Supply, demand and the economic effectiveness of urine-diverting technologies and products: A systematic literature review

The broader adoption of urine-diverting technologies (UDTs) and related products has been proposed as a strategy for moving towards a more circular economy. While some studies have explored the performance of UDTs, the interconnected factors involving supply, demand, and economic feasibility of UDTs remain under-researched. Our systematic review addresses this gap. Our search identified only 64 relevant, peer-reviewed studies, 71 % of which addressed the supply side (primarily the technical aspect of UDTs) and 58 % of which addressed the demand side (focusing on consumers' perceptions). Approximately one-third (18) of these studies delved into the economic feasibility of UDTs, with only 9 employing a cost benefit analysis (CBA) framework. However, none of these studies have analysed the economic performance of UDTs that have been fully deployed, indicating a significant knowledge gap. Our review suggests that overcoming challenges in scaling up UDTs can be achieved by engaging those stakeholders driving the uptake, developing business cases that offer an overall understanding of both market and non-market benefits of UDTs, addressing technological constraints by optimising urine treatment options for efficiency and economic viability, and enhancing stakeholders' acceptance of UDTs.

Mechanisms underlying the associations between different types of nature exposure and sleep duration: An 18-country analysis

Whilst green space has been linked to healthier sleep outcomes, the roles of specific types of nature exposure, potential underlying mechanisms, and between-country variations in nature-sleep associations have received little attention. Drawing on cross-sectional survey data from an 18-country sample of adults (N = 16,077) the current study examined: 1) the relative associations between six different types of nature exposure (streetscape greenery, blue view from home, green space within 1 km, coast within 1 km, green space visits, blue space visits) and insufficient sleep (<6 h vs. 7-10 h per day); 2) whether these relationships were mediated by better mental wellbeing and/or physical activity; and 3) the consistency of these pathways among the different countries. After controlling for covariates, neighbourhood nature measures (green space, coast within 1 km) were not significantly associated with insufficient sleep; but nature visible from home (streetscape greenery, blue views) and recreational visits to green and blue spaces were each associated with less insufficient sleep. Significant nature-sleep associations were mediated, to varying degrees, by better mental wellbeing, but not self-reported physical activity. Country-level heterogeneity in the strength of nature-sleep associations was observed. Increasing nature visible from the home may represent a promising strategy for promoting healthier sleep duration at the population level, whilst nature-based interventions encouraging individuals to spend time in local green/blue spaces may be an appropriate target to assist individuals affected by insufficient sleep.

Therapeutic Hospital Gardens: Literature Review and Working Definition

AIM

This review explores the role of purposefully designed and well-integrated therapeutic hospital gardens (THGs) for the benefits of patients, their families, and staff.

BACKGROUND

Significant benefits are realized when people are in contact with nature in the city. Although hospital gardens are prevalent and the beneficial effects of nature on health are widely acknowledged, the establishment of a consistent definition for hospital gardens that promote health is vital to attain reliable and quantifiable health outcomes.

METHODS

Twenty-eight peer-reviewed journals were critiqued for the period of 2016-2021 and updated with 12 articles from 2021 to 2023 to analyze and synthesize the latest thinking and development in this emergent field. Subsequently, current books and exemplar practice literature were synthesized with the results of the literature review to produce a working definition of THGs.

RESULTS

Three themes and 14 subthemes were established showing the interconnectedness of THG definition, user needs and experiences, and the benefits and values of THGs. Two original findings can be established-a need to have a consensus on terminology and to establish design processes. The working definition was produced as a foundational step to guide stakeholders in implementing THGs.

CONCLUSION

THGs can play a role in improving well-being when they are purposefully designed and well-integrated in hospital programs and health policy. Hospital CEOs, designers, and healthcare experts can use the findings and working definition to assist the establishment of such health promoting gardens.

Nature contact and general health: Testing multiple serial mediation pathways with data from adults in 18 countries

The role of neighbourhood nature in promoting good health is increasingly recognised in policy and practice, but consistent evidence for the underlying mechanisms is lacking. Heterogeneity in exposure methods, outcome measures, and population characteristics, little exploration of recreational use or the role of different types of green or blue space, and multiple separate mediation models in previous studies have limited our ability to synthesise findings and draw clear conclusions. We examined multiple pathways linking different types of neighbourhood nature with general health using a harmonised international sample of adults. Using cross-sectional survey data from 18 countries (n = 15,917), we developed a multigroup path model to test theorised pathways, controlling for sociodemographic variables. We tested the possibility that neighbourhood nature (e.g. greenspace, inland bluespace, and coastal bluespace) would be associated with general health through lower air pollution exposure, greater physical activity attainment, more social contact, and higher subjective well-being. However, our central prediction was that associations between different types of neighbourhood nature and general health would largely be serially mediated by recent visit frequency to corresponding environment types, and, subsequently, physical activity, social contact, and subjective well-being associated with these frequencies. Several subsidiary analyses assessed the robustness of the results to alternative model specifications as well as effect modification by sociodemographics. Consistent with this prediction, there was statistical support for eight of nine potential serial mediation pathways via visit frequency which held for a range of alternative model specifications. Effect modification by financial strain, sex, age, and urbanicity altered some associations but did not necessarily support the idea that nature reduced health inequalities. The results demonstrate that across countries, theorised nature-health linkages operate primarily through recreational contact with natural environments. This provides arguments for greater efforts to support use of local green/blue spaces for health promotion and disease prevention.

An exploration of challenges associated with machine learning for time series forecasting of COVID-19 community spread using wastewater-based epidemiological data

Wastewater-based epidemiology (WBE) has gained increasing attention as a complementary tool to conventional surveillance methods with potential for significant resource and labour savings when used for public health monitoring. Using WBE datasets to train machine learning algorithms and develop predictive models may also facilitate early warnings for the spread of outbreaks. The challenges associated with using machine learning for the analysis of WBE datasets and timeseries forecasting of COVID-19 were explored by running Random Forest (RF) algorithms on WBE datasets across 108 sites in five regions: Scotland, Catalonia, Ohio, the Netherlands, and Switzerland. This method uses measurements of SARS-CoV-2 RNA fragment concentration in samples taken at the inlets of wastewater treatment plants, providing insight into the prevalence of infection in upstream wastewater catchment populations. RF's forecasting performance at each site was quantitatively evaluated by determining mean absolute percentage error (MAPE) values, which was used to highlight challenges affecting future implementations of RF for WBE forecasting efforts. Performance was generally poor using WBE datasets from Catalonia, Scotland, and Ohio with 'reasonable' or better forecasts constituting 0 %, 5 %, and 0 % of these regions' forecasts, respectively. RF's performance was much stronger with WBE data from the Netherlands and Switzerland, which provided 55 % and 45 % 'reasonable' or better forecasts respectively. Sampling frequency and training set size were identified as key factors contributing to accuracy, while inclusion of too many unnecessary variables (or e.g., flow data) was identified as a contributing factor to poor performance. The contribution of catchment population on forecast accuracy was more ambiguous. This study determined that the factors governing RF's forecast performance are complicated and interrelated, which presents challenges for further work in this space. A sufficiently accurate further iteration of the tool discussed within this study would provide significant but varying value for public health departments for monitoring future, or ongoing outbreaks, assisting the implementation of on-time health response measures.

Enabling Transformational Leadership to Foster Disaster-Resilient Hospitals

Hospitals' operational performance during disasters varies from failing, to being responsive and resilient, to dealing with disruption and surprise. Transformational leaders enable continuously learning hospitals that are resilient in the face of disasters by adapting regeneratively and evolving beyond undertaking conventional lesson-learning after each disaster. However, learning from successful transformational leaders in healthcare is still ad hoc with a lack of guidance on how to develop such leaders. Hence, this study sought to identify key competencies of transformational leaders by exploring hospital leaders' actions in dealing with disasters, considering the disaster cycle of prevention, preparedness, response, and recovery (PPRR). A qualitative case-study design was adopted comprising in-depth semi-structured interviews with twelve senior hospital staff with operational leadership experience with disasters. Three significant categories (themes) and seven key component competencies (sub-themes, in brackets) of transformational leaders were revealed through the analysis of transcripts: (1) 'Governance and leadership' ('transformative agency' and 'decisive accountability'); (2) 'Planning and risk assessment' ('risk navigation', 'disaster attunement', and 'planning agility'); and (3) 'Communication and network engagement' ('communication accelerator' and 'collaboration innovator'). The authors propose a transformational leadership model for hospital disaster resilience and an assessment checklist for leaders' self-reflection to support hospitals in their transition to resilient operations.

Rotary Bend Fatigue of Nitinol to One Billion Cycles

Nitinol implants, especially those used in cardiovascular applications, are typically expected to remain durable beyond 10⁸ cycles, yet literature on ultra-high cycle fatigue of nitinol remains relatively scarce and its mechanisms not well understood. To investigate nitinol fatigue behavior in this domain, we conducted a multifaceted evaluation of nitinol wire subjected to rotary bend fatigue that included detailed material characterization and finite element analysis as well as post hoc analyses of the resulting fatigue life data. Below approximately 10⁵ cycles, cyclic phase transformation, as predicted by computational simulations, was associated with fatigue failure. Between 10⁵ and 10⁸ cycles, fractures were relatively infrequent. Beyond 10⁸ cycles, fatigue fractures were relatively common depending on the load level and other factors including the size of non-metallic inclusions present and the number of loading cycles. Given observations of both low cycle and ultra-high cycle fatigue fractures, a two-failure model may be more appropriate than the standard Coffin-Manson equation for characterizing nitinol fatigue life beyond 10⁸ cycles. This work provides the first documented fatigue study of medical grade nitinol to 10⁹ cycles, and the observations and insights described will be of value as design engineers seek to improve durability for future nitinol implants.

Maintaining a social license to operate for wastewater-based monitoring: The case of managing infectious disease and the COVID-19 pandemic

Wastewater monitoring as a public health tool is well-established and the SARS-CoV-2 (COVID-19) pandemic has seen its widespread uptake. Given the significant potential of wastewater monitoring as a public health surveillance and decision support tool, it is important to understand what measures are required to allow the long-term benefits of wastewater monitoring to be fully realized, including how to establish and/or maintain public support. The potential for positive SARS-CoV-2 detections to trigger enforced, community-wide public health interventions (e.g., lockdowns and other impacts on civil liberties) further emphasises the need to better understand the role of public engagement in successful wastewater-based monitoring programs. This paper systematically reviews the processes of building and maintaining the social license to operate wastewater monitoring. We specifically explore the relationship between different stakeholder communities and highlight the information and actions that are required to establish a social license to operate and then prevent its loss. The paper adds to the literature on social license to operate by extending its application to new domains and offers a dynamic model of social license to help guide the agenda for researcher and practitioner communities.

Healthcare Workers' Resilience Toolkit for Disaster Management and Climate Change Adaptation

Climate change has been recognised as a multiplier of risk factors affecting public health. Disruptions caused by natural disasters and other climate-driven impacts are placing increasing demands on healthcare systems. These, in turn, impact the wellness and performance of healthcare workers (HCWs) and hinder the accessibility, functionality and safety of healthcare systems. This study explored factors influencing HCWs' disaster management capabilities with the aim of improving their resilience and adaptive capacity in the face of climate change. In-depth, semi-structured interviews were conducted with thirteen HCWs who dealt with disasters within two hospitals in Queensland, Australia. Analysis of the results identified two significant themes, HCWs' disaster education and HCWs' wellness and needs. The latter comprised five subthemes: HCWs' fear and vulnerability, doubts and uncertainty, competing priorities, resilience and adaptation, and needs assessment. This study developed an 'HCWs Resilience Toolkit', which encourages mindfulness amongst leaders, managers and policymakers about supporting four priority HCWs' needs: 'Wellness', 'Education', 'Resources' and 'Communication'. The authors focused on the 'Education' component to detail recommended training for each of the pre-disaster, mid-disaster and post-disaster phases. The authors conclude the significance of the toolkit, which provides a timely contribution to the healthcare sector amidst ongoing adversity.

Preparing health professionals to practice environmentally sustainable healthcare

Background

In 2019 the WHO identified climate change and air pollution as the top global threat to health. This was illustrated by the health consequences of the catastrophic 2019-20 Australian bushfire season. Health-care systems also contribute to climate change and environmental degradation. For Australia, health care contributes 7% of total carbon emissions and produces considerable clinical and non-clinical waste which is either incinerated or sent to landfill. Despite these threats to health there is a limited response by health professions education to include climate change and environmentally sustainable healthcare in curricula.

Methods

Medical Deans of Australia and New Zealand (MDANZ) is the peak body for professional medical education in Australasia. MDANZ formed a Climate Change and Health Working Group to develop curriculum and learning resources. The Group comprises representatives of Australasian medical schools and student representative organisations. The scope for curriculum was defined by searching the literature, reviewing teaching experience, and benchmarking against relevant courses developed for medical students by peers.

Results

Five broad areas of learning were identified; graduate outcome statements and learning objectives were developed aligned with these. Once endorsed by MDANZ these were circulated to all medical schools to inform curriculum review. A resource repository is being developed to support curriculum change. Ways to measure and monitor inclusion in medical programs are being researched.

Conclusions

We must prepare future practitioners for their role in transforming health care to become carbon neutral. Using a public health approach, system level change in medical education is being supported in Australasia. All health professions have a role in providing environmentally sustainable health care. The Group provides a model that can be used by other health professions to create change at the necessary pace and scale.

Key messages

The health education sector must prepare graduates for climate change and environmentally sustainable healthcare. By working collaboratively at a systems level, change can occur at pace and scale.

Utility of QMRA to compare health risks associated with alternative urban sewer overflow management strategies

Wet weather sewer overflows pose potential short-term public health risks. With increasing populations, aging infrastructure and climate change, utilities are challenged with managing sewerage infrastructure to provide optimum outcomes. This study compared how modelled public health risk profiles could change under alternative sewer overflow management strategies during 12 and 24-month rainfall-runoff events. Specifically, existing conditions were compared with both a 'business-as-usual' (BAU) sewer upgrade and a more holistic 'effects-based planning' (EBP) approach based on pumped wet weather sewage overflows directed to a local receiving waterway. Options were compared based on their efficacy to reduce manhole overflows, recreational waterway guideline exceedances and downstream recreational waterway health risks estimated through a screening-level Quantitative Microbial Risk Assessment (QMRA). Results indicated that the two management strategies would be equally effective in reducing the frequency, duration and volume of manhole sewer overflows, eliminating them in the 12-month scenarios and reducing them from >5000 m³ for the 24-month baseline scenario, to 23 and 35 m³ for BAU and EBP, respectively. Baseline, BAU and EBP scenarios produced similar hours of enterococci guideline exceedances, ranging from 1 to 4 h difference. The QMRA produced similar health risk profiles for downstream recreational waterway users for all design events, suggesting that sewer overflows are not the primary driver of public health risks during and immediately following high rainfall events. As such, QMRA provided evidence that an EBP strategy may be used to manage wet weather sewer overflows in lieu of an expensive BAU upgrade, without exacerbating the public health of downstream waterway users. Further investigation of the broader environmental health impacts of implementing this type of innovative approach is warranted. Nonetheless, this work highlights the value of integrating QMRA with other modelling approaches to guide and inform sewer overflow management.

Challenges for environmental hygiene practices in Australian paramedic-led health care: A brief report

This study explored the self-reported behaviors and perceptions of Australian paramedics in relation to their environmental hygiene practices. A national online survey was conducted with Paramedics Australasia members (N = 417). Participants reported working in ambulances often contaminated with body fluids. Widespread noncompliance with routine and deep cleaning of ambulances, and misunderstandings about environmental hygiene practices were apparent. Improvements to environmental hygiene practices of Australian paramedics are recommended to avoid pathogen transmission and ensure patient safety.

DNA Heat Treatment for Improving qPCR Analysis of Human Adenovirus in Wastewater

PCR inhibitory substances in complex sample matrices can cause false negatives or under-estimation of target concentration. This study assessed DNA heat treatment for reducing inhibition during qPCR analysis of human adenovirus (HAdV) in wastewater samples. Inhibition was reduced by heat treating DNA, where mean HAdV concentration was increased by 0.71 log10 GC/L (and up to 3.04 log10 GC/L in one case), and replicate variability and false negatives were reduced. DNA heat treatment should be further investigated for improving reliability of HAdV concentration estimates in water, which can support more accurate assessment of health risks associated with viral pathogen exposure.

Guidelines for Use of the Approximate Beta-Poisson Dose-Response Model

For dose-response analysis in quantitative microbial risk assessment (QMRA), the exact beta-Poisson model is a two-parameter mechanistic dose-response model with parameters α>0 and β>0, which involves the Kummer confluent hypergeometric function. Evaluation of a hypergeometric function is a computational challenge. Denoting PI(d) as the probability of infection at a given mean dose d, the widely used dose-response model PI(d)=1-(1+dβ)-α is an approximate formula for the exact beta-Poisson model. Notwithstanding the required conditions α<<β and β>>1, issues related to the validity and approximation accuracy of this approximate formula have remained largely ignored in practice, partly because these conditions are too general to provide clear guidance. Consequently, this study proposes a probability measure Pr(0 < r < 1 | α̂, β̂) as a validity measure (r is a random variable that follows a gamma distribution; α̂ and β̂ are the maximum likelihood estimates of α and β in the approximate model); and the constraint conditions β̂>(22α̂)0.50 for 0.02<α̂<2 as a rule of thumb to ensure an accurate approximation (e.g., Pr(0 < r < 1 | α̂, β̂) >0.99) . This validity measure and rule of thumb were validated by application to all the completed beta-Poisson models (related to 85 data sets) from the QMRA community portal (QMRA Wiki). The results showed that the higher the probability Pr(0 < r < 1 | α̂, β̂), the better the approximation. The results further showed that, among the total 85 models examined, 68 models were identified as valid approximate model applications, which all had a near perfect match to the corresponding exact beta-Poisson model dose-response curve.

Self-reported behaviors and perceptions of Australian paramedics in relation to hand hygiene and gloving practices in paramedic-led health care

BACKGROUND

Noncompliance with recommended hand hygiene and gloving practices by workers in the emergency medical services may contribute to the transmission of health care-associated infections and lead to poor patient outcomes. The aim of this study was to explore the self-reported behaviors and perceptions of Australian paramedics in relation to their hand hygiene and gloving practices in paramedic-led health care.

METHODS

A national online survey (n = 417; 17% response rate) and 2 semistructured focus groups (6 per group) were conducted with members of Paramedics Australasia.

RESULTS

Although most of the study participants perceived hand hygiene and gloving to be important, the findings suggest poor compliance with both practices, particularly during emergency cases. All participants reported wearing gloves throughout a clinical case, changing them either at the completion of patient care or when visibly soiled or broken. Hand hygiene was missed at defined moments during patient care, possibly from the misuse of gloves.

CONCLUSIONS

Paramedic hand hygiene and gloving practices require substantial improvement to lower potential transmission of pathogens and improve patient safety and clinical care. Further research is recommended to explore how to alleviate the barriers to performing in-field hand hygiene and the misuse of gloves during paramedic-led health care.

A practical model for sunlight disinfection of a subtropical maturation pond

Maturation ponds are a type of waste stabilisation pond (WSP) designed to reduce carbon, nutrients and pathogens in the final stages of a WSP wastewater treatment system. In this study, a one-dimensional plug-flow pond model is proposed to predict temperature and E. coli concentration distributions and overall pond disinfection performance. The model accounts for the effects of vertical mixing and ultraviolet light-dependent die-off rate kinetics. Measurements of radiation, wind-speed, humidity and air temperature are recorded for model inputs and good agreement with measured vertical temperature distributions and outlet E. coli concentrations is found in an operational, subtropical maturation pond. Measurements and the model both show a diurnal pattern of stratification during daylight hours and natural convective mixing at night on days corresponding to low wind speeds, strong heat input from solar radiation and clear night skies. In the evenings, the thermal stratification is shown to collapse due to surface energy loss via longwave radiation which triggers top-down natural convective mixing. The disinfection model is found to be sensitive to the choice of die-off kinetics. The diurnal mixing pattern is found to play a vital role in the disinfection process by ensuring that pathogens are regularly transported to the near-surface layer where ultraviolet light penetration is effective. The model proposed in this paper offers clear advantages to pond designers by including geographical specific, time-varying boundary conditions and accounting for the important physical aspects of vertical mixing and sunlight inactivation processes, yet is computationally straightforward.

A Generalized QMRA Beta-Poisson Dose-Response Model

Quantitative microbial risk assessment (QMRA) is widely accepted for characterizing the microbial risks associated with food, water, and wastewater. Single-hit dose-response models are the most commonly used dose-response models in QMRA. Denoting PI(d) as the probability of infection at a given mean dose d, a three-parameter generalized QMRA beta-Poisson dose-response model, PI(d|α,β,r*), is proposed in which the minimum number of organisms required for causing infection, K_min , is not fixed, but a random variable following a geometric distribution with parameter 0<r*≤1. The single-hit beta-Poisson model, PI(d|α,β), is a special case of the generalized model with K_min = 1 (which implies r*=1). The generalized beta-Poisson model is based on a conceptual model with greater detail in the dose-response mechanism. Since a maximum likelihood solution is not easily available, a likelihood-free approximate Bayesian computation (ABC) algorithm is employed for parameter estimation. By fitting the generalized model to four experimental data sets from the literature, this study reveals that the posterior median r* estimates produced fall short of meeting the required condition of r* = 1 for single-hit assumption. However, three out of four data sets fitted by the generalized models could not achieve an improvement in goodness of fit. These combined results imply that, at least in some cases, a single-hit assumption for characterizing the dose-response process may not be appropriate, but that the more complex models may be difficult to support especially if the sample size is small. The three-parameter generalized model provides a possibility to investigate the mechanism of a dose-response process in greater detail than is possible under a single-hit model.

Technical aspects of using human adenovirus as a viral water quality indicator

Despite dramatic improvements in water treatment technologies in developed countries, waterborne viruses are still associated with many of cases of illness each year. These illnesses include gastroenteritis, meningitis, encephalitis, and respiratory infections. Importantly, outbreaks of viral disease from waters deemed compliant from bacterial indicator testing still occur, which highlights the need to monitor the virological quality of water. Human adenoviruses are often used as a viral indicator of water quality (faecal contamination), as this pathogen has high UV-resistance and is prevalent in untreated domestic wastewater all year round, unlike enteroviruses and noroviruses that are often only detected in certain seasons. Standard methods for recovering and measuring adenovirus numbers in water are lacking, and there are many variations in published methods. Since viral numbers are likely under-estimated when optimal methods are not used, a comprehensive review of these methods is both timely and important. This review critically evaluates how estimates of adenovirus numbers in water are impacted by technical manipulations, such as during adenovirus concentration and detection (including culturing and polymerase-chain reaction). An understanding of the implications of these issues is fundamental to obtaining reliable estimation of adenovirus numbers in water. Reliable estimation of HAdV numbers is critical to enable improved monitoring of the efficacy of water treatment processes, accurate quantitative microbial risk assessment, and to ensure microbiological safety of water.

Utility of Bayesian networks in QMRA-based evaluation of risk reduction options for recycled water

BACKGROUND

Quantitative microbial risk assessment (QMRA), the current method of choice for evaluating human health risks associated with disease-causing microorganisms, is often constrained by issues such as availability of required data, and inability to incorporate the multitude of factors influencing risk. Bayesian networks (BNs), with their ability to handle data paucity, combine quantitative and qualitative information including expert opinions, and ability to offer a systems approach to characterisation of complexity, are increasingly recognised as a powerful, flexible tool that overcomes these limitations.

OBJECTIVES

We present a QMRA expressed as a Bayesian network (BN) in a wastewater reuse context, with the objective of demonstrating the utility of the BN method in health risk assessments, particularly for evaluating a range of exposure and risk mitigation scenarios. As a case study, we examine the risk of norovirus infection associated with wastewater-irrigated lettuce.

METHODS

A Bayesian network was developed following a QMRA approach, using published data, and reviewed by domain experts using a participatory process.

DISCUSSION

Employment of a BN facilitated rapid scenario evaluations, risk minimisation, and predictive comparisons. The BN supported exploration of conditions required for optimal outcomes, as well as investigation of the effect on the reporting nodes of changes in 'upstream' conditions. A significant finding was the indication that if maximum post-treatment risk mitigation measures were implemented, there was a high probability (0.84) of a low risk of infection regardless of fluctuations in other variables, including norovirus concentration in treated wastewater.

CONCLUSION

BNs are useful in situations where insufficient empirical data exist to satisfy QMRA requirements and they are exceptionally suited to the integration of risk assessment and risk management in the QMRA context. They allow a comprehensive visual appraisal of major influences in exposure pathways, and rapid interactive risk assessment in multifaceted water reuse scenarios.

Modelling microbial health risk of wastewater reuse: A systems perspective

There is a widespread need for the use of quantitative microbial risk assessment (QMRA) to determine reclaimed water quality for specific uses, however neither faecal indicator levels nor pathogen concentrations alone are adequate for assessing exposure health risk. The aim of this study was to build a conceptual model representing factors contributing to the microbiological health risks of reusing water treated in maturation ponds. This paper describes the development of an unparameterised model that provides a visual representation of theoretical constructs and variables of interest. Information was collected from the peer-reviewed literature and through consultation with experts from regulatory authorities and academic disciplines. In this paper we explore how, considering microbial risk as a modular system, following the QMRA framework enables incorporation of the many factors influencing human exposure and dose response, to better characterise likely human health impacts. By using and expanding upon the QMRA framework we deliver new insights into this important field of environmental exposures. We present a conceptual model of health risk of microbial exposure which can be used for maturation ponds and, more importantly, as a generic tool to assess health risk in diverse wastewater reuse scenarios.

Beyond QMRA: Modelling microbial health risk as a complex system using Bayesian networks

BACKGROUND

Quantitative microbial risk assessment (QMRA) is the current method of choice for determining the risk to human health from exposure to microorganisms of concern. However, current approaches are often constrained by the availability of required data, and may not be able to incorporate the many varied factors that influence this risk. Systems models, based on Bayesian networks (BNs), are emerging as an effective complementary approach that overcomes these limitations.

OBJECTIVES

This article aims to provide a comparative evaluation of the capabilities and challenges of current QMRA methods and BN models, and a scoping review of recent published articles that adopt the latter for microbial risk assessment. Pros and cons of systems approaches in this context are distilled and discussed.

METHODS

A search of the peer-reviewed literature revealed 15 articles describing BNs used in the context of QMRAs for foodborne and waterborne pathogens. These studies were analysed in terms of their application, uses and benefits in QMRA.

DISCUSSION

The applications were notable in their diversity. BNs were used to make predictions, for scenario assessment, risk minimisation, to reduce uncertainty and to separate uncertainty and variability. Most studies focused on a segment of the exposure pathway, indicating the broad potential for the method in other QMRA steps. BNs offer a number of useful features to enhance QMRA, including transparency, and the ability to deal with poor quality data and support causal reasoning.

CONCLUSION

The method has significant untapped potential to describe the complex relationships between microbial environmental exposures and health.

Experiences of birth and breastfeeding following assisted conception

The short and long-term benefits that breastfeeding has for both infant and mother are well recognised. With births increasingly occurring as a result of assisted conception (AC) technologies, the impact that these treatments have on a woman's experience of breastfeeding is an important issue to explore. This paper reports findings from a qualitative study exploring this association. Women who had undergone AC and planned to give birth at one private institution in regional Queensland, Australia, were approached to participate in this study (n = 12). Utilising narrative enquiry in the form of pre and post-birth interviews, participants' accounts of their experiences of breastfeeding were analysed as a means of understanding and representing their journeys. Findings demonstrated that during pregnancy the women were focused on healthy outcomes, showing ambivalence towards the mode of birth. There was a determination to breastfeed that was seen as one way to counteract the intervention and medicalisation they had undergone to conceive. Postnatally, for a number of women in the study breastfeeding difficulties were experienced--a finding that supports recent research. Further mixed method investigation into the impact that assisted conception has on breastfeeding intention, initiation and ability is indicated.

Outcomes for women and infants following assisted conception: implications for perinatal education, care, and support

Assisted conception is becoming an increasingly more common treatment option for women and couples who experience fertility problems. Links have been made in the literature between assisted conception and a greater incidence of pregnancy or birth complications, low birth weight or premature babies, and babies with congenital abnormalities. In addition, evidence suggests that the experience of assisted conception may influence the development of early mothering relationships and impact parenting adjustment. Although this commentary article does not strategically review all available literature, it provides an overview of the health issues that women and families undergoing assisted conception have experienced or may experience. Through raising awareness and promoting discussion of these issues, practitioners will be better equipped to provide informed education and support.

Evaluation of pathogen removal in a solar sludge drying facility using microbial indicators

South East Queensland is one of the fastest growing regions in Australia with a correspondingly rapid increase in sewage production. In response, local councils are investing in more effective and sustainable options for the treatment and reuse of domestic and industrial effluents. A novel, evaporative solar dryer system has been installed on the Sunshine Coast to convert sewage sludge into a drier, usable form of biosolids through solar radiation exposure resulting in decreased moisture concentration and pathogen reduction. Solar-dried biosolids were analyzed for selected pathogenic microbial, metal and organic contaminants at the end of different drying cycles in a collaborative study conducted with the Regional Council. Although fecal coliforms were found to be present, enteroviruses, parasites, E. coli, and Salmonella sp. were not detected in the final product. However, elevated levels of zinc and copper were still present which restricted public use of the biosolids. Dilution of the dried biosolids with green waste as well as composting of the biosolids is likely to lead to the production of an environmentally safe, Class A end-product.