A method and system for monitoring bioaerosols

Abstract

A method and apparatus are provided for monitoring one or more bioaerosols in a building. The apparatus comprises: a surface 140 for exposure to ambient air, wherein the surface is configured to receive and cultivate a bioaerosol from the ambient air; a camera 130 for acquiring one or more images of the surface and of one or more bioaerosols cultivated thereon; and a sensor device 160 for obtaining one or more measurements of the relative humidity and temperature of the ambient air. The one or more images of the surface and the one or measurements of the relative humidity support management of the bioaerosols by identification of the one or more bioaerosols.

Description

Brief Description of the Figures Various implementations of the claimed invention will now be described by way of example only with reference to the following drawings. Figure 1 is a schematic diagram of one example of an apparatus for monitoring bioaerosols according to the present disclosure. Figure 2 is a schematic diagram of another example of an apparatus for monitoring bioaerosols according to the present disclosure. Figure 3 is a flowchart showing an example of the operation of the apparatus for monitoring bioaerosols according to the present disclosure. Detailed Description A method and apparatus are disclosed herein for monitoring one or more bioaerosols. Such bioaerosols may include bacterial and mould spores, as well as toxins, fungi and viruses. The monitoring of bioaerosols may include monitoring the bioproducts of such bioaerosols, such as a mould which is biologically generated from spores; this monitoring of the bioproducts may provide information about the spores which produced them. A fungus (or fungi) responsible for mould generally grow in damp places. Common causes for such damp places is condensation within a building, rising damp, penetrating moisture from leaks, and building defects such as roof problems etc. Thus air is able to hold a certain amount of water vapour in gaseous form. The maximum amount of water vapour that can be held in this form depends on the temperature - the hotter the air, the greater the amount of water vapour that can be held in the air. Humidity is generally measured in terms of relative humidity with reference to the maximum amount of water vapour that can be held by the air at that temperature. If the relative humidity is low, say 10%, the air will generally feel quite dry and the skin may tend to lose moisture. Conversely, if the relatively humidity is high, say 90%, this will generally feel quite humid and it may be more difficult for a human to cool by perspiration. At high relative humidity, especially approaching 100% relative humidity, saturation occurs, and the atmosphere cannot hold all the moisture. In these circumstances, the water vapour tends to condense out of the air into small drops (droplets) of moisture. Within a building, these small drops of moisture may join together to form condensation which typically accumulates on surfaces such as walls. In a buildings, structure and domestic residence, there are various typical sources of water vapour and hence condensation. Humans breathe in ambient air and exhale air that is generally warmer and more humid than the ambient. As the exhaled air cools down to ambient, this may lead to increased relative humidity because the maximum capacity of the air for holding moisture is reduced with such cooling. In other words, even if the amount of moisture in the air does not change, the relative humidity rises because of a fall in temperature, and hence a corresponding fall in the maximum capacity of the air to hold moisture. This effect is readily visible by exhaling on a cold day, when breathing out produces a fine mist of condensed water droplets. Another source of moisture in a building, particularly a domestic residence is typically the kitchen, where steam may be generated from boiling water in a kettle, in cooking, and so on. A further source of moisture in a building, particularly a domestic residence (and typically the most significant source) is the bathroom, especially showers and baths. In some cases, particularly for showers, dampness may arise not only from condensation but also from small droplets of water that are splashed out from the shower and then deposited directly onto the walls (without going through a process of vaporisation and then condensation). One way to reduce the level of dampness in a building or structure is to exchange air in the building (having a relatively high humidity) with air from outside the building (having a lower humidity). Such an exchange may be performed actively by using a fan and / or passively by opening a window to allow airflow therethrough. Although such operations may be effective in the warmer summer months when the air outside the building is typically mild, it may be less effective in winter months when the air outside the building is relatively cold. The incoming cold air cannot absorb much water vapour (because of the relatively low maximum capacity of cold air for water vapour). Furthermore, the introduction of such cold air lowers the temperature within the building, and further heating must therefore be applied to maintain a comfortable temperature within the building. However, there may be a significant additional cost associated with such further heating. Other aspects of behaviour in winter may further increase the presence of dampness and hence mould indoors. For example, in summer months it may be possible to hang washing out to dry on a clothes line. In contrast, for winter months when it is colder and often wetter, drying outside may not be feasible. In such circumstances, washed items of clothing may be placed onto or near a radiator to dry, but this again will increase the level of water moisture within the building, and hence potentially raise the amount of condensation. Another potential source of dampness within a building (apart from the condensation) is a leak of water. Such a leak may allow external water (rain) to pass into the building thereby causing dampness. Alternatively, a leak may arise from a of plumbing defect within the building, and this may again cause dampness and lead to increased water vapour. It is possible to combat mould using a variety of chemical cleaners or treatments. The application and use of such cleaners may require considerable physical effort, especially if the mould is growing in a relatively inaccessible location, such as at ceiling level. Although these cleaners may be effective at removing mould, it is common for such mould to re-establish itself at a later date. The above problems arising from mould in domestic buildings may be particularly acute for people living in social housing. For example, such people may be more likely to have other medical conditions that make them more vulnerable to disease or other adverse effects from mould. In some cases, their physical and / or medical condition may make it difficult for them to clean or treat mould properly. In some cases, they may occupy a dwelling that is relatively compact and so will typically have a higher concentration of water vapour (humidity) in the dwelling. In some cases, their financial situation may lead to fuel poverty, whereby they cannot afford to pay to properly heat a dwelling. Having a cooler indoors temperature will tend to increase the amount of dampness and hence mould. The approach described herein may be used to provide a combination of technology, product and service which may be delivered on a subscription basis to address at least some of the issues arousing from bioaerosols, such as mould in buildings such as set out above. This approach addresses a specific environmental issue in housing, especially in social housing, which is damaging to the mental and physical wellbeing of occupiers (this is referred to herein as a Category 1 risk - see “Housing, Health and Safety Rating System” - https: / / www.staffordbc.gov.uk / housing-health-and-safety-rating-system). The approach described herein helps (inter alia) to: - reduce the financial and / or environmental costs of managing high risk properties occupied by vulnerable residents - reduce the incidence of mental and physical harm to occupiers from high levels of Category 1 risks - reduce the incidence of human error with the adoption of technology to gather empirical data - monitor in real time the effectiveness of resultant remediation works. As described herein, a single (combined) monitoring and communicating unit is provided for detecting and recording (i) airborne fungal spores and (ii) Relative Humidity (RH) and temperature. Measurements may be taken both internally and externally, the latter to establish a base line. These measurements may be communicated over a suitable network to a host system (remote server) for data analysis and modelling of the captured data. The remote server may be implemented as a cloud computing facility or as any other suitable computational resource. Based on the above analysis and modelling, an action-based report can be supplied to the relevant housing provider, (or building owner or other interested party) for a building in which the bioaerosol level, for example mould level has been monitored as described herein. The housing provider (and / or other interested parties) may receive some form of alert, for example via text, email, phone, etc, if the analysis suggests a particularly problematic situation, for example, one that might impact human health. The housing provider / owner / tenant may also be provided with guidance on one or more remedial actions that should be taken to address such a bioaerosol problem, for example mould problem as determined by the approach described herein. The approach described recognises that the relative humidity (RH) and temperature within a building or structure (e.g. dwelling) is one factor responsible for the rate of bioaerosol development and growth, for example mould development and growth. The high incidence of fuel poverty amongst the occupiers of such properties is forecast to make the existing problem significantly worse as a result of increasing fuel costs. Real time RH and temperature monitoring enables predictions to be made as to the rate of bioaerosol growth, for example mould growth of a property and therefore the resulting health risk to occupiers of the property. The approach described herein therefore supports the widescale adoption of proactive remote monitoring and reporting of bioaerosol conditions, for example mould conditions in social housing. Such monitoring and reporting may be used, inter alia, to enable a property owner or a (private or public) landlord to initiate one or more preventative actions for a building e.g. a dwelling before the bioaerosol populations, for example mould populations in that dwelling reach a level that poses a risk to the mental and / or physical health of the occupiers. Figure 1 is a schematic diagram of one example of a method or apparatus for monitoring mould and other bioaerosols according to the present disclosure. In particular, Figure 1 depicts a monitoring and communicating system 100 which may be used to implement a system, apparatus or method for monitoring mould and other bioaerosols in a building. In operation, the monitoring and communicating system 100 may communicate with a remote server such as a host system (not shown in Figure 1), as will be described further below. The monitoring and communicating system may be fastened to a wall 20. The wall 20 is typically an external wall, but may be an internal wall if appropriate. The arrow 101 generally indicates the “up” direction for the wall 20 and the installation of the monitoring and communicating system 100 mounted thereon. The monitoring and communicating system 100 includes a channel 170 which defines a pathway corresponding to arrow 180. This pathway 180 extends from an ingress into the channel 170 to an egress from the channel. The monitoring and communicating system 100 further includes a fan 150 to draw air along this pathway 180 from the ingress to the egress. It is however to be understood that the air may be moved along this pathway by any suitable means and is not to be limited to the use of a fan. For example, the air may be moved along this pathway by the use of a vacuum. The system may comprise an airflow driver configured in use to move air along this pathway, the airflow driver being selected from one or more of: a fan, a vacuum or any combination thereof. The ingress is provided with a first aperture seal 120A to control the flow of air through the ingress into the pathway, while the egress is provided with a second aperture seal 120B to control the flow of air out of the pathway 180 via the egress. The aperture seals 120A, 120B include shutters or doors which can be open or shut. The aperture seals 120A, 120B are generally operated in synchronism with one another, so that both are open or both are shut together. The aperture seals 120A, 120B are generally closed, but open to obtain a sample of ambient air from within the room (building) which incorporates the monitoring and communicating system 100. In particular, such a sample is obtained by opening the aperture seals 120A, 120B for a predetermined time duration, and operating the fan 150 during this time duration to draw air from the room through (open) aperture seal 120A, along the pathway 180 towards aperture seal 120B, and then exiting the monitoring and communicating system 100 through aperture seal 120B. The ingress of the channel 170 is provided with a sensor 160 which is located slightly upstream of the first aperture seal 120A. The sensor 160 is used to measure the relative humidity and temperature of ambient air that is drawn towards the monitoring and communicating system to travel along the pathway 180. As explained above, the level of relative humidity and temperature in a building has a significant impact on the rate of growth of bioaerosols, such as mould in the building. The pathway 180 is further provided with an Petri-dish / plate 140 (containing a growth medium such as Agar) located on the pathway 180 between the first aperture seal 120A and the second aperture seal 120B. The dish / plate 140 is typically provided with some growing medium for microscopic cultures. The dish / plate plate 140 is shown in Figure 1 as extending across the channel 170, but may contain openings, apertures or adopt any other suitable configuration to allow an airflow to pass over, around or through the dish / plate 140 without undue hindrance as the airflow progresses from the ingress to the egress. The system may further comprise one or more filters, for example HEPA filters. The system may further comprise one or more baffle plates located at the openings / appartures or adjacent the dish / plate 140 in order to provide air turbulence over the plate 140. The system may further include one or more vibration sensors configured in use to detect movement within the room and / or to determine the rate of use of the room by a user and / or when the system can be operated with least disturbance to the occupants. This may provide an indication as to the airflow within the room and for example the opening / closing of windows. Accordingly, the air flows past the relative humidity and temperature sensor 160, past the first aperture seal 120A, and then past the dish / plate 140. If this flow of air includes microscopic spores of fungi (or other bioaerosols), these spores may settle or be deposited on the dish / plate 140 and then start to grow and propagate on the dish / plate . The monitoring and communicating system 100 further includes a camera 130 which is positioned and controlled to take images of the dish / plate 140. These images indicate the level of fungal and / or bacterial growth on the dish / plate, which in turn reflects the level of mould and fungi (and spores thereof) in the building which houses the monitoring and communicating system 100. In this context, the dish / plate can be considered as a form of amplifier, in that even if the level of spore in the airflow is relatively low, this will lead to a measurable level of fungi developing on the dish / plate 140, since the growth medium of the dish / plate 140 is favourable to growth and propagation of the fungi. It will be appreciated that this amplification allows relatively low levels of mould spores to be detected and then treated before they have become too firmly established in a given building and while the concentration of mould is still relatively low and unlikely to cause or exacerbate medical (health) problems for occupants within the building or room which houses the monitoring and communicating system 100. The camera 130 may image the dish / plate 140 at regular intervals to track the development of the mould on the growth medium 140. When a sample is initially collected by opening the aperture seals 120A, 120B and operating fan 150, a relatively small amount of mould spores may be deposited onto the dish / plate , which may not be easily visible to the camera 130 at this early stage. However, a sequence of further images may be acquired at subsequent times to track the proliferation and growth of the mould on the growth medium of the dish / plate 140 which renders the mould increasingly visible. The type of mould may be identified from the images acquired by the camera 130, in particular from the appearance of the mould, including the way the mould spreads as it grows. In some cases, two or more different types of mould may be present in a single sample obtained by the growth plate 140 within the monitoring and communicating system 100, and the multiple different moulds may be individually identified based on their appearance and pattern of growth. The dish / plate 140 may be extracted from the monitoring and communicating system 100 at suitable times (such as visits by remote microscopy or by a suitable operator of the monitoring and communicating system 100). In this case the operator may replace the existing dish / plate 140 with a new plate. The existing dish / plate 140 may be taken away for analysis and refurbishment for subsequent re-use. In some cases, the operator may clean and refurbish the existing dish / plate 140 while at the same location as the monitoring and communicating system 100, and then directly reinsert the dish / plate 140 into the monitoring and communication system 100 (thereby avoiding the need for the operator to have a replacement dish / plate 140). The monitoring and communicating system 100 further includes a control unit 110. In Figure 1, the control unit 110 is shown mounted together with the other components of the monitoring and communicating system 100. In other implementations, the control unit may have a different location. For example, in some cases the control unit may be separately attached to the wall 20, or may be configured in any other suitable arrangement. The control unit 110 may contain or have access to a power source which can be used to operate the camera 130 and / or fan 150 and / or the aperture seals 120A, 120B and / or the sensor 160 (and the control unit 110 itself). In some cases, the power source may comprise some form of (rechargeable) lithium (or similar) battery. In other cases, the control unit may receive mains power which is then distribute to devices such as camera 130 and / or fan 150. The distribution of mains electrical power may be performed at a suitably reduced voltage, for example, if the monitoring and communicating system 100 is located in or near a bathroom. In some cases, the monitoring and communicating system 100 is mains-powered, but is also provided with a rechargeable Li-ion battery or other suitable type of battery (not shown in Figure 1) to provide resilience against any failure in the supply of mains power. In particular, in the event of a failure in the mains power, the control unit 110 may continue to operate the monitoring and communicating system 100 using power from the rechargeable battery. This continued operation may include reporting to the remote server the failure of mains power, as well as potentially reporting the restoration of mains power, and also the charge level of the battery. The control unit 110 also contains a communications facility for sending messages to and / or receiving messages from a remote host system (remote server). Such communications may be performed over the Internet and / or over any other suitable network. In some cases, the communications to and from the control unit 110 may be performed at least partly using a wireless network. For example, the control unit may interact with a wireless local area network (LAN) in the building in order to access the Internet. In some implementations, the control unit 110 may utilise a mobile telephone (cellphone) to perform wireless communications with the host system, such as by using a 4G or 5G (or their successors) wireless data communications network. In some cases, the control unit 110 may support multiple communications facilities and may select a facility which is most suitable for each installation and / or for each data communication. The control unit 110 sends information to the host system, including the output from sensor 160 about the relative humidity and temperature level of the ambient air and the images acquired by camera 130 of the dish / plate showing any growth of the mould. The host system can then use this received information to determine the mould(s) which have been captured by the monitoring and communicating system 100, and also to determine the likely future growth rate of the mould (having regard to the measured relative humidity and temperature). This then allows the host system to identify dwellings that are most in need of remedial action in relation to mould, and also to prioritise between such buildings / dwellings having regard to the predicted growth rate of mould for each such building / dwelling. Figure 2 is a schematic diagram of another example of a monitoring and communicating system 200 for addressing bioaerosols in a building according to the present disclosure. Again, the monitoring and communicating system 200 may communicate with a remote server (not shown in Figure 2), as will be described further below. The general motivation and high-level operation of the monitoring and communicating system 200 of Figure 2 matches the monitoring and communicating system 100 of Figure 1. In addition, the monitoring and communicating system of 200 has various components and operations in common with the monitoring and communicating system 100 - for reasons of conciseness, these common components and operations are generally not described again in detail. However, the monitoring and communicating system 200 also has some differences from the monitoring and communicating system 100, as will become apparent from the description below. More generally, the examples 100, 200 of Figures 1 and 2, help to illustrate (without limitation) the range of monitoring and communicating systems according to the present disclosure. In common with monitoring and communicating system 100 of Figure 1, the monitoring and communicating system 200 of Figure 2 is generally intended for mounting on a wall 20, with arrow 101 showing the ‘up’ direction for wall 20 (note that the orientation of the ‘up’ direction 101 as shown in Figure 2 is rotated by 90 degrees from the orientation of the ‘up’ direction 101 as shown in Figure 1). As in Figure 1, the monitoring and communicating system 200 also includes a channel 170 extending between an ingress and an egress with baffles at the ends of the channel. The channel 170 defines a pathway 180 for airflow into, through, and then out of the monitoring and communicating system 200 of Figure 2 via the ingress and egress. An aperture seal 120A is located at the ingress, and an aperture seal 120B is located at the egress. Each aperture seal 120A, 120B may be opened, to allow airflow into and / or out of the channel 170. As described above, the first and second aperture seals 120A, 120B are generally operated in synchronism with one another, whereby the first and second aperture seals 120A, 120B are both closed or are both opened. In the former configuration, the channel 170 is in effect sealed off from ambient air in the building or room which accommodates wall 20 and the monitoring and communicating system 200. In contrast, for the latter configuration, the first and second aperture seals 120A, 120B may be opened to allow ambient air to flow through the channel 170 of the monitoring and communicating system 200 along the pathway 180 for temperature control purposes. As in Figure 1, a fan 150 is located within the channel 170 and may be operated to encourage this ambient airflow through the monitoring and communicating system 200. In some implementations, the fan 150 may comprise multiple fan units; in some implementations, the fan may be replaced or supplemented by some form of suction device which is provided within the monitoring and communicating system 200 to impel the ambient airflow along the pathway 180. Accordingly, it will be understood that the monitoring and communicating systems 100, 200 may create the flow of ambient air along the pathway 180 in any suitable manner. Likewise, the aperture seals 120A, 120B can be provided in any suitable manner to open or close channel 170 to the flow of ambient air. For example, the aperture seals 120A, 120B may each comprise one or more doors or shutters that swing open to allow airflow, and swing back to close off the airflow. In another example, the aperture seals 120A, 120B may comprise one or more sliding doors that slide between an overlapping (open) position and a non-overlapping (closed) position. In another example, the aperture seals 120A, 120B may act in a similar manner to a sluice gate having one or more passages therethrough which can be opened or closed. Other types of aperture seal may be based on a shutter, barrier, or any other suitable facility for opening and closing the ingress and egress to / from the channel 170. The operation to open and close the aperture seals 120A, 120B may be powered by the control unit 110. For example, the control unit may operate an electrical actuator (not shown) to open and close the aperture seal 120A and another electrical actuator (not shown) to open and close the aperture seal 120B. The control unit may also be responsible for controlling the timing of operating the aperture seals 120A, 120B. In particular, the timing of the aperture seal control may be based on an exposure time and an exposure duration. The exposure time identifies when (time / day) the aperture seals 120A, 120B have been opened, in effect to obtain a sample of ambient air, while the exposure duration reflects how long the aperture seals 120A, 120B were held open to obtain the sample before closing again. The exposure time and duration are discussed further below. As in Figure 1, the monitoring and communicating system 200 includes a sensor 160 to determine the relative humidity of the ambient air. In the implementation shown in Figure 2, the sensor 160 may comprise two sensor units (which may be co-mounted on or close to one another). The first sensor unit 161 in sensor 160 is a temperature sensor to measure the temperature of the ambient air, while the second sensor unit 162 in sensor 160 is a humidity sensor to measure the moisture level (humidity) of the ambient air. These measurements of temperature and moisture level allow the relative humidity (RH) to be determined, for example by dividing the measured moisture level by the maximum (saturation) moisture level for the measured temperature (the moisture saturation level being known for any given temperature). It will be appreciated that the sensor 160 shown in Figure 2 represents an example of a device to measure RH, and other implementations of a relative humidity sensor 160 may be adopted as appropriate. The control unit 110 may control the RH sensor 160 to take regular measurements of the RH in the ambient air, by way of example, every T minutes, where T might (without limitation) be in the range 0.1-30 minutes, 30—120 minutes, or in the range 120 minutes or more, or in any aggregation of such ranges which are contiguous to one another. These measurements provide a record of relative humidity and temperature in the ambient air, which in turn allow an estimate (prediction) to be made of the rate of microbial growth of bioaerosols (mould, bacteria, etc) in the room or building containing monitoring and communicating system 100, 200. This in turn helps to identify locations for which timely action is most urgent (such as a treatment to remove or reduce mould). Note that the RH sensor 160 is located on the exterior of the monitoring and communicating system 100, 200 (rather than being located, for example, within channel 170). This reflects the fact that the rate of bioaerosol growth, for example mould growth within the room which contains the monitoring and communicating system 100, 200 generally depends on the RH and temperature level within the ambient air of this room. In contrast, the RH and temperature level in the channel 170 itself may potentially differ from the RH and temperature in the room in general, especially when the aperture seals have been closed for a while, for example because of heating within the monitoring and communicating system 100, 200 (as described in more detail below). The provision of a growth substrate in the monitoring and communicating system 200 of Figure 2 is somewhat different from the provision of the dish / plate 140 in Figure 1. In particular, the monitoring and communicating system 200 includes a cassette 225 containing multiple cartridges 222A ... 222D and a collector 230 comprising a chamber or cavity located below the cassette 225. The cassette 225 is shown in Figure 2 as accommodating up to four cartridges (dishes / plates), but this is by way of example, and other forms of cassette 225 may accommodate more or fewer cartridges. Each cartridge 222A ... 222D is somewhat analogous to the dish / plate 140 of Figure 1, in that such a cartridge provides a base (substrate) coated with a growth medium for receiving spores from the airflow through channel 170, whereby these spores are then able to proliferate and propagate on the growth medium of the cartridge. The bottom of the cassette 225 is provided with a shutter or door 221, likewise the top of the collector 230 is also provided with a corresponding shutter or door 241. The shutter or door 241 of the collector 230 is located underneath, and opposite to, the shutter or door 221 of the cassette 225. In operation, the cassette 225 is initially full of cartridges 222A ... 222D, while the collector 230 is empty. To commence operations, shutter 221 is temporarily opened (for example, via a retraction) to allow a single cartridge 222D to be lowered or fall from the cassette 225 onto the trap door 241 of collector 230. At this stage, the trap door 241 of the collector 230 is kept closed, so that the cartridge 222D is received onto and supported by the trap door 241 - as indicated by arrow 223, and also the broken line version of cartridge 222D. In this position (on top of trap door 241), cartridge 222D represents an active cartridge, and the ambient air flowing along pathway 180 may deposit spores onto this cartridge (dish / plate), which provides for the collection and cultivation of the spores. When cartridge 222D has been completely used, the trap door 241 is temporarily opened to allow the cartridge 222D to fall, or be lowered into the cavity of the collector 230. The above processing is repeated for each further cartridge in the cassette 225, namely next cartridge 2220 is dropped onto trap door 241 for operational use collecting and propagating the spores. When the use of cartridge 222C has been completed, for example because space on the cartridge and / or the growth medium has fully been consumed, trap door 241 again opens to allow the cartridge 222C to fall into the cavity of collector 230. The trap door 241 then closes again, the cycle repeats next for cartridge 222B and lastly for cartridge 222A. When all the cartridges 222D-222A have been utilised and consumed in this manner, the consumed cartridges 222D-222A may be extracted from the collector 230 to be refurbished (reconditioned) for reinsertion into a cassette 225 for re-use in the monitoring and communicating system 200. In some implementations the empty cassette 225 may be replaced with a new cassette, complete with new cartridges. In other implementations, an existing cassette 235 may generally be retained in situ as part of the monitoring and communicating system 200, such that new or refurbished cartridges are loaded into the existing cassette 225, without the need for any further cassette to be utilised. (Such a cassette 225 may nevertheless by removable, for example for cleaning or replacement by a different cassette adapted to different cartridges). The operation of the cartridge feed from cassette 225 and the shutters 221,241, may be controlled and / or powered via the control unit 110. The operation of the cassette 225 and / or shutter 221 may be configured to ensure that only a single cartridge falls or is lowered / dispensed from the cassette 225 onto the trap door 241 when aperture 221 opens. It will be appreciated that this provision of a single item is common to many dispensing machines and may be implemented in any suitable manner. For example, the cassette 225 may be provided with clamps (not shown in Figure 2) that can be actuated by the control unit 110 to hold the cartridge (if any) immediately above the cartridge to be dispensed. Thus in the configuration shown in Figure 2, for a dispensing operation, the control unit 110 may first clamp cartridge 222C in place, then open shutter 221 to allow cartridge 222D to fall / be lowered onto closed shutter 241. The control unit now closes shutter 221 and releases the clamp(s) on cartridge 222C, thereby allowing cartridge 222C to fall down onto shutter 221, with cartridges 222B, 222A then likewise each falling down a single position (step) towards cartridge 222C. As for Figure 1, the monitoring and communicating system 200 includes a camera 130. The positioning and orientation of the camera 130 have been changed compared with the positioning of Figure 1 to allow good imaging of the configuration of Figure 2, in which the active cartridge lies on (and extends across) the shutter 241 (compared with the perpendicular arrangement of the dish / plate 140 in Figure 1). The monitoring and communicating system 200 of Figure 2 further includes a control unit 110 and a SIM (subscribed interface module) card 112. In some implementations, the SIM card 112 may be integrated into the control unit 110. The SIM card provides data connectivity over a mobile telephone (cellphone) network, for example using 3G, 4G or 5G protocols (or its successors). Some implementations of the monitoring and communicating system 200 may support, instead of or in addition to SIM 112, one or more other forms of data communication - for example, Wi-Fi connectively to a wireless Lan and / or a USB wired connection. In addition, the control unit may support communications with a smartphone or similar device using another wireless connection such as Bluetooth. The above data communication facilities may be used to support communications to and / or from the control unit 110. For example, the communications facilities may be used to adjust settings in the control unit 110 - such as the exposure times and / or exposure durations for acquiring samples of ambient air, the format of images to be acquired, and so on. The data communications facilities may also be used to transmit data to the remote server (not shown in Figure 2) such as images acquired from camera 130 and RH readings from the RH sensor 160. Figure 3 is a flowchart showing an example of the operation of the apparatus for monitoring bioaerosols in a building according to the present disclosure. Although this method follows the operation of the monitoring and communicating system 200 of Figure 2 (because it involves the cartridges and cassette 225), an analogous flowchart could be provided for the operation of the monitoring and communicating system 100 of Figure 1 (using the dish / plate 140 instead of the cartridges and cassette). In operation 310 of Figure 3, a cartridge 222D is provided in the channel 170. Such a cartridge may, for example, be dispensed from cassette 225, or loaded in any other appropriate manner within the monitoring and communicating system. In some implementations, the cartridges may be initially provided with a protective seal / lid to protect them from contamination; such seal may for example comprise a film which extends across the cartridge. These seals may be removed by a user or operator as the cartridges are loaded into the cassette 225; the cartridges are then protected from contamination by the cassette itself until each cartridge is dispensed in turn out of the cassette 225 into the channel 170 to acquire a sample of mould spore as described herein. In operation 320, a sample of ambient air is obtained, generally by opening the aperture seals 120A, 120B and activating fan 150 in accordance with an exposure time and duration as set by the control unit 110 whilst the lid / seal on the dish / plate / cartridge is temporarily removed, before being replaced post exposure to retain the integrity of the growth medium. In operation 330, relative humidity (RH) readings are obtained for the ambient air - generally on a regular and relatively frequent basis (which again may be set by the control unit 110). In operation 340, spores from the sample of ambient air that have settled or been deposited on the cartridge (dish / plate) in the channel are provided with time to grow.in situ (on or within the cartridge). For example, the spores on the cartridge may produce fungi which grow larger and more prominent, and hence are also easier to identify, and it is also easier to determine their growth rate. In operation 350, the camera 130 is used to acquire images of the fungal growth on the cartridge. A succession of images may be obtained at a suitable time intervals, for example every hour, every four hours and so on. In operation 360, the acquired images and the RH readings are transmitted from the monitoring and communicating system 100, 200 to the remote server (not shown in Figures 1 or 2). Note that the server may receive data from multiple monitoring and communicating systems located across different buildings (and / or potentially from different rooms in a given building). In operation 370, the images are analysed to identify the type(s) of fungal moulds (or bacteria) that are growing on the cartridge. The camera 130 is configured (e.g. via control unit 110) to provide a suitable resolution and colour response for identifying the mould(s) that grow on a plate or cartridge. In practice, there are a few different moulds that may pose a Category 1 risk to human health; each of these moulds has its own distinctive colour, shape, and so on to support such identification. Furthermore, the population size of each such mould may be counted or estimated. In some cases, the population may be split into a series of contiguous population ranges and the analysis determines which population range applies to each of the identified mould types. In other words, for each of the moulds which are identified as being present, the assessment may select the population range relevant to that mould from the acquired image(s). These images may also be further analysed, in conjunction with the RH and temperature readings, to predict the rate at which the fungal moulds will grow (since RH level is generally the most important factor controlling the rate of growth of such fungal moulds). An initial estimate of growth rate may be determined from the (known) time interval between acquiring a sample, and then later acquiring an image of the sample showing the growth of the mould(s) in this known time interval. This initial estimate of growth rate may then be refined based on the measured RH levels. (In this respect, the growth rate in the building is based on the measured RH level of the ambient air - which may be different from the RH level in the channel 170 that controls the growth rate on the cartridges dish / plate). The analysis of operation 370 to identify the mould type(s) and / or the expected rate of growth may be performed by a trained clinician and / or laboratory and / or by some sort of automated facility. For example, an artificial intelligence (Al) model may use a machine learning algorithm (ML) based on images (and RH levels) that have already been analysed by trained clinicians or laboratory to provide a labelled training data set. The Al model is updated (as part of the ML) to provide a best fit to the training data set in accordance with normal Al training. This then allows subsequent analysis and identification of fungal moulds in the images to be performed automatically by a computer system which implements the trained Al model. In operation 380, the information on the identity (and predicted growth, if available) of the fungal moulds can be used to assess when an intervention is required and if so, how quickly. For example, a type of fungal mould which is known to have a significant deleterious effect on human health is more of a priority to treat than a type of fungal mould which is more benign to human health. Similarly, a fungal mould which is predicted to grow quickly (e.g. because of a high measured RH level) is more of a priority to address than a fungal mould which is predicted to grow relatively slowly in comparison. The information about which fungal moulds to treat with the greatest priority (based on the identity of the mould and on the predicted growth rates) may be supplied to a person or agency responsible for the buildings (or rooms) that are the subject of this information. The person or agency may then take appropriate action to prevent or suppress the mould(s) that provide the most serious threat to human health. In some case, the person who receives the information may be the home owner. In other cases, the person or agency which receives the information may be an external party, for example, a private landlord, a council, or their subcontractor, which is responsible for looking after the relevant buildings or rooms and the environment therein. In some cases it may be a health care professional or similar agency. The external party may typically be responsible for the safe upkeep of multiple properties such as blocks of social housing. The images and RH levels may be received by the remote server from monitoring and communicating systems 100, 200 in some or all of these different multiple properties. The outcome of the analysis of operation 370 may help the external party to prioritise the order in which bioaerosol growth, for example mould growth is treated across the multiple properties. Note that various operations in the flowchart of Figure 3 may not necessarily occur in the precise order shown in Figure 3, and a certain degree of parallelism may be implemented. For example, one possibility is for the RH and temperature readings to be obtained on an ongoing basis -including while the fungal mould is growing on the cartridge and / or while the camera 130 is being used to acquire images of the fungal mould growing on the cartridge. Likewise, as mentioned above, the remote server may receive information (camera images RH and temperature readings) from a set of multiple properties, and these may be assessed in parallel with one another. Accordingly, the monitoring and communicating system described herein is configured to capture, for example on cartridges 222A-D, bioaerosols, for example airborne mould and bacteria spores which can then, in a controlled environment within the unit, develop to become distinct and identifiable by type (as per operations 310, 320 and 340 of Figure 3). The bioaerosols are then subsequently incubated within the system. During this controlled growth of bioaerosols, for example the mould or spores, the integral camera 130 is used to take one or more images of the cartridge (dish / plate) and the fungal growth thereon. These images may then be communicated using the SIM card 112 via the 4G network (or similar) to the remote server. At intervals controlled by software running in the control unit 110, the two aperture seals 120A, 120B are opened (typically based on instructions from the control unit 110) and a volume of air flows for the exposure time over a horizontally aligned cartridge growth surface. In one example, during the collection of a sample of ambient air, the channel 170 between the ingress and egress supports a typical flow rate of 4.2 litres per minute and the exposure duration is 4 hours. Note that the total airflow volume significantly exceeds the air volume within channel 170, so that the air within the channel 170 is replenished many times over for this exposure duration. The apertures 120A, 120B close after the exposure duration, so the slide (cartridge) is not contaminated by spores etc. from any subsequent air sample unless it is otherwise protected by a seal or lid, such that the apatures 120A and 120B may then be opened and closed as required for temperature control purposes. The cartridges for use in the monitoring and communicating system 200 may be provided with a growth medium, such as a contact broth or viscose liquid (e.g. Agar), on which the fungal and bacterial spores are captured. The environment in the channel 170 may be generally maintained at a temperature between 20 and 30 degrees Celsius to enable the spores captured on the slide to develop into identifiable moulds. The monitoring and communicating system 200 may use a temperature sensor (not shown in Figures 1 and 2) to track the internal temperature of the channel 170. The control unit 110 may be provided with a heating facility to warm the channel / cartridge / dish / plate 170 if needed. In some implementations, the control unit 110 may also be provided with a cooling facility (such as an air conditioning unit) to prevent the temperature exceeding 30 degrees. In general, the fan 150 and / or any cooling device should operate quietly so that it is relatively unobtrusive, especially where the fan or cooling device is installed in an occupied building, for example a residential or domestic building. Note that measuring the temperature inside channel 170 may allow a comparison to be made between the internal and external RH for the monitoring and communicating system 200. This in turn helps to estimate the bioaerosol growth rate, for example mould growth rate in the room containing the monitoring and communicating system 200 based on the bioaerosol growth rate, for example mould growth rate observed in the channel 170. At one or more predetermined timings after the sampling exposure, the camera 130 may be used to acquire image(s) of the dish / plate or cartridge 222A, ...D. For example, 48 hours after the end of the 4-hour sampling period (with the apertures 120A, 120B open), the camera 130 may take an image of the dish / plate which is then communicated such as via the 4G / 5G network (and its successors) to the remote server which is provided with software for analysing and interpreting the received image (with or without the use of artificial intelligence). A further image may be taken 24 hours later, i.e. 72 hours after the end of the sampling period, and likewise transmitted to the remote server. After the second image has been taken, the trap door 241 may be opened to allow the cartridge (slide) to fall / lower into the collector 230 as described above. The completed dish / plate is replaced by the cartridge / dish / plate which is now located at the base of the cassette 225. This lowest available cartridge is dispensed from the cassette 225 into the airflow chamber 170 by temporarily opening shutter 221, while any remaining cartridge(s) drop down one place within the cassette 225 and are held in place by shutter 221 (which has now been closed again). The timing for curing the fungal mould from airborne spore captured by the cartridge 222A, ...D is dependent on the RH and may also be dependent on the temperature within the monitoring and communicating device 200. In broad terms, the mould is likely to proliferate more quickly with a higher temperature, so this may reduce the timings for obtaining the images, i.e. down from 48 hours and 72 hours as described above. Another approach is that the camera 130 acquires a sequence of images, say one every 30 minutes or one every hour, after the apertures 120A, 120B have been closed. The selection of which image(s) to use for identification of fungal mould and the prediction of growth can then be deferred to the subsequent analysis at the remote server. In general, having images taken at regular periodic intervals may provide a better estimate of the past growth rate, which can then be suitably extrapolated to provide an estimate for future growth. In one embodiment, the camera 130 may be a video camera. In an example implementation, the monitoring and communicating system 200 shown in Figure 2 may be configured to acquire a sample of ambient air approximately every week. Assuming that each cartridge is used once within the monitoring and communicating system 200, the four cartridges 222A-222D shown in the cassette 225 of Figure 2 therefore correspond approximately to one month’s supply for monitoring. It will be appreciated that other implementations may use multiple cassettes, or more than four cartridges per cassette to lengthen the monitoring period which can be performed prior to having to restock the monitoring and communicating system 200 with fresh (new or refurbished) cartridges. Another maintenance operation on the monitoring and communicating system 100, 200 is to clean the lens of the camera 130 to remove any items or material that have been deposited thereon from the ambient. Such cleaning may be performed remotely or each time a new plate or set of cartridges is installed, or on any other suitable basis. In addition, the surfaces of the channel 170 within the monitoring and communicating system 100, 200 may likewise be cleaned to remove dirt and / or other contaminants that may have settled on such surfaces. In some implementations, these surfaces of the channel 170 may be provided with an anti-microbial coating to reduce the risk of any bioaerosols settling onto these surfaces (rather than onto a plate 140 or cartridge 222A ... 222D as intended). The anti-microbial coating may be directly incorporated into the material of these surfaces, or may be provided as a form of lining. In some implementations, an anti-microbial formulation, for example spray, UV light, or ultrasonic device, may be applied to the surfaces of channel 170 either at the monitoring location or elsewhere, (for example at the same time as the plate 140 or cartridges 222A-222D are replaced and / or the camera 130 is cleaned). Accordingly, the surfaces of the channel 170 are generally prevented from harbouring spores that might compromise the level of spores deposited onto dish / plate 140 or cartridge / dish / plate 222A .. .222D. The operations of Figure 3 have mainly been presented in the context of identifying situations in which some remedial action (treatment) is required or desirable to counter the growth of bioaerosol, for example mould However, analogous monitoring operations might be performed after the application of such a treatment to see whether the treatment is successful at providing good protection against a bioaerosol, for example mould (or whether the treatment may be somewhat ineffective). In conclusion, while various implementations and examples have been described herein, they 5 are provided by way of illustration, and many potential modifications will be apparent to the skilled person having regard to the specifics of any given implementation. In particular, features from different implementations may be included in new combinations of features unless it is apparent to the skilled person that such a combination would not be beneficial. Accordingly, the scope of the present case should be determined from the appended claims and their equivalents. 10

Claims

1. Apparatus for monitoring one or more bioaerosols, the apparatus comprising:a surface for exposure to ambient air, wherein the surface is configured to receive and cultivate a bioaerosol from the ambient air;a camera for acquiring one or more images of the surface and of one or more bioaerosols cultivated thereon; anda sensor device for obtaining one or more measurements of the relative humidity and / or temperature of the ambient air;wherein the one or more images of the surface depicting the appearance of the one or more bioaerosols cultivated on the surface and the one or more measurements of the relative humidity and / or temperature support management of the bioaerosols by identification of the type of the one or more bioaerosols from the appearance of the one or more bioaerosols cultivated on the surface.

2. The apparatus of claim 1, wherein the apparatus defines a channel having a first end COto provide an ingress of ambient air into the channel and a second end to provide an egress of ambient air from the channel, such that the channel provides a pathway of ambient air C\J through the apparatus, and wherein the surface is located on the pathway between the first end and the second end.

3. The apparatus of claim 2, wherein the apparatus further comprises at least one air flow driver configured to propel a flow of the ambient air along the pathway from the ingress to the egress.

4. The apparatus of claim 2 or 3, wherein the channel is provided with a first shutter located upstream of the surface, wherein the apparatus is configured to open the first shutter to allow a sample of the ambient air to flow along the pathway for controlled exposure to the surface, and to close the first shutter when the sample of ambient air has been obtained.21 03 245. The apparatus of claim 4, wherein the channel is provided with a second shutter located downstream to open and close in coordination with opening and closing of the first shutter to allow the flow of ambient air along the pathway.

6. The apparatus of any of claims 2 to 5, wherein the channel is provided with an antimicrobial coating.

7. The apparatus of any preceding claim, wherein the surface is provided with a growth medium to support the cultivation of the one or more bioaerosols.

8. The apparatus of any preceding claim, wherein the surface is provided by a cartridge / dish / plate9. The apparatus of claim 8, wherein the apparatus is provided with multiple cartridges / dishes / plates, each cartridge / dish / plate providing at least one respective surface for receiving and cultivating a bioaerosol.

10. The apparatus of claim 9, further comprising a dispensing mechanism for utilising each of the multiple cartridges / dishes / plates in turn to provide the at least one respective surface for receiving and cultivating a bioaerosol.

11. The apparatus of claim 9 or 10, further comprising a cassette for collecting each of the multiple cartridges / dishes / plates after they have been used for receiving and cultivating a bioaerosol.

12. The apparatus of any preceding claim, wherein the apparatus is configured for wall mounting, or mounting on any other suitable surface.

13. The apparatus of any one of claims 1 to 11, wherein the apparatus is configured to be free standing.21 03 2414. The apparatus of any preceding claim, wherein the apparatus is configured to detect bioaerosols comprising one or more types of fungal spores that are likely to produce mould and / or one or more types of bacteria.

15. The apparatus of any preceding claim, further comprising a communications interface for transmitting the one or more images of the surface and / or the one or more measurements of the relative humidity and temperature of the ambient air to a remote server.

16. A system comprising the apparatus of claim 15 and the remote server, wherein the remote server is configured to analyse one or more images and / or the one or more measurements to determine an identification of the one or more bioaerosols of the one or more bioaerosols.

17. The system of claim 16, wherein the remote server is further configured to analyse one or more images and / or the one or more measurements to determine a predicted rate of growth for each of the identified bioaerosols.

18. The system of claim 16 or 17, wherein the system is configured to generate an alert, if the predicted rate of growth of the one or more bioaerosols exceeds a specified threshold.

19. A method for monitoring one or more bioaerosols, the method comprising:exposing to ambient air a surface, wherein the surface is configured to receive and cultivate a bioaerosol from the ambient air;acquiring one or more images of the surface and of one or more bioaerosols cultivated thereon; andobtaining by a sensor device one or more measurements of the relative humidity of the ambient air;wherein the one or more images of the surface depicting the appearance of the one or more bioaerosols cultivated on the surface and the one or more measurements of the relative humidity and / or temperature support management of the bioaerosols by identification of the type of the one or more bioaerosols from the appearance of the one or more bioaerosols cultivated on the surface.

20. The method of claim 19, further comprising transmitting the one or more images of the surface and / or the one or more measurements of the relative humidity and / or temperature of the ambient air via a communications interface to a remote machine.

21. The method of claim 19 or 20, further comprising analysing, by the remote server, one or more images and / or the one or more measurements to determine an identification of the one or more bioaerosols and / or a predicted rate of growth of the one or more bioaerosols.

22. The method of any of claims 19 to 21, further comprising generating an alert if the predicted rate of growth of the one or more bioaerosols exceeds a specified threshold.21 03 24

Images