Potential pollution risks of historic landfills in England: Further analysis of climate change impacts

Five years ago, an article in WIREs Water provided the first comprehensive analysis of historic (legacy) landfill sites vulnerable to coastal flooding and erosion at a national scale (England). This update expands upon that article by considering the potential impacts of climate change upon inland historic landfills. Globally, there are hundreds of thousands of landfills that predate modern environmental regulations, and where waste is not isolated from the surrounding environment, but climate change impacts on the pollution risk from historic landfills in freshwater environments has received little attention. Where climate change causes an increase in the frequency and magnitude of fluvial flood events, this will increase leachate generation and the probability of landfill erosion and solid waste release. Where there is increased drought the landfill capping materials may crack, opening up new pollutant pathways, and increasing the risk of solid waste release. Changes to groundwater movement resulting from climate change may open new leachate pathways, and in England alone, thousands of historic landfills are in (groundwater) Source Protection Zones where modern regulations to protect drinking water supplies would not permit their construction. This increased contaminant release from historic landfills in freshwater environments may impact surface and/or groundwater quality and ecological health, increase costs for drinking water monitoring/treatment, or make some abstraction sources unviable. This is especially of concern where receptors are subject to multiple pressures and may cause tipping points to be reached. Further research is warranted into contaminant behavior, receptor vulnerability, historic landfill risk prioritization, and mitigation/remediation methods. This article is categorized under: Engineering Water > Engineering Water Science of Water > Water Quality Science of Water > Water and Environmental Change Water and Life > Stresses and Pressures on Ecosystems

Validation of a guideline-based composite outcome assessment tool for asthma control.

Background: A global definition of asthma control does not currently exist. The purpose of this study was to validate two new guideline-based composite measures of asthma control, defined as totally controlled (TC) asthma and well controlled (WC) asthma. Methods: We used data from 3416 patients randomised and treated in the multi-centre Gaining Optimal Asthma controL (GOAL) study. The criteria comprising the asthma control measures were based on Global Initiative for Asthma/National Institutes of Health guidelines. This validation study examined the measurement properties of the asthma control measures using data from runin, baseline, 12 and 52 weeks. Forced expiratory volume in 1 second (FEV1) and the Asthma Quality of Life Questionnaire (AQLQ) were used as the reference criteria in the validation analysis. Results: Both measures had good discriminative ability showing significant differences in FEV1 and AQLQ scores between control classification both cross-sectionally and longitudinally (p < 0.001). Overall both of the composite measures accounted for more of the variance in FEV1 after 52 weeks than the individual components of each asthma control measure. Both of the reference criteria were independently related to each asthma control measure (p < 0.0001). The measures also had good predictive validity showing significant differences in FEV1 and AQLQ scores at 52 weeks by control classification at 12 weeks (p < 0.0001). Conclusion: The guideline-based composite asthma control measures of WC asthma and TC asthma have good psychometric properties and are both valid functional indices of disease control in asthma

Palliative radiotherapy

Palliative radiotherapy offers a quick, inexpensive, and effective way of reducing many of the focal symptoms of advanced, incurable cancer, whether these arise from the primary tumour or from metastatic deposits. It can improve quality of life while being associated with limited treatment burden in terms of both hospital attendances and side effects. The average UK general practice oversees care for around 20 patients with terminal cancer each year with higher numbers seen in secondary care, while a Canadian survey of general practitioners found that 85% had provided care for patients with advanced cancer within the previous month. This article aims to update non-specialists on the benefits, practicalities, and side effects of palliative radiotherapy to ensure that patients are considered and referred for these treatments when appropriate

Integrated and Sustainable Management of Post-industrial Coasts

The sustainable management of post-industrial coasts is a major emerging issue globally. Along such coasts, there may be a significant legacy of both contaminated land (including historic landfills and non-managed waste disposal) and contaminated sediments in and around urban and industrial areas, which require new strategies for cost-effective and integrated risk management under future sea-level rise and climate change scenarios. Here, we review current approaches to managing contamination in post-industrial coastlines, discuss emerging integrated management strategies (building on low input approaches to sustainable brownfields regeneration) and present an approach and framework for assessing and comparing different scenarios for coastal brownfield regeneration to soft re-use and other end-points. This framework can be applied to explore the opportunities for synergy and realization of wider environmental, economic and societal benefits between coastal protection, dredged material re-use and the management of brownfield land. As such, the approach we propose supports planning and options appraisal to realize maximum benefit and value from integrated coastal management strategies

A novel 3D volumetric method for directly quantifying porosity and pore space morphology in flocculated suspended sediments.

Flocculated suspended sediments (flocs) are found in a variety of environments globally, and their transport and behavior bear substantial importance to several industries including fisheries, aquaculture, and shipping. Additionally, the modelling of their behavior is important for estuarine and coastal flood prediction and defence, and the process of flocculation occurs in other unrelated industries such as paper and chemical production. Floc porosity is conventionally assessed using inferential indirect or proxy data approaches. These methods underestimate floc porosity % by c. 30% and cannot measure the micro-scale complexity of these pore spaces and networks, rendering inputs to models sub-optimal. This study introduces a novel 3D porosity and pore space quantification protocol, that produces directly quantified porosity % and pore space data.•3D floc data from micro-CT scanning is segmented volumetrically•This segmented volume is quantified to extract porosity and several pore space parameters from the floc structure

A structure-function based approach to floc hierarchy and evidence for the non-fractal nature of natural sediment flocs

Abstract Natural sediment flocs are fragile, highly irregular, loosely bound aggregates comprising minerogenic and organic material. They contribute a major component of suspended sediment load and are critical for the fate and flux of sediment, carbon and pollutants in aquatic environments. Understanding their behaviour is essential to the sustainable management of waterways, fisheries and marine industries. For several decades, modelling approaches have utilised fractal mathematics and observations of two dimensional (2D) floc size distributions to infer levels of aggregation and predict their behaviour. Whilst this is a computationally simple solution, it is highly unlikely to reflect the complexity of natural sediment flocs and current models predicting fine sediment hydrodynamics are not efficient. Here, we show how new observations of fragile floc structures in three dimensions (3D) demonstrate unequivocally that natural flocs are non-fractal. We propose that floc hierarchy is based on observations of 3D structure and function rather than 2D size distribution. In contrast to fractal theory, our data indicate that flocs possess characteristics of emergent systems including non-linearity and scale-dependent feedbacks. These concepts and new data to quantify floc structures offer the opportunity to explore new emergence-based floc frameworks which better represent natural floc behaviour and could advance our predictive capacity

Pore, live root and necromass quantification in complex heterogeneous wetland soils using X-ray computed tomography

Subsurface structures and especially the interactions between pores, roots and other organic matter elements have a strong impact on ecosystem functioning. Yet despite recent progress in the application of X-ray Computed Microtomography (µCT) to soil structure in agricultural science, applications to the more complex and heterogeneous substrates found in natural soils, specifically wetland soils, remain sparse. We apply X-ray µCT to a complex heterogenous soil and develop a robust segmentation method to quantify the pores, live roots and necromass. This approach significantly improves the detection of the organic matter elements, and gives us unprecedented detail and resolution in the segmentation of pores, live roots and necromass at a high spatial resolution (62.5 µm in this study). We identify several situations where pores and organic matter interact in the soil, including the disconnected air spaces (aerenchyma) that run within the Spartina stem and roots, tubular-shaped pores left behind by decaying roots, and lateral roots deploying within structural fragilities in the sediment. The capacity of X-ray µCT to distinguish the connected live root system from the necromass opens possibilities for applications to determine key wetland soil functions such as soil cohesivity, soil nutrient exchanges and soil carbon dynamics

The impact of pre-restoration land-use and disturbance on sediment structure, hydrology and the sediment geochemical environment in restored saltmarshes

Saltmarshes are being lost or degraded as a result of human activity resulting in loss of critical ecosystem services including the provision of wild species diversity, water quality regulation and flood regulation. To compensate, saltmarshes are being restored or re-created, usually driven by legislative requirements for increased habitat diversity, flood regulation and sustainable coastal defense. Yet, there is increasing evidence that restoration may not deliver anticipated ecosystem services; this is frequently attributed to poor drainage and sediment anoxia. However, physical sediment characteristics, hydrology and the sediment geochemical environment are rarely examined in restoration schemes, despite such factors being critical for plant succession. This study presents the novel integration of 3D-computed X-ray microtomography to quantify sediment structure and porosity, with water level and geochemical data to understand the impact of pre-restoration land use and disturbance on the structure and functioning of restored saltmarshes. The study combines a broad-scale investigation of physical sediment characteristics in nine de-embanked saltmarshes across SE England, with an intensive study at one site examining water levels, sediment structure and the sediment geochemical environment. De-embankment does not restore the hydrological regime, or the physical/chemical framework in the saltmarshes and evidence of disturbance includes a reduction in microporosity, pore connectivity and water storage capacity, a lack of connectivity between the sub-surface environment and overlying floodwaters, and impeded sub-surface water flow and drainage. This has significant consequences for the sediment geochemical environment. This disturbance is evident for at least two decades following restoration and is likely to be irreversible. It has important implications for plant establishment in particular, ecosystem services including flood regulation, nutrient cycling and wild species diversity and for future restoration design