Quantitative Microbial Risk Assessment Framework Incorporating Water Ages with Legionella pneumophila Growth Rates.

Water age in drinking water systems is often used as a proxy for water quality but is rarely used as a direct input in assessing microbial risk. This study directly linked water ages in a premise plumbing system to concentrations of Legionella pneumophila via a growth model. In turn, the L. pneumophila concentrations were used for a quantitative microbial risk assessment to calculate the associated probabilities of infection (Pinf) and clinically severe illness (Pcsi) due to showering. Risk reductions achieved by purging devices, which reduce water age, were also quantified. The median annual Pinf exceeded the commonly used 1 in 10,000 (10-4) risk benchmark in all scenarios, but the median annual Pcsi was always 1-3 orders of magnitude below 10-4. The median annual Pcsi was lower in homes with two occupants (4.7 × 10-7) than with one occupant (7.5 × 10-7) due to more frequent use of water fixtures, which reduced water ages. The median annual Pcsi for homes with one occupant was reduced by 39-43% with scheduled purging 1-2 times per day. Smart purging devices, which purge only after a certain period of nonuse, maintained these lower annual Pcsi values while reducing additional water consumption by 45-62%.

Research to Move Toward Evidence-Based Recommendations for Lead Service Line Disclosure Policies in Home Buying and Home Renting Scenarios.

Lead service lines (LSLs)-lead pipes connecting the water main under the street to a building's plumbing-contribute an estimated 50% to 75% of lead in tap water when they are present. Although Congress banned lead in plumbing materials in 1986, over 6 million LSLs remain in homes across the United States today. This paper summarizes three different home buying or renting scenario-based experimental studies used to evaluate disclosure styles, to assess if these influenced respondents' perceived risk of the LSL in a home, and their willingness to act. In renting scenarios, having landlords disclose the presence of an LSL, but also provide water test results showing lead levels below the EPA's lead action level resulted in lower levels of perceived risk, and of willingness to act. In seller-disclosure home buying scenarios, levels of perceived risk and willingness to act were consistently high, and three different disclosure styles did not differentially influence those outcomes. In home inspector-disclosure home buying scenarios, levels of perceived risk and willingness to act were high, but having explicit recommendations to replace LSLs and/or information about risk did not further influence those outcomes. In some cases, including the specific recommendations backfired. Implications for policy and regulation are discussed.

Evolution of urban scaling: Evidence from Brazil.

During the last years, the new science of cities has been established as a fertile quantitative approach to systematically understand the urban phenomena. One of its main pillars is the proposition that urban systems display universal scaling behavior regarding socioeconomic, infrastructural and individual basic services variables. This paper discusses the extension of the universality proposition by testing it against a broad range of urban metrics in a developing country urban system. We present an exploration of the scaling exponents for over 60 variables for the Brazilian urban system. Estimating those exponents is challenging from the technical point of view because the Brazilian municipalities' definition follows local political criteria and does not regard characteristics of the landscape, density, and basic utilities. As Brazilian municipalities can deviate significantly from urban settlements, urban-like municipalities were selected based on a systematic density cut-off procedure and the scaling exponents were estimated for this new subset of municipalities. To validate our findings we compared the results for overlaying variables with other studies based on alternative methods. It was found that the analyzed socioeconomic variables follow a superlinear scaling relationship with the population size, and most of the infrastructure and individual basic services variables follow expected sublinear and linear scaling, respectively. However, some infrastructural and individual basic services variables deviated from their expected regimes, challenging the universality hypothesis of urban scaling. We propose that these deviations are a product of top-down decisions/policies. Our analysis spreads over a time-range of 10 years, what is not enough to draw conclusive observations, nevertheless we found hints that the scaling exponent of these variables are evolving towards the expected scaling regime, indicating that the deviations might be temporally constrained and that the urban systems might eventually reach the expected scaling regime.

Statistical models to predict discharge overflow.

In the paper, a comparison of prediction results concerning the annual number of discharges of stormwater from the drainage system due to stormwater overflows is depicted. The prediction has been computed by means of storm water management model (SWMM) and probabilistic models. Regarding the probabilistic modelling some simple statistical models such as logit, probit, Gompertz and linear discriminant analysis model have been applied, and as for the hydrodynamic modelling a generator of synthetic rainfall based on the Monte Carlo method has been used. The analyses conducted has shown that logit, probit and Gompertz models give outputs that are comparable with the results of hydrodynamic modelling and are concordant with observations. Whereas the annual number of stormwater discharge predicted by the linear discriminant analysis model is significantly lower than the number obtained by hydrodynamic modelling. The calculations made have confirmed the possibility of using statistical models as an alternative for developing labour-consuming and complex hydrodynamic models. The statistical models can be used successfully to predict the stormwater overflows operation provided that the measurements of rainfall in the catchment and of filling the overflow are available.

Control inalámbrico de mesa quirúrgica desde dispositivo móvil / Wireless control of operating tables from a mobile device

Para la mayoría de las mesas quirúrgicas del hospital, el proveedor ya no comercializa controles remotos compatibles, lo cual implicaría un gasto importante para su actualización o renovación. Para evitar dicho gasto, se diseñó un control inalámbrico para manejar los movimientos de las mesas quirúrgicas a través de un dispositivo móvil.

The provider no longer provides compatible remote controls for most of operating tables at the hospital, which would imply an important expense for their upgrading or renewal. In order to avoid that expenditure, a wireless control was designed to improve operating table movements from a mobile device.

Relationship between race and community water and sewer service in North Carolina, USA.

Previous evidence has identified potential racial disparities in access to community water and sewer service in peri-urban areas adjacent to North Carolina municipalities. We performed the first quantitative, multi-county analysis of these disparities. Using publicly available data, we identified areas bordering municipalities and lacking community water and/or sewer service in 75 North Carolina counties. Logistic regression was performed to evaluate the relationship between race and access to service in peri-urban areas, controlling for population density, median home value, urban status, and percent white in the adjacent municipality. In the peri-urban areas analyzed, 67% of the population lacked community sewer service, and 33% lacked community water service. In areas other than those with no black residents, odds of having community water service (p<0.01) or at least one of the two services (p<0.05) were highest for census blocks with a small proportion of black residents and lowest in 100% black census blocks, though this trend did not hold for access to community sewer service alone. For example, odds of community water service were 85% higher in areas that were greater than 0% but less than 22% black than in 100% black areas (p<0.001). Peri-urban census blocks without black populations had the lowest odds of community water service, community sewer service, and at least one of the two services, but this difference was only statistically significant for sewer. Peri-urban areas lacking service with no black residents were wealthier than 100% black areas and areas with any percent black greater than 0%. Findings suggest two unserved groups of differing racial and socioeconomic status: (1) lower-income black populations potentially excluded from municipal services during the era of legal racial segregation and (2) higher-income non-black populations. Findings also suggest greater racial disparities in community water than community sewer services statewide.

Processing Technology Selection for Municipal Sewage Treatment Based on a Multi-Objective Decision Model under Uncertainty.

This study considers the two factors of environmental protection and economic benefits to address municipal sewage treatment. Based on considerations regarding the sewage treatment plant construction site, processing technology, capital investment, operation costs, water pollutant emissions, water quality and other indicators, we establish a general multi-objective decision model for optimizing municipal sewage treatment plant construction. Using the construction of a sewage treatment plant in a suburb of Chengdu as an example, this paper tests the general model of multi-objective decision-making for the sewage treatment plant construction by implementing a genetic algorithm. The results show the applicability and effectiveness of the multi-objective decision model for the sewage treatment plant. This paper provides decision and technical support for the optimization of municipal sewage treatment.

Identification of potential sewer mining locations: a Monte-Carlo based approach.

Rapid urbanization affecting demand patterns, coupled with potential water shortages due to supply side impacts of climatic changes, has led to the emergence of new technologies for water and wastewater reuse. Sewer mining (SM) is a novel decentralized option that could potentially provide non-potable water for urban uses, including for example the irrigation of urban green spaces, providing a mid-scale solution to effective wastewater reuse. SM is based on extracting wastewater from local sewers and treatment at the point of demand and entails in some cases the return of treatment residuals back to the sewer system. Several challenges are currently in the way of such applications in Europe, including public perception, inadequate regulatory frameworks and engineering issues. In this paper we consider some of these engineering challenges, looking at the sewer network as a system where multiple physical, biological and chemical processes take place. We argue that prior to implementing SM, the dynamics of the sewer system should be investigated in order to identify optimum ways of deploying SM without endangering the reliability of the system. Specifically, both wastewater extraction and sludge return could result in altering the biochemical process of the network, thus unintentionally leading to degradation of the sewer infrastructure. We propose a novel Monte-Carlo based method that takes into account both spatial properties and water demand characteristics of a given area of SM deployment while simultaneously accounting for the variability of sewer network dynamics in order to identify potential locations for SM implementation. The outcomes of this study suggest that the method can provide rational results and useful guidelines for upscale SM technologies at a city level.

Synergistic benefits between stormwater management measures and a new pricing system for stormwater in the City of Hamburg.

Hamburg is a growing metropolitan city. The increase in sealed surfaces of about 0.36% per year and the subsequent increased runoff impacts on the city's wastewater infrastructure. Further potential risks to the drainage infrastructure arise also from effects of climate change, e.g. increased intensity and frequency of heavy rainfalls. These challenges were addressed in the Rain InfraStructure Adaption (RISA) project conducted 2009-2015 by HAMBURG WASSER and the State Ministry for Environment and Energy, supported by several municipal stakeholders. RISA addressed intensifying conflicts in the context of urban development and stormwater management at that time. Major results of the project are improvements and recommendations for adequate consideration of stormwater management issues during urban planning as well as new funding mechanisms for stormwater management measures. The latter topic resulted in the introduction of a separated stormwater charge based on the amount of sealed area connected to the sewer system of each property. For both undertakings - the RISA project and the introduction of the separated stormwater charge - a novel, comprehensive, digital database was built. Today, these geographical information system (GIS)-based data offer various scale-independent analysis and information opportunities, which facilitate the day-to-day business of HAMBURG WASSER and stormwater management practice in Hamburg.

Water budget analysis and management for Bangkok Metropolis, Thailand.

The water budget of the Bangkok Metropolis system was analyzed using a material flow analysis model. Total imported flows into the system were 80,080 million m3 per year (Mm3 y-1) including inflows from the Chao Phraya and Mae Klong rivers and rainwater. Total exported flows out of the system were 78,528 Mm3 y-1 including outflow into the lower Chao Phraya River and tap water (TW) distributed to suburbs. Total rates of stock exchange (1,552 Mm3 y-1) were found in the processes of water recycling, TW distribution, domestic use, swine farming, aquaculture, and paddy fields. Only 21% of the total amount of wastewater (1,255 Mm3 y-1) was collected, with insufficient treatment capacity of about 415 Mm3 y-1. Domestic and business (industrial and commercial sectors) areas were major point sources, whereas paddy fields were a major non-point source of wastewater. To manage Bangkok's water budget, critical measures have to be considered. Wastewater treatment capacity and efficiency of wastewater collection should be improved. On-site wastewater treatment plants for residential areas should be installed. Urban planning and land use zoning are suggested to control land use activities. Green technology should be supported to reduce wastewater from farming.

Micropollutants in groundwater from septic systems: Transformations, transport mechanisms, and human health risk assessment.

Septic systems may contribute micropollutants to shallow groundwater and surface water. We constructed two in situ conventional drainfields (drip dispersal and gravel trench) and an advanced drainfield of septic systems to investigate the fate and transport of micropollutants to shallow groundwater. Unsaturated soil-water and groundwater samples were collected, over 32 sampling events (January 2013 to June 2014), from the drainfields (0.31-1.07 m deep) and piezometers (3.1-3.4 m deep). In addition to soil-water and groundwater, effluent samples collected from the septic tank were also analyzed for 20 selected micropollutants, including wastewater markers, hormones, pharmaceuticals and personal care products (PPCPs), a plasticizer, and their transformation products. The removal efficiencies of micropollutants from septic tank effluent to groundwater were similar among three septic systems and were 51-89% for sucralose and 53->99% for other micropollutants. Even with high removal rates within the drainfields, six PPCPs and sucralose with concentrations ranging from <0.3 to 154 ng/L and 121 to 32,000 ng/L reached shallow groundwater, respectively. The human health risk assessment showed that the risk to human health due to consumption of groundwater is negligible for the micropollutants monitored in the study. A better understanding of ecotoxicological effects of micropollutant mixtures from septic systems to ecosystem and human health is warranted for the long-term sustainability of septic systems.

Management of Risks From Water and Ice From Ice Machines for the Very Immunocompromised Host: A Process Improvement Project Prompted by an Outbreak of Rapidly Growing Mycobacteria on a Pediatric Hematopoietic Stem Cell Transplant (Hsct) Unit.

BACKGROUND In 2011, pediatric hematopoietic stem cell transplant (HSCT) patients were moved from an older hospital to a new children's hospital. To minimize bacterial growth in the new hospital's water during construction, the plumbing system was flushed and disinfected before occupancy. However, 6 months after occupancy, an increased incidence of rapidly growing mycobacteria (RGM) was detected in clinical cultures. Over 10 months, 15 pediatric HSCT patients were infected, while no pediatric HSCT patients had been infected in the preceding 12 months. OBJECTIVE To determine the cause of the outbreak and to interrupt patient acquisition of RGM. METHODS Water samples were collected from water entering the hospital and from drinking water and ice machines (DWIMs) from the old and new hospitals. Total heterotrophic plate counts (HPCs, CFU/mL) of water were undertaken, and select isolates were identified as RGM. RESULTS The cause of the outbreak was increased bacterial levels in the water (including RGM) in the DWIMs in the new (2011) hospital. Tests revealed higher HPCs in drinking water and ice from the DWIMs in the new hospital than in the DWIMs in the old hospital. Ultimately, HPCs were reduced by several different interventions. CONCLUSION In response to an RGM outbreak, HSCT patients were banned from ingesting DWIM ice and water and bottled water was provided. Since this interverntion 4 years ago, no additional RGM isolates have been identified in HSCT patient cultures. Our measures to reduce HPCs to goal levels in drinking water from DWIMs were successful, but the HPCs for ice have not consistently reached the goal of <500 CFU/mL. Infect Control Hosp Epidemiol 2017;38:792-800.

Impacto en la salud pública del sistema de telediagnóstico implementado en Paraguay / Public health impact of a remote diagnosis system implemented in regional and district hospitals in Paraguay / Impacto sobre a saúde pública do sistema de teledi¬agnóstico implementado em hospitais regionais e dis¬tritais do Paraguai

Objetivo. Determinar la viabilidad y puesta en marcha de un sistema de telediagnóstico para dar asistencia sanitaria a poblaciones remotas y dispersas del Paraguay. Métodos. El estudio fue realizado en todos los hospitales regionales, generales y principales hospitales distritales de las 18 regiones sanitarias del Paraguay. En el sistema se registraron los datos clínicos y las imágenes tomográficas, ecográficas y trazados electrocardiográficos del paciente que precisaba de un diagnóstico por parte de un médico especialista. Esta información se transmitió a los especialistas en imagenología y en cardiología para su diagnóstico remoto y posterior envío del informe a los hospitales conectados al sistema. Se analizó el costo-beneficio e impacto de la herramienta de telediagnóstico desde la perspectiva del Sistema Nacional de Salud. Resultados. Entre enero de 2014 y mayo de 2015 se realizaron 34 096 telediagnósticos distribuidos en 25 hospitales a través del Sistema de Telemedicina del Ministerio de Salud. El costo unitario promedio del diagnóstico remoto fue de USD 2,6 (dólares estadounidenses) para electrocardiograma (ECG), tomografía y ecografía, mientras que el costo unitario para el diagnóstico “cara a cara” fue de UDS 11,8 para ECG; USD 68,6 para tomografía y USD 21,5 para ecografía. La reducción del costo mediante el diagnóstico remoto fue de 4,5 veces para ECG; 26,4 veces para tomografía y de 8,3 veces para ecografía. En términos monetarios, la implementación del sistema de telediagnóstico, durante los 16 meses del estudio, significó un ahorro promedio de USD 2 420 037. Conclusión. Paraguay cuenta con un sistema de telediagnóstico para electrocardiografía, tomografía y ecografía aplicando las tecnologías de la información y comunicación (TIC) de bajo costo, basadas en software libre y escalable a otros tipos de estudios diagnósticos a distancia; de interés para la salud pública. Con una aplicación práctica del telediagnóstico, se contribuyó al fortalecimiento de la red integrada de servicios y programas de salud, lo que permitió maximizar el tiempo del profesional y su productividad, mejorar la calidad, aumentar el acceso y la equidad, y disminuir los costos.

Objective. Determine the viability of a remote diagnosis system implemented to provide health care to remote and scattered populations in Paraguay. Methods. The study was conducted in all regional and general hospitals in Paraguay, and in the main district hospitals in the country’s 18 health regions. Clinical data, tomographic images, sonography, and electrocardiograms (ECGs) of patients who needed a diagnosis by a specialized physician were entered into the system. This information was sent to specialists in diagnostic imaging and in cardiology for remote diagnosis and the report was then forwarded to the hospitals connected to the system. The cost-benefit and impact of the remote diagnosis tool was analyzed from the perspective of the National Health System. Results. Between January 2014 and May 2015, a total of 34 096 remote diagnoses were made in 25 hospitals in the Ministry of Health’s telemedicine system. The average unit cost of remote diagnosis was US$2.6 per ECG, tomography, and sonography, while the unit cost of “face-to-face” diagnosis was US$11.8 per ECG, US$68.6 per tomography, and US$21.5 per sonography. As a result of remote diagnosis, unit costs were 4.5 times lower for ECGs; 26.4 times lower for tomography, and 8.3 times lower for sonography. In monetary terms, implementation of the remote diagnosis system during the 16 months of the study led to average savings of US$2 420 037. Conclusion. Paraguay has a remote diagnosis system for electrocardiography, tomography, and sonography, using low-cost information and communications technologies (ICTs) based on free software that is scalable to other types of remote diagnostic studies of interest for public health. Implementation of remote diagnosis helped to strengthen the integrated network of health services and programs, enabling professionals to optimize their time and productivity, while improving quality, increasing access and equity, and reducing costs.

Objetivo. Avaliar a viabilidade e a implementação de um sistema de telediagnóstico destinado a oferecer assistência de saúde a populações remotas e dispersas do Paraguai. Métodos. O estudo foi realizado em todos os hospitais regionais e gerais e nos principais hospitais distritais das 18 regiões sanitárias do Paraguai. Foram registrados no sistema os dados clínicos, as imagens tomográficas e ecográficas e os traçados eletrocardiográficos de pacientes que precisavam de um diagnóstico por parte de um médico especialista. Estas informações foram transmitidas a especialistas em diagnóstico por imagem e cardiologia para que fizessem o diagnóstico remoto e enviassem então os laudos aos hospitais conectados ao sistema. Analisou-se a relação custo- benefício e o impacto da ferramenta de telediagnóstico da perspectiva do Sistema Nacional de Saúde. Resultados. Entre janeiro de 2014 e maio de 2015, foram realizados 34.096 telediagnósticos em 25 hospitais através do Sistema de Telemedicina do Ministério da Saúde. O custo unitário médio do diagnóstico remoto foi de US$ 2,6 (dólares americanos) para eletrocardiografia (ECG), tomografia e ecografia, enquanto que o custo unitário para o diagnóstico presencial foi de US$ 11,8 para ECG, US$ 68,6 para tomografia e US$ 21,5 para ecografia. A redução do custo pelo uso do diagnóstico remoto foi de 4,5 vezes para ECG, 26,4 vezes para tomografia e 8,3 vezes para ecografia. Em termos monetários, a implementação do sistema de telediagnóstico, ao longo dos 16 meses do estudo, representou uma economia média de US$ 2.420.037. Conclusão. O Paraguai conta com um sistema de telediagnóstico para eletrocardiografia, tomografia e ecografia que utiliza tecnologias da informação e comunicação (TIC) de baixo custo, baseadas em software livre e ampliáveis a outros tipos de exames diagnósticos à distância que são de interesse para a saúde pública. A aplicação prática do telediagnóstico contribuiu para o fortalecimento da rede integrada de serviços e programas de saúde, o que permitiu maximizar o tempo dos profissionais e sua produtividade, melhorar a qualidade, aumentar o acesso e a equidade e reduzir os custos.

Health Hazards in the Home: An Assessment of a Southern Nevada Community.

As a sub-grantee of a Department of Housing and Urban Development (HUD) Lead Hazard Control and Healthy Homes Program, the University of Nevada, Las Vegas' Department of Environmental and Occupational Health performed lead and Healthy Homes investigations and collected data regarding conditions in the home environment in Henderson, Nevada. The purpose of this research is to characterize housing conditions in southern Nevada, compare data to census data, and to highlight the health outcomes associated with adverse housing conditions. Visual home assessments were conducted in 106 homes in southern Nevada, and specific hazards were characterized using the Healthy Homes Rating System. The results were then compared, when possible, to American Housing Survey (AHS) data for the Las Vegas metropolitan area. Lead, domestic hygiene, carbon monoxide, damp and mold, excess cold and heat, and structural collapse were the most frequently identified hazards, found in at least 101 (90%) of participant households. Median household income of program participants was half (50%) that of the surrounding zip code, which was expected, as classification as "low-income" by HUD standards was a requirement for participation. Our data indicated that the AHS data may not be representative of very low income housing in southern Nevada and may underreport actual conditions. In-home inspections performed by trained personnel provide a more accurate picture of conditions than the self-report method used by the AHS. In addition, we recommend the development of a standardized Healthy Homes visual assessment tool to allow for the comparison of housing conditions between communities.

Seasonal Assessment of Opportunistic Premise Plumbing Pathogens in Roof-Harvested Rainwater Tanks.

A seasonal study on the occurrence of six opportunistic premise plumbing pathogens (OPPPs) in 24 roof-harvested rainwater (RHRW) tanks repeatedly sampled over six monthly sampling events (n = 144) from August 2015 to March 2016 was conducted using quantitative qPCR. Fecal indicator bacteria (FIB) Escherichia coli (E. coli) and Enterococcus spp. were enumerated using culture-based methods. All tank water samples over the six events were positive for at least one OPPP (Legionella spp., Legionella pneumophila, Mycobacterium avium, Mycobacterium intracellulare, Pseudmonas aeruginosa, or Acanthamoeba spp.) during the entire course of the study. FIB were positively but weakly correlated with P. aeruginosa (E. coli vs P. aeruginosa τ = 0.090, p = 0.027; Enterococcus spp. vs P. aeruginosa τ = 0.126, p = 0.002), but not the other OPPPs. FIBs were more prevalent during the wet season than the dry season, and L. pneumophila was only observed during the wet season. However, concentrations of Legionella spp., M. intracellulare, Acanthamoeba spp., and M. avium peaked during the dry season. Correlations were assessed between FIB and OPPPs with meteorological variables, and it was determined that P. aeruginosa was the only OPPP positively associated with an increased antecedent dry period, suggesting stagnation time may play a role for the occurrence of this OPPP in tank water. Infection risks may exceed commonly cited benchmarks for uses reported in the rainwater usage survey such as pool top-up, and warrant further exploration through quantitative microbial risk assessment (QMRA).

International experiences in stormwater fee.

Stormwater management (SWM) includes a wide range of services aimed at environmental protection, enhancement of water resources and flood control. Local governments are responsible for managing all these aspects within their jurisdiction, but they often present limitations in generating revenues. Thus, many municipalities have been seeking a dedicated funding source for these programs and practices. This publication provides a brief overview of current legal issues associated with stormwater funding focusing on the most used method: fees. It is a successful mechanism to fund legal obligations of municipalities; however, it must have a significant value to motivate the reduction of runoff. Through literature, we found stormwater fees in Australia, Brazil, Canada, Ecuador, France, Germany, Poland, South Africa and the United States (USA). France had the highest average monthly fee, but this financing experience was suspended in 2014. Brazil has the lowest fee by m², comparable to the US fee. While in Brazil overall SWM represents low priority investments, the USA represents one of the most evolved countries in stormwater funding practices. It was noticed by reviewing the international experience that charging stormwater fees is a successful mechanism to fund the legal obligations and environmental protection.

Valuing information for sewer replacement decisions.

Decision-making for sewer asset management is partially based on intuition and often lacks explicit argumentation, hampering decision transparency and reproducibility. This is not to be preferred in light of public accountability and cost-effectiveness. It is unknown to what extent each decision criterion is appreciated by decision-makers. Further insight into this relative importance improves understanding of decision-making of sewer system managers. As such, a digital questionnaire (response ratio 43%), containing pairwise comparisons between 10 relevant information sources, was sent to all 407 municipalities in the Netherlands to analyse the relative importance and assess whether a shared frame of reasoning is present. Thurstone's law of comparative judgment was used for analysis, combined with several consistency tests. Results show that camera inspections were valued highest, while pipe age was considered least important. The respondents were pretty consistent per individual and also showed consistency as a group. This indicated a common framework of reasoning among the group. The feedback of the group showed, however, the respondents found it difficult to make general comparisons without having a context. This indicates decision-making in practice is more likely to be steered by other mechanisms than purely combining information sources.