Browsing by Author "Longhurst, Philip J."
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Item Open Access The application of a new research and development project selection model in SMEs.(Elsevier Science B.V., Amsterdam., 2006-02-01T00:00:00Z) Lawson, Craig P.; Longhurst, Philip J.; Ivey, Paul C.The work reported in this paper investigates Research and Development (R&D) project selection models, focusing on the application of a new hybrid project selection model in a UK based engineering Small to Medium-sized Enterprise (SME). Work is done to enable the new project selection model to be applied in an SME and the model is then field tested. Field test results provide insight into the barriers to the adoption of such a model in an SME, either as a decision support tool or as a knowledge acquisition and learning tool. Insights are gained into the suitability and limits that exist within SMEs for the use of such decision support models. As an outcome of the field test results a simple R&D project portfolio cash-flow tracking method is proposed.Item Open Access Appraisal for options of solid recovered fuel (SRF) utilisation within the UK(2006-11-29T00:00:00Z) Hill, D.; Garg, A.; Smith, Richard; Pollard, Simon J. T.; Longhurst, Philip J.In view of the rising prices of non-renewable fossil fuels and regulatory obligations affecting waste management, interest is growing for the use of waste derived fuels in energy intensive facilities in Europe. However, major concerns with the use of such fuels include the quality of fuels, its source of generation, gaseous emissions and public acceptability. This paper presents the various production methods for solid recovered fuels (SRF) from municipal solid waste (MSW) and the potential options for its use in the UK. SRF can be produced by mechanical biological treatment (MBT) methods using bio-drying process or by extensive mechanical treatment. MBT involves a series of mechanical and biological steps, depending upon the input waste properties, aimed at producing an SRF. SRF compositions vary according to the application and can comprise of paper, plastic, wood, textile and organics. The European Technical Committee CEN/TC 343 “Solid Recovered Fuels” classifies SRF on the basis of net calorific value (NCV), chlorine content and mercury content. This classification system was prepared after extensive consultation with end-users. In the UK, the main potential outlets for MSW derived SRF include cement kilns, power plants, industrial boilers (such as pulp and paper mill), dedicated SRF incineration facilities and advanced thermal treatment plants (such as gasification and Venice 2006: Biomass and Waste to Energy Symposium. Cini Foundation, Venice, Italy. 29 November – 1 December 2006. pyrolysis). Cement kiln operators prefer high NCV fuel, however, in spite of its lower CV in comparison to other waste derived fuels (like liquid solvents, tyres and MBM), it remains attractive due to its biomass fraction and cheap availability. Power plants are much more concerned with the biomass fraction, as it may bring revenues for them in the form of Renewable Obligation Certificates (ROCs). Similarly, gasification and pyrolysis techniques are also eligible for ROCs, but these are still not fully proven in the UK. The use of SRF is also of interest because of its potential to reduce greenhouse gas emissions, as the biomass rich fraction is considered ‘carbon neutral’. Thus, this assists energy facilities to meet the EU Emissions Trading Scheme targets. However, the application of SRF is not straightforward as legislation exists at EU and National level, which users need to comply with. In addition, technical, environmental and economic issues need to be addressed. On the other hand if more SRF can be used then this will greatly help the UK meet its obligations under the Landfill Directive and the mitigation of greenhouse gases.Item Open Access Appropriateness of selecting different averaging times for modelling chronic and acute exposure to environmental odours(2007-04-01T00:00:00Z) Drew, Gillian H.; Smith, Richard; Gerard, Valerie; Burge, C.; Lowe, M.; Kinnersley, R.; Sneath, R.; Longhurst, Philip J.Odour emissions are episodic, characterised by periods of high emission rates, interspersed with periods of low emissions. It is frequently the short term, high concentration peaks that result in annoyance in the surrounding population. Dispersion modelling is accepted as a useful tool for odour impact assessment, and two approaches can be adopted. The first approach of modelling the hourly average concentration can underestimate total odour concentration peaks, resulting in annoyance and complaints. The second modelling approach involves the use of short averaging times. This study assesses the appropriateness of using different averaging times to model the dispersion of odour from a landfill site. We also examine perception of odour in the community in conjunction with the modelled odour dispersal, by using community monitors to record incidents of odour. The results show that with the shorter averaging times, the modelled pattern of dispersal reflects the pattern of observed odour incidents recorded in the community monitoring database, with the modelled odour dispersing further in a north easterly direction. Therefore, the current regulatory method of dispersion modelling, using hourly averaging times, is less successful at capturing peak concentrations, and does not capture the pattern of odour emission as indicated by the community monitoring database. The use of short averaging times is therefore of greater value in predicting the likely nuisance impact of an odour source and in framing appropriate regulatory controls.Item Open Access Assessing the perception and reality of arguments against thermal waste treatment plants in terms of property prices(Elsevier, 2013-09-21) Philips, K. J. O.; Longhurst, Philip J.; Wagland, Stuart ThomasThe thermal processing of waste materials, although considered to be an essential part of waste management, is often sharply contested in the UK. Arguments such as health, depletion of resources, cost, noise, odours, traffic movement and house prices are often cited as reasons against the development of such facilities. This study aims to review the arguments and identify any effect on property prices due to the public perception of the plant. A selection of existing energy from waste (EfW) facilities in the UK, operational for at least 7 years, was selected and property sales data, within 5 km of the sites, was acquired and analysed in detail. The locations of the properties were calculated in relation to the plant using GIS software (ArcGIS) and the distances split into 5 zones ranging from 0 to 5 km from the site. The local property sale prices, normalised against the local house price index, were compared in two time periods, before and after the facility became operational, across each of the 5 zones. In all cases analysed no significant negative effect was observed on property prices at any distance within 5 km from a modern operational incinerator. This indicated that the perceived negative effect of the thermal processing of waste on local property values is negligible.Item Open Access Assessment of municipal waste compost as a daily cover material for odour control at landfill sites.(Elsevier Science B.V., Amsterdam., 2005-01-01T00:00:00Z) Hurst, C.; Longhurst, Philip J.; Pollard, Simon J. T.; Smith, Richard; Jefferson, Bruce; Gronow, Jan R.The ability of municipal waste compost as a daily cover material to reduce the odorous emissions associated with landfill surfaces was investigated. Trials were carried out using landfill gas, a certified sulphurous gas mix and ambient air as a control. Odorous gas was passed through portable test column filled with compost at different densities (590 kg/m3 and 740 kg/m3). Gas samples were taken from the inlet, outlet and at varying column depths and examined using a combination of sensory analysis (olfactometry) and a novel analytical method (Transportable Selected Ion Flow Tube – TSIFT). Results for the trials using landfill gas showed a 69% odour reduction (OU/m3) through the column for compost with a bulk density of 590 kg/m3, and a reduction of 97% using compost with a bulk density of 740 kg/m3. TSIFT analysis showed an overall decrease in the concentration of terpenes, and sulphurous compounds in the outlet gas from the column for both bulk densities. No significant trend could be identified for the concentrations at different depths within the column. Results show the ability of compost to reduce landfill odours under differing conditions. The inconclusive data provided by TSIFT analysis may be due to the analysis of compounds that are not contributing to odour, and thus highlights the potential for synergetic effects and the importance of sensory measurement when examining odorous emissionItem Open Access Biodrying for mechanical-biological treatment of wastes: A review of process science and engineering(Elsevier Science B.V., Amsterdam., 2009-06-01T00:00:00Z) Velis, C. A.; Longhurst, Philip J.; Drew, Gillian H.; Smith, Richard; Pollard, Simon J. T.Biodrying is a variation of aerobic decomposition, used within mechanical–biological treatment (MBT) plants to dry and partially stabilise residual municipal waste. Biodrying MBT plants can produce a high quality solid recovered fuel (SRF), high in biomass content. Here, process objectives, operating principles, reactor designs, parameters for process monitoring and control, and their effect on biodried output quality are critically examined. Within the biodrying reactors, waste is dried by air convection, the necessary heat provided by exothermic decomposition of the readily decomposable waste fraction. Biodrying is distinct from composting in attempting to dry and preserve most of biomass content of the waste matrix, rather than fully stabilise it. Commercial process cycles are completed within 7–15 days, with mostly H2O(g) and CO2 loses of ca. 25–30% w/w, leading to moisture contents of <20% w/w. High airflow rate and dehumidifying of re-circulated process air provides for effective drying. We anticipate this review will be of value to MBT process operators, regulators and end-users oItem Open Access The biogenic content of process streams from mechanical-biological treatment plants producing solid recovered fuel. Do the manual sorting and selective dissolution determination methods correlate?(Elsevier Science B.V., Amsterdam., 2010-07-31T00:00:00Z) Severin, M.; Velis, C. A.; Longhurst, Philip J.; Pollard, Simon J. T.The carbon emissions trading market has created a need for standard methods for the determination of biogenic content (chi(B)) in solid recovered fuels (SRF). We compare the manual sorting (MSM) and selective dissolution methods (SDM), as amended by recent research, for a range of process streams from a mechanical biological treatment (MBT) plant. The two methods provide statistically different biogenic content values, as expressed on a dry mass basis, uncorrected for ash content. However, they correlate well (r(2) > 0.9) and the relative difference between them was <5% for chi(B) between 21% (w)/W-d and 72% (w)/W-d (uncorrected for ash content). This range includes the average SRF biogenic content of ca. 68% (w)/W-d. Methodological improvements are discussed in light of recent studies. The repeatability of the SDM is characterised by relative standard deviations on triplicates of <2.5% for the studied population. (C) 2010 Elsevier Ltd. All rights reserved.Item Open Access Carbon Brainprint Case Study: training for landfill gas inspectors(2011-07-31T00:00:00Z) Parsons, David J.; Chatterton, Julia C.; Longhurst, Philip J.Anaerobic deterioration of biodegradable wastes in landfill sites is an important source ofgreenhouse gases. Of the estimated UK total of 2330 kt methane emitted in 2008, 966 kt(equivalent to 24 Mt of carbon dioxide) came from landfill, compared with 876 kt from livestockagriculture, the next largest source. Increasing the amount of methane that is recovered andused as fuel is an important method of reducing emissions. In 2008 Cranfield University was asked by the Environment Agency (EA) to run a 12 day course to train 12 EA officers, based on the knowledge of a retired EA industry expert. At the end of thecourse, the students split into two groups, each of which undertook 12 site visits. These 24sites were subsequently assessed by the EA, who estimated that the additional measuresrecommended had collected an additional 7,600 m3/hr of landfill gas. A further 12 officers havenow received the advanced training, and another 70 have attended a foundation course inwhich they learn how to audit and assess landfill gas controls on sites. The additional collection of methane resulting from the first set of visits is equivalent to453 kt CO2e/year. Extrapolating from this by making conservative assumptions about possiblediminishing returns, the savings to the end of 2010 from the two groups (the retrospectivebrainprint) are about 1,330 kt CO2e with a 95% confidence range of 1,091-1,570 kt CO2e. Usingthe same assumptions, if both groups continue working for a further three years, the savingsover the five year period (the prospective brainprint) will be 5,380 kt CO2e with a 95%confidence range of 3,695-7,309 kt CO2e.Item Open Access CFD modelling of particle shrinkage in a fluidized bed for biomass fast pyrolysis with quadrature method of moment(Elsevier, 2017-05-08) Liu, Bo; Papadikis, Konstantinos; Gu, Sai; Fidalgo, Beatriz; Longhurst, Philip J.; Li, Zhongyuan; Kolios, AthanasiosAn Eulerian-Eulerian multi-phase CFD model was set up to simulate a lab-scale fluidized bed reactor for the fast pyrolysis of biomass. Biomass particles and the bed material (sand) were considered to be particulate phases and modelled using the kinetic theory of granular flow. A global, multi-stage chemical kinetic mechanism was integrated into the main framework of the CFD model and employed to account for the process of biomass devolatilization. A 3-parameter shrinkage model was used to describe the variation in particle size due to biomass decomposition. This particle shrinkage model was then used in combination with a quadrature method of moment (QMOM) to solve the particle population balance equation (PBE). The evolution of biomass particle size in the fluidized bed was obtained for several different patterns of particle shrinkage, which were represented by different values of shrinkage factors. In addition, pore formation inside the biomass particle was simulated for these shrinkage patterns, and thus, the density variation of biomass particles is taken into account.Item Open Access China's soil and groundwater management challenges: Lessons from the UK's experience and opportunities for China(Elseveir, 2016-03-10) Coulon, Frederic; Jones, Kevin; Li, Hong; Hu, Qing; Gao, Jingyang; Li, Fasheng; Chen, Mengfang; Zhu, Yong-Guan; Liu, Rongxia; Liu, Ming; Canning, Kate; Harries, Nicola; Bardos, Paul; Nathanail, C. Paul; Sweeney, Rob; Middleton, David; Charnley, Maggie; Randall, Jeremy; Richell, Martin; Howard, Trevor; Martin, Ian; Spooner, Simon; Weeks, Jason; Cave, Mark; Yu, Fang; Zhang, Fang; Jiang, Ying; Longhurst, Philip J.; Prpich, George; Bewley, Richard; Abra, Jonathan; Pollard, Simon J. T.There are a number of specific opportunities for UK and China to work together on contaminated land management issues as China lacks comprehensive and systematic planning for sustainable risk based land management, encompassing both contaminated soil and groundwater and recycling and reuse of soil. It also lacks comprehensive risk assessment systems, structures to support risk management decision making, processes for verification of remediation outcome, systems for record keeping and preservation and integration of contamination issues into land use planning, along with procedures for ensuring effective health and safety considerations during remediation projects, and effective evaluation of costs versus benefits and overall sustainability. A consequence of the absence of these overarching frameworks has been that remediation takes place on an ad hoc basis. At a specific site management level, China lacks capabilities in site investigation and consequent risk assessment systems, in particular related to conceptual modelling and risk evaluation. There is also a lack of shared experience of practical deployment of remediation technologies in China, analogous to the situation before the establishment of the independent, non-profit organisation CL:AIRE (Contaminated Land: Applications In Real Environments) in 1999 in the UK. Many local technology developments are at lab-scale or pilot-scale stage without being widely put into use. Therefore, a shared endeavour is needed to promote the development of technically and scientifically sound land management as well as soil and human health protection to improve the sustainability of the rapid urbanisation in China.Item Open Access Comparative evaluation of SRF and RDF co-combustion with coal in a fluidised bed combustor(2007-10-01T00:00:00Z) Garg, A.; Smith, Richard; Longhurst, Philip J.; Pollard, Simon J. T.; Simms, Nigel J.; Hill, D.The experimental study reported here was carried out to assess the feasibility of municipal solid waste (MSW) derived solid recovered fuel (SRF) in energy recovery applications. SRF was prepared by grinding and blending the major MSW constituents such as paper, plastics, wood and textile. The percentage of various constituents was the same as from the Ecodeco process employing bio- drying followed by mechanical treatment. The heating value of synthetic SRF was ca. 21 MJ/kg (as received basis). The metal emission results from the SRF co- combustion with coal were compared with that obtained from coal mono-combustion and refuse derived fuel (RDF) co-combustion with coal. RDF was also derived from MSW and was obtained from a local mechanical treatment waste facility. Use of SRF as co-fuel does not increase the emissions of metals to the environment in the flue gas stream when compared to coal mono-combustion. In addition, use of MSW derived fuel reduces the arsenic release to the atmosphere. The results showed that most of the metals are retained in the ash components (except mercury). The mobility of metals depends on the volatility and type of feedstock.Item Open Access Comparison of coal/solid recovered fuel (SRF) with coal/refuse derived fuel (RDF) in a fluidised bed reactor.(Elsevier Science B.V., Amsterdam., 2011-06-01T00:00:00Z) Wagland, Stuart Thomas; Kilgallon, P.; Coveney, R.; Garg, A.; Smith, Richard; Longhurst, Philip J.; Pollard, Simon J. T.; Simms, Nigel J.An experimental study was undertaken to compare the differences between municipal solid waste (MSW) derived solid recovered fuel (SRF) (complying with CEN standards) and refuse derived fuel (RDF). Both fuels were co-combusted with coal in a 50kW fluidised bed combustor and the metal emissions were compared. Synthetic SRF was prepared in the laboratory by grinding major constituents of MSW such as paper, plastic, textile and wood. RDF was obtained from a local mechanical treatment plant. Heavy metal emissions in flue gas and ash samples from the (coal+10% SRF) fuel mixture were found to be within the acceptable range and were generally lower than that obtained for coal+10% RDF fuel mixture. The relative distribution of heavy metals in ash components and the flue gas stream shows the presence of a large fraction (up to 98%) of most of the metals in the ash (except Hg and As). Thermo-gravimetric (TG) analysis of SRF constituents was performed to understand the behaviour of fuel mixtures in the absence and presence of air. The results obtained from the experimental study will enhance the confidence of fuel users towards using MSW-derived SRF as an alternative fuel.Item Open Access A conceptual framework for negotiating public involvement in municipal waste management decision-making in the UK(Elsevier, 2017-04-13) Garnett, Kenisha; Cooper, Tim; Longhurst, Philip J.; Jude, Simon; Tyrrel, SeanThe technical expertise that politicians relied on in the past to produce cost-effective and environmentally sound solutions no longer provides sufficient justification to approve waste facilities. Local authorities need to find more effective ways to involve stakeholders and communities in decision-making since public acceptance of municipal waste facilities is integral to delivering effective waste strategies. This paper presents findings from a research project that explored attitudes towards greater levels of public involvement in UK waste management decision-making. The study addressed questions of perception, interests, the decision context, the means of engagement and the necessary resources and capacity for adopting a participatory decision process. Adopting a mixed methods approach, the research produced an empirical framework for negotiating the mode and level of public involvement in waste management decision-making. The framework captures and builds on theories of public involvement and the experiences of practitioners, and offers guidance for integrating analysis and deliberation with public groups in different waste management decision contexts. Principles in the framework operate on the premise that the decision about ‘more’ and ‘better’ forms of public involvement can be negotiated, based on the nature of the waste problem and wider social context of decision-making. The collection of opinions from the wide range of stakeholders involved in the study has produced new insights for the design of public engagement processes that are context-dependent and ‘fit-for-purpose’; these suggest a need for greater inclusivity in the case of contentious technologies and high levels of uncertainty regarding decision outcomes.Item Open Access Coupling Hidden Flows and Waste Generation for Enhanced Materials Flow Accounting(2007-06-01T00:00:00Z) Raffield, Thomas; Herben, Martin; Billington, Stephen; Longhurst, Philip J.; Pollard, Simon J. T.We present an adaptation of an existing materials flow model to account for waste flows in the domestic environment. The revised approach offers added functionality for economic parameters that influence waste production and disposal. Hypothetical waste and resource management futures illustrate the utility of model. A sensitivity analysis confirms that imports, domestic extraction and their associated hidden flows impact mostly on wastes generation. The model offers enhanced utility for policy and decision makers with regard to economic mass balance and strategic waste flows.Item Open Access Critical reflections on designing product service systems(Taylor and Francis, 2015-04-28) Dewberry, Emma; Cook, Matthew; Angus, Andrew; Gottberg, Annika; Longhurst, Philip J.In response to unsustainability and the prospect of resource scarcity, lifestyles dominated by resource throughput are being challenged. This paper focuses on a design experiment that sought to introduce alternative resource consumption pathways in the form of product service systems (PSS) to satisfy household demand and reduce consumer durable household waste. In contrast to many other PSS examples this project did not begin with sustainability benefits, rather the preferences of supply and demand actors and the bounded geographical locations represented by two UK housing developments. The paper addresses the process through which the concept PSS were designed, selected and evaluated, alongside the practical and commercial parameters of the project. It proposes the need for a shift to further emphasize the importance of the design imperative in creating different PSS outcomes that reorganize relationships between people, resources and the environment.Item Open Access Critical review of real-time methods for solid waste characterisation: Informing material recovery and fuel production(Elsevier, 2017-01-28) Vrancken, Carlos; Longhurst, Philip J.; Wagland, Stuart ThomasWaste management processes generally represent a significant loss of material, energy and economic resources, so legislation and financial incentives are being implemented to improve the recovery of these valuable resources whilst reducing contamination levels. Material recovery and waste derived fuels are potentially valuable options being pursued by industry, using mechanical and biological processes incorporating sensor and sorting technologies developed and optimised for recycling plants. In its current state, waste management presents similarities to other industries that could improve their efficiencies using process analytical technology tools. Existing sensor technologies could be used to measure critical waste characteristics, providing data required by existing legislation, potentially aiding waste treatment processes and assisting stakeholders in decision making. Optical technologies offer the most flexible solution to gather real-time information applicable to each of the waste mechanical and biological treatment processes used by industry. In particular, combinations of optical sensors in the visible and the near-infrared range from 800 nm to 2500 nm of the spectrum, and different mathematical techniques, are able to provide material information and fuel properties with typical performance levels between 80% and 90%. These sensors not only could be used to aid waste processes, but to provide most waste quality indicators required by existing legislation, whilst offering better tools to the stakeholders.Item Open Access Determination of renewable energy yield from mixed waste material from the use of novel image analysis methods(Elsevier, 2013-07-20) Wagland, Stuart Thomas; Dudley, R.; Naftaly, M.; Longhurst, Philip J.Two novel techniques are presented in this study which together aim to provide a system able to determine the renewable energy potential of mixed waste materials. An image analysis tool was applied to two waste samples prepared using known quantities of source-segregated recyclable materials. The technique was used to determine the composition of the wastes, where through the use of waste component properties the biogenic content of the samples was calculated. The percentage renewable energy determined by image analysis for each sample was accurate to within 5% of the actual values calculated. Microwave-based multiple-point imaging (AutoHarvest) was used to demonstrate the ability of such a technique to determine the moisture content of mixed samples. This proof-of-concept experiment was shown to produce moisture measurement accurate to within 10%. Overall, the image analysis tool was able to determine the renewable energy potential of the mixed samples, and the AutoHarvest should enable the net calorific value calculations through the provision of moisture content measurements. The proposed system is suitable for combustion facilities, and enables the operator to understand the renewable energy potential of the waste prior to combustion.Item Open Access Development of an image-based analysis method to determine the physical composition of a mixed waste material(Elsevier Science B.V., Amsterdam., 2012-02-01T00:00:00Z) Wagland, Stuart Thomas; Veltre, F.; Longhurst, Philip J.An experimental study was undertaken to assess the suitability of an image-based approach for determining the physical composition of mixed organic wastes. Samples arriving at different waste sorting facilities, each visited twice during the study, were physically sorted to examine the composition these materials. During these surveys the waste was processed in order to obtain digital images covering 30 m 2 , representing approximately 250-500 kg of mixed waste. The images were processed using ERDAS Imagine software in order to assess the area covered by each component within the waste material. The composition determined from the image analysis was compared with the results from the physical hand sorting. The image analysis results indicated a strong correlation between the physical results (mean r = 0.91) however it was evident that components such as film plastics and paper were over-estimated by the image analysis approach. This short communication provides initial results, demonstrating the potential of an image-based method, and discusses further research requirements and future applications of this technique.Item Open Access Dispersion of bioaerosols from composting facilities.(2006-09-01T00:00:00Z) Drew, Gillian H.; Tamer Vestlund, Asli; Taha, M. P. M.; Smith, Richard; Longhurst, Philip J.; Kinnersley, R.; Pollard, Simon J. T.The promotion of composting as an option for sustainable waste management has raised concerns regarding public health impacts of exposures to potentially hazardous bioaerosols. Recent source term experiments show that bioaerosol emissions are episodic and that peak emissions are related to compost agitation. The Environment Agency requires risk assessments for facilities that have sensitive receptors within 250m of their boundary. In order to improve current risk assessment methodologies, improved predictions of bioaerosol dispersal are required. Dispersion modelling has been successfully used to determine dispersion of odours from waste management. In this paper, bioaerosol concentration data measured at a composting facility is analysed in an ongoing series of model experiments, using the ADMS air dispersion model. Initial modelling results reveal that the concentrations of bioaerosols decrease rapidly with distance from the site, although under certain circumstances, it is possible that higher concentrations may still be present at 200m from the site boundary. However, dispersion models are not yet able to take into account all the properties of bioaerosols, in particular, their viability and their ability to aggregate and form clumps, which will affect the rate of dispersal. A series of experiments were designed to examine how the options within dispersion model affect the dispersion of bioaerosols and under which circumstances high concentrations may disperse to sensitive receptors. The results will be compared with bioaerosol measurements taken downwind of a composting facility, to determine the accuracy of the model predictions. This is the first stage in an attempt to design a best practice method for modelling bioaerosols.Item Open Access Endotoxin emissions from commercial composting activities(BioMed Central, 2009-12-21T00:00:00Z) Deacon, Lewis J.; Pankhurst, Louise J.; Liu, Jian; Drew, Gillian H.; Hayes, Enda T.; Jackson, Simon; Longhurst, James; Longhurst, Philip J.; Pollard, Simon J. T.; Tyrrel, Sean F.This paper describes an exploratory study of endotoxin emissions and dispersal from a commercial composting facility. Replicated samples of air were taken by filtration at different locations around the facility on 10 occasions. Measurements were made of endotoxin and associated culturable microorganisms. The inflammatory response of cell cultures exposed to extracts from the filters was measured. Endotoxin was detected in elevated concentrations close to composting activities. A secondary peak, of lesser magnitude than the peak at source was detected at 100-150 m downwind of the site boundary. Unexpectedly high concentrations of endotoxin were measured at the most distant downwind sampling point. Extracted endotoxin was found to stimulate human monocytes and a human lung epithelial cell line to produce significant amounts of pro- inflammatory cytokines. On a weight basis, endotoxin extracted from the composting source has a greater inflammatory cytokine inducing effect than commercial E. coli endotoxin.
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