Water sector resilience in the United Kingdom and Ireland: The COVID-19 challenge

The outbreak of COVID-19 led to restrictions on movements and activities, which presented a serious challenge to the resilience of the water sector. It is essential to understand how successfully water companies responded to this unprecedented event so effective plans can be built for future disruptive events. This study aimed to evaluate how the water sectors in the UK and Ireland were affected from a holistic sustainability and resilience-based perspective. Using pre-COVID data for 18 indicators of company performance and comparing them to the first year of the pandemic, the direction and magnitudes of change varied across companies. Financial indicators were significantly negatively affected, with interest cover ratio, post-tax return on regulated equity, and operating profit, exhibiting the greatest average declines of 21%, 21%, and 18%, respectively, a trend that would be dangerous to provisions and company operations if continued. Despite this, service and environmental indicators improved during the first year of the pandemic, exemplified by unplanned outage, risk of sewer storm flooding, and water quality compliance risk decreasing by a mean average of 37%, 32%, and 27%, respectively. Analysis using the Hicks-Moorsteen Productivity Index concluded that average productivity increased by 35%. The results suggest that the water sector was relatively resilient to the COVID-19 pandemic in terms of services, but adverse effects may have manifested in a deteriorated financial position that could exacerbate future challenges arising from exogenous pressures such as climate change. Specific advice for the UK water sector is to scrutinize non-critical spending, such as shareholder payments, during periods of economic downturn to ensure essential capital projects can be carried out. Although results are temporal and indicator selection sensitive, we recommend that policy, regulation, and corporate culture embrace frameworks that support long-term resilience to since the relative success in response to COVID-19 does not guarantee future success against differing challenges. This study generates a timely yet tentative insight into the diverse performance of the water sector during the pandemic, pertinent to the water industry, regulators, academia, and the public.

Heat recovery and water reuse in micro-distilleries improves eco-efficiency of alcohol production

The number of micro-scale spirit distilleries worldwide has grown considerably over the past decade. With an onus on the distillery sector to reduce its environmental impact, such as carbon emissions, opportunities for increasing energy efficiency need to be implemented. This study explores the potential environmental benefits and financial gains achievable through heat recovery from different process and by-product streams, exemplified for a Scotch whisky distillery, but transferrable to micro-distilleries worldwide. The eco-efficiency methodology is applied, taking into account both climate change and water scarcity impacts as well as economic performance of alcohol production with and without heat recovery. A Life Cycle Assessment, focusing on climate change and water scarcity, is combined with a financial assessment considering investment costs and the present value of the savings over the 20-year service life of the heat recovery system. The proposed heat recovery systems allow carbon emission reductions of 8-23% and water scarcity savings of 13-55% for energy and water provision for 1 L of pure alcohol (LPA). Financial savings are comparatively smaller, at 5-13%, due to discounting of the future savings - but offer a simple payback of the investment costs in under two years. The eco-efficiency of the distillery operations can be improved through all proposed heat recovery configurations, but best results are obtained when heat is recovered from mashing, distillations and by-products altogether. A sensitivity analysis confirmed that the methodology applied here delivers robust results and can help guide other micro-distilleries on whether to invest in heat recovery systems, and/or the heat recovery configuration. Uptake should be enhanced through increased information and planning support, and in cases where the distillery offers insufficient heat and water sinks to use all pre-warmed water, opportunities to link with a heat sink outside the distillery are encouraged. A 10% reduction in heating fuel use through heat recovery has the potential to save 47 kt of CO₂ eq. or £7.4 M per annum in United Kingdom malt whisky production alone, based on current fuel types used and current prices (2021).

Pitfalls in international benchmarking of energy intensity across wastewater treatment utilities

The collection, treatment and disposal of wastewater is estimated to consume more than 2% of the world's electrical energy, whilst some wastewater treatment plants (WWTPs) can account for over 20% of electrical consumption within municipalities. To investigate areas to improve wastewater treatment, international benchmarking on energy (electrical) intensity was conducted with the indicator kWh/m³ and a quality control of secondary treatment or better for ≥95% of treated volume. The core sample included 321 companies from 31 countries, however, to analyse regional differences, 11 countries from an external sample made up of various studies of WWTPs was also used in places. The sample displayed a weak-negative size effect with energy intensity, although Kruskal-Wallace analyses showed there was a significant difference between the size of groups (p-value of 0.015), suggesting that as companies get larger; they consume less electricity per cubic metre of wastewater treated. This relationship was not completely linear, as mid to large companies (10,001-100,000 customers) had the largest average consumption of 0.99 kWh/m³. In the regional analysis, EU states had the largest average kWh/m³ with 1.18, which appeared a result of the higher wastewater effluent standards of the region. This was supported by Denmark being the second largest average consuming country (1.35 kWh/m³), since it has some of strictest effluent standards in the world. Along with energy intensity, the associated greenhouse gas (GHG) emissions were calculated enabling the targeting of regions for improvement in response to climate change. Poland had the highest carbon footprint (0.91 kgCO₂e/m³) arising from an energy intensity of 0.89 kWh/m³; conversely, a clean electricity grid can affectively mitigate wastewater treatment inefficiencies, exemplified by Norway who emit just 0.013 kgCO₂e per cubic meter treated, despite consuming 0.60 kWh/m³. Finally, limitations to available data and the analysis were highlighted from which, it is advised that influent vs. effluent and net energy, as opposed to gross, data be used in future analyses. The large international sample size, energy data with a quality control, GHG analysis, and specific benchmarking recommendations give this study a novelty which could be of use to water industry operators, benchmarking organisations, and regulators.

Spatial behaviour of sheep during the neonatal period: Preliminary study on the influence of shelter

Effective shelter has been demonstrated to reduce neonatal lamb mortality rates during periods of inclement weather. Periods of high wind speed and rainfall have been shown to influence shelter usage; however, it is not yet known how ewe factors such as breed, age and body condition score influence shelter-seeking behaviour. This study, conducted on a working upland farm in the UK, examined impact of artificial shelter on the biological and climatic factors that influence peri-parturient ewe behaviour. Pregnant ewes (n = 147) were randomly allocated between two adjacent fields which were selected for their similarity in size, topography, pasture management, orientation to the prevailing wind and available natural shelter. In one field, three additional artificial shelters were installed to increase the available shelter for ewes, this field was designated the Test field; no additional artificial shelter was provided in the second field which was used as the Control field. Individual ewes were observed every 2 h between 0800 and 1600 for 14 continuous days to monitor their location relative to shelter. Ewe breed (Aberfield and Highlander), age (2-8 years) and body condition score were considered as explanatory variables to explain flock and individual variance in shelter-seeking behaviour and the prevalence of issues which required the intervention of the shepherd, termed 'shepherding problems'. Any ewe observed with dystocia, a dead or poor vigour lamb or who exhibited mismothering behaviour was recorded as a shepherding problem. The prevalence of these shepherding problems which necessitate human intervention represents arguably the most critical limiting factor for the successful management of commercial sheep flocks in outdoor lambing systems. Overall, ewes in the Test field with access to additional artificial shelter experienced fewer shepherding problems than those in the Control field (P < 0.05). A significant breed effect was also observed, with Highlander ewes more likely to seek shelter than Aberfield ewes (P < 0.001), and experiencing significantly fewer shepherding interventions (P < 0.05). These findings demonstrate the substantial and significant benefits to animal welfare and productivity that can be achieved through the provision of shelter in commercial, upland, outdoor lambing systems in the UK.

Aligning efficiency benchmarking with sustainable outcomes in the United Kingdom water sector

The provision of fundamental services by water and sewage companies (WaSCs) requires substantial energy and material inputs. A sustainability assessment of these companies requires a holistic evaluation of both performance and efficiency. The Hicks-Moorsteen productivity index was applied to 12 WaSCs in the United Kingdom (UK) over a 6-year period to benchmark their sustainability, based on eight approaches using different input and output variables for efficiency assessment. The choice of variables had a major influence on the ranking and perceived operational efficiency among WaSCs. Capital expenditure (utilised as part of total expenditure) for example, is an important input for tracking company operations however, potential associated efficiency benefits can lag investment, leading to apparent poor short-term performance following capital expenditure. Furthermore, water supplied and wastewater treated was deemed an unconstructive output from a sustainability perspective since it contradicts efforts to improve sustainability through reduced leakage and consumption per capita. Customer satisfaction and water quality measures are potential suitable alternatives. Despite these limitations, total expenditure and water supplied and wastewater treated were used alongside customer satisfaction and self-generated renewable energy for a holistic sustainability assessment within a small sample. They indicated the UK water sector has improved in productivity by 1.8% on average for 2014-18 and still had room for improvement, as a technical decline was evident for both the best and worst performers. Collectively the sample's production frontier was unchanged but on average companies moved 2.1% closer to it, and further decomposition of productivity revealed this was due to improvements in economies of scale and scope. Careful selection of appropriate input and output variables for efficiency benchmarking across water companies is critical to align with sustainability objectives and to target future investment and regulation within the water sector.

Elevated serum antibody responses to synthetic mycobacterial lipid antigens among UK farmers: an indication of exposure to environmental mycobacteria?

Background: mycobacterial cells contain complex mixtures of mycolic acid esters. These can be used as antigens recognised by antibodies in the serum of individuals with active tuberculosis, caused by Mycobacterium tuberculosis. In high burden populations, a significant number of false positives are observed; possibly these antigens are also recognised by antibodies generated by other mycobacterial infections, particularly ubiquitous 'environmental mycobacteria'. This suggests similar responses may be observed in a low burden TB population, particularly in groups regularly exposed to mycobacteria. Methods: ELISA using single synthetic trehalose mycolates corresponding to major classes in many mycobacteria was used to detect antibodies in serum of individuals with no known mycobacterial infection, comprising farmers, abattoir workers, and rural and urban populations. Results: serum from four Welsh or Scottish cohorts showed lower (with some antigens significantly lower) median responses than those reported for TB negatives from high-burden TB populations, and significantly lower responses than those with active TB. A small fraction, particularly older farmers, showed strong responses. A second study examined BCG vaccinated and non-vaccinated farmers and non-farmers. Farmers gave significantly higher median responses than non-farmers with three of five antigens, while there was no significant difference between vaccinated or non-vaccinated for either farmer or non-farmer groups. Conclusions: this initial study shows that serodiagnosis with mycobacterial lipid antigens can detect antibodies in a population sub-group that is significantly exposed to mycobacteria, in an assay that is not interfered with by vaccination. Given the links between mycobacterial exposure and a range of immune system diseases, further understanding such responses may provide a new opportunity for monitoring public health and directing treatment.

Impact of Sediment Concentration on the Survival of Wastewater-Derived blaCTX-M-15-Producing E. coli, and the Implications for Dispersal into Estuarine Waters

The environmental cycling of antibiotic-resistant bla_CTX-M-15-producing E. coli following release from wastewater treatment plants is a major public health concern. This study aimed to (i) assess the impact of sediment concentrations on the rate of their inactivation following release from human wastewater into freshwater, and (ii) simulate their subsequent dispersal to the nearby coastline during a “worst-case” event where heavy rainfall coincided with high spring tide in the Conwy Estuary, North Wales. Freshwater microcosms of low, medium and high turbidity were inoculated with bla_CTX-M-15-producing E. coli, then exposed to ultraviolet (UV) radiation. Typical regional wintertime exposure to UV was found to be insufficient to eradicate E. coli, and in highly turbid water, many bacteria survived simulated typical regional summertime UV exposure. Modelling results revealed that bla_CTX-M-15-producing E. coli concentrations reduced downstream from the discharge source, with ~30% of the source concentration capable of dispersing through the estuary to the coast, taking ~36 h. Offshore, the concentration simulated at key shellfisheries and bathing water sites ranged from 1.4% to 10% of the upstream input, depending on the distance offshore and tidal regime, persisting in the water column for over a week. Our work indicates that the survival of such organisms post-release into freshwater is extended under typical wintertime conditions, which could ultimately have implications for human health.

Emissions down the drain: Balancing life cycle energy and greenhouse gas savings with resource use for heat recovery from kitchen drains

Although the food service sector is a major user of water, the potential for heat recovery from commercial kitchens' drain water remains largely unexplored. For the first time, we compare the life cycle environmental burdens of producing and installing a heat recovery system with the environmental credits arising from energy savings for a restaurant case study, and for the entire UK food service sector. Life Cycle Assessment was applied to determine the impacts of heat recovery systems made from different materials and comprising a heat exchanger in the shape of a concentric double-walled pipe, pipework and fittings. The design option with the smallest environmental footprint combined a heat exchanger made out of polypropylene-graphite (PP-GR) with polyethylene pipework, exhibiting 80-99% less environmental impact compared with components made out of (35% recycled) copper. Contrasting the environmental impacts of two heat recovery set-ups with energy savings shows that a PP-GR based system pays back all burdens of the seven assessed environmental impact categories, within two years, while payback times for the copper-based system vary depending on the replaced energy source, and can exceed the 10 year operational lifetime of the system. When looking at typical flow-rates in UK food outlets, net environmental savings can be realised across all analysed impact categories above a threshold water consumption of 555 L/day, using current technology. Extrapolation to the UK food service sector indicates annual greenhouse gas emission mitigation potential of about 500 Gg CO₂ equivalent.

Key performance indicators to explain energy & economic efficiency across water utilities, and identifying suitable proxies

Water companies consume up to 8% of global energy demand, at billions of dollars' cost. Benchmarking of performance between utilities can facilitate improvements in efficiency; however, inconsistencies in benchmarking practices may obscure pathways to improvement. The aspiration was to conduct an unbiased efficiency comparison within a sample of 17 water only companies and water and sewerage companies in England and Wales, accounting for exogenous factors, whilst evaluating the accuracy of common proxies. Proxies were tested, and bias-corrected energy and economic efficiency scores with explanatory factors were analysed using a double-bootstrap data envelopment method. Bias correction altered the rankings of two companies for energy efficiency only. Results imply that on average, companies could reduce energy inputs by 91.7%, and economic inputs by 92.3%, which was symptomatic of the companies specialising in drinking water supply considerably out-performing combined water and sewerage companies. As exogenous influences were likely to be a factor in the disparity between the companies, five indicators were evaluated. The results varied but of note were average pumping head height, which displayed a significant negative effect for energy efficiency, and proportion of water passing through the largest four treatment works, that exhibited a significant negative effect on economic efficiency. Within proxy performance, population served for drinking water was an adequate replacement for volume of water produced, with results matching the core variable apart from two companies changing rank in the economic analysis. Conversely, length of water mains performed poorly when replacing capital expenditure, implying companies were on average 12.6% more efficient, resulting in ten companies changing their rank and causing explanatory variables to contradict direction of influence and significance. The findings contribute new insights for benchmarking, including how different types of water companies perform under bias-correcting methods, the degree to which factors affect efficiency and how appropriate some proxies are.

Historical droughts recorded in extended Juniperus procera ring-width chronologies from the Ethiopian Highlands

In the Horn of Africa, little is known about temporal changes in hydroclimate owing to the influence of multiple weather systems, the complex terrain, and the sparse instrumental records. Absolutely dated tree-ring records offer the potential to extend our understanding of climate into the pre-instrumental era, but tree-ring studies in this region, and indeed all of tropical Africa, have been rare largely due to lack of an annual climate cycle that reliably produces annual tree-rings. In this study, 40 cores were obtained from 31 Juniperus procera trees growing in the grounds of Ethiopian Orthodox Tewahedo churches in the Gonder region of Ethiopia. The samples were cross-dated using a re-iterative process involving identifying anatomical features from high-resolution images. The tentative ring-width chronologies were revised after the determination of bomb-peak accelerator mass spectrometry radiocarbon dates. Individual series were significantly correlated to the respective master chronologies (r > 0.55; P < 0.05), and expressed population signal values ranged from 0.55 to 0.92. Historical drought years were successfully traced in the chronologies by pointer year analysis. This study confirms that Juniperus procera growing in areas of unimodal precipitation exhibits annual tree-rings and offers the potential as an indirect measure of past climate.

Economic and environmental efficiency of UK and Ireland water companies: Influence of exogenous factors and rurality

For water companies, benchmarking their performance relative to other companies can be an effective way to identify the scope for efficiency gains to be made through infrastructure investment and operational improvements. However, a key limitation to benchmarking is the confounding effect of exogenous factors, which may not be factored in to benchmarking methodologies. The purpose of this study was to provide an unbiased comparison of efficiency across a sample of water and sewage companies, accounting for important exogenous factors. Bias-corrected economic and environmental efficiency estimates with explanatory factors were evaluated for a sample of 13 water and sewage companies in the UK and Ireland, using a double-bootstrap data envelopment analysis (DEA) approach. Bias correction for economic and environmental efficiency changed the rankings of nine and eight companies, respectively. On average, companies could reduce economic inputs by 19% and carbon outputs by 16% if they performed at the efficiency frontier. Variables explaining efficiency were: source of water, leakage rate, per capita consumption and population density. Population density showed statistical significance with both economic (p-value 0.002) and environmental (p-value 0.001) efficiency. Consequently, a rurality factor was defined for each company's operational area, which was then regressed against normalised water company performance data. More rural water companies spend more per property (R² of 0.633), in part reflecting a larger number of smaller sewage treatment works serving rural populations (R² of 0.823). These findings provide new insight into methods for benchmarking, and factors affecting, water company efficiency, pertinent for both regulators and water companies.

Clinical and laboratory features of seventy-eight UK patients with Good's syndrome (thymoma and hypogammaglobulinaemia)

Good’s syndrome (thymoma and hypogammaglobulinaemia) is a rare secondary immunodeficiency disease, previously reported in the published literature as mainly individual cases or small case series. We use the national UK‐Primary Immune Deficiency (UKPID) registry to identify a large cohort of patients in the UK with this PID to review its clinical course, natural history and prognosis. Clinical information, laboratory data, treatment and outcome were collated and analysed. Seventy‐eight patients with a median age of 64 years, 59% of whom were female, were reviewed. Median age of presentation was 54 years. Absolute B cell numbers and serum immunoglobulins were very low in all patients and all received immunoglobulin replacement therapy. All patients had undergone thymectomy and nine (12%) had thymic carcinoma (four locally invasive and five had disseminated disease) requiring adjuvant radiotherapy and/or chemotherapy. CD4 T cells were significantly lower in these patients with malignant thymoma. Seventy‐four (95%) presented with infections, 35 (45%) had bronchiectasis, seven (9%) chronic sinusitis, but only eight (10%) had serious invasive fungal or viral infections. Patients with AB‐type thymomas were more likely to have bronchiectasis. Twenty (26%) suffered from autoimmune diseases (pure red cell aplasia, hypothyroidism, arthritis, myasthenia gravis, systemic lupus erythematosus, Sjögren’s syndrome). There was no association between thymoma type and autoimmunity. Seven (9%) patients had died. Good’s syndrome is associated with significant morbidity relating to infectious and autoimmune complications. Prospective studies are required to understand why some patients with thymoma develop persistent hypogammaglobulinaemia.

Quantifying the contribution of riparian soils to the provision of ecosystem services

Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a diverse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types; 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils; and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7-17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research is required to critically test this across a wider range of ecosystems.

Clinical efficacy of a next-generation sequencing gene panel for primary immunodeficiency diagnostics

Primary immunodeficiencies (PIDs) are rare monogenic inborn errors of immunity that result in impairment of functions of the human immune system. PIDs have a broad phenotype with increased morbidity and mortality, and treatment choices are often complex. With increased accessibility of next-generation sequencing (NGS), the rate of discovery of genetic causes for PID has increased exponentially. Identification of an underlying monogenic diagnosis provides important clinical benefits for patients with the potential to alter treatments, facilitate genetic counselling, and pre-implantation diagnostics. We investigated a NGS PID panel of 242 genes within clinical care across a range of PID phenotypes. We also evaluated Phenomizer to predict causal genes from human phenotype ontology (HPO) terms. Twenty-seven participants were recruited, and a total of 15 reportable variants were identified in 48% (13/27) of the participants. The panel results had implications for treatment in 37% (10/27) of participants. Phenomizer identified the genes harbouring variants from HPO terms in 33% (9/27) of participants. This study shows the clinical efficacy that genetic testing has in the care of PID. However, it also highlights some of the disadvantages of gene panels in the rapidly moving field of PID genomics and current challenges in HPO term assignment for PID.

Association of Surgeons in Training conference: Bournemouth 2017

The Association of Surgeons in Training (ASiT) is a professional body and registered charity working to promote excellence in surgical training for the benefit of junior doctors and patients alike. The Association provides support at both regional and national levels throughout the United Kingdom and Republic of Ireland. Originally founded in 1976, ASiT is independent of the National Health Service (NHS), Surgical Royal Colleges, and specialty associations. The 2017 Annual Conference in Bournemouth brought together over 700 delegates for a diverse educational weekend with numerous expert guest speakers. With a theme of '#AdvancesIn,' we looked to celebrate cutting edge progress in training, clinical management, medical technology, leadership and entrepreneurialism. These updates were complimented by debates on current training in surgery and an array of focussed parallel sessions. For the first time, delegates were also able to interact with the conference digitally, with the debut of our conference smartphone App. The weekend started with 9 pre-conference courses covering a diverse range of topics including core laparoscopic, vascular, orthopaedics, neurosurgical skills, leadership and global surgery. Over 1000 abstract submissions were received and those successful competed for over 30 awards, representing nearly £4000 in trainee prizes and bursaries. As the only national surgical trainee meeting for all specialties, ASiT continues to grow and we look forward to an even larger and more successful international conference next year in Edinburgh 6-8th April 2018 with the theme of #nurturingexcellence.

IL-10 production by CLL cells is enhanced in the anergic IGHV mutated subset and associates with reduced DNA methylation of the IL10 locus

Chronic lymphocytic leukemias (CLLs) with unmutated (U-CLL) or mutated (M-CLL) IGHV have variable features of immunosuppression, possibly influenced by those CLL cells activated to produce interleukin 10 (IL-10). The two subsets differ in their levels of anergy, defined by low surface immunoglobulin M levels/signaling capacity, and in their DNA methylation profile, particularly variable in M-CLL. We have now found that levels of IL-10 produced by activated CLL cells were highly variable. Levels were higher in M-CLL than in U-CLL and correlated with anergy. DNA methylation analysis of IL10 locus revealed two previously uncharacterized 'variably methylated regions' (CLL-VMRs1/2) in the gene body, but similarly low methylation in the promoter of both U-CLL and M-CLL. CLL-VMR1/2 methylation was lower in M-CLL than in U-CLL and inversely correlated with IL-10 induction. A functional signal transducer and activator of transcription 3 (STAT3) binding site in CLL-VMR2 was confirmed by proximity ligation and luciferase assays, whereas inhibition of SYK-mediated STAT3 activation resulted in suppression of IL10. The data suggest epigenetic control of IL-10 production. Higher tumor load may compensate the reduced IL-10 production in U-CLL, accounting for clinical immunosuppression in both subsets. The observation that SYK inhibition also suppresses IL-10 provides a potential new rationale for therapeutic targeting and immunological rescue by SYK inhibitors in CLL.

Current and Future Environmental Balance of Small-Scale Run-of-River Hydropower

Globally, the hydropower (HP) sector has significant potential to increase its capacity by 2050. This study quantifies the energy and resource demands of small-scale HP projects and presents methods to reduce associated environmental impacts based on potential growth in the sector. The environmental burdens of three (50-650 kW) run-of-river HP projects were calculated using life cycle assessment (LCA). The global warming potential (GWP) for the projects to generate electricity ranged from 5.5-8.9 g CO2 eq/kWh, compared with 403 g CO2 eq/kWh for UK marginal grid electricity. A sensitivity analysis accounted for alternative manufacturing processes, transportation, ecodesign considerations, and extended project lifespan. These findings were extrapolated for technically viable HP sites in Europe, with the potential to generate 7.35 TWh and offset over 2.96 Mt of CO2 from grid electricity per annum. Incorporation of ecodesign could provide resource savings for these HP projects: avoiding 800 000 tonnes of concrete, 10 000 tonnes of steel, and 65 million vehicle miles. Small additional material and energy contributions can double a HP system lifespan, providing 39-47% reductions for all environmental impact categories. In a world of finite resources, this paper highlights the importance of HP as a resource-efficient, renewable energy system.

Multi-centre retrospective analysis of anaphylaxis during general anaesthesia in the United Kingdom: aetiology and diagnostic performance of acute serum tryptase

This is the first multi-centre retrospective survey from the United Kingdom to evaluate the aetiology and diagnostic performance of tryptase in anaphylaxis during general anaesthesia (GA). Data were collected retrospectively (2005-12) from 161 patients [mean ± standard deviation (s.d.), 50 ± 15 years] referred to four regional UK centres. Receiver operating characteristic curves (ROC) were constructed to assess the utility of tryptase measurements in the diagnosis of immunoglobulin (Ig)E-mediated anaphylaxis and the performance of percentage change from baseline [percentage change (PC)] and absolute tryptase (AT) quantitation. An IgE-mediated cause was identified in 103 patients (64%); neuromuscular blocking agents (NMBA) constituted the leading cause (38%) followed by antibiotics (8%), patent blue dye (6%), chlorhexidine (5%) and other agents (7%). In contrast to previous reports, latex-induced anaphylaxis was rare (0·6%). A non-IgE-mediated cause was attributed in 10 patients (6%) and no cause could be established in 48 cases (30%). Three serial tryptase measurements were available in 34% of patients and a ROC analysis of area under the curve (AUC) showed comparable performance for PC and AT. A ≥ 80% PPV for identifying an IgE-mediated anaphylaxis was achieved with a PC of >141% or an AT of >15·7 mg/l. NMBAs were the leading cause of anaphylaxis, followed by antibiotics, with latex allergy being uncommon. Chlorhexidine and patent blue dye are emerging important health-care-associated allergens that may lead to anaphylaxis. An elevated acute serum tryptase (PC >141%, AT >15·7 mg/l) is highly predictive of IgE-mediated anaphylaxis, and both methods of interpretation are comparable.

Changes in the physicochemical properties and enzymatic activity of waste during bioreduction of pig carcasses

Bioreduction is a novel method for the on-farm storage of fallen stock in a vessel containing water that is heated and aerated, prior to disposal. The combination of a mesophilic temperature and high bacterial population leads to rapid degradation of carcasses due to microbial and enzymatic breakdown of protein material; and ultimately the reduction in volume of waste to be disposed. The system could, however, be improved if more was known about the changes that occur during a bioreduction cycle. Pig carcasses were placed within two commercial-scale bioreduction vessels (BVs) (6.5 m3 capacity) and the changes in physicochemical parameters, enzymatic activity, gas emissions and microbial communities were analysed over 56 days. Analyses showed that each vessel displayed different physicochemical parameters. The microbial communities within both vessels were also distinct, though they converged between days 28 and 42 before again diverging. Of the enzymes assayed, acetylesterases showed the highest activity during initial stages, with a subsequent increase in lipase towards the end. All other enzymes showed little activity in comparison. Despite active aeration of the vessels, conditions were redox-constrained, leading to the emission of gases associated with anaerobic conditions, namely NH3 and H2S. It was concluded that no single parameter governed the biochemical processes and that each BV will have its own unique microbial population and hence rate of decomposition. Further work is needed to increase the rate of bioreduction through bioaugmentation or developing enzyme additives.

Subclinical infection and asymptomatic carriage of gastrointestinal zoonoses: occupational exposure, environmental pathways, and the anonymous spread of disease

Asymptomatic carriage of gastrointestinal zoonoses is more common in people whose profession involves them working directly with domesticated animals. Subclinical infections (defined as an infection in which symptoms are either asymptomatic or sufficiently mild to escape diagnosis) are important within a community as unknowing (asymptomatic) carriers of pathogens do not change their behaviour to prevent the spread of disease; therefore the public health significance of asymptomatic human excretion of zoonoses should not be underestimated. However, optimal strategies for managing diseases where asymptomatic carriage instigates further infection remain unresolved, and the impact on disease management is unclear. In this review we consider the environmental pathways associated with prolonged antigenic exposure and critically assess the significance of asymptomatic carriage in disease outbreaks. Although screening high-risk groups for occupationally acquired diseases would be logistically problematical, there may be an economic case for identifying and treating asymptomatic carriage if the costs of screening and treatment are less than the costs of identifying and treating those individuals infected by asymptomatic hosts.

Bioreduction of sheep carcasses effectively contains and reduces pathogen levels under operational and simulated breakdown conditions

Options for the storage and disposal of animal carcasses are extremely limited in the EU after the introduction of the EU Animal By-products Regulations (ABPR; EC/1774/2002), leading to animosity within the livestock sector and the call for alternative methods to be validated. Novel storage technologies such as bioreduction may be approved under the ABPR provided that they can be shown to prevent pathogen proliferation. We studied the survival of Enterococcus faecalis, Salmonella spp., E. coli O157 and porcine parvovirus in bioreduction vessels containing sheep carcasses for approximately 4 months. The vessels were operated under two different scenarios: (A) where the water within was aerated and heated to 40 °C, and (B) with no aeration or heating, to simulate vessel failure. Microbial analysis verified that pathogens were contained within the bioreduction vessel and indeed reduced in numbers with time under both scenarios. This study shows that bioreduction can provide an effective and safe on-farm storage system for livestock carcasses prior to ultimate disposal. The findings support a review of the current regulatory framework so that bioreduction is considered for approval for industry use within the EU.

The role of the natural environment in the emergence of antibiotic resistance in gram-negative bacteria

During the past 10 years, multidrug-resistant Gram-negative Enterobacteriaceae have become a substantial challenge to infection control. It has been suggested by clinicians that the effectiveness of antibiotics is in such rapid decline that, depending on the pathogen concerned, their future utility can be measured in decades or even years. Unless the rise in antibiotic resistance can be reversed, we can expect to see a substantial rise in incurable infection and fatality in both developed and developing regions. Antibiotic resistance develops through complex interactions, with resistance arising by de-novo mutation under clinical antibiotic selection or frequently by acquisition of mobile genes that have evolved over time in bacteria in the environment. The reservoir of resistance genes in the environment is due to a mix of naturally occurring resistance and those present in animal and human waste and the selective effects of pollutants, which can co-select for mobile genetic elements carrying multiple resistant genes. Less attention has been given to how anthropogenic activity might be causing evolution of antibiotic resistance in the environment. Although the economics of the pharmaceutical industry continue to restrict investment in novel biomedical responses, action must be taken to avoid the conjunction of factors that promote evolution and spread of antibiotic resistance.