Local monitoring of traffic related air pollution around schools in South-East London

Outdoor air quality (OAQ) presents a significant challenge for public health globally, especially in urban areas, with road traffic acting as the primary contributor to air pollution. Several studies have documented the antagonistic relation between Traffic-Related Air Pollution (TRAP) and the impact on health, especially to vulnerable members of the population, particularly young pupils. Generally, TRAP could restrict the ability of schoolchildren to learn and, more importantly, cause detrimental respiratory disease in their later life. But little is known about the specific exposure of children commuting to school and during the school day and the impact this may have on their overall exposure to pollution at a crucial time in their development. This project has set out to examine the air quality across primary schools in South-East London (Due to their massively increasing amount of re-development and population) and assesses the variability of data found based on their geographic location and surroundings. Nitrogen Dioxide (NO2), PM contaminants (PM 2.5 and 10) were collected with diffusion tubes and portable monitoring equipment for eight schools across three local areas, that are Greenwich, Lewisham and Tower Hamlets. This study first examines the morphological features of the schools surrounding), then utilises two different methods to capture pollutant data. Moreover, comparing the obtained results with existing data from the London Air Quality Network (LAQN) to understand the differences in air quality before and post-pandemic. Most studies in this field have unfortunately neglected human exposure to pollutants and calculated referring to values from fixed monitoring stations. This paper introduces an alternative approach by calculating human exposure to air pollution from real-time data obtained when commuting around selected schools (Driving routes and field walking)

Application of CO2 monitoring methods for post occupancy evaluation

The Covid-19 pandemic led to the widespread closure of events. Between April and July 2021, the AIRBODS consortium carried out an Environmental Study as part of the UK government Events Research Programme to assess environmental risk factors for Covid transmission at events. A detailed post-occupancy evaluation of Indoor Air Quality was employed to assess the effectiveness of ventilation systems in operation. CO2 monitors were installed at high spatial resolution throughout the occupied spaces of ten venues around the UK. Data from 55 events was obtained and average and maximum CO2 values were used to classify the spaces in relation to a proposed Air Quality Index. Indoor spaces where ventilation could be improved were rapidly identified and mitigations were tested to reduce the risk of airborne transmission of respiratory diseases

Transcending disciplines in architecture, structural and building services engineering: A new multidisciplinary educational approach

This paper reflects upon the mechanisms that enable development of curricular approaches to multidisciplinary architecture/engineering higher education. Building upon recent calls for integrated multidisciplinary building design practice, academics at UCL, industry partners and respective professional bodies embarked upon developing a new course that challenged disciplinary boundaries and defined the needs of a new design professional. Whilst there have been attempts internationally to better integrate architecture as well as engineering education, efforts have largely been focused on bolt-on solutions based on pre-existing education programmes. In addition, there has been little discussion (empirical or theoretical) on practical measures associated with developing multidisciplinary education in the built environment. Drawing on mixed data including documentary evidence, semi structured interviews and observations, the study begins to shed light on the approaches underpinning the development of a multidisciplinary built environment MEng course at UCL that integrates architecture, building services and civil engineering. The paper’s contribution is threefold. First, the findings have implications for developing multidisciplinary built environment education curricula, through revealing key mechanisms including the need for shared attitudes and expectations. Second, the paper highlights the conditions that enable the negotiation of multidisciplinary curricula including institutional support, shared values and a collective need and willingness to explore new solutions. Third, the paper reflects upon the value of design studio learning as a critical integrative component to the delivery of multidisciplinary education in the built environment and STEM more widely

Measurement of ventilation effectiveness and indoor air quality in toilets at mass gathering events

Mass gathering events were closed in 2020 to reduce the spread of SARS-CoV-2. These events included music concerts, theatre shows, and sports matches. It is known, however, that the long-range aerosol transmission of pathogens, such as SARS-CoV-2, can be reduced with sufficient ventilation indoors. This paper examines the risk of reopening these mass gathering events by measuring the CO2 concentration, as a proxy for ventilation effectiveness, at 58 events, with a specific focus on small enclosed spaces with short occupancy. Toilets (sanitary accommodation) are spaces that are densely and continuously occupied for short durations throughout the events, such as during theatre intervals or half-time at sports events. The results showed that the average air quality in toilets was good at most events. There were, however, considerable peaks in CO2 concentration of up to 3431 ppm in toilets at times when occupancy was presumed high, indicating that the risk of exposure to exhaled breath, which may contain virus-laden aerosols, is higher in toilets than elsewhere in the venue (although occupancy duration will be much lower). Recommendations are provided to encourage building designers and operators to be mindful of the ventilation strategies used in toilets given their occupancy and size

Findings and Guidance for Airborne Infection Resilience

This guidance provides insights into airborne infection risks and proposes mitigation measures to improve airborne infection resilience of indoor and semi-outdoor spaces. In some poorly-ventilated and/or highly occupied spaces, the provision of increased ventilation performance can be the key to reducing airborne infection risk down to 'acceptable' (although currently undefined) levels.This is a complex area of study with many areas of uncertainty that form the basis of ongoing research. That said, the AIRBODS programme, in the context of the global research efforts associated with the COVID-19 pandemic, has generated a sound basis for improving airborne infection resilience. Key aspects of the guide with its many recommendations include:• Experiments carried out in a test chamber showing how screens can improve or, even, worsen airborne infection risk.• Field studies undertaken as part of the Events Research Programme which underpinned the opening up of the UK hospitality sector in summer of 2021. Good practice advice is provided on how to drive high resolution CO2 and microbiological studies and then appropriately interpret results.• Analytical models were developed to understand how infection risk, using a mass balance approach with many different parameters, might be mitigated in some circumstances when compared to reference spaces. These models were then developed into a 'full building' tool which can be downloaded as part of this guidance.• Computational fluid dynamics (CFD) models were developed to provide insights into the physics of droplets or aerosols at microscale. Following completion of a test chamber validation exercise, models were developed to investigate breathing or coughing mannequins at single human moving towards audience or crowd scale.Local ventilation effectiveness and associated airborne infection risk aspects of some real spaces may significantly differ from assumed 'fully-mixed' equivalent spaces. This, along with a number of other issues, will form part of ongoing research activities.• Focus groups were also used to provide some wider context and support some of our recommendations.AIRBODS has produced a repository of data and modelling methods with the mindset of enabling building professionals to inform their design and operation decisions towards improving airborne infection resilience in their buildings

COVID-19 risk-mitigation in reopening mass events: population-based observational study for the UK Events Research Programme in Liverpool City Region

OBJECTIVES: To understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission risks, perceived risks and the feasibility of risk mitigations from experimental mass cultural events before coronavirus disease 2019 (COVID-19) restrictions were lifted. DESIGN: Prospective, population-wide observational study. SETTING: Four events (two nightclubs, an outdoor music festival and a business conference) open to Liverpool City Region UK residents, requiring a negative lateral flow test (LFT) within the 36 h before the event, but not requiring social distancing or face-coverings. PARTICIPANTS: A total of 12,256 individuals attending one or more events between 28 April and 2 May 2021. MAIN OUTCOME MEASURES: SARS-CoV-2 infections detected using audience self-swabbed (5-7 days post-event) polymerase chain reaction (PCR) tests, with viral genomic analysis of cases, plus linked National Health Service COVID-19 testing data. Audience experiences were gathered via questionnaires, focus groups and social media. Indoor CO2 concentrations were monitored. RESULTS: A total of 12 PCR-positive cases (likely 4 index, 8 primary or secondary), 10 from the nightclubs. Two further cases had positive LFTs but no PCR. A total of 11,896 (97.1%) participants with scanned tickets were matched to a negative pre-event LFT: 4972 (40.6%) returned a PCR within a week. CO2 concentrations showed areas for improving ventilation at the nightclubs. Population infection rates were low, yet with a concurrent outbreak of >50 linked cases around a local swimming pool without equivalent risk mitigations. Audience anxiety was low and enjoyment high. CONCLUSIONS: We observed minor SARS-CoV-2 transmission and low perceived risks around events when prevalence was low and risk mitigations prominent. Partnership between audiences, event organisers and public health services, supported by information systems with real-time linked data, can improve health security for mass cultural events

AIRBODS: Findings and guidance for airborne infection resilience

This guidance provides insights into airborne infection risks and proposes mitigation measures to improve airborne infection resilience of indoor and semi-outdoor spaces. In some poorly-ventilated and/or highly occupied spaces, the provision of increased ventilation performance can be the key to reducing airborne infection risk down to 'acceptable' (although currently undefined) levels.This is a complex area of study with many areas of uncertainty that form the basis of ongoing research. That said, the AIRBODS programme, in the context of the global research efforts associated with the COVID-19 pandemic, has generated a sound basis for improving airborne infection resilience. Key aspects of the guide with its many recommendations include:•Experiments carried out in a test chamber showing how screens can improve or, even, worsen airborne infection risk.•Field studies undertaken as part of the Events Research Programme which underpinned the opening up of the UK hospitality sector in summer of 2021. Good practice advice is provided on how to drive high resolution CO2 and microbiological studies and then appropriately interpret results.• Analytical models were developed to understand how infection risk, using a mass balance approach with many different parameters, might be mitigated in some circumstances when compared to reference spaces. These models were then developed into a 'full building' tool which can be downloaded as part of this guidance.• Computational fluid dynamics (CFD) models were developed to provide insights into the physics of droplets or aerosols at microscale.Following completion of a test chamber validation exercise, models were developed to investigate breathing or coughing mannequins at single human moving towards audience or crowd scale. Local ventilation effectiveness and associated airborne infection risk aspects of some real spaces may significantly differ from assumed 'fully-mixed' equivalent spaces. This, along with a number of other issues, will form part of ongoing research activities.• Focus groups were also used to provide some wider context and support some of our recommendations.AIRBODS has produced a repository of data and modelling methods with the mindset of enabling building professionals to inform their design and operation decisions towards improving airborne infection resilience in their buildings

Carbon Dioxide Monitoring in Refuse Collection Vehicle Cabins to Reduce the Risk of SARS-CoV-2 Airborne Transmission

During the COVID-19 pandemic, essential workers such as waste collection crews continued to provide services in the UK, but due to their small size, maintaining social distancing inside waste collection vehicle cabins is impossible. Ventilation in cabins of 11 vehicles operating in London was assessed by measuring air supply flow rates and carbon dioxide (CO2) in the driver’s cabin, a proxy for exhaled breath. The indoor CO2 indicated that air quality in the cabins was mostly good throughout a working day. However, short episodes of high CO2 levels above 1500 ppm did occur, mainly at the beginning of a shift when driving towards the start of their collection routes. This data indicated that the ventilation systems on the vehicles were primarily recirculating air and the fresh air supply made up only 10-20 % of the total airflow. Following recommendations to partly open windows during shifts and to maintain ventilation systems, a second monitoring campaign was carried out, finding on average, an improvement in ventilation on board the vehicles

Bayesian calibration of the constants of the k–ε turbulence model for a CFD model of street canyon flow

AbstractIn this paper we carry out a Bayesian calibration for uncertainty analysis in Computational Fluid Dynamics modelling of urban flows. Taking the case of airflow in a regular street canyon, and choosing turbulent kinetic energy (TKE) as our quantity of interest, we calibrate 3-D CFD simulations against wind tunnel observations. We focus our calibration on the model constants contained within the standard RANS k–ε turbulence model and the uncertainties relating to these values. Thus we are able to narrow down the space of k–ε model constants which provide the best match with experimental data and quantify the uncertainty relating to both the k–ε model constants in the case of street canyon flow and the TKE outputs of the CFD simulation. Furthermore, we are able to construct a statistical emulator of the CFD model. Finally, we provide predictions of TKE based on the emulator and the estimated bias between model and observations, accompanied with uncertainties in these predictions