This article focuses on the experiences of waste workers in Glasgow at the height of the COVID-19 pandemic, to explore how the ordinary workings of the UK waste industry are pushing bodies and infrastructures to the point of collapse. Drawing on in-depth interviews with waste workers, and in conversation with Lauren Berlant's concepts of 'slow death' and the 'crisis ordinary', this article makes two key contributions. First, it reveals that waste workers are enduring conditions that are marked by chronic exhaustion, debilitation and poverty. Second, it argues that this experience of 'slow death' was not created by the 'COVID crisis' but by the 'crisis ordinary': the normal workings of neoliberalism that stretch workers beyond their limits in ways that are simultaneously egregious yet entirely ordinary. During the emergence of the pandemic, being designated a 'key worker' was not a cause for protection or compensation, but, rather, placed already marginalised bodies at greater exposure to risk, exploitation and exhaustion. Although the pandemic exacerbated long-standing challenges, it also brought them into sharper focus, creating spaces for resistance. Waste workers confronted slow death through radical acts of refusal, mobilising for labour justice during COP26, making their 'ordinary' crisis appear disordinary. This article situates these acts of refusal within a broader geographical framework, contributing to understandings of crisis as an ongoing process, deeply intertwined with the ordinary functions of neoliberal capitalism. The complex infrastructures that sustain our economic, political and biological lives-including the waste sector-depend on workers for whom 'slow death' has become a pervasive and commonplace crisis. By foregrounding the lived experiences of key workers, we can begin to make the ordinary crisis of neoliberalism feel disordinary, and confront the widespread 'state of acceptance' that has allowed slow death to persist for so many.

Cushion and working gas management plays a critical role during underground H2 storage, as injection strategies can directly influence gas mixing, H2 purity and overall storage performance. Although alternative cushion gases such as CO2 or in-situ CH4 can significantly reduce capital costs compared with using H2 cushion gas, their interaction with the working gas may increase mixing and downstream separation requirements. However, the relative effectiveness of cushion gas injection strategies for limiting gas mixing in laterally extensive reservoirs remains poorly understood.This study evaluates vertical and lateral separation strategies for cushion and working gases in reservoir settings representative of the Southern North Sea. Numerical simulations were performed using GEM-CMG, considering both gas type and the quantity of each gas, with emphasis on the impacts on mixing behaviour and well placement. A conventional vertical separation strategy reduced H2 mixing with in-situ CH4 but increased H2-CO2 mixing. In contrast, lateral separation limited H2-CO2 contact by injecting CO2 cushion gas and H2 working gas at opposite sides of the reservoir, thereby reducing their mixing, although mixing between H2 and in-situ CH4 was enhanced. On average, the lateral separation strategy increased H2 purity by approximately 4%. Well placement also influenced mixing, with a central configuration reducing CH4 mixing in vertical cases but having little effect on CO2 mixing. Overall, the results highlight key trade-offs between gas injection strategy, cushion gas selection, and well configuration, thereby providing practical guidance for designing cost effective injection strategies to minimise gas mixing in future large scale underground hydrogen storage operations.

Large-scale H2 storage in depleted hydrocarbon reservoirs offers a practical way to use existing energy infrastructure to address renewable energy intermittency. Cushion gases often constitute a large initial investment, especially when expensive H2 is used. Cheaper alternatives such as CO2 or in-situ CH4 can reduce costs and, in the case of CO2, integrate within carbon capture and storage systems. This study explored cushion and working gas dynamics through numerically modelling a range of storage scenarios in laterally extensive reservoirs - such as those in the Southern North Sea. In all simulations, the cushion and working gases were separated laterally to limit contact surface area, and therefore mixing. This work provides valuable insights into (i) capacity estimations of CO2 storage and H2 withdrawal, (ii) macro-scale fluid dynamics, and (iii) the effects of gas mixing trends on H2 purity. The results underscore key trade-offs between CO2 storage volumes and H2 withdrawal and purity.

Large-scale H2 storage within porous geological formations – such as depleted hydrocarbon reservoirs – presents a practical opportunity leveraging existing energy industry infrastructure to address renewable energy intermittency (e.g., from wind and solar). H2 can be generated from excess renewable energy, stored in these reservoirs, and drawn when needed. Depleted gas reservoirs have proven to trap gases (e.g., natural CH4) over geological timescales, and have been used for large-scale CH4 storage. The working gas (i.e., H2) is the fraction that is injected, stored temporarily, and produced from the reservoir. The cushion gas, the share of the injected gas that remains in the reservoir to maintain operational pressures and drive the production, represents an initial investment in the storage operation. Therefore, because H2 is relatively expensive, the use of a cheaper alternative cushion gas – such as CO2 and / or in-situ CH4 – can reduce the investments needed. Furthermore, the use of CO2 storage can simultaneously contribute to Net-Zero goals (as the CO2 will remain fixed in the reservoir). One of the main challenges associated with the use of alternative cushion gases in these storage systems is the mixing with the working gas. Increased mixing will increase the cost of separation after production. In this study, we explore how the mixing of cushion and working gas can be minimised by using the reservoir geometry of laterally extensive reservoirs such as the Southern North Sea gas fields. Ultimately, the reservoir architecture and the infrastructure will dictate the extend of the contact area between the cushion and working gases, and by reducing this, the risk of mixing will be reduced. This work proposes an alternative operational strategy that investigates the storage of H2 working gas and CO2 cushion gas in a depleted system, where both gases are kept separated by injecting them at opposing ends of a reservoir to reduce the surface area of the mixing gas interface.

Many national governments, organisations and environmental groups have pledged to plant trees in an effort to increase carbon sequestration and mitigate climate change. Tree planting is commonly used as a restoration strategy for former landfill sites, and it is likely that many urban and urban-fringe areas, including closed landfills, will continue to be prioritised for tree planting in the coming years. Trees growing in natural and managed environments have the capacity to act as conduits for the transport of methane (CH4) produced belowground to the atmosphere. This process has also been observed in natural ecosystems for nitrous oxide (N2O) and we examined whether trees growing on closed landfills also mediate N2O emissions to the atmosphere. We investigated whether trees on a closed UK landfill site emitted more N2O than those on a comparable natural site. Measurements were made from stem and soil surfaces over a four-month period using flux chambers and Gas Chromatography. Results were then scaled up and the contributions of N2O stem fluxes to the total surface fluxes in different environments were compared. Analyses showed that stem and soil N2O fluxes from landfill were larger than from trees on the comparable non-landfill site. Tree stem N2O emissions on the former landfill also showed seasonal patterns and decreased with higher sampling positions above ground level. Findings indicated that tree stem N2O emissions accounted for less than 1% of the estimated total landfill surface flux, which was comparable to findings from a mesocosm study, but lower than estimates of the total N2O ecosystem flux in dry and flooded boreal forests (8% and 18%, respectively). Overall, this investigation suggested that trees planted on closed landfill sites may result in additional N2O emissions to the atmosphere, although the tree stem contribution to the total surface flux on the former landfill was a lower magnitude than that of fluxes previously reported from natural forested ecosystems.

Trees growing in natural and managed environments have the capacity to act as conduits for the transport of greenhouse gases produced belowground to the atmosphere. Nitrous oxide (N2O) emissions have been observed from tree stems in natural ecosystems but have not yet been measured in the context of forested former landfill sites. This research gap was addressed by an investigation quantifying stem and soil N2O emissions from a closed UK landfill and a comparable natural site. Measurements were made by using flux chambers and gas chromatography over a four-month period. Analyses showed that the average N2O stem fluxes from the landfill and non-landfill sites were 0.63 ± 0.06 μg m–2 h–1 and 0.26 ± 0.05 μg m–2 h–1, respectively. The former landfill site showed seasonal patterns in N2O stem emissions and decreasing N2O fluxes with increased stem sampling position above the forest floor. Tree stem emissions accounted for 1% of the total landfill N2O surface flux, which is lower than the contribution of stem fluxes to the total surface flux in dry and flooded boreal forests.

Waste has become a pivotal public health and environmental problem during the COVID-19 pandemic. In this interdisciplinary review, we move beyond the 'coronalitter' and 'coronawaste' discourses, which have come to dominate public imaginaries of waste, to consider less-visible dimensions of waste infrastructures and systems . We demonstrate how waste is coming to matter in new ways that offer opportunities for reconfiguring health research. By examining the literature addressing the impacts of COVID-19 on the geographies of waste, we shed light on how waste is being problematised and researched through logics of public, environmental, and occupational health. We argue that these logics structure understandings and practice, whilst drawing attention to the overlaps and limits that allow links across disciplinary silos and problem domains to be forged. Developing a multi-logics approach, the paper outlines a research agenda for approaching waste as a critical public health problem at a time of intersecting health crises.

Trees in natural and managed environments can act as conduits for the transportation of methane (CH4) from below ground to the atmosphere, bypassing oxidation in aerobic surface soils. Tree stem emissions from landfill sites exhibit large temporal and spatial variability in temperate environments and can account for approximately 40% of the total surface CH4 flux. Emission variability was further investigated in this study by measuring CH4 and CO2 fluxes from landfill sites with different management strategies and varying tree species over a 7-month period. Stem and soil measurements were obtained using flux chambers and an off-axis integrated cavity output spectroscopy analyser. Analysis showed average stem and soil CH4 emissions varied significantly (p < 0.01) between landfills with different management practices. On average, tree stem CH4 fluxes from sites with no clay cap but gas extraction, clay cap and gas extraction, and no clay cap and no gas extraction were 1.4 ± 0.4 μg m-2 h-1, 47.2 ± 19.0 μg m-2 h-1, and 111.9 ± 165.1 μg m-2 h-1, respectively. There was no difference in stem CH4 fluxes between species at each site, suggesting environmental conditions (waterlogging) and site age had a greater influence on both stem and soil fluxes. These results highlight the importance of management practices, and the resultant environmental conditions, in determining CH4 emissions from historic landfill sites.

Trees have morphological adaptations that allow methane (CH4) generated below ground to bypass oxidation in aerobic surface soils. This natural phenomenon however has not been measured in a landfill context where planted trees may alter the composition and magnitude of CH4 fluxes from the surface. To address this research gap, we measured tree stem and soil greenhouse gas (GHG) emissions (CH4 and CO2) from a closed UK landfill and comparable natural site, using an off-axis integrated cavity output spectroscopy analyser and flux chambers. Analyses showed average CH4 stem fluxes from the landfill and non-landfill sites were 31.8 ± 24.4 µg m-2 h-1 and -0.3 ± 0.2 µg m-2 h-1, respectively. The landfill site showed seasonal patterns in CH4 and CO2 stem emissions, but no significant patterns were observed in CH4 and CO2 fluxes at different stem heights or between tree species. Tree stem emissions accounted for 39% of the total CH4 surface flux (7% of the CO2); a previously unknown contribution that should be included in future carbon assessments.

Tree planting has the potential to increase carbon sequestration and is used as a common management strategy on former landfill sites to improve their visual appeal and manage issues such as leachates from decomposing organic matter. Tree stems mediate methane (CH4) emissions to the atmosphere from anaerobic soils, bypassing bacterial populations that would otherwise break down CH4 before it is released to the atmosphere. This process has been observed in wetland forests but has yet to be measured in a landfill context. We examined whether trees emitted more CH4 and carbon dioxide (CO2) on a closed UK landfill site relative to a more natural, comparable control site to determine the importance of this natural phenomenon in a managed environment. CH4 and CO2 fluxes from tree stem and soil surfaces were measured using flux chambers and an off-axis integrated cavity output spectroscopy analyser. Temporal and seasonal variations in greenhouse gas emissions from landfill tree stems were also investigated, as well as the impact of different landfill management techniques including site closure methods and tree species planted. Analyses showed that tree stem emissions from landfill were larger than from trees in the non-landfill control site. However, there was high variability in the greenhouse gas fluxes from trees on the landfill. Findings from this investigation suggest that conditions associated with landfill construction may increase CH4 emissions from trees planted on their surface after closure of the site. Trees planted on former landfill sites may therefore result in additional CH4 emissions to the atmosphere.

Intensive farming is widespread throughout the UK and yet the health effects of bioaerosols which may be generated by these sites are currently not well researched. A scoping study was established to measure bioaerosols emitted from intensive pig (n = 3) and poultry farms (n = 3) during the period 2014-2015. The concentration of culturable mesophilic bacteria, Gram-negative bacteria, Staphylococcus spp., and fungi selecting for presumptive Aspergillus fumigatus were measured using single-stage impaction Andersen samplers, whilst endotoxin and (1 -> 3)-beta-D-glucan was undertaken using inhalable personal samplers. Particulate matter concentration was determined using an optical particulate monitor. Results showed that culturable bacteria, fungi, presumptive Staphylococcus aureus (confirmed only as Staphylococcus spp.) and endotoxin concentrations were elevated above background concentrations for distances of up to 250 m downwind of the source. Of all the culturable bioaerosols measured, bacteria and Staphylococcus spp. were identified as the most significant, exceeding published or proposed bioaerosol guidelines in the UK. In particular, culturable Staphylococcus spp. downwind was at least 61 times higher than background at the boundary and at least 8 times higher 70m downwind on the four farms tested. This research represents a novel dataset of intensive farm emissions within the UK. Future research should exploit the use of innovative culture-independent methods such as next generation sequencing to develop deeper insights into the make-up of microbial communities emitted from intensive farming facilities and which would better inform species of interest from a public health perspective.

In 2014, the Chartered Institution of Wastes Management, waste management and recycling company Biffa and StreetLink, the national rough sleeping service, came together to carry out a study into people sleeping in bins following several near misses and, tragically, one fatality. Five years on, this research has been repeated to determine the scale of the issue now, to assess how far the issue has progressed since the first report and to identify whether best practice is being adopted by waste producers and waste management companies. The intention was to also seek to set out a range of recommendations for the industry as a whole - and to determine how everyone involved can work better together to address the issue of people in bins.

Bioaerosol emissions arising from biowaste treatment are an issue of public concern. To better characterise the bioaerosols, and to assess a range of measurement methods, we aerosolised green waste compost under controlled conditions. Viable and non-viable Andersen samplers, cyclone samplers and a real time bioaerosol detection system (Spectral Intensity Bioaerosol Sensor (SIBS)) were deployed simultaneously. The number-weighted fraction of fluorescent particles was in the range 22–26% of all particles for low and high emission scenarios. Overall fluorescence spectral profiles seen by the SIBS exhibited several peaks across the 16 wavelength bands from 298 to 735 nm. The size-fractionated endotoxin profile showed most endotoxin resided in the 2.1–9 μm aerodynamic diameter fraction, though up to 27% was found in a finer size fraction. A range of microorganisms were detected through culture, Matrix Assisted Laser Desorption and Ionisation Time of Flight Mass Spectrometry (MALDI-TOF) and quantitative polymerase chain reaction (qPCR), including Legionella pneumophila serogroup 1. These findings contribute to our knowledge of the physico-chemical and biological characteristics of bioaerosols from composting sites, as well as informing future monitoring approaches and data interpretation for bioaerosol measurement.

Bioaerosols, comprised of bacteria, fungi and viruses are ubiquitous in ambient air.Known to adversely affect human health, the impact of bioaerosols on a population often manifests as outbreaks of illnesses such as Legionnaires Disease and Q fever, although the concentrations and environmental conditions in which these impacts occur are not well understood.Bioaerosol concentrations vary from source to source, but specific industrialised human activities such as water treatment, intensive agriculture and open windrow composting facilitate the generation of bioaerosol concentrations many times higher than natural background levels.Bioaerosol sampling is currently undertaken according to the requirements of the Environment Agency's regulatory framework, in which the collection of bioaerosols and not its long-term measurement is of most importance.As a consequence, sampling devices are often moved around site according to changing wind direction and sampling intervals are invariably short-term.The dispersion modelling of bioaerosols from composting facilities typically relies on proxy pollutant parameters.In addition, the use of short term emission data gathering strategies in which monitors are moved frequently with wind direction, do not provide a robust reliable and repeatable dataset by which to validate any modelling or to verify its performance.New sampling methods such as the Spectral Intensity Bioaerosol Sensor (SIBS) provide an opportunity to address several gaps in bioaerosol model validation and verification.In the context of model validation, this paper sets out the current weaknesses in bioaerosol monitoring from the perspective of robust modelling requirements.

Endotoxin is a bioaerosol component that is known to cause respiratory effects in exposed populations. To date, most research focused on occupational exposure, whilst much less is known about the impact of emissions from industrial operations on downwind endotoxin concentrations. A review of the literature was undertaken, identifying studies that reported endotoxin concentrations in both ambient environments and around sources with high endotoxin emissions. Ambient endotoxin concentrations in both rural and urban areas are generally below 10 endotoxin units (EU) m−3; however, around significant sources such as compost facilities, farms, and wastewater treatment plants, endotoxin concentrations regularly exceeded 100 EU m−3. However, this is affected by a range of factors including sampling approach, equipment, and duration. Reported downwind measurements of endotoxin demonstrate that endotoxin concentrations can remain above upwind concentrations. The evaluation of reported data is complicated due to a wide range of different parameters including sampling approaches, temperature, and site activity, demonstrating the need for a standardised methodology and improved guidance. Thorough characterisation of ambient endotoxin levels and modelling of endotoxin from pollution sources is needed to help inform future policy and support a robust health-based risk assessment process.

A novel dual excitation wavelength based bioaerosol sensor with multiple fluorescence bands called Spectral Intensity Bioaerosol Sensor (SIBS) has been assessed across five contrasting outdoor environments. The mean concentrations of total and fluorescent particles across the sites were highly variable being the highest at the agricultural farm (2.6 cm-3 and 0.48 cm-3, respectively) and the composting site (2.32 cm-3 and 0.46 cm-3, respectively) and the lowest at the dairy farm (1.03 cm-3 and 0.24 cm-3, respectively) and the sewage treatment works (1.03 cm-3 and 0.25 cm-3, respectively). In contrast, the number-weighted fluorescent fraction was lowest at the agricultural site (0.18) in comparison to the other sites indicating high variability in nature and magnitude of emissions from environmental sources. The fluorescence emissions data demonstrated that the spectra at different sites were multimodal with intensity differences largely at wavelengths located in secondary emission peaks for λex 280 and λex 370. This finding suggests differences in the molecular composition of emissions at these sites which can help to identify distinct fluorescence signature of different environmental sources. Overall this study demonstrated that SIBS provides additional spectral information compared to existing instruments and capability to resolve spectrally integrated signals from relevant biological fluorophores could improve selectivity and thus enhance discrimination and classification strategies for real-time characterisation of bioaerosols from environmental sources. However, detailed lab-based measurements in conjunction with real-world studies and improved numerical methods are required to optimise and validate these highly resolved spectral signatures with respect to the diverse atmospherically relevant biological fluorophores.

Bioaerosols are ubiquitous organic particles that comprise viruses, bacteria and coarser fractions of organic matter. Known to adversely affect human health, the impact of bioaerosols on a population often manifests as outbreaks of illnesses such as Legionnaires Disease and Q fever, although the concentrations and environmental conditions in which these impacts occur are not well understood. Bioaerosol concentrations vary from source to source, but specific human activities such as water treatment, intensive agriculture and composting facilitate the generation of bioaerosol concentrations many times higher than natural background levels. Bioaerosols are not considered ‘traditional’ pollutants in the same way as PM10, PM2.5, and gases such as NO2, and consequently dispersion models do not include a bespoke method for their assessment. As identified in previous studies, priority areas for improving the robustness of these dispersion models include: 1) the development of bespoke monitoring studies designed to generate accurate modelling input data; 2) the publication of a robust emissions inventory; 3) a code of practice to provide guidelines for consistent bioaerosol modelling practices; and 4) a greater understanding of background bioaerosol emissions. The aim of this research project, funded by the Natural Environmental Research Council (NERC), is to address these key areas through a better understanding of the generation, concentration and potential dispersion of bioaerosols from intensive agricultural and biowaste facilities, using case studies developed at specific locations within the UK. The objective is to further refine existing bioaerosol monitoring and modelling guidelines to provide a more robust framework for regulating authorities and site operators. This contribution outlines the gaps that hinder robust dispersion modelling, and describes the on-site bioaerosol data collection methods used in the study, explaining how they might be used to close these gaps. Examples of bioaerosol dispersion modelled using ADMS 5 are presented and discussed.