Water Supply Interruptions Are Associated with More Frequent Stressful Behaviors and Emotions but Mitigated by Predictability: A Multisite Study.

Water supply interruptions contribute to household water insecurity. Unpredictable interruptions may particularly exacerbate water insecurity, as uncertainty limits households' ability to optimize water collection and storage or to modify other coping behaviors. This study used regression models of survey data from 2873 households across 10 sites in 9 middle-income countries to assess whether water supply interruptions and the predictability of interruptions were related to composite indicators of stressful behaviors and emotional distress. More frequent water service interruptions were associated with more frequent emotional distress (ß = 0.49, SE = 0.05, P < 0.001) and stressful behaviors (ß = 0.39, SE = 0.06, P < 0.001). Among households that experienced interruptions, predictability mitigated these respective relationships by approximately 25 and 50%. Where the provision of continuous water supplies is challenged by climate change, population growth, and poor management, water service providers may be able to mitigate some psychosocial consequences of intermittency through scheduled intermittency and communication about water supply interruptions. Service providers unable to supply continuous water should optimize intermittent water delivery to reduce negative impacts on users, and global monitoring regimes should account for intermittency and predictability in post-2030 water service metrics to better reflect household water insecurity experiences.

Enhancing water security: Statistical measurement and spatiotemporal analysis.

Water security is essential for ensuring energy security, sustainable development, and human survival. However, due to a series of challenges, including rising water demand, environmental pollution, and water resource shortages, the global water security situation remains concerning and poses a threat to global sustainable development. To assess water security in China, this study uses data from 30 provinces in China from 2012 to 2021. A comprehensive evaluation method was applied to determine the level of water resource security in China. The Dagum Gini coefficient, Moran index, and spatial model were used to clarify regional differentiation characteristics and the driving factors. The results indicate that while China's water resource security is relatively low, it has shown steady improvement in recent years. Significant regional disparities exist in water resource security across China, with notable spatial characteristics, and socio-economic factors are the primary causes of these differences. Based on the above research, we put forward policy recommendations from the aspects of water resources management, public participation and inter-regional water resources cooperation, to provide reference for water resources security in developing countries.

A coupled human-natural system analysis of freshwater security under climate and population change.

Limited water availability, population growth, and climate change have resulted in freshwater crises in many countries. Jordan's situation is emblematic, compounded by conflict-induced population shocks. Integrating knowledge across hydrology, climatology, agriculture, political science, geography, and economics, we present the Jordan Water Model, a nationwide coupled human-natural-engineered systems model that is used to evaluate Jordan's freshwater security under climate and socioeconomic changes. The complex systems model simulates the trajectory of Jordan's water system, representing dynamic interactions between a hierarchy of actors and the natural and engineered water environment. A multiagent modeling approach enables the quantification of impacts at the level of thousands of representative agents across sectors, allowing for the evaluation of both systemwide and distributional outcomes translated into a suite of water-security metrics (vulnerability, equity, shortage duration, and economic well-being). Model results indicate severe, potentially destabilizing, declines in freshwater security. Per capita water availability decreases by approximately 50% by the end of the century. Without intervening measures, >90% of the low-income household population experiences critical insecurity by the end of the century, receiving <40 L per capita per day. Widening disparity in freshwater use, lengthening shortage durations, and declining economic welfare are prevalent across narratives. To gain a foothold on its freshwater future, Jordan must enact a sweeping portfolio of ambitious interventions that include large-scale desalinization and comprehensive water sector reform, with model results revealing exponential improvements in water security through the coordination of supply- and demand-side measures.

Exploring the potential of bacterial-augmented floating treatment wetlands for the remediation of detergent-contaminated water.

Due to industrialization and urbanization, the use of detergents inadvertently led to contamination of aquatic environments, thus posing potential threat to aquatic organisms and human health. One of the main components of detergents is linear alkylbenzene sulfonate (LAS), which can cause toxic effects on living organisms, particularly aquatic life in the environment. In this study, floating treatment wetlands (FTWs) mesocosms were developed and augmented with LAS-degrading bacteria. The plant species, Brachiaria mutica (Para grass), was vegetated to establish FTWs and bacterial consortium (1:1:1:1) of Pseudomonas aeruginosa strain PJRS20, Bacillus sp. BRRH60, Acinetobacter sp. strain CYRH21, and Burkholderia phytofirmans Ps.JN was augmented (free or immobilized) in these mesocosms. Results revealed that the FTWs removed LAS from the contaminated water and their augmentation with bacteria slightly increased LAS removal during course of the experiment. Maximum reduction in LAS concentration (94%), chemical oxygen demand (91%), biochemical oxygen demand (93%), and total organic carbon (91%) was observed in the contaminated water having FTWs augmented with bacterial consortium immobilized on polystyrene sheet. This study highlights that the FTWs supported with immobilized bacteria on polystyrene sheets can provide an eco-friendly and sustainable solution for the remediation of LAS-bearing water, especially for developing countries like Pakistan.

This pilot-scale study provided insights to resolve the detergent-contaminated wastewater issue, using floating treatment wetlands (FTWs) augmented with bacteria. The FTWs augmented with bacteria immobilized on a polystyrene sheet and vegetated with Brachiaria mutica led to high degradation of LAS, a toxic compound of detergent, from the contaminated water.

Sustaining ex-mining lake-converted constructed wetlands as nature-based solutions: A comprehensive assessment of the carbon-water nexus in Paya Indah Wetlands, Malaysia.

Water and carbon, essential for Earth's well-being, face imminent threats from human activities that fuel climate change. This study investigates nature-based solutions, focusing on the carbon-water nexus of ex-mining lake-converted constructed wetlands, specifically in Malaysia's Paya Indah Wetlands (PIW). Addressing research gaps, it assesses the ecosystem services of these wetlands, emphasising integrated evaluations for informed land management and employing a top-down conservation approach. Methodologically, spatial assessments, soil and water sampling, carbon quantification, water quality index calculations, land cover classification and stakeholder surveys were conducted. Results underscore the significant carbon sequestration and water quality improvement potential of constructed wetlands, with soil and sediment carbon accumulation reaching 1553.11 Mg C ha-1 (equivalent to 5700 Mg CO2 ha-1), translating to an annual sequestration capacity of 67.5 Mg C ha-1 year-1. Water quality index values ranged from 58 to 81 (Classes II to III). PIW's establishment led to a reduction of over 90% in barren land, with increases in water bodies (36%) and vegetation-covered land (38%), boosting wildlife populations by 30%. Spatial variations in organic carbon density and water quality underscore the complexity of the carbon-water nexus and its impacts on ecosystem health and water security. Despite land use changes, PIW demonstrates resilience, contributing to climate change mitigation. Stakeholder perceptions vary, emphasising the need for adaptive strategies. The study proposes transdisciplinary conservation initiatives and adaptive plans, stressing the pivotal role of ex-mining lake-converted constructed wetlands in enhancing climate resilience.

A declaration on the value of experiential measures of food and water insecurity to improve science and policies in Latin America and the Caribbean.

BACKGROUND: Water security is necessary for good health, nutrition, and wellbeing, but experiences with water have not typically been measured. Given that measurement of experiences with food access, use, acceptability, and reliability (stability) has greatly expanded our ability to promote food security, there is an urgent need to similarly improve the measurement of water security. The Water InSecurity Experiences (WISE) Scales show promise in doing so because they capture user-side experiences with water in a more holistic and precise way than traditional supply- side indicators. Early use of the WISE Scales in Latin American & the Caribbean (LAC) has revealed great promise, although representative data are lacking for most of the region. Concurrent measurement of experiential food and water insecurity has the potential to inform the development of better-targeted interventions that can advance human and planetary health. MAIN TEXT: On April 20-21, 2023, policymakers, community organizers, and researchers convened at Universidad Iberoamericana in Mexico City to discuss lessons learned from using experiential measures of food and water insecurity in LAC. At the meeting's close, organizers read a Declaration that incorporated key meeting messages. The Declaration recognizes the magnitude and severity of the water crisis in the region as well as globally. It acknowledges that traditional measurement tools do not capture many salient water access, use, and reliability challenges. It recognizes that the WISE Scales have the potential to assess the magnitude of water insecurity more comprehensively and accurately at community, state, and national levels, as well as its (inequitable) relationship with poverty, poor health. As such, WISE data can play an important role in ensuring more accountability and strengthening water systems governance through improved public policies and programs. Declaration signatories express their willingness to promote the widespread use of the WISE Scales to understand the prevalence of water insecurity, guide investment decisions, measure the impacts of interventions and natural shocks, and improve public health. CONCLUSIONS: Fifty-three attendees endorsed the Declaration - available in English, Spanish and Portuguese- as an important step to making progress towards Sustainable Development Goal 6, "Clean Water and Sanitation for All", and towards the realization of the human right to water.

Health risk assessment of heavy metals and disinfection by-products in drinking water in megacities in China: A study based on age groups and Monte Carlo simulations.

Heavy metal(loid)s (HMs) and disinfection by-products (DBPs) in drinking water pose risks to human health and jeopardize drinking water. Water-related behaviors vary significantly among different age groups and regions. In this study, the carcinogenic and non-carcinogenic risks of HMs (As, Cd, Cr6+, Cu, Pb, and Zn) and DBPs (bromodichloromethane (BDCM), bromoform, chloroform, dibromochloromethane (DBCM), dichloroacetic acid (DCAA), and trichloroacetic acid (TCAA)) in drinking water in two Chinese megacities (Beijing in North China and Guangzhou in South China) via multiple exposure pathways were assessed. The results showed that children aged 9 months to 2 years had a total carcinogenic risk (TCR) and hazard index (HI) above acceptable levels, indicating that despite the drinking water quality in the selected megacities meeting the current Chinese national standards (GB 5749-2022), the health risks of exposure to HMs and DBPs in drinking water for local young children should not be neglected. Specifically, the carcinogenic risk (CR) of exposure to As in drinking water for children < 18-years-old, who were divided into different age groups, was 1.5-2.0- and 4.5-5.9-times higher than the TCR of exposure to DBPs in Beijing and Guangzhou, respectively. Regarding children aged 9 months to 2 years, the exposure to TCAA accounted for the largest proportion (35.6 %) of the TCR of exposure to DBPs in Beijing drinking water, 5.4-times higher than that in Guangzhou; whereas, the TCR of exposure to DBPs in Guangzhou drinking water was predominantly caused by exposure to chloroform, accounting for 40.6 % of the TCR and 1.5-times higher than that in Beijing. In addition, the CR of exposure to DCAA in drinking water in both megacities accounted for a large proportion of the TCR for children aged 9 months to 2 years. Monte Carlo simulations showed that 62.2 % and 42.6 % of the TCR of simultaneous exposure to As and DBPs in drinking water exceeded the acceptable level for sensitive populations, that is, children aged 1-2 years in Beijing (95th percentile = 4.2 × 10-4) and children aged 9-12 months in Guangzhou (95th percentile = 5.2 × 10-4), respectively. This elaborate health risk assessment sheds light on improving the water quality indices to guarantee drinking water safety in China.

Environmental impacts, exposure pathways, and health effects of PFOA and PFOS.

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that have been widely utilized in various industries since the 1940s, and have now emerged as environmental contaminants. In recent years, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been restricted and replaced with several alternatives. The high persistence, bioaccumulation, and toxicity of these substances have contributed to their emergence as environmental contaminants, and several aspects of their behavior remain largely unknown and require further investigation. The trace level of PFAS makes the development of a monitoring database challenging. Additionally, the potential health issues associated with PFAS are not yet fully understood due to ongoing research and inadequate evidence (experimental and epidemiological studies), especially with regard to the combined effects of exposure to PFAS mixtures and human health risks from drinking water consumption. This in-depth review offers unprecedented insights into the exposure pathways and toxicological impacts of PFAS, addressing critical knowledge gaps in their behaviors and health implications. It presents a comprehensive NABC-Needs, Approach, Benefits, and Challenges-analysis to guide future strategies for the sustainable monitoring and management of these pervasive environmental contaminants.

Linking ecosystem service flow to water-related ecological security pattern: A methodological approach applied to a coastal province of China.

Water security is a critical concern due to intensifying anthropogenic activities and climate change. Delineating a water-related ecological security pattern can help to optimize spatial configuration, which in turn can inform sustainable water management. However, the methodology remains unclear. In this study, we developed a framework linking ecosystem service flow to water-related ecological security pattern; hence, we identified the sources, sinks, key corridors, and vulnerable nodes in Fujian Province, China. Our results revealed that the sources were located inland at high altitudes with a decreasing area trend in the south and an increasing area trend in the north, whereas the sinks were spread in coastal areas and exhibited a decreasing trend with relatively stable spatial distribution. The water-related ecological security has degraded as represented by a decreasing ecological supply-demand ratio over the last 30 years. Key corridors were identified in 17.12% of the rivers, and 22.5% of the vulnerable nodes were recognized as early warning nodes. Climate variability affected source distribution, while anthropogenic activities drove sink dynamics. These findings have important implications including landscape pattern planning and sustainable water management in the context of accelerated land use/cover and climate changes.

Modeling water inequality and water security: The role of water governance.

Water Inequality, Water Security and Water Governance are fundamental parameters that affect the sustainable use of water resources. Through policy formulation and decision-making, Water Governance determines both Water Security and Water Inequality. Largely, where Water Inequality exists, Water Security is undermined through unsustainable water use practices that lead to pollution of water resources, conflicts, hoarding of water, and poor sanitation. Incidentally, the interconnectedness of Water Governance, Water Inequality and Water Security has not been investigated previously. This study modified the Gini coefficient and used a Logistics Growth of Water Resources Model (LGWR Model) to access Water Inequality and Water Security mathematically, and discussed the connected role of Water Governance. We tested the validity of both models by calculating the actual Water Inequality and Water Security of Ghana. We also discussed the implications of Water Inequality on Water Security and the overarching role of Water Governance. The results show that regional Water Inequality is widespread in some parts. The Volta region showed the highest Water Inequality (Gini index of 0.58), while the Central region showed the lowest (Gini index of 0.15). Water Security is moderately sustainable. The use of water resources is currently stress-free. It was estimated to maintain such status until 2132 ± 18 when Ghana will consume half of the current total water resources of 53.2 billion cubic meters. Effectively, Water Inequality is a threat to Water Security, results in poverty, under-development heightens tensions in water use, and causes instability. With proper Water Governance, Water Inequality can be eliminated through formulating and implementing approaches that engender equal allocation and sustainable use of water resources.

Protecting environmental flows to achieve long-term water security.

In this work, we propose a new approach to diagnose if a water allocation scheme is compatible with long-term water security at the catchment scale, and suggest steps to achieve such compatibility. We argue that when the remaining flow of a river after upstream withdrawals is not sufficient to safeguarding ecological river functions, the basin is at extreme risk of water scarcity, which indicates that the water management is failing. To test this, we analysed the water scarcity risks and the safeguarded environmental flows (e-flows) in 277 basins across a wide range of hydro-climatic conditions in Chile (17-55°S). For each basin, water scarcity risks were assessed based on water stress indices (WSIs, computed as the ratio of withdrawals to water availability), considering two water-use scenarios: (i) WSImax, where total withdrawals correspond to the maximum consumptive water allowed by the law, i.e., where only the e-flows protected by law remain in the river, and (ii) WSIalloc, where total withdrawals correspond to the actual allocated consumptive water uses within the basins. Further, we evaluated the adequacy of the water management system to protect ecological river functions by contrasting the e-flows protected in Chile with those safeguarded in six other countries. The water allocation system in Chile incorporated the protection of minimum e-flows in 2005 and established that these do not exceed 20% of the mean annual streamflow, except in some exceptional cases. This upper limit is consistently lower than the e-flows safeguarded in other countries, where 20%-80% of the mean annual streamflow are protected. This turns out in WSImax values between 80% and 100% in all basins, well above the threshold associated with over-committed basins under extreme risk of water scarcity (70% typically). When moving from the legally allowed to the actually allocated water use scenario, we found contrasting results: about 70% of the basins show low water scarcity risk (WSIalloc <40%), while an 18% have WSIalloc above 100%, indicating the allocation is going beyond current law limits and even beyond physical limits. Our results reveal that the link between e-flows, water allocation and water security has not been adequately incorporated in the current law. E-flows stipulated by law are insufficient to fulfil environmental requirements, while placing the basins under extreme risk of water scarcity if the total allowed withdrawals were exerted. To move towards a system that can effectively achieve long-term water security, we recommend: (i) To define tolerable water scarcity risks for basins, considering environmental requirements. (ii) To translate those risks into measurable basin indices to measure water security, such as the WSI. (iii) To set maximum water use limits (or minimum e-flows) within the basins that are compatible to the water security goals. If, under current and projected water availability conditions, the existing withdrawals exceed these limits, water managers should be able to adapt total consumption to the required limits.

Water struggles and contested use: A capabilities assessment of household water security in marginalized communities.

In this study, we apply a capabilities approach to analyze a water consolidation project and water security outcomes following a severe drought in East Porterville, California. By combining hydro-social theory with the capabilities approach, we provide a holistic approach to household water security that is historically situated, considers residents' needs, and accounts for areas of life beyond hydration and domestic use. In addition, we offer a critical analysis of water system consolidation, a process of combining water systems physically and/or managerially as a solution to water insecurity in small towns. Drawing on interviews with residents, local experts, and government officials as well as archival research and participant observation, we find that the water consolidation project has mixed results for the East Porterville community, with beneficial, limiting, and contested effects on residents' social, cultural, and economic life. Although residents now have a consistent source of water in their homes, they find themselves limited in their ability to use water for drinking and cultural and economic purposes. Water negotiations and contestations also affected property values, independence, and livability. Through this empirical application of the capabilities approach, we demonstrate the need to expand the concept of water security and consolidation outcomes through needs-based perspectives. Furthermore, we show how the coupling of capabilities approach with a hydro-social framework provides descriptive, analytical, and explanatory tools for understanding and addressing household water security.

Differential exposure to drinking water contaminants in North Carolina: Evidence from structural topic modeling and water quality data.

To better understand water security of communities in North Carolina, this research uses structural topic modeling (STM) and geographic mapping to identify the main topics and pollutant categories being researched and the areas exposed to drinking water contaminants. The textual data derived from the journal article abstracts that examined water pollution in North Carolina is from 1964 to present. The STM analysis of textual data is paired with socio-demographic data from the 2015-2019 American Community Survey (ACS) 5-year estimates and water pollution data from North Carolina state agencies. The STM findings show that the most discussed topics relate to runoff management, wastewater from concentrated agricultural feeding operations, emerging contaminants, land development, and health impacts as a result of water contamination. The article discusses how the topics especially threaten groundwater resources used by community water systems and private wells. Those communities served by private wells are predominantly low-income and minority populations. As a result, threats to groundwater supplies exacerbate existing issues of environmental justice in North Carolina, especially in the Coastal Plains Region. The STM findings revealed that several key threats to safe drinking water are less covered by academic literature, such as poultry concentrated agricultural feeding operations and climate impacts, which may increase disparities in water access in North Carolina.

Flood risk assessment by using an interpretative structural modeling based Bayesian network approach (ISM-BN): An urban-level analysis of Shenzhen, China.

With increasingly uncertain environmental conditions under global change, it is rather important for water security management to evaluate the flood risk, which is influenced by the compound effect of severe weather events and strong anthropogenic activities. In this paper, a risk assessment model in the framework of Bayesian network (BN) was proposed through incorporating with the Interpretative Structural Modeling method (ISM), which would produce an integrated ISM-BN model for reliable flood assessments. The ISM is employed to identify the relations among multiple risk factors, and then helps to configure the BN structure to conduct a risk inference. The established model was further demonstrated in Shenzhen city of China to perform an urban-level risk analysis of the flood disaster, and the Enhanced Water Index (EWI) was introduced to derive model parameters for training and verification. The obtained results of risk assessment lead to an accuracy of 76% with the Area Under ROC Curve (AUC) of 0.82, and spatial distribution of risk levels also showed a satisfactory performance. In addition, it was found that the maximum daily rainfall among ten risk factors play a key part in flood occurrence, while the elevation and storm frequency are also sensitive indicators for the study area. Besides, the spatial flood risk map generated under various design rainfall scenarios would contribute to identifying potential areas that are worth paying particular attention. Thus, the developed assessment model would be a useful tool for supporting flood risk governance to achieve reliable urban water security.

Farmers' Lived Experiences of Water Crisis: Lessons Learned from a Phenomenology Study.

Understanding the perception of farmers is essential for successful water resources management especially during water crisis. Therefore, this paper examines farmers' perception about the local water crisis in Gawshan dam basin, Iran. Qualitative phenomenological methodology was used to depict the lived experiences of farmers regarding water crisis. Using critical sampling, out of all water users of the Gawshan dam, the selected participants were farmers having lived experience of water crisis and interested to express and share their experiences. Sixty important statements and five themes were extracted from participants' experiences (PE) in water crisis. Finding showed that farmers have perceived agricultural water crisis at the local level but different pattern of perception also is detected among them. The results also revealed that farmers' perception is related to their direct experience, the way they define water crisis, their memories of water crisis and their expectation of what it holds for future water crisis. It is expected that this study will support decision makers at local level to address water crisis in the region.

The integration of nature values and services in the nature-based solution assessment framework of constructed wetlands for carbon-water nexus in carbon sequestration and water security.

As the climate change impacts are expected to become increasingly disruptive, affecting water security, environmental health and ecosystem, constructed wetlands receive attention for their functions in delivering various life-sustaining services to human and environmental systems. In this article, a systematic review was conducted through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard to identify the current research on constructed wetlands' nature values and services from 2011 to 2020 of two databases, namely Scopus and Web of Science. The criteria of assessment focus on holistic deliberation of subject matters, namely carbon sequestration and water security as regulating and provisioning services, as well as nature values of constructed wetlands, namely instrumental and intrinsic values. As a result, 38 articles were selected and comprehensively examined. As the lack of an interdisciplinary approach makes data and information integration difficult, this study derived an integrated classification of constructed wetlands' services and mapped with its nature values, guided by the Millennium Ecosystem Assessment framework. Besides, mechanisms and factors affecting carbon sequestration and water security were also discussed. The carbon-water nexus was then conceptualised as interlinkages between engineered and natural physicochemical processes at the interface between carbon and water cycles. To fill the gaps, based on the carbon-water nexus concept, a new framework was synthesised at the end of the deliberation for constructed wetlands in regulating local climate through carbon sequestration and ensuring water security through water treatment and purification as well as influencing socio-cultural values, which needs an integrated approach that is the novelty of this work. The framework integrates the dichotomy of the instrumental-intrinsic nature values of constructed wetlands to evaluate the importance and benefit of the carbon-water nexus. The framework that reveals the vitality of nature values provided by constructed wetlands can help improve the decision-making to prioritise ecosystem services and conservation efforts, particularly in the sustainable management of constructed wetlands.

Water security and health risk assessment of an urban household-level drinking water and sanitation system, Punjab, India.

The water scarcity and deteriorating water quality are major issues of concern to the agrarian state of Punjab, India. The focus of the study is to assess the status of drinking water and sanitation systems of Punjab using an exhaustive dataset of 1575 drinking water samples from 433 sampling locations in 63 urban local bodies of Punjab. Water security index (WSI) indicate that out of 63 urban local bodies, 13 are categorized into good class, 31 fall under fair class, and 19 fall under poor class. The access indicator under sanitation dimension shows that Bathinda region has maximum sewerage network coverage relative to other regions, whereas ca. 50% of the ULBs in Amritsar region do not have sewerage facility. It is clearly depicted that the variation in WSI is mainly attributable to sanitation dimension (10-22.5) as variation in water supply dimension (29-35) is relatively less. Hence, emphasis on indicators and variables of sanitation dimension is required for the improvement of overall WSI. The assessment of qualitative aspects of drinking water and health risk depicts that the drinking water quality of southwest part of the state (i.e. Malwa region) is under good quality class contrary to its poor groundwater quality. Kapurthala district shows high health risk due to the presence of trace metals despite being classified into good class within water security index. The drinking water quality is better and health risks are minimal in regions where drinking water is supplied via treated surface water sources (e.g. Bathinda region). Furthermore, the results of health risk assessment correlate with M[Formula: see text]-Water Quality Index outcome owing to presence of trace metals in groundwater above permissible limits. These results will help in identification of shortcomings in water supply and sanitation infrastructure and its management in urban areas.

Deep Cyanobacteria Layers: An Overlooked Aspect of Managing Risks of Cyanobacteria.

The risk of human exposure to cyanotoxins is partially influenced by the location of toxin-producing cyanobacteria in waterbodies. Cyanotoxin production can occur throughout the water column, with deep water production representing a potential public health concern, specifically for drinking water supplies. Deep cyanobacteria layers are often unreported, and it remains to be seen if lower incident rates reflect an uncommon phenomenon or a monitoring bias. Here, we examine Sunfish Lake, Ontario, Canada as a case study lake with a known deep cyanobacteria layer. Cyanotoxin and other bioactive metabolite screening revealed that the deep cyanobacteria layer was toxigenic [0.03 µg L-1 microcystins (max) and 2.5 µg L-1 anabaenopeptins (max)]. The deep layer was predominantly composed of Planktothrix isothrix (exhibiting a lower cyanotoxin cell quota), with Planktothrix rubescens (exhibiting a higher cyanotoxin cell quota) found at background levels. The co-occurrence of multiple toxigenic Planktothrix species underscores the importance of routine surveillance for prompt identification leading to early intervention. For instance, microcystin concentrations in Sunfish Lake are currently below national drinking water thresholds, but shifting environmental conditions (e.g., in response to climate change or nutrient modification) could fashion an environment favoring P. rubescens, creating a scenario of greater cyanotoxin production. Future work should monitor the entire water column to help build predictive capacities for identifying waterbodies at elevated risk of developing deep cyanobacteria layers to safeguard drinking water supplies.

The effects of seasonal variations on household water security and burden of diarrheal diseases among under 5 children in an urban community, Southwest Nigeria.

BACKGROUND: Household water security encompasses water-related factors that pose threats to public health at the household level. It presents a reliable access to water in sufficient quantity and quality towards meeting basic human needs. This study assessed the dynamics of seasonal variations in household water security and the association between household water security and diarrheal disease across dry and wet seasons in an urban settlement in Southwest Nigeria. METHODS: A panel study design was employed to study 180 households selected using a multistage sampling technique. The selected households were studied during dry and rainy seasons. Household water security was assessed through the application of the all or none principle to 9 indicators associated with household water security. The intensity of water insecurity was also assessed using the nine indicators. The higher the number of indicators a household failed, the higher the intensity of household water insecurity. The association between the intensity of household water insecurity and the burden of diarrheal disease across the seasons was assessed using the Mantel-Haenszel test. RESULTS: No household was water-secure in both dry and rainy seasons; however, the intensity of insecurity was more pronounced during the dry season compared with the rainy season. Ninety households (52.0%), had water insecurity intensity scores above fifty percentiles during the dry season while 21 (12.1%) households had a water insecurity score above the 50th percentile during raining season, p < 0.001. The burden of diarrheal disease was significantly higher among households with a water insecurity intensity score above the 50th percentile, 9 (8.1%) compared to households with a water insecurity intensity score below the 50th percentile 7 (3.0%), p = 0.034. There was no statistically significant association between the intensity of water insecurity and diarrheal disease burden across the dry and rainy seasons, p = 0.218. CONCLUSION: The high burden of household water insecurity deserves concerted efforts from all concerned stakeholders, a panacea to an important health threat in the developing world.

[Water safety and quality and school feeding: approaches in Latin America and the CaribbeanInocuidade e qualidade da água e alimentação escolar: abordagens na América Latina e no Caribe]. / Inocuidad y calidad del agua y alimentación escolar: enfoques en América Latina y el Caribe.

Objective: Identify approaches to water safety and quality in documents describing school feeding programs in Latin American and Caribbean (LAC) countries. Methods: Descriptive, cross-sectional, exploratory study of documents on school feeding in LAC countries and territories. A documentary analysis was carried out and four initial categories were determined: "water for consumption", "water for hygiene", "water for food preparation", and "local/family agriculture", according to the use of water in school feeding programs. Documents were identified in 2018 and 2019 on the official websites of LAC countries and territories, the United Nations Food and Agriculture Organization, and the World Food Programme. Absolute and relative frequencies were obtained for quantitative data; thematic content analysis was applied to qualitative data. Results: Of the 114 documents analyzed, 29 were eligible. In the categories "water for consumption", "water for hygiene" and "water for food preparation", the only characteristic attributed to water was that it be potable. In the category "local/family farming", no approaches were found that addressed water for irrigation. Conclusion: The documents address water, but do not focus on its safety and quality. Governments and local authorities should review their documents and ensure that their approaches are mutually coherent and based on intersectoral support and dialogue to achieve the targets of the Sustainable Development Goals.

Objetivo: Identificar as abordagens sobre a inocuidade e qualidade da água em documentos que descrevem os programas de alimentação escolar nos países da América Latina e do Caribe (ALC). Métodos: Estudo descritivo, transversal e exploratório de documentos sobre alimentação escolar nos países e territórios da ALC. Foi realizada uma análise documental e, a priori, foram determinadas quatro categorias: "água para consumo", "água para higiene", "água para preparo" e "agricultura local/familiar", conforme o uso da água na alimentação escolar. Os documentos foram pesquisados durante 2018-2019 nos sites oficiais dos países e territórios da ALC, da Organização das Nações Unidas para a Alimentação e a Agricultura e do Programa Mundial de Alimentos. Foram obtidas as frequências absolutas e relativas dos dados quantitativos e, para os dados qualitativos, aplicou-se a análise de conteúdo do tipo temática. Resultados: Foram analisados 114 documentos, dos quais 29 eram elegíveis. As abordagens das categorias "água para consumo", "água para higiene" e "água para preparo" somente atribuíram à água a característica de ser potável. Na categoria "agricultura local/familiar" não foram encontradas abordagens sobre água para irrigação. Conclusão: Os documentos abordam a água, mas não focam em sua inocuidade e qualidade. Os governos e autoridades locais devem revisar seus documentos e garantir a unanimidade de abordagens com base no apoio e no diálogo intersetorial, a fim de alcançar as metas dos Objetivos de Desenvolvimento Sustentável.