This chapter explores how changes in land use, climate, and the function of ecosystems may act synergistically to alter exposure to infectious disease and natural disasters and curtail access to food, clean air, and clean water – basic components of the public’s health. It focuses on the greatest emerging threats from climate and large-scale, anthropogenic changes to landscapes and natural systems for ecosystem services: food production and clean water provision. These 2 are difficult to study using traditional approaches as they are multi-factoral and complex and often occur over very large scales. Ample evidence exists regarding alterations to disease transmission; most but not all show increases. Mechanisms by which changes occur include: changes in the density or presence of disease-related organisms; changes in exposure pathways; and changes in community species composition. Food and water scarcity combined with greater vulnerability to natural disasters may lead to much higher morbidity and mortality e.g. from malnutrition and chronic hunger, particularly in SSA and parts of SE Asia experiencing ecological constraints to local food production due to soil degradation and water scarcity. Water is also needed for drinking, sanitation, hygiene, and food preparation - inadequate access causes millions of deaths. Climate change is expected to worsen water scarcity. Depletion of ecosystem services might impact health only when resources are very constrained and a threshold is reached. Vulnerability to natural disasters (fires, floods, storms, tidal waves, landslides) influences how changing environmental conditions may impact human health. Vulnerability differs by socioeconomic status and by gender (especially women) and age. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
- Institutional mechanisms can be grouped into seven types: organisational; legal; participation; decentralisation; and markets; privatisation and infrastructure, with most articles considering multiples of these. Clusters emerge by geography and type (i.e. IWRM in East Africa, water markets in Chile).
- Factors which influence outcomes can be organised using six typologies and according to their origins: exogenous, endogenous or interface (after Saleth and Dinar 2005).
- A quarter of papers were judged to exhibit a weak chain of reasoning with only 11% judged as strong.
- Most were published since 2002, and where reported, important funding sources are DFID, IWMI, World Bank and the Natural Sciences Foundation of China. 19 countries feature with clusters of research in India, China, Tanzania and Chile.
- Less than half of the papers in the sample provide an adequate description of methodology. Almost one in five provide no methodological description.
Background: Hypertensive disorders in pregnancy are among the leading causes of maternal and perinatal death in low- income countries, but the aetiology remains unclear. We investigated the relationship between salinity in drinking water and the risk of (pre)eclampsia and gestational hypertension in a coastal community.
Methods: A population-based case-control study was conducted in Dacope, Bangladesh among 202 pregnant women with (pre)eclampsia or gestational hypertension, enrolled from the community served by the Upazilla Health Complex, Dacope and 1,006 matched controls from the same area. Epidemiological and clinical data were obtained from all participants. Urinary sodium and sodium levels in drinking water were measured. Logistic regression was used to calculate odds ratios, and 95% confidence intervals.
Findings: Drinking water sources had exceptionally high sodium levels (mean 516.6 mg/L, S.D 524.2). Women consuming tube-well (groundwater) were at a higher disease risk than rainwater users (p,0.001). Adjusted risks for (pre)eclampsia and gestational hypertension considered together increased in a dose-response manner for increasing sodium concentrations (300.01–600 mg/L, 600.1–900 mg/L, .900.01 mg/L, compared to ,300 mg/L) in drinking water (ORs 3.30 [95% CI 2.00– 5.51], 4.40 [2.70–7.25] and 5.48 [3.30–9.11] (p-trend,0.001). Significant associations were seen for both (pre)eclampsia and gestational hypertension separately.
Interpretation: Salinity in drinking water is associated with increased risk of (pre)eclampsia and gestational hypertension in this population. Given that coastal populations in countries such as Bangladesh are confronted with high salinity exposure, which is predicted to further increase as a result of sea level rise and other environmental influences, it is imperative to develop and evaluate affordable approaches to providing water with low salt content.
Lymphatic filariasis (LF) is a debilitating disease overwhelmingly caused by Wuchereria bancrofti, which is transmitted by various mosquito species. Here, we present a systematic literature review with the following objectives: (i) to establish global and regional estimates of populations at risk of LF with particular consideration of water resource development projects, and (ii) to assess the effects of water resource development and management on the frequency and transmission dynamics of the disease. We estimate that globally, 2 billion people are at risk of LF. Among them, there are 394.5 million urban dwellers without access to improved sanitation and 213 million rural dwellers living in close proximity to irrigation. Environmental changes due to water resource development and management consistently led to a shift in vector species composition and generally to a strong proliferation of vector populations. For example, in World Health Organization (WHO) subregions 1 and 2, mosquito densities of the Anopheles gambiae complex and Anopheles funestus were up to 25-fold higher in irrigated areas when compared with irrigation-free sites. Although the infection prevalence of LF often increased after the implementation of a water project, there was no clear association with clinical symptoms. Concluding, there is a need to assess and quantify changes of LF transmission parameters and clinical manifestations over the entire course of water resource developments. Where resources allow, integrated vector management should complement mass drug administration, and broad-based monitoring and surveillance of the disease should become an integral part of large-scale waste management and sanitation programs, whose basic rationale lies in a systemic approach to city, district, and regional level health services and disease prevention.
Cholera is generally regarded as the prototypical waterborne and environmental disease. In Africa, available studies are scarce, and the relevance of this disease paradigm is questionable. Cholera outbreaks have been repeatedly reported far from the coasts: from 2009 through 2011, three-quarters of all cholera cases in Africa occurred in inland regions. Such outbreaks are either influenced by rainfall and subsequent floods or by drought- and water-induced stress. Their concurrence with global climatic events has also been observed. In lakes and rivers, aquatic reservoirs of Vibrio cholerae have been evocated. However, the role of these reservoirs in cholera epidemiology has not been established. Starting from inland cholera-endemic areas, epidemics burst and spread to various environments, including crowded slums and refugee camps. Human displacements constitute a major determinant of this spread. Further studies are urgently needed to better understand these complex dynamics, improve water and sanitation efforts, and eliminate cholera from Africa.
Water is one of the most important physical, aesthetic landscape elements and possesses importance e.g. in environmental psychology, landscape design, and tourism research, but the relationship between water and health in current literature is only investigated in the field of environmental toxicology and microbiology, not explicitly in the research field of blue space and human well-being. Due to the lack of a systematic review of blue space and well-being in the various fields of research, the aim of this review is to provide a systematic, qualitative meta-analysis of existing studies that are relevant to this issue. Benefits for health and well-being clearly related to blue space can be identified with regard to perception and preference, landscape design, emotions, and restoration and recreation. Additionally, direct health benefits have already been stated. The studies included in the review are mostly experimental studies or cross-sectional surveys, focusing on students as the subject group. There is a need for more qualitative and multi-faceted, interdisciplinary studies, using triangulation as a method to achieve a resilient image of reality. A broader study design considering all age groups would contribute to identifying benefits for the whole of society. The inattentiveness to blue space makes it difficult to measure long-term effects of blue space on well-being. There is still little respect for water and health in planning issues, although salutogenetic health benefits can be identified. To close the gap regarding missing systematic concepts, a concept for assessing salutogenetic health effects in blue space is provided. Blue space is considered therein as a multi-dimensional term including four dimensions of appropriation, as well as at least five ontological dimensions of substantiality. The aim of the concept is to support researchers and practitioners analysing health effects in blue space.
OBJECTIVES: This article aimed to review all literature on drought and vector-borne disease to enable an assessment of the possible impact of drought on the changing risk of vector-borne diseases in the UK. STUDY DESIGN: A systematic literature review was performed. METHODS: Using a search strategy developed from a combination of terms for drought and selected outcomes, the authors systematically reviewed all available literature from 1990 to 2012 on the impact of drought on vector-borne diseases. The following databases were searched: PubMed, Web of Science, and EMBASE. After reviewing the abstracts, 38 articles were found to fit the inclusion and exclusion criteria. RESULTS: Evidence found drought followed by re-wetting can have a substantial effect on water table levels, vegetation, and aquatic predators; all factors which influence mosquito populations. Several studies found an association between a drought during the previous year and West Nile virus incidence. Urban mosquito vectors of dengue virus and chikungunya virus are adaptable by nature and are able to exploit a multitude of additional aquatic habitats created as a response to drought (i.e. water storage containers). Tick populations are likely to be negatively affected by drought as they are dependent upon high levels of humidity and soil moisture. CONCLUSIONS: Further research is needed to identify public health interventions and environmental control measures for an invasive mosquito problem or arthropod-borne disease outbreak in the UK.
Freshwater scarcity has been cited as the major crisis of the 21st century, but it is surprisingly hard to describe the nature of the global water crisis. We conducted a meta-analysis of 22 coupled human-water system case studies, using qualitative comparison analysis (QCA) to identify water resource system outcomes and the factors that drive them. The cases exhibited different outcomes for human wellbeing that could be grouped into a six "syndromes": groundwater depletion, ecological destruction, drought-driven conflicts, unmet subsistence needs, resource capture by elite, and water reallocation to nature. For syndromes that were not successful adaptations, three characteristics gave cause for concern: (1) unsustainability-a decline in the water stock or ecosystem function that could result in a long-term steep decline in future human wellbeing; (2) vulnerability-high variability in water resource availability combined with inadequate coping capacity, leading to temporary drops in human wellbeing; (3) chronic scarcity-persistent inadequate access and hence low conditions of human wellbeing. All syndromes could be explained by a limited set of causal factors that fell into four categories: demand changes, supply changes, governance systems, and infrastructure/technology. By considering basins as members of syndrome classes and tracing common causal pathways of water crises, water resource analysts and planners might develop improved water policies aimed at reducing vulnerability, inequity, and unsustainability of freshwater systems.
Background: This mapping exercise explores the nature of empirical research regarding: What factors determine the performance of institutional mechanisms for water resources management in developing countries in terms of delivering pro-poor outcomes, and supporting sustainable economic growth?
Adequate water resources for health, ecosystems and production are a global concern. Institutions capable of water resource management (WRM) in ways which support social and economic progress are urgently needed, particularly in developing countries. Participation, decentralisation, reform, and marketization are promoted, but evidence of what works, where and why is difficult to find: a significant problem for those faced with decisions about appropriate approaches to adopt and support. This work is a timely response to imperatives for evidence based decision making, and is a touchstone for improved analysis, policy and practice in the field of WRM.
Methods: Relevant academic and grey literature were identified through a comprehensive and peer reviewed search strategy. To be included, studies had to: (1) concern formal and informal rules, norms and strategies, including organisations, laws, regulations, conventions, systems and agreements relating to freshwater in rivers, lakes and groundwater; (2) show primary, empirical evidence of pro-poor or sustainable economic growth outcomes; (3) concern developing countries; and (4), be in English. Articles were progressively screened at abstract, title and full text level, prior to coding and mapping against agreed criteria. Mapped data were analysed and cross-tabulated to support interpretation.
Results: 29,844 articles returned by the search were reduced to a final sample of 38 relevant studies based on full text review. Analysis of this sample reveals:
Conclusions: The systematic map confirms that the pool of reliable knowledge from which to draw is diminutive when the exacting standards of systematic mapping are applied. Whilst the imperatives for getting WRM ‘right’ are intuitively strong, we currently lack the evidence to: (a) confirm whether WRM institutions are performing; and (b) comprehend and manage the range of factors which shape that performance. Whilst clear cut evidence for universal determinants of institutional performance is not anticipated, it is startling how little good quality research links policy and institutions to outcomes, or diagnoses the root causes of performance.
The implications for international policy and practice are significant and demand an urgent response. Without adequate knowledge or metrics of the social and economic outcomes, and determinants of WRM, efforts to improve performance lack strategic direction and operational accountability, and funding, political and other support for improved performance is at risk. These findings demonstrate the need for radical improvement across the research cycle, including in commissioning, design, delivery, reporting, review and publishing. Specific recommendations based on the evidence and insights generated by this systematic map are set out in the report.
The aim of this study was to identify whether there was a relationship between the distance that people have to carry water home and ill health. We conducted a systematic review for papers that reported on the association between diarrheal risk and distance. Six papers were identified for inclusion in the meta-analysis. These were all observational studies, and only two reported effect sizes that adjusted for possible confounding. Multiple different types of water sources supplied the study communities. The combined odds ratio (OR) showed a significant increase in illness risk in people living farther away from their water source (OR = 1.45; 95% confidence interval [CI] = 1.04-1.68). There is a need for better designed studies to further elucidate the health impacts on having to carry water home.
Water shortages as a result of extreme weather events, such as flooding and severe cold, have the potential to affect significant numbers of people. Therefore, the need to build robust, coordinated plans based on scientific evidence is crucial. The literature review outlined in this short communication was conducted as part of a joint Drinking Water Inspectorate and Health Protection Agency (now Public Health England) report which aimed to review the scientific evidence base on extreme events, water shortages and the resulting health impacts. A systematic literature review was undertaken to identify published literature from both peer-reviewed and grey literature sources. The retrieved literature was then assessed using the Scottish Intercollegiate Guidelines Network quality assessment. The authors found very few scientific studies. However, a great deal of valuable grey literature was retrieved and used by the research team. In total, six main themes of importance that were identified by the review and discussed included health impacts, water quantity and quality, alternative supplies, vulnerable groups, communication with those affected and the emergency response. The authors conclude that more research needs to be conducted on health impacts and extreme events water shortages in order to build the future knowledge base and development of resilience.
OBJECTIVES: To review the published literature examining the impacts of the Aral Sea disaster on children's health. METHODS: A systematic review of the English language literature. RESULTS: The literature search uncovered 26 peer-reviewed articles and four major reports published between 1994 and 2008. Anemia, diarrheal diseases, and high body burdens of toxic contaminants were identified as being among the significant health problems for children. These problems are associated either directly with the environmental disaster or indirectly via the deterioration of the region's economy and social and health care services. While links between persistent organic pollutant exposures and body burdens are clear, health impacts remain poorly understood. No clear evidence for the link between dust exposure and respiratory function was identified. CONCLUSION: While important questions about the nature of the child health and environment relationships remain to be answered, the literature unequivocally illustrates the seriousness of the public health tragedy and provides sufficient evidence to justify immediate action. Regrettably, international awareness of the crisis continues to be poor, and the level of action addressing the situation is wholly inadequate.
This textbook covers global climate change, ozone depletion, water resources management, and ecology and infectious disease with case studies on cholera, malaria and the effects of water resource limitations.
This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
Approximately half of all childhood deaths in developing countries are attributable to mild and moderate malnutrition. Despite some improvement over the past two decades, Ethiopia has one of the highest child malnutrition rates in the world - approximately half of all children under age five. Several biological and social economic factors contribute to the problem. An analysis of 2000 Ethiopia Demographic and Health Survey data revealed that biological factors such as child's age and mother's height and social economic factors such as household wealth and mother's education are important determinants of a child's nutritional status. On the environmental side, the analysis identified significant externalities associated with access to water and sanitation at the community level that affected the probability of children being stunted and/or underweight. Their results showed that the external impact of access to water was larger for children living in rural areas. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
Healthy watersheds provide a supply and purification of fresh water. Because these services lie outside the traditional domain of commercial markets, they are undervalued. Development pressures leading to rapid modification of watershed lands is leading to the loss of valuable hydrological services, posing risk to the quality and cost of drinking water and the reliability of water supplies. This article summarizes key attributes of hydrological services and their economic benefits; presents mechanisms for safeguarding those services; and discusses programs in Quito, Costa Rica and New York City. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
The global disease burden in 1990 caused by unsafe water, sanitation and hygiene (WSH) was estimated to be 5.3% of all deaths and 6.8% of all DALYs. Specifically, this estimate measures the text to which diarrhoeal and selected parasitic diseases were attributable to WSH risk factors. The burden of some parasitic diseases (schistosomiasis, trachoma, ascariasis, trichuriasis and hookworm disease) was wholly attributable to unsafe WSH. For infectious diarrhoea, the burden was estimated by establishing exposure scenarios according to water supply and sanitation infrastructure, the level of faecal–oral pathogens in the environment and populations assigned to these scenarios. Unsafe WSH is also an important determinant in a number of diseases not included in the above estimates (e.g. malaria, yellow fever, filariasis, dengue, hepatitis A and hepatitis E, typhoid fever, arsenicosis, fluorosis and legionellosis), some of which present a high disease burden at the global level. WSH risk factors include multiple dimensions: the ingestion of unsafe water, lack of water linked to inadequate hygiene, poor personal and domestic hygiene and agricultural practices, contact with unsafe water, and inadequate development and management of water resources or water systems. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
A Bayesian spatial method was used to examine effects of environmental degradation (dryland salinity) on the mental health of rural residents. Dryland salinity and depression were associated suggesting environmental processes are driving the degree of psychological ill-health in these populations. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
In northern Ethiopia, water scarcity is a key factor in food security. Small-scale irrigation using micro-dams improved food security in Tigray but negative impacts included soil salinity and erosion. Additionally, malaria has become a growing concern in micro-dam areas at lower altitudes. Both positive and negative impacts of micro-dam water harvesting systems need to be well understood before up-scaling. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
This document provides a succinct overview of valuation methods and issues related to water resources. It includes a table on selection criteria for choosing a valuation method and a brief review of case studies from the Caribbean. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract
Pressures on agriculture to reduce its ‘successful’ capture of raw water will require transparent methods of negotiation. The authors purport there is confusion between the basic economics of natural resource allocation and the implications of water valuation and its relationship to water ‘pricing’. This publication focuses on agricultural use of water as it will continue to dominate global water withdrawals. This summary is not an official abstract. Users should refer to the original published version of the material for the full abstract