Catching nano: Evaluating the fate and behaviour of nano-TiO2 in swimming pools through dynamic simulation modelling.

Engineered titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreens widely used by swimmers in aquatic settings have raised concerns about their potential adverse impact on ecosystems and human health due to their small size and unique physicochemical properties. Therefore, this research paper aims to investigate the fate and behaviour of nano-TiO2 from sunscreens in swimming pools using System Dynamics Modelling. The study developed a dynamic simulation model that considers various factors, including weather conditions, sunscreen and pool usage behaviour, filtration efficacy, pool maintenance, water chemistry, pool chemicals, and TiO2 concentration levels, which can affect exposure levels for different scenarios. The study considered non-linear interdependent relationships, feedback structures, and temporal changes and dealt with parameter uncertainties through Monte Carlo analyses. The results reveal that the regular use of sunscreen leads to nano-TiO2 concentrations ranging from 0.001 to 0.05 mg/L within a year, reflecting seasonal and pool usage variations. The study also found that changes in the weight percentage of TiO2 in the sunscreen formulation and the filtration duration per day are the most sensitive factors affecting TiO2 concentrations. Scenario analyses exploring different nano-TiO2 removal strategies suggested that one daily turnover is necessary for sufficient removal. Regular manual pool maintenance and monthly use of a pool clarifier are recommended for enhanced and accelerated removal without substantial additional costs. The study is novel in its integrated approach, combining empirical work with dynamic simulations, resulting in a novel approach to model the environmental fate and behaviour of nano-TiO2. The study makes important methodological contributions to the field and has initiated an interdisciplinary collaboration to create more accurate models. This study is of great significance as it presents a pioneering analysis of the impact of sunscreen properties, user behaviour, and environmental stressors on the fate and behaviour of nano-TiO2 in swimming pools.

Integrated Environmental Assessment and Management.

Increasing demand for metals used in clean energy technologies, including electric vehicles, has led to an increased demand in certain metals such as Ni, Co, and Mn. This demand has in turn led to an expanding interest in deep-seabed mining (DSM) of polymetallic nodule deposits that contain these exact metals. The main concerns about DSM relate to the incomplete information available about the environmental risks associated with seabed mineral extraction. Key uncertainties need to be systematically addressed to refine environmental impact predictions and establish effective mitigation measures. Adaptive management is an iterative process for reducing the uncertainty that can be applied by both mining companies and regulatory bodies. This Special Series paper reviews the key opportunities and challenges to operationalizing adaptive management in DSM projects and highlights the need for a framework to move from theory to practice. The discussion proposes a systems approach to adaptive management, which could help to guide the environmental management of deep-sea mineral extraction. Integr Environ Assess Manag 2022;18:674-681. © 2021 SETAC.

Taxonomy and model for valuing the contribution of digital water meters to sustainability objectives.

Water security is an issue across the world as communities face ageing infrastructure, population increases and climate change. The application of digital water metering (DWM) to properties has had a demonstrable impact on water savings at the property and network levels, on efficiencies within water utilities, as well as on improvements to customer satisfaction scores. Gathering and processing near-real-time water usage data is very important for both end-users and utilities, as well as demand and supply management planning. The potential contribution of DWM to the three pillars of water sustainability (environmental, economic development and social equity) is often overlooked. In Australia and other jurisdictions water utilities are facing up to the challenge of climate change. However, business cases promoting DWM are often unsuccessful because the benefit side falls short of the cost side. This study sought to identify possible DWM benefits not previously considered through an extensive review of academic and industry literature, and then to view those benefits through the lens of sustainability. The 77 identified benefits of DWM were catalogued and a taxonomy was created. The study elicited the opinions of experts, before quantifying them, thus identifying two distinct contexts of benefit value; subsequently, it surveyed the views of customers and developed a stochastic model of benefit value. The model, named DWM360, was applied to the project data of a large metropolitan water utility in Australia to model their DWM proposal for cost savings, contribution to sustainability and uplift in customer satisfaction. This paper presents a novel focus on how the benefits of DWM assist water sustainability. It considers differing social norms that impact consumer acceptance of changes in metering and water charges. The study will be of interest to researchers as well as practitioners looking to identify sustainability aspects of DWM.

Dynamic modelling of Australian rooftop solar photovoltaic product stewardship transition.

As rooftop solar photovoltaic (PV) adoption in Australia is exponentially growing in the past decade, there is a need to promote effective product stewardship for PV panels reaching their end-of-life (EoL). This paper presents the development of a System Dynamics (SD) model for managing EoL rooftop PV panels based on the circular economy concept. Four stages of the SD modelling process include problem scoping and variable identification, model conceptualisation, SD model development, and scenario analysis. Stakeholder engagement is central to this research as the system under study is underpinned by high uncertainties and limited data availability. Four socio-technical transition pathways examined in this study include market-driven growth, conservative development, shared responsibility, and disruptive change. The simulation results indicated an improvement of collection and recovery performance when a stringent product stewardship scheme is enabled and improvement of installers' participation in the collection program. This study argued that a system of shared responsibility will be capable of balancing techno-economic motivations of stakeholders across the supply chain to participate in the recovery scheme, while being less disruptive to PV adoption. Under this scenario, a gradual change in regulatory requirements (e.g. recovery target and material recovery rate requirements) is introduced to allow a period of industry and market development.

Evaluating coral reef ecosystem services outcomes from climate change adaptation strategies using integrative system dynamics.

Coral reef ecosystems provide a broad spectrum of essential ecological, economic and cultural services for Small Island Developing State (SIDS) communities. However, coral reef communities are increasingly threatened by the adverse impacts of human activities at both global and local scales. This study aims to develop an integrated dynamic assessment framework to evaluate coral reef conditions under different adaptation and climate change scenarios, and their consequential economic impacts in the small island community of Port Resolution on Tanna Island in Vanuatu. Our assessment framework follows a sequential multilayered modelling approach that uses System Dynamics (SD) coupled with Bayesian Network (BN) modelling to deal with the complexity and dynamicity of socioeconomic and environmental systems, and impacts from trans-discipline variables. The BN incorporated existing data and expert knowledge to project the future conditions of coral reefs under different scenario settings, and to parametrise and quantify the SD model where the existing data and information was insufficient. The SD was then used to simulate the dynamic relationship between coral reef condition and the economic benefits derived from its ecosystem services under different climate change (i.e. RCPs) and management scenarios through to 2070. Our findings show that sustainable community-based conservation management strategies are key to preserving the flow of coral reef ecosystem services under RCP 2.6 and 6.0. Importantly, we demonstrate that the implementation of an integrated portfolio of management strategies better protects ecosystem services provided by coral reefs and maximises the total economic benefits achieved over the long-term despite a temporary and short-term economic loss due to high initial capital investments and income reduction due to fishing and tourism restrictions.

Addressing dynamic uncertainty in the whale-watching industry under climate change and system shocks.

Whale-watching is a global tourism industry whose annual revenue exceeds two billion dollars. Australia is a key player in this industry, especially on the east and west coast where humpback whales migrate each year between their breeding and feeding grounds. However, the global whale-watching industry faces uncertainty from changing whale migration patterns, with whales progressively 'arriving' at the traditional whale-watching areas earlier than in previous years/decades. If the whale-watching industry cannot evolve with these changing dynamics then the arrival of the whales might be missed resulting in a potential loss of revenue. This social-ecological issue has suddenly been exacerbated by the disruption to tourism caused by the global pandemic COVID-19. In this study, we use a systems modelling framework, which combines qualitative and quantitative processes, to evaluate the social-ecological system behaviour of the whale-watching industry. We apply this systems approach to the Gold Coast, one of Australia's premier tourist destinations and home to a vibrant whale-watching industry. The outcome of this systems assessment is that the efficacy of the whale-watching industry is affected through determinants of both supply (ability to respond to changes in whale behaviour) and demand (attractiveness of whale-watching). Furthermore, the recovery time of all tourism after COVID-19 will take years if not decades.

Integrating statistical and mechanistic approaches with biotic and environmental variables improves model predictions of the impact of climate and land-use changes on future mosquito-vector abundance, diversity and distributions in Australia.

Changes to Australia's climate and land-use patterns could result in expanded spatial and temporal distributions of endemic mosquito vectors including Aedes and Culex species that transmit medically important arboviruses. Climate and land-use changes greatly influence the suitability of habitats for mosquitoes and their behaviors such as mating, feeding and oviposition. Changes in these behaviors in turn determine future species-specific mosquito diversity, distribution and abundance. In this review, we discuss climate and land-use change factors that influence shifts in mosquito distribution ranges. We also discuss the predictive and epidemiological merits of incorporating these factors into a novel integrated statistical (SSDM) and mechanistic species distribution modelling (MSDM) framework. One potentially significant merit of integrated modelling is an improvement in the future surveillance and control of medically relevant endemic mosquito vectors such as Aedes vigilax and Culex annulirostris, implicated in the transmission of many arboviruses such as Ross River virus and Barmah Forest virus, and exotic mosquito vectors such as Aedes aegypti and Aedes albopictus. We conducted a focused literature search to explore the merits of integrating SSDMs and MSDMs with biotic and environmental variables to better predict the future range of endemic mosquito vectors. We show that an integrated framework utilising both SSDMs and MSDMs can improve future mosquito-vector species distribution projections in Australia. We recommend consideration of climate and environmental change projections in the process of developing land-use plans as this directly impacts mosquito-vector distribution and larvae abundance. We also urge laboratory, field-based researchers and modellers to combine these modelling approaches. Having many different variations of integrated (SDM) modelling frameworks could help to enhance the management of endemic mosquitoes in Australia. Enhanced mosquito management measures could in turn lead to lower arbovirus spread and disease notification rates.

Mapping long-term coral reef ecosystems regime shifts: A small island developing state case study.

Coral reefs are among the most fragile ecosystems that provide essential services to local Small Island Developing States (SIDS) communities. As such, exploring the characteristics and interactions shaping regime shifts of coral reefs is of paramount importance in managing system pressures; enhancing resilience; aiding their regeneration and recovery process; and restoring habitat complexity. However, understanding the dynamics of coral reef ecosystems regime shift requires employing an approach capable of dealing with systems being affected by multiple climatic and socio-economic non-climatic pressures as well as an effective treatment of systemic embedded uncertainties. This study applies Fuzzy Cognitive Mapping (FCM) in a participatory stepwise and systematic procedure to reflect dynamic casualties and temporal changes of coral reef ecosystem regime change over a long-time perspective. This mapping technique allows conceptualising dynamic models to represent causalities and modelling input values to simulate fluctuations within a complex temporal system. Port Resolution on Tanna Island in Vanuatu was selected as the case study region representative of Pacific-SIDS geography and human communities. As an initial outcome and an indicator of multidisciplinary of this study, twenty-seven principal influential factors and their corresponding causal relationships were identified. Subsequently, the coral reef regime shift was analysed under four main plausible scenarios representing major climatic and non-climatic trajectories. The results indicate that climate change factors play pivotal roles in the regime shift of the coral reef ecosystem globally. At the focal scale of this study, the tourism industry and coral fisheries are the most vulnerable services provided by coral reefs. As such, coupled local management interventions and global efforts in mitigating the adverse impacts of climate change is likely to yield better coral reef ecosystem services at a local community level.

Modeling Research Topics for Artificial Intelligence Applications in Medicine: Latent Dirichlet Allocation Application Study.

BACKGROUND: Artificial intelligence (AI)-based technologies develop rapidly and have myriad applications in medicine and health care. However, there is a lack of comprehensive reporting on the productivity, workflow, topics, and research landscape of AI in this field. OBJECTIVE: This study aimed to evaluate the global development of scientific publications and constructed interdisciplinary research topics on the theory and practice of AI in medicine from 1977 to 2018. METHODS: We obtained bibliographic data and abstract contents of publications published between 1977 and 2018 from the Web of Science database. A total of 27,451 eligible articles were analyzed. Research topics were classified by latent Dirichlet allocation, and principal component analysis was used to identify the construct of the research landscape. RESULTS: The applications of AI have mainly impacted clinical settings (enhanced prognosis and diagnosis, robot-assisted surgery, and rehabilitation), data science and precision medicine (collecting individual data for precision medicine), and policy making (raising ethical and legal issues, especially regarding privacy and confidentiality of data). However, AI applications have not been commonly used in resource-poor settings due to the limit in infrastructure and human resources. CONCLUSIONS: The application of AI in medicine has grown rapidly and focuses on three leading platforms: clinical practices, clinical material, and policies. AI might be one of the methods to narrow down the inequality in health care and medicine between developing and developed countries. Technology transfer and support from developed countries are essential measures for the advancement of AI application in health care in developing countries.

Spatial Bayesian Network for predicting sea level rise induced coastal erosion in a small Pacific Island.

An integrated approach combining Bayesian Network with GIS was developed for making a probabilistic prediction of sea level rise induced coastal erosion and assessing the implications of adaptation measures. The Bayesian Network integrates extensive qualitative and quantitative information into a single probabilistic model while GIS explicitly deals with spatial data for inputting, storing, analysing and mapping. The integration of the Bayesian Network with GIS using a cell-by-cell comparison technique (aka map algebra) provides a new tool to perform the probabilistic spatial analysis. The spatial Bayesian Network was utilised for predicting coastal erosion scenarios at the case study location of Tanna Island, Vanuatu in the South Pacific. Based on the Bayesian Network model, a rate of the island shoreline change was predicted probabilistically for each shoreline segment, which was transferred into GIS for visualisation purposes. The spatial distribution of shoreline change prediction results for various sea level rise scenarios was mapped. The outcomes of this work support risk-based adaptation planning and will be further developed to enable the incorporation of high resolution coastal process models, thereby supporting localised land use planning decisions.

A soft traffic management approach for achieving environmentally sustainable and economically viable outcomes: An Australian case study.

Transport infrastructural strain is a pressuring issue for the urbanised world due to the increasing demand for public transport. Transport operators, planners and policymakers are constantly searching for low-cost solutions to such transport issues. Therefore, it is critical to developing an environmentally sustainable and economically viable efficient traffic network to relieve traffic pressure (i.e., traffic congestion, transport infrastructure investment needs). The objective of this research is to propose a "Soft Traffic Management (STM)" concept to proactively analyse the traffic impact of transport planning strategy before implementation. This study investigates the effectiveness of a STM for easing the traffic pressure by carrying out a pilot research project on the proposed South East Busway extension in Logan City, Australia, by employing a stepwise process consisting of a multi-stage analysis and stakeholder-based modelling approach. The results indicate that the extended busway can significantly relieve traffic congestion. In addition, the proposed strategy has significantly positive impacts on the environment since it aims to reduce air pollution and fuel consumption as well as to improve the safety and efficiency of the whole transport system. This study confirms the effects of STM on improving the use of existing infrastructure more efficiently and deferring future transport infrastructure investments.

Evaluating a novel tiered scarcity adjusted water budget and pricing structure using a holistic systems modelling approach.

Population growth, coupled with declining water availability and changes in climatic conditions underline the need for sustainable and responsive water management instruments. Supply augmentation and demand management are the two main strategies used by water utilities. Water demand management has long been acknowledged as a least-cost strategy to maintain water security. This can be achieved in a variety of ways, including: i) educating consumers to limit their water use; ii) imposing restrictions/penalties; iii) using smart and/or efficient technologies; and iv) pricing mechanisms. Changing water consumption behaviours through pricing or restrictions is challenging as it introduces more social and political issues into the already complex water resources management process. This paper employs a participatory systems modelling approach for: (1) evaluating various forms of a proposed tiered scarcity adjusted water budget and pricing structure, and (2) comparing scenario outcomes against the traditional restriction policy regime. System dynamics modelling was applied since it can explicitly account for the feedbacks, interdependencies, and non-linear relations that inherently characterise the water tariff (price)-demand-revenue system. A combination of empirical water use data, billing data and customer feedback on future projected water bills facilitated the assessment of the suitability and likelihood of the adoption of scarcity-driven tariff options for a medium-sized city within Queensland, Australia. Results showed that the tiered scarcity adjusted water budget and pricing structure presented was preferable to restrictions since it could maintain water security more equitably with the lowest overall long-run marginal cost.

An integrated risk and vulnerability assessment framework for climate change and malaria transmission in East Africa.

BACKGROUND: Malaria is one of the key research concerns in climate change-health relationships. Numerous risk assessments and modelling studies provide evidence that the transmission range of malaria will expand with rising temperatures, adversely impacting on vulnerable communities in the East African highlands. While there exist multiple lines of evidence for the influence of climate change on malaria transmission, there is insufficient understanding of the complex and interdependent factors that determine the risk and vulnerability of human populations at the community level. Moreover, existing studies have had limited focus on the nature of the impacts on vulnerable communities or how well they are prepared to cope. In order to address these gaps, a systems approach was used to present an integrated risk and vulnerability assessment framework for studies of community level risk and vulnerability to malaria due to climate change. RESULTS: Drawing upon published literature on existing frameworks, a systems approach was applied to characterize the factors influencing the interactions between climate change and malaria transmission. This involved structural analysis to determine influential, relay, dependent and autonomous variables in order to construct a detailed causal loop conceptual model that illustrates the relationships among key variables. An integrated assessment framework that considers indicators of both biophysical and social vulnerability was proposed based on the conceptual model. CONCLUSIONS: A major conclusion was that this integrated assessment framework can be implemented using Bayesian Belief Networks, and applied at a community level using both quantitative and qualitative methods with stakeholder engagement. The approach enables a robust assessment of community level risk and vulnerability to malaria, along with contextually relevant and targeted adaptation strategies for dealing with malaria transmission that incorporate both scientific and community perspectives.

A case report of retroperitoneal extrahepatic hepatocellular carcinoma presented with elevated level of Alpha fetoprotein.

BACKGROUND: High level of alpha-fetoprotein is usually associated with testis cancer or hepatocellular carcinoma a primary tumor of the liver. CASE: We report the case of a 72-year-old male patient with chronic renal failure who presented with a high alpha-fetoprotein (AFP) level and a retroperitoneal mass, which was subsequently diagnosed to be an extrahepatic hepatocellular carcinoma. CONCLUSION: A retroperitoneal mass with elevated AFP level and no detected liver lesions is not always caused by a testicular cancer.