Method for inactivating fungi or viruses, and device for inactivating fungi or viruses

Abstract

Provided are a method and apparatus for inactivating fungi or viruses that sterilizes fungi or viruses attached to an object while suppressing odor. The fungi or virus inactivation method of the present invention comprises a step (a) of irradiating an object with ultraviolet light having a specific wavelength within the range of 200 nm to 235 nm. Step (a) is performed at an illuminance (X) [mW / cm 2 ](X>0) and the cumulative exposure within two hours (Y) [mJ / cm 2 ] A process of irradiating ultraviolet light in a manner that satisfies the following formula (1). 0<Y<10.704X ‑0.373 …(1).

Description

Technical Field

[0001] The present invention relates to a method for inactivating fungi or viruses, and more particularly to a method for inactivating fungi or viruses using ultraviolet rays. Furthermore, the present invention relates to a device for inactivating fungi or viruses. Background Art

[0002] Traditionally, sterilization technology using ultraviolet radiation has been known. DNA is known to exhibit peak absorption characteristics around a wavelength of 260 nm. Furthermore, low-pressure mercury lamps exhibit a peak emission spectrum around a wavelength of 254 nm. Therefore, sterilization technology using low-pressure mercury lamps has become widely used.

[0003] However, it is well known that exposure to ultraviolet radiation in this wavelength range poses a risk of harm to the human body. The skin is divided into three layers, starting from the surface: the epidermis, the dermis, and the subcutaneous tissue beneath. The epidermis is further divided into four layers, starting from the surface: the stratum corneum, the stratum granulosum, the stratum spinosum, and the stratum basale. Exposure to ultraviolet radiation with a wavelength of 254nm passes through the stratum corneum, stratum granulosum, and stratum spinosum, sometimes even reaching the stratum basale, where it is absorbed by the DNA of cells within these layers. This can lead to the risk of skin cancer.

[0004] Based on this viewpoint, Patent Document 1 below discloses a technology for performing sterilization treatment in a medical setting by using ultraviolet rays within a wavelength range of 200 nm to 235 nm while avoiding risks to the human body.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6025756

[0008] Non-patent literature

[0009] Non-patent document 1: Yuba and Kio et al., "Analysis of UVB irradiation of によるリノレン acid, スクワレン peracid compound and ultra-weak light and light スペクトル", Journal of the Japanese Society of Dermatology, Vol. 92, No. 1, 1982

[0010] Non-patent document 2: Manuela Buonanno et.al., "207-nm UV Light-A Promising Tool for Safe Low-Cost Reduction of Surgical Site Infections.I: In Vitro Studies", Plos One, 2013

[0011] Non-Patent Document 3: Tokyo Metropolitan Institute of Environmental Science, “Tokyo Metropolitan Institute of Environmental Science Annual Report 2008,” 2008 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] Through intensive research, the inventors have discovered a new problem: when ultraviolet light sources exhibiting light output within the wavelength range of 200 nm to 235 nm are used to irradiate the surfaces of indoor objects (such as tables, desks, and walls) with ultraviolet light to inactivate fungi or viruses present on these surfaces, an unpleasant odor is generated. The inventors speculate that this is due to the following reasons.

[0014] Indoor objects such as tables, desks, and walls are more likely to be touched by human hands. When an object is touched by a human hand, human sebum (triglycerides, squalene, wax esters, etc.) and free fatty acids (palmitoleic acid) generated by the decomposition of this sebum adhere to its surface.

[0015] Squalene, a type of sebum, generates squalene hydroperoxide (SQHPO) when exposed to ultraviolet light. When SQHPO coexists with palmitoleic acid, it produces odorous components (the source of odor) such as nonanal, hexanal, octenal, and heptenal. This is similar to the mechanism of age odor in the human body, which typically develops slowly due to the temperature of the living environment and ultraviolet rays contained in sunlight, causing odor to originate from the skin.

[0016] However, it is believed that by irradiating the surface of an object with ultraviolet rays having a wavelength of 200 nm to 235 nm, the above-mentioned reaction is significantly accelerated, resulting in generation of an odor at a level that can be detected by humans.

[0017] The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a method and apparatus for inactivating fungi and viruses attached to an object while suppressing the generation of odor.

[0018] Means for solving problems

[0019] The method for inactivating fungi or viruses of the present invention is characterized by comprising the step (a) of irradiating ultraviolet rays exhibiting light output at a specific wavelength within the range of 200 nm to 235 nm.

[0020] The process (a) is carried out with an illumination (X) [mW / cm 2 ](X>0) and the cumulative exposure within two hours (Y) [mJ / cm 2 ] The process of irradiating the ultraviolet rays in a manner that satisfies the following formula (1).

[0021] 0<Y<10.704X -0.373 …(1)

[0022] By irradiating ultraviolet rays in a manner that satisfies the above formula (1), it is possible to suppress the generation of odor while performing sterilization or inactivation of viruses. This point will be described later in the "Specific Implementation" section. In addition, by making Y < 8.563X -0.373 By irradiating ultraviolet light L1 in a manner, the effect of suppressing the generation of strong odors can be improved.

[0023] The above step (a) may also be performed at an illumination (X) [mW / cm 2 ](X>0) and the cumulative exposure within two hours (Y) [mJ / cm 2 ] The process of irradiating the ultraviolet rays in a manner that satisfies the following formula (2).

[0024] 0<Y<0.4534X -0.697 …(2)

[0025] By irradiating ultraviolet rays in a manner that satisfies the above formula (2), it is possible to inactivate fungi or viruses while more significantly suppressing the generation of odor. This point will be described later in the "Specific Embodiments". By making Y < 0.36272X -0.697 By irradiating ultraviolet light L1 in a manner, the effect of suppressing the generation of odor can be improved.

[0026] The above step (a) may also be performed at an illumination (X) [mW / cm 2 ](X≥0.0002) the process of irradiating the ultraviolet rays.

[0027] The above step (a) may also be performed at an illumination (X) [mW / cm 2 ](X≥0.001) the process of irradiating the ultraviolet rays.

[0028] The step (a) may be a step of intermittently irradiating the ultraviolet rays so as to satisfy the formula (1).

[0029] Here, "intermittent irradiation" refers to a method of repeatedly irradiating for a predetermined first time period and then stopping irradiation for a predetermined second time period. In addition, in this treatment, the continuous irradiation time (the first time period) and the irradiation interval (the second time period) may also be changed each time.

[0030] In the method for inactivating fungi or viruses,

[0031] The step (a) is a step of irradiating the ultraviolet rays indoors.

[0032] The method for inactivating fungi or viruses comprises the step (b) of ventilating the air in the room at least once within two hours.

[0033] The fungus or virus inactivation device of the present invention is characterized by having:

[0034] a light source emitting ultraviolet light exhibiting light output at a specific wavelength falling within the range of 200 nm to 235 nm; and

[0035] a control unit, controlling the luminous intensity of the light source,

[0036] The control unit is configured to determine the illuminance (X) [mW / cm 2 ](X>0) and the cumulative exposure within two hours (Y) [mJ / cm 2 ]The luminous intensity of the light source is controlled in a manner that satisfies the following formula (1).

[0037] 0<Y<10.704X -0.373 …(1)

[0038] In the above device, the control unit may also be configured to adjust the illuminance (X) [mW / cm 2 ](X>0) and the cumulative exposure within two hours (Y) [mJ / cm 2 ]The luminous intensity of the light source is controlled in a manner that satisfies the following formula (2).

[0039] 0<Y<0.4534X -0.697 …(2)

[0040] The fungus or virus inactivation device may include an illuminometer for measuring the illuminance (X) on the irradiation surface and transmitting the illuminance to the control unit.

[0041] In the above-mentioned device, the control unit may control the light source to be intermittently lit so as to satisfy the above-mentioned formula (1).

[0042] Effects of the Invention

[0043] According to the present invention, fungi and viruses adhering to an object can be inactivated while suppressing the generation of odor. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a diagram schematically showing a state in which the method for inactivating fungi or viruses of the present invention is implemented.

[0045] Figure 2 It is a block diagram schematically showing the configuration of an inactivation device.

[0046] Figure 3 It is a perspective view schematically showing an example of the appearance of a light source.

[0047] Figure 4 yes Figure 3Exploded perspective view of the light source shown.

[0048] Figure 5 It is schematically indicated in Figure 3 A top view showing the positional relationship between the excimer lamp and the electrode block in the light source shown.

[0049] Figure 6 This is a diagram showing the spectrum of ultraviolet rays emitted from an excimer lamp containing KrCl in the luminescent gas.

[0050] Figure 7A This graph shows the results of GC-MS analysis of indoor air after irradiating the room with ultraviolet light until an odor was generated.

[0051] Figure 7B This is a graph showing the absorption spectrum of squalene.

[0052] Figure 7C This is a graph showing the relationship between the absorption coefficient of protein and wavelength.

[0053] Figure 8 This graph plots the relationship between the cumulative exposure Y and the illuminance X for which more than half of the evaluators judged the odor index N to be 20 or higher.

[0054] Figure 9 This graph plots the relationship between the cumulative exposure amount Y and the illuminance X for which more than half of the evaluators judged the odor index N to be 30 or higher.

[0055] Figure 10 This is another drawing schematically showing an implementation state of the fungus or virus inactivation method of the present invention.

[0056] Figure 11 This is another block diagram schematically showing the configuration of the inactivation device.

[0057] Figure 12 This is another block diagram schematically showing the configuration of the inactivation device.

[0058] Description of Reference Numerals

[0059] 1: Room

[0060] 2: Processing object

[0061] 3: Fungi, etc.

[0062] 5: Inactivation device

[0063] 7: Lux meter

[0064] 8: Door

[0065] 9: Ventilation port

[0066] 11: Light Source

[0067] 12: Control Department

[0068] 13: Receiving Department

[0069] 14: Distance measurement unit

[0070] 22: Lampshade

[0071] 22a: Main body shell

[0072] 22b: Cover

[0073] 23: Excimer lamp

[0074] 23G: Luminous gas

[0075] 28: Power supply line

[0076] 30: Light extraction surface

[0077] i7: Illumination information. DETAILED DESCRIPTION

[0078] Embodiments of the fungus or virus inactivation method and inactivation device of the present invention will be described with reference to the accompanying drawings as appropriate.

[0079] In this specification, the concept of "inactivation" includes killing bacteria and viruses or making them lose their infectivity and toxicity. In addition, in this specification, "fungi" refers to microorganisms such as bacteria and fungi (molds).

[0080] Figure 1 The accompanying drawings schematically illustrate an embodiment of the method for inactivating fungi or viruses according to the present invention. The method of the present invention involves irradiating an object 2, which is assumed to have fungi or viruses attached to its surface (hereinafter referred to as "fungi, etc. 3"), with ultraviolet light L1 from an inactivation device 5 to inactivate the fungi, etc. 3.

[0081] In this embodiment, the treatment object 2 is placed in a room 1. The room 1 is configured so that the air inside the room 1 can be ventilated through gaps such as a door 8 and a ventilation port 9. However, as will be described later, the method of the present invention is not limited to the case where the treatment object 2 is placed in the room 1, and can also be implemented when the treatment object 2 is placed "inside a building," including a corridor.

[0082] In Japan, the Building Standards Act stipulates that the ventilation rate for room 1 within a building is set at 0.5 times / hour or higher, and assumes that the indoor air is exchanged at least once every two hours. Furthermore, other countries such as Norway, Sweden, Finland, Denmark, Belgium, France, Germany, Switzerland, and Canada mandate or recommend a ventilation rate of 0.5 times / hour or higher. In other words, it is assumed that the indoor air in room 1 is exchanged at least once every two hours.

[0083] That is, even if an odor is generated in room 1, it is assumed that the odor will be removed by ventilation over time. In other words, if there is a cause of the odor in room 1, it is important to suppress the generation of the odor within the period of odor accumulation (two hours).

[0084] Furthermore, the standards assume highly airtight residential buildings, which impose stricter conditions for suppressing odors. For example, wooden buildings with low airtightness or spacious living rooms with ceilings of 3 meters or more are less likely to accumulate odors, making it easier to suppress odors.

[0085] The inactivation device 5 includes a light source that generates ultraviolet light L1. The ultraviolet light L1 exhibits light output at a specific wavelength within the range of 200 nm to 235 nm. The ultraviolet light L1 may have a main peak wavelength within the range of 200 nm to 235 nm. As another example, the ultraviolet light L1 may have a main peak wavelength outside the range of 200 nm to 235 nm, but may exhibit light output within at least a portion of the wavelength range within the range of 200 nm to 235 nm.

[0086] Figure 2 1 is a block diagram schematically showing the configuration of the inactivation device 5. The inactivation device 5 includes a light source 11 and a control unit 12 that controls the light emission of the light source 11.

[0087] Figure 3 It is a perspective view schematically showing an example of the appearance of the light source 11 . Figure 4 It will Figure 3 FIG. 1 is a perspective view of the exploded main body shell portion 22 a and the cover portion 22 b of the lampshade 22 of the light source 11 in FIG.

[0088] In the following Figures 3 to 5 In the description, the XYZ coordinate system is described with reference to the direction in which the ultraviolet light L1 is taken out as the X direction and the plane perpendicular to the X direction as the YZ plane. Figure 4 as well as Figure 5 As will be described later, the tube axis direction of the excimer lamp 23 is referred to as the Y direction, and the direction perpendicular to the X direction and the Y direction is referred to as the Z direction.

[0089] like Figure 3 as well as Figure 4As shown, the light source 11 includes a lampshade 22 having a light extraction surface 30 formed on one side. The lampshade 22 includes a main body shell 22a and a cover 22b. The main body shell 22a contains an excimer lamp 23 and electrode blocks (31, 32). Figure 4 2 , four excimer lamps 23 are housed in a lamp housing 22. The electrode blocks (31, 32) are electrically connected to the power supply line 28, and constitute electrodes for supplying power to the excimer lamps 23. Figure 5 It is a plan view schematically showing the positional relationship between the excimer lamp 23 and the electrode blocks (31, 32).

[0090] like Figures 3 to 5 As shown, the light source 11 in this embodiment is configured with two electrode blocks (31, 32) in a manner that contacts the outer surface of the light-emitting tube of each excimer lamp 23. The electrode blocks (31, 32) are configured at positions separated in the Y direction. The electrode blocks (31, 32) are made of a conductive material, preferably a material that shows reflectivity to the ultraviolet rays emitted by the excimer lamp 23. As an example, the electrode blocks (31, 32) are made of Al, Al alloy, stainless steel, etc. The electrode blocks (31, 32) are both configured to contact the outer surface of the light-emitting tube of each excimer lamp 23 and span across each excimer lamp 23 in the Z direction.

[0091] The excimer lamp 23 has a light-emitting tube with the Y direction as the tube axis direction. The outer surface of the light-emitting tube of the excimer lamp 23 contacts the electrode blocks (31, 32) at positions separated in the Y direction. A light-emitting gas 23G is sealed in the light-emitting tube of the excimer lamp 23. Figure 2 ) is controlled by power supply line 28 (refer to Figure 3 ) applies a high-frequency AC voltage, for example, of several kHz to 5 MHz, between the electrode blocks (31, 32), and applies the voltage to the luminescent gas 23G via the luminescent tube of the excimer lamp 23. At this time, a discharge plasma is generated in the discharge space enclosed by the luminescent gas 23G, and the atoms of the luminescent gas 23G are excited to become an excimer state. When the atoms transition to the ground state, excimer luminescence is generated.

[0092] The luminescent gas 23G is made of a material that emits ultraviolet light L1 that emits light at a specific wavelength within a range of 200 nm to 235 nm during excimer emission. For example, the luminescent gas 23G contains KrCl and KrBr.

[0093] For example, when the luminescent gas 23G contains KrCl, ultraviolet light L1 having a main peak wavelength of approximately 222 nm is emitted from the excimer lamp 23. When the luminescent gas 23G contains KrBr, ultraviolet light L1 having a main peak wavelength of approximately 207 nm is emitted from the excimer lamp 23. Figure 6 1 and 2 are diagrams showing the spectrum of ultraviolet light L1 emitted from the excimer lamp 23 containing KrCl in the light emitting gas 23G.

[0094] When the inactivation method of the present invention is implemented, the inactivation device 5 (more specifically, the light source 11) is set to the illuminance (X) [mW / cm 2 ](X>0) and the cumulative exposure within two hours (Y) [mJ / cm 2 ] Irradiate ultraviolet light L1 in a manner that satisfies the following formula (1) (step (a)).

[0095] 0<Y<10.704X -0.373 …(1)

[0096] By irradiating the ultraviolet rays L1 so as to satisfy this relational expression, it is possible to inactivate the fungi and the like 3 while suppressing the generation of odor in the room 1. This point will be described below.

[0097] Figure 7A This is a graph showing the results of GC-MS analysis of the air in the room 1 after continuously irradiating the treatment object 2 in the room 1 with ultraviolet light L1 using the same light source as the light source 11 described above and confirming the presence of odor. Figure 7A In the figure, the horizontal axis is the detection time and the vertical axis is the detection intensity. Figure 7A , hexanal and 2-ethylhexanal, which are odor components, were detected in the air in room 1 after ultraviolet irradiation.

[0098] also, Figure 7B This is a diagram showing the absorption spectrum of a squalene solution having a molar concentration of 30 mol / L using ethanol as a solvent (see Non-Patent Document 1). Figure 7B It is clear that squalene exhibits significantly high absorbance for ultraviolet light L1 with a wavelength of 200 to 235 nm. This suggests that odor is more likely to occur than when inactivating fungi, etc., by irradiating them with ultraviolet light from a low-pressure mercury lamp, which has a peak wavelength of 254 nm.

[0099] also, Figure 7CThis graph shows the relationship between the absorption coefficient of protein and wavelength (see Non-Patent Document 2). It shows that in the wavelength range shorter than 240 nm, the absorption coefficient of protein increases significantly as the wavelength becomes shorter. Therefore, ultraviolet light with a wavelength of 200 nm to 235 nm is easily absorbed by protein, which is speculated to be a major factor in the generation of off-flavors.

[0100] Given that Figure 7A The results shown indicate that when fungi, etc. 3 are inactivated by ultraviolet light L1 exhibiting a light output within a wavelength range of 200 nm to 235 nm, an unpleasant odor is generated. The inventors speculate that this is due to sebum adhering to the surface of the treatment object 2. More specifically, the inventors speculate that when squalene, a type of sebum, and a free fatty acid (palmitoleic acid) produced by the decomposition of sebum are present on the surface of the treatment object 2, squalene hydroperoxide (SQHPO) generated by irradiating squalene with ultraviolet light L1 exhibiting a light output within a wavelength range of 200 nm to 235 nm reacts with palmitoleic acid, thereby generating unpleasant odor components such as hexanal.

[0101] [Verification 1]

[0102] Therefore, we conducted a sensory test on odor using squalene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and ethyl palmitoleate (manufactured by Tokyo Ohka Kogyo Co., Ltd.) while varying the illuminance and the cumulative exposure dose. The test method is described below.

[0103] Multiple sample bottles were prepared by mixing 1 μL of squalene and 0.1 μL of ethyl palmitoleate in soda-lime glass bottles measuring 41 mm (L x W x H) x 83.5 mm (D x H) x 152 mm. While maintaining airtightness, the bottles were irradiated with ultraviolet light L1 from the open side. The illuminance within the reagent section was derived based on a previously determined relationship between distance and illuminance.

[0104] With each sample bottle sealed, the 2 , 0.01mW / cm 2 , 0.1mW / cm 2 , 1mW / cm 2 The sample bottle was irradiated with ultraviolet light L1 at these four illuminances. At this time, the cumulative irradiation amount was varied by changing the irradiation time of ultraviolet light L1 at each illuminance.

[0105] After the UV L1 irradiation treatment was completed, the sample bottle cap was opened and the air inside the sample bottle was sealed in a bag (hereinafter referred to as the "sample bag"). Five evaluators (M1 to M5) conducted a sensory test on the odor of the air inside the sample bag. The details of the sensory test measurement method are described below.

[0106] First, the evaluator smells the air in the sample bag. Next, the air in the sample bag is diluted 10-fold and the evaluator smells it. This dilution and odor test is repeated until the evaluator no longer detects the odor. The odor index is calculated based on the dilution factor at which the evaluator no longer detects the odor. The odor index N is calculated based on the odor concentration D using the following formula (3).

[0107] N=10×Log(D)…(3)

[0108] In addition, in the above formula (3), the odor concentration D means the value at which the odor is not felt for the first time at the stage of dilution to D times. That is, when the evaluator M1 still feels the odor when the air in the sample bag is diluted 10 times, but does not feel the odor when it is diluted 100 times, the odor concentration D = 100. Odors are felt when odorous substances stimulate olfactory cells. The higher the concentration of odorous substances in the air, the stronger the odor is felt. Generally, the intensity of odor is called odor intensity, and it is generally recognized that the Weber-Fechner law holds true between odor intensity and the concentration (amount) of odorous substances. That is, odor intensity and odor concentration are in a logarithmic relationship. Based on this situation, a method of evaluating the intensity of odor by using the odor index N calculated based on the above formula (3) is generally used.

[0109] Tables 1 to 4 are respectively illuminance X = 0.003 mW / cm 2 , Illuminance X = 0.01 mW / cm 2 , illuminance X = 0.1mW / cm 2 , illuminance X = 1mW / cm 2 The evaluation results in .

[0110]

Table 1

[0111]

[0112]

Table 2

[0113]

[0114]

Table 3

[0115]

[0116]

Table 4

[0117]

[0118] In addition, the following Table 5 is a table showing the correspondence between the odor index and the actual odor (see Non-Patent Document 3).

[0119]

Table 5

[0120]

[0121] According to Table 1, at illumination X = 0.003 mW / cm 2 In the case of 2 , three of the five evaluators determined that the odor index N was 20 or higher. An odor index N of 20 is generally considered to be equivalent to the intensity of the scent of Daphne koreana or bathroom freshener, and is considered an easily perceptible level of odor. Furthermore, the management standards for building site boundaries within the management standards of the Malodor Prevention Act are determined based on an odor index range of 10 to 21, which corresponds to an odor intensity of 2.5 to 3.5 under the six-stage odor intensity display method. In other words, an odor index N of 20 is close to the upper limit of the management standards, a level at which the occurrence of an odor is easily perceived.

[0122] Likewise, from Tables 2 to 4, the following results were confirmed.

[0123] According to Table 2, at illumination X = 0.01 mW / cm 2 In the case of 2 , four out of five evaluators judged that the odor index N was 20 or higher.

[0124] According to Table 3, at illumination X = 0.1 mW / cm 2 In the case of 2 , five of the five evaluators judged that the odor index N was 20 or more.

[0125] According to Table 4, at illumination X = 1mW / cm 2 In the case of 2 , three of the five evaluators judged that the odor index N reached 20.

[0126] From the above results, it can be seen that the value of the cumulative radiation amount Y at which the generation of an odor begins varies depending on the value of the illuminance X. Figure 8 Based on the results of Tables 1 to 4 above, the relationship between the cumulative exposure amount Y and the illuminance X is plotted, which is determined by three or more evaluators to have an odor index N of 20 or more. Figure 8 In the figure, the horizontal axis represents the illuminance X [mW / cm 2 ], the vertical axis represents the cumulative exposure Y [mJ / cm 2 ]. In addition, Figure 8 The approximate curve that actually passes through the four points is Y=0.4534X -0.697 , and Y = 0.36272X taking into account the safety ratio of 0.8-0.697 Shown superimposed.

[0127] The results show that the irradiance (X) [mW / cm 2 ](X>0), and cumulative exposure (Y)[mJ / cm 2 ] is in the relationship of Y<0.4534X -0.697 The UV rays L1 are irradiated in a manner within a certain range, thereby suppressing the generation of odor. Moreover, as mentioned above, since the room 1 is ventilated at least once every two hours, it is assumed that the air in the room 1 containing the substance causing the odor is discharged through the door 8 and the ventilation port 9, and the concentration of the substance is reduced. Therefore, it can be seen that by keeping the cumulative exposure (Y) within two hours within Y < 0.4534X -0.697 The generation of odor can be suppressed by irradiating ultraviolet light L1 in a manner within the range of . -0.697 Irradiating ultraviolet light L1 in a manner can enhance the effect of suppressing odor generation.

[0128] Moreover, according to Table 1, at illuminance X = 0.003 mW / cm 2 In the case of 2 , three of the five evaluators judged the odor index N to be 30 or higher. An odor index N = 30 is generally considered to be extremely strong, comparable to the intensity of tobacco smoke, gasoline at a gas station, or the smell of curry cubes up close.

[0129] Likewise, from Tables 2 to 4, the following results were confirmed.

[0130] According to Table 2, at illumination X = 0.01 mW / cm 2 In the case of 2 , four out of five evaluators judged that the odor index N was 30 or higher.

[0131] According to Table 3, at illumination X = 0.1 mW / cm 2 In the case of 2 , three of the five evaluators judged that the odor index N was 30 or above.

[0132] According to Table 4, at illumination X = 1mW / cm 2 In the case of 2 , four out of five evaluators judged that the odor index N was 30 or higher.

[0133] From the above results, it can be seen that the value of the integrated radiation amount Y at which an extremely strong odor begins to be generated varies depending on the value of the illuminance X. Figure 9 Based on the results of Tables 1 to 4 above, the relationship between the cumulative exposure amount Y and the illuminance X is plotted, for which more than half (three or more in this case) of the evaluators judged the odor index N to be 30 or more. Figure 9 In the figure, the horizontal axis represents the illuminance X [mW / cm 2 ], the vertical axis represents the cumulative exposure Y [mJ / cm 2 ]. In addition, Figure 9 The approximate curve that actually passes through the four points is Y=10.704X -0.373 , and Y = 8.563X considering the safety ratio of 0.8 -0.373 Shown superimposed.

[0134] The results show that the irradiance (X) [mW / cm 2 ](X>0), and cumulative exposure (Y)[mJ / cm 2 ] is in the relationship of Y<10.704X -0.373 By irradiating the ultraviolet light L1 in a manner within the range of , it is possible to suppress the generation of strong odors. Moreover, as mentioned above, since the room 1 is ventilated at least once every two hours, it is assumed that the air in the room 1 containing the substance that causes the odor is discharged through the ventilation port 9, the door 8, and the gap, and the concentration of the substance is reduced. It can be seen from this that by keeping the cumulative exposure (Y) within two hours within Y < 10.704X -0.373 The ultraviolet rays L1 are irradiated in a manner within the range of , which can suppress the generation of strong odor. In addition, by taking into account the safety ratio of 0.8, Y<8.563X -0.373 By irradiating ultraviolet light L1 in a manner, the effect of suppressing the generation of strong odors can be improved.

[0135] In other words, it can be seen that the illuminance (X) [mW / cm 2 ](X>0), and cumulative exposure (Y)[mJ / cm 2 ] is at 0.4534X -0.697 <Y<10.704X -0.373 When the air is within the range of , although people can confirm that an odor is generated in room 1, the intensity of the odor is suppressed to a relatively weak range.

[0136] The reason why the lower limit of the cumulative radiation amount Y at which the generation of an odor is confirmed varies with the illuminance X is currently unknown, but the present inventors speculate as follows.

[0137] The bactericidal effect of ultraviolet light in the 200-235 nm range has been shown to be illuminance-dependent. Specifically, at the same irradiation level, higher illuminance results in greater bactericidal activity. This suggests that the decomposition of squalene also exhibits illuminance-dependence, with higher illuminance levels promoting greater progress at the same irradiation level.

[0138] [Verification 2]

[0139] For example, the illuminance X in Table 1 is 0.003 mW / cm 2 This value is an extremely weak illumination. Even at this weak illumination, a sterilizing effect on fungi 3 attached to the treatment object 2 can be achieved, and this has been verified through experiments. The test method is described below.

[0140] 1mL of concentration 10 6 Approximately 100 μg / mL of Staphylococcus aureus was placed in a 35 mm diameter petri dish and irradiated with UV light L1 at a prescribed dose from above. The solution in the dish after UV light L1 exposure was then diluted with physiological saline to a prescribed multiple, and 0.1 mL of the diluted solution was inoculated onto a standard agar medium. The culture was then incubated for 24 hours at a temperature of 37°C and a humidity of 70%, and the number of colonies was counted.

[0141] As a result, at illuminance X = 0.003 mW / cm 2 Under this extremely weak illumination, the ultraviolet irradiation time is 83 minutes (the cumulative irradiation dose is about 15mJ / cm 2 ) ultraviolet irradiation, it can be confirmed that Staphylococcus aureus can be inactivated to 99.7%.

[0142] Furthermore, it can be seen that even with an illuminance of X = 0.0002 mW / cm 2 , X=0.0005mW / cm 2 , X=0.00075mW / cm 2 Less than 1μW / cm 2 Even with such low illumination, the ultraviolet light L1 can kill bacteria. 2 Under this extremely weak illumination, the ultraviolet irradiation time is 13 hours (the cumulative irradiation dose is about 10mJ / cm 2 ) ultraviolet irradiation, it can be confirmed that Staphylococcus aureus can be inactivated up to 60%.

[0143] In addition, as another verification, the same verification was carried out on feline coronavirus. When the illumination was X = 0.1 mW / cm 2 The cumulative exposure dose of ultraviolet radiation is Y = 1.5 mJ / cm 2In contrast, in the case of Staphylococcus aureus, to achieve the same inactivation rate of -2.5Log, X=0.1mW / cm 2 The cumulative exposure dose of ultraviolet radiation is Y = 5mJ / cm 2 The results showed that even with about 1 / 5 of the cumulative irradiation dose of ultraviolet light L1 applied to fungi, the same number of viruses could be inactivated.

[0144] That is, it can be seen that in the inactivation device 5 of the present invention, the control unit 12 sets the relationship between the illuminance (X) and the cumulative irradiation amount (Y) within two hours to be Y < 10.704X -0.373 More preferably, it is in the range of Y<8.563X -0.373 By controlling the lighting of the light source 11 in a manner within the range of , it is possible to suppress the generation of strong odor while inactivating the fungi 3 attached to the treatment object 2. In addition, it is known that the control unit 12 controls the relationship between the illuminance (X) and the cumulative irradiation amount (Y) within two hours to be Y < 0.4534X -0.697 More preferably, Y<0.36272X -0.697 By controlling the lighting of the light source 11 in a manner, it is possible to inactivate fungi 3 attached to the treatment object 2 while significantly suppressing the generation of odor.

[0145] In the present invention, the method by which the control unit 12 detects the illuminance X on the surface of the processing object 2 is an arbitrary method. Figure 10 As shown in FIG. 1 , an illuminometer 7 for detecting the illuminance X on the surface of the object 2 may be provided. In this case, Figure 11 As shown, the inactivation device 5 includes a receiving unit 13 for receiving the illuminance information i7 sent from the illuminometer 7, and the control unit 12 can also be configured such that the relationship between the illuminance (X) based on the illuminance information i7 and the cumulative exposure (Y) within two hours is Y < 10.704X -0.373 The lighting of the light source 11 is controlled in a manner within a range of.

[0146] In addition, as another example, Figure 12As shown, the deactivation device 5 may also include a distance measuring unit 14, such as a distance measuring sensor, for measuring the distance between the light extraction surface of the light source 11 and the surface of the treatment object 2. In this case, the control unit 12 may also calculate the illuminance X on the surface of the treatment object 2 based on the light output of the light source 11 and information about the distance measured by the distance measuring unit 14. As another example, even if the deactivation device 5 does not include the distance measuring unit 14, when the deactivation device 5 is fixed to the ceiling, the control unit 12 may calculate the illuminance X on the surface of the treatment object 2 based on the light output of the light source 11 and information related to the typical ceiling height.

[0147] As described above, the inactivation device 5 in this embodiment is such that the control unit 12 sets the relationship between the illuminance (X) and the cumulative irradiation amount (Y) within two hours to be Y < 10.704X -0.373 The lighting of the light source 11 is controlled in a manner within the range of . In this case, within the range satisfying the above formula, the control unit may continuously light the light source 11, or may light the light source 11 so that the illumination fluctuates between high and low illumination values ​​over time or periodically, or may light the light source 11 intermittently. In addition, when lighting the light source 11 so that the illumination fluctuates periodically or over time, the lighting waveform may be a rectangular wave.

[0148] There are individual differences in the ability to perceive odors. That is, even if Y < 10.704X -0.373 Even when irradiating with ultraviolet light L1 under certain conditions, some people may detect the presence of an unpleasant odor in room 1. Furthermore, since the substance that generates the odor is generated during the period of irradiation with ultraviolet light L1, intermittent lighting can reduce the amount of odor-generating substance generated during a given period. Furthermore, when the light is off, the air circulating in room 1 diffuses the odor-containing air, which is expected to make the odor less noticeable.

[0149] As described above, by changing the illumination over time or periodically between a high illumination value that easily generates odor and a low illumination value that does not easily generate odor, the amount of substances that are the source of odor generated at the same time can be reduced.

[0150] Based on the above viewpoint, the control unit 12 may repeatedly perform the following control, that is, after continuously lighting the light source 11 for a predetermined first time, it extinguishes the light source 11 for a predetermined second time that is longer than the first time. In this case, the duty ratio of the lighting time is preferably set to 50% or less, more preferably to 25% or less, further preferably to 10% or less, and particularly preferably to 5% or less.

[0151] In addition, from the same point of view, the control unit 12 may repeatedly perform the following control, namely, after continuously lighting the light source 11 for a predetermined first time, lighting the light source 11 with reduced light intensity for a predetermined second time longer than the first time.

[0152] In either case, the first time and the second time may each be variable.

[0153] [Other embodiments]

[0154] Other embodiments will be described below.

[0155] <1> In the above embodiment, the treatment object 2 is described as being placed in "Room 1." However, the method of the present invention is not limited to the case where the treatment object 2 is placed in "Room 1." The same method can be used even when the treatment object 2 is placed "inside a building," including a corridor. Furthermore, the same method can be used even when the treatment object 2 (such as a seat, handrail, or handle) is placed in a vehicle such as a train, car, airplane, or ship.

[0156] <2> When the cumulative exposure (Y) within two hours is close to 10.704X in relation to the illuminance (X) -0.373 When the light source 11 is off, the control unit 12 can also automatically control the light source 11 to turn off or reduce the light output.

[0157] <3> In the above embodiment, the light source 11 is described as comprising an excimer lamp 23 enclosing a luminescent gas 23G containing KrCl or KrBr. However, as described above, in the present invention, the light source 11 may also be an excimer lamp 23 enclosing another luminescent gas 23G, or a lamp other than an excimer lamp 23, or a solid-state light source such as an LED or LD. The light source 11 may have any structure or light-emitting principle, as long as it emits ultraviolet light L1 exhibiting a light output within a specific wavelength range of 200 nm to 230 nm.

Claims

1. A method for inactivating fungi or viruses, characterized in that: The method comprises the steps of continuously or intermittently irradiating an object touched by a person with ultraviolet rays having a specific wavelength within a range of 200 nm to 235 nm and exhibiting a light output. The process (a) is carried out with an illumination (X) [mW / cm 2 ] and the cumulative exposure within two hours (Y) [mJ / cm 2 ] The process of irradiating the ultraviolet light in a manner satisfying the following formula (1), wherein X≥0.003, 0Y10.704X -0.373 ...(1)。 2. The method for inactivating fungi or viruses according to claim 1, wherein: The process (a) is carried out with an illumination (X) [mW / cm 2 ] and the cumulative exposure within two hours (Y) [mJ / cm 2 ] The process of irradiating the ultraviolet light in a manner satisfying the following formula (2), wherein X≥0.003, 0<Y<0.4534X -0.697 …(2)。 3. The method for inactivating fungi or viruses according to claim 1 or 2, wherein: The step (a) is a step of intermittently irradiating the ultraviolet rays so as to satisfy the formula (1).

4. The method for inactivating fungi or viruses according to claim 1 or 2, wherein: The step (a) is a step of irradiating the ultraviolet rays indoors. The method for inactivating fungi or viruses comprises the step (b) of ventilating the air in the room at least once within two hours.

5. A fungus or virus inactivation device, characterized in that: have: a light source that continuously or intermittently emits ultraviolet light having a specific wavelength within a range of 200 nm to 235 nm toward an object touched by a person; and a control unit, controlling the luminous intensity of the light source, The control unit is configured to determine the illuminance (X) [mW / cm 2 ] and the cumulative exposure within two hours (Y) [mJ / cm 2 ] The luminous intensity of the light source is controlled in a manner that satisfies the following formula (1), wherein X ≥ 0.003, 0Y10.704X -0.373 ...(1)。 6. The fungus or virus inactivation device according to claim 5, characterized in that: The control unit controls the illuminance (X) on the irradiation surface [mW / cm 2 ] and the cumulative exposure within two hours (Y) [mJ / cm 2 ] The luminous intensity of the light source is controlled in a manner that satisfies the following formula (2), wherein X ≥ 0.003, 0<Y<0.4534X -0.697 …(2)。 7. The fungus or virus inactivation device according to claim 5 or 6, characterized in that: An illuminometer is provided to measure the illuminance (X) on the irradiated surface and transmit the measurement to the control unit.

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