IV is installed on the outer tube of the microbial aerosol flow tube, preferably a high-resolution optical microscope, a scanning probe microscope, or a DNA microscope, but not limited to these.

[0026] Furthermore, the microbial aerosol flow tube of the test section IV is arranged on the stage and installed in sections. Each flow tube has an inner tube and an outer tube, made of transparent materials such as quartz glass or acrylic, with a total length of not less than 0.2m. The tube shape is round, square, or rectangular sleeve, but not limited to these.

[0027] Furthermore, a flow straightener is installed between the microbial aerosol flow tubes in the test section IV, and a C-shaped groove is opened with a groove width not exceeding 0.1m and a length not exceeding 0.5m.

[0028] Furthermore, the drainage system of the test section IV includes one or a combination of several of the following: flow meter, solenoid valve, capillary copper tube, and pump, but is not limited to these.

[0029] Furthermore, the temperature control system of the test section IV includes a temperature control plate, which is located at the top of the microbial aerosol inner tube and the temperature control plate is arranged at the bottom of the microbial aerosol inner tube.

[0030] The power section V of the precipitation wind tunnel consists of an airlock chamber, a cooling fan system, a heat exchange module, and an online sealing device.

[0031] Furthermore, the cooling fan system of the power section V is connected to the outlet of the airlock chamber, generating a cold source to cool the test section and the diffusion propagation section, maintaining the stability of the operating conditions of temperature and humidity.

[0032] Furthermore, the power section V is connected to the heat exchange module for biochemical reactions and energy transfer between the air-cooled fan system and the test section, ensuring the simulation of precipitation and snowfall generated by the cooling fan system and the precipitation section.

[0033] Furthermore, the power section V has an online sealing device and is connected to one or more of the following combinations: a gas flow regulating valve, an inlet and outlet pipe, a steam heater, and an adjustable wavelength UV lamp strip, but is not limited to these.

[0034] Furthermore, the online sealing device of the power section V, which can serve as the core component of risk assessment, has a biochip platform, connects several inlet pipes and an outlet pipe, and is used to atomize and spray in one or more combinations of DNA-binding dyes, TRITCPhalloidin, fungal fluorescent staining solution, antifungal antibiotics, antifungal immunosuppressants, and nanoparticle drugs. After exposure risk assessment, the gas is discharged from the outlet.

[0035] This invention discloses a live-cell microscopic imaging environmental precipitation wind tunnel and its health risk assessment and application, characterized in that: bioaerosols in the air sequentially pass through one or more sections of the wind tunnel, including a precipitation section, a mixing and stabilization section, a diffusion and propagation section, a testing section, and a dynamic section, to conduct risk assessment and application following the steps of precipitation simulation, mixing and diffusion, and microscopic observation. The specific health risk assessment steps are characterized as follows:

[0036] S1, the precipitation simulation step, is a step that uses a precipitation generation module on a 3D-printed urban cluster model to simulate the processes of wind, rain, snow, and hail in a real environment, with precipitation ranging from 0.1 to 100 mm / m. 3 The wind speed is 0.1 to 51 m / s.

[0037] S2, the mixing and diffusion step, simulates biochemical reactions such as gene transfer in airborne microbial communities to observe the diffusion and propagation process of bioaerosols in precipitation environments in situ, and records process parameters such as cell apoptosis and proliferation. At a temperature setting of -20 to 60°C and a humidity setting of 0.1% RH to 99.9% RH, one or more combinations of DNA-binding dyes, TRITC Phalloidin, fungal fluorescent staining solutions, antifungal antibiotics, antifungal immunosuppressants, and nanoparticle drugs are atomized and sprayed into an online sealed device in a precipitation wind tunnel. These substances are fully mixed and reacted with bioaerosols and non-bioaerosols in the air, and then the air is stored in grid units and quantitatively delivered.

[0038] S3, the microscopic observation step, employs one or a combination of biological microscopy and laser particle imaging techniques, preferably using a fluorescence microscope or confocal microscope, a fluorescence probe, and a solid-state laser module. This measures the mass transfer rate of a small-scale local flow field surrounding the bioaerosol released from the source, with a flow field solution resolution of 0.001 μm to 5 mm. Subsequently, the laser emission path is perpendicular to the spectral collection path, and a detector is used to observe the resistance of colonized living cells and the spectral intensity of airborne bioaerosols in each grid cell. The number of bioaerosols passing through the observation path is counted, enabling automated monitoring of important parameters such as particle size, concentration, composition, activity, cell membrane receptors, and surface antigens of airborne bioaerosols in complex exposure scenarios. Combined with spectral fringe contrast, the precise location information of microorganisms is determined, completing the assessment of living cell migration behavior and exposure risk.

[0039] The present invention proposes an environmental precipitation wind tunnel based on live cell microscopy and its health risk assessment. This method is based on a simulation method of an environmental precipitation wind tunnel using live cell microscopy and can be applied to solve the problem of human exposure research on the spread of bioaerosols.

[0040] The beneficial effects of the present invention are as follows:

[0041] 1. By coupling precipitation spatial distribution numerical simulation technology, live cell imaging technology, microreactor technology and bioaerosol monitoring technology into wind tunnel experimental technology, the control of environmental rainfall and snowfall amount and frequency is accurate, the precipitation environment flow field solution has high resolution, and it is suitable for evaluating the state of live cells on the carrier, thus expanding the scenarios and applications of traditional wind tunnel environmental simulation.

[0042] 2. The present invention provides a health risk assessment method for a live cell microscopic imaging environmental precipitation wind tunnel, which records the three-dimensional migration path of pathogenic microbial communities by observing the effects of complex microphysical, chemical and biological conditions on live cells through microscopic observation, thus solving the problem of in-situ tracing and monitoring of live cell migration.

[0043] 3. It features intelligent data analysis, is simple and easy to use, and is suitable for assessing the risk of cell resistance gene transfer, drug resistance and sensitivity evaluation of conditionally pathogenic microbial communities under rain and snow conditions. It solves the problem of insufficient data on the transmission activities of infectious bacteria and provides new ideas and methods for health risk assessment in small-scale areas. Attached Figure Description

[0044] Figure 1 This is a front view of a live-cell microscopic imaging environmental precipitation wind tunnel according to the present invention;

[0045] Figure 2 This is a flowchart illustrating the application of the environmental precipitation wind tunnel in health risk assessment according to the present invention.

[0046] Figure 3 This is a front view of the environmental precipitation wind tunnel and health risk assessment method according to Embodiment 1 of the present invention;

[0047] Figure 4 This is a partial enlarged view of the wind tunnel bioaerosol diffusion and propagation section of Embodiment 2 of the present invention.

[0048] In the diagram: 1-Precipitation solution; 2-Microbial solution; 3-Contaminant solution; 4-Precipitation generation module; 5-Snowball wheel; 6-Precipitation section I; 7-Rectifying component; 8-Venturi mixing chamber; 9-Honeycomb mesh; 10-Water supply and drainage system; 11-Mixing stabilization section II; 12-Stage; 13-Nozzle; 14-Live cell microscopic observation lens; 15-Temperature control system; 16-Diffusion propagation section III; 17-Temperature control plate; 18-Test section IV; 19-Airlock chamber; 20-Heat exchange system; 21-Air-cooled fan system; 22-Online sealing device; 23-Power section V; 24-Air outlet; 25-Exposure device. Detailed Implementation

[0049] To make this invention clearer and easier to understand, the following description is in conjunction with the appendix. Figure 1 The present invention will be further described in detail with reference to specific embodiments.

[0050] An environmental precipitation wind tunnel for live-cell microscopy imaging comprises five parts: a precipitation section I, a mixing and stabilization section II, a diffusion and propagation section III, an experimental section IV, and a power section V. The precipitation section I consists of a precipitation generation module 4, a snow-throwing wheel 5, a housing, and a water supply and drainage system 10, used for simulating the precipitation environment. The mixing and stabilization section II consists of a honeycomb mesh 9, a rectifier component 7, and a Venturi mixing chamber 8, used for biochemical reactions and energy transfer. The diffusion and propagation section III consists of a diffuser pipe and a nozzle 13, located on the upper side of the outer cavity of the experimental section. The experimental section IV consists of a stage 12, a live-cell microscopic observation lens 14, a microbial aerosol flow pipe, and a temperature control system 14, enabling microscopic observation of the fluid dynamics and other characteristics of microorganisms. The power section V connects to the air inlet and includes an airlock chamber 18, a heat exchange system 19, a cooling fan system 20, and an online sealing device 21, used for heat exchange and cooling of accumulated water and snow in the precipitation section, and for collecting rainfall and snowfall.

[0051] The embodiments illustrate specific details of the present invention and facilitate understanding of its innovative features. The present invention can also be implemented in ways different from the described embodiments, and those skilled in the art can make similar modifications without departing from the claims of the present invention. The present invention is not limited to the following embodiments.

[0052] Example 1

[0053] Reference Appendix Figure 2 A schematic flowchart of the overall connection structure for detecting the bioaerosol diffusion process in an environmental precipitation wind tunnel, and an environmental precipitation wind tunnel for live cell microscopy imaging of the present invention, comprising six links.

[0054] Appendix Figure 3The structural diagram of the precipitation wind tunnel is presented. The wind tunnel is divided into five parts: precipitation section 6, mixing and stabilizing section 11, diffusion and propagation section 15, test section 17, and power section 22. A precipitation solution 1, a 105 CFU / ml solution of *Bacillus luminifera* 2, and a 0.25 mg / L aqueous solution of silica pollutants 3 are pumped into the precipitation generation module via a micro-pump, with the temperature controlled at 35℃. Air containing precipitation enters the diffusion and propagation section 15 through the Venturi mixing chamber 8 of the mixing and stabilizing section 11. After passing through an organosilicon micro-capillary network substrate interlayer installed on the wall of the diffusion and propagation section 15, the precipitation rate is controlled within the range of 1–1.5 mm / min, and the air is sprayed from top to bottom onto the test section 17. A laser dust sensor is installed in the capillary network substrate interlayer to obtain data on PM1.0, PM2.5, PM5, and PM10, with the wind speed controlled at 3.0–3.2 m / s, the wind direction W, and the airborne microbial concentration at 100–150 CFU / m³. 3 .

[0055] Data such as the diffusion trajectory of bioaerosols at 10, 20, 30, 40, 50, and 60 cm in the air and the concentration of culturable bacteria were obtained through microscopic observation. Bacterial detection sensors were installed in the test section to statistically analyze the growth rate and extracellular polymer concentration of *Bacillus luminifera*. A microscopic laser particle velocimetry system was used to observe the flow field information around the bioaerosols, such as velocity, turbulent kinetic energy, and eddy current. Some of the bioaerosols in the air entered the exposure device 24, and the inhalation exposure risks at six points were measured to be 3.72E-5, 3.11E-5, 2.33E-5, 2.47E-5, 1.99E-5, and 1.17E-5, respectively, showing a gradually decreasing trend. Subsequently, the air entered the online sealing device 21 of the power section 22. The remaining bioaerosols were disinfected for 5 minutes under a 253.7 nm UV lamp and then discharged into the atmosphere through the outlet 23.

[0056] Example 2

[0057] The present invention provides an environmental precipitation wind tunnel for live cell microscopy imaging, which is divided into five parts: a precipitation section 6, a mixing and stabilization section 11, a diffusion and propagation section 15, a test section 17, and a power section 22; a precipitation generation module 4 generates snowflakes. A micro-pump pumps sterile water, 1 ml of 10⁵ CFU / ml E. coli solution, and a sterile aqueous solution of 225 μmol / L hydrogen peroxide into the precipitation generation module. The speed of the snow-throwing wheel 5 is adjusted to 120 rpm, and the snowfall is controlled at 1.0, 2.5, and 4 mm / min (low, medium, and high snowfall), with a relative humidity of 50–55% RH% and a temperature of -15℃.

[0058] Health risk assessment is conducted as follows: Figure 4The diffusion propagation segment 15 shown was conducted within which a 3D-printed respiratory tract model with a 37°C warm-body mannequin, heated to 1200W / ㎡, was installed. The mannequin's body temperature was set at 35.8°C, 36.0°C, 36.2°C, 36.4°C, 36.8°C, 37.0°C, and 37.2°C. The respiratory rate was 15 breaths / min, and the expiratory volume was 20L / min. A Pitot tube monitored the airflow quality at the air inlet, with a wind speed of 1.5–1.7 m / s. A biosensor measured the concentration of *E. coli* in the air under no-snowfall and low, medium, and high snowfall conditions at 1 CFU / m³. 3 55 CFU / m 3 35 CFU / m 3 68 CFU / m 3 The bacterial counts were 100 dN / dh, 3200 dN / dh, 5100 dN / dh, and 2760 dN / dh. It was found that under moderate snowfall, the skin contact and respiratory exposure risks of the model were 2.95E-1 and 3.91E-5, respectively.

[0059] Although the present invention has been disclosed with the embodiments described above, it can be applied to various fields suitable for this invention. Other modifications can be readily implemented by those skilled in the art. Therefore, without departing from the concepts defined by the claims and their equivalents, the present invention is not limited to the specific detailed embodiments described and illustrated.

Claims

1. An environmental dewar for live cell microscopy, characterized by: The device comprises a precipitation section, a mixing stabilization section, a diffusion propagation section, a test section and a power section; the precipitation section is composed of a precipitation generating module, a snow throwing wheel, a box, a water supply and drainage system; the mixing stabilization section comprises a honeycomb net, a rectifier and a Venturi mixing chamber; the diffusion propagation section comprises a diffusion pipe and a nozzle, the diffusion pipe is combined and installed in the form of a sleeve on the outer wall of the test section, the nozzle is composed of a bio-aerosol releaser, a capillary net base sandwich, a connecting pipe and a pump, the bio-aerosol releaser of the nozzle of the diffusion propagation section is wrapped around the outer wall of the test section, and the released bio-aerosol enters the test section through the pores of the capillary net base sandwich; the test section comprises a carrier table, a living cell microscopic observation lens, a microbial aerosol flow pipe and a temperature control system, and the microbial aerosol flow pipe is arranged with a drainage system; the power section is composed of an air locking chamber, a cooling fan system, a heat exchange module and an online sealing device; the precipitation section is connected with air, environmental precipitation is simulated through the precipitation generating module, and precipitation solution, microbial solution and pollutant solution are pumped into the precipitation generating module through a micro pump; after the air containing precipitation enters the honeycomb net, the rectifier and the Venturi mixing chamber of the mixing stabilization section, biochemical reactions and mass, heat and energy transfer are carried out; then the precipitation is uniformly distributed in the test section along the diffusion pipe and the nozzle of the diffusion propagation section in the form of a sleeve, and the bio-aerosol is fully diffused and propagated in the air; the air bio-aerosol is observed under the carrier table and the living cell microscopic observation lens of the test section; the living cell microscopic observation lens is assembled on the outer wall of the microbial aerosol flow pipe, the bio-aerosol microscopic observation temperature is constant under the action of the temperature control system, and living cell positioning microscopic imaging is carried out; finally, the air enters the air locking chamber and the online sealing device of the power section, and is discharged from the air outlet; the rainfall and snowfall are collected by the heat exchange module and the cooling fan system, and the energy recycling of the precipitation section is carried out. The precipitation generating module of the precipitation section is used for: weather data collection, which is used to realize the data set of the reanalysis of the external field ground meteorological data, to provide input meteorological data for the operation of the dynamic driving numerical simulation platform of the grid region of the precipitation generating module; regional gridding, which is used to discretize the calculation region in the time and space dimensions by taking the ground meteorological data set as the initial and boundary conditions of the numerical simulation platform, to obtain precipitation spatial distribution data meeting the measurement accuracy through iterative calculation; precipitation simulation data output, which is based on the precipitation spatial distribution data, includes the precipitation intensity, rainfall and snowfall flow, and precipitation duration simulation data of the urban grid region, and realizes the output of the optimal precipitation generating scheme. 2.A health risk assessment method, characterized in that: the wind tunnel of claim 1 is used to carry out the steps of precipitation simulation, mixing diffusion and microscopic observation to assess the health risk of the population.

3. The health risk assessment method of claim 2, wherein, The precipitation simulation step arranges the 3D printed urban cluster model in the wind tunnel, and simulates the wind, rain and snow processes of the real natural environment by the precipitation section, wherein the simulated precipitation range is 0.1-100 mm / m 3 , and the wind speed range is 0.1-51 m / s.

4. The health risk assessment method of claim 2, wherein, The mixing diffusion step simulates the mixing and diffusion of air bio-aerosol, is used for the biochemical reaction process in the microbial community, and in-situ observes the cell-cell interaction in the diffusion and propagation process of bio-aerosol in the precipitation environment multiphase medium, wherein the temperature range of the diffusion and mixing process is -20-60℃, and the humidity range is 0.1%RH-99.9%RH.

5. The health risk assessment method of claim 2, wherein, The micro-observation step adopts biological micro-observation technology and laser particle imaging technology to measure the small-scale local flow field around the source-released bio-aerosol, and the flow field solution resolution is maintained at 0.001-5mm.

6. Use of a health risk assessment, characterized in that The health risk assessment method of any one of claims 2-5 is used for the evaluation of the local regional population health risk of bio-aerosol diffusion and propagation in the air medium.

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