The inadequacy of water resources to meet the needs of food production is a very important issue that will increase in importance in the future. If local renewable water sources (in soil) and water (in rivers, lakes, reservoirs, aquifers) are sufficient to produce a reference food supply (including 3000 kcal of daily requirement, of which animal products include 20 percent) for all residents. If not, we consider a food production unit to have a lack of green-blue water. If it is not enough for all residents, we consider a food production unit to have a lack of green-blue water. The number of people living in food production units affected by green-blue water scarcity has increased from 360 million people in 1905 (21% of the world's population at that time) to 2.2 billion (34%) in 2005. During this period, the lack of green-blue water has spread to large areas and has increased in previous areas. Water security is a concept that is examined in different dimensions and aspects. Four dimensions of these cases were identified, each of which consists of two complementary aspects: direct-indirect, macro-micro, technical-political and peace-conflict. In this study, the indirect role of water on food security on a global scale was investigated using a quantitative spatial approach. Since food security is intertwined with water security in many ways, the role of water scarcity on the disruption of food production and the impact of trade on this interaction was analyzed, and while examining the relationship of social resilience with these issues, the areas that It was identified that they were facing certain challenges in this field. With this work, the concept of water security became systematic and finally related to the issues of vulnerability, resilience and sustainability.

This study evaluated the comprehensive Water-Energy-Food-Carbon Nexus (WEFC) by focusing on energy assessment in northwest Iran. The energy evaluation indices for different products were calculated by estimating the total input and output energies. Multi-objective optimization based on five individual objectives and WEFC Nexus policies was used to identify the optimal land-use allocation of wheat, barley, rapeseed, and sugar beet, silage corn, and potato while minimizing water and energy consumption and CO2 emissions, and maximizing food production and profit. The results indicate that the suggested framework provides a practical methodology for determining the optimal land-use allocation considering quantitative WEFC Nexus. To increase economic efficiency and reduce energy consumption, agricultural practices and policy recommendations should be adopted, including promoting renewable energy sources, implementing energy-saving technologies, improving fertilizer management, improving crop rotation practices, conservation tillage, and improving water management and adoption of sustainable farming practices. The results allow policymakers to optimize multiple resources and recommend the best resource allocation under recommendation policy, technology, and constraints to achieve sustainable development in agriculture.

We develop a theoretical framework and present a corresponding empirical analysis of the Food and Drug Administration’s irrigation water quality regulatory standard under the Food Safety Modernization Act using lettuce as a case study. We develop a stochastic price endogenous partial equilibrium model with recourse to examine the standard’s efficacy under various scenarios of foodborne illness severity, standard implementation, demand response to foodborne outbreaks, and irrigation costs. The stringency of regulation is evaluated with endogenous producer response to regulatory requirements and corresponding implications for economic surplus. The baseline results show that in the case of the lettuce market, the proposed microbial irrigation water quality regulation in the Food Safety Modernization Act (FSMA) is not cost effective relative to the existing Leafy-Greens Marketing Agreements relying on water treatment for mitigation of microbial contamination. However, FSMA can be cost effective if water treatment is sufficiently expensive.

The coordinated development of the Water-Land-Food (WLF) nexus is important for realizing sustainable food production and ensuring national food security. Based on the symbiosis system theory, this study used the Entropy weight TOPSIS method to calculate the WLF nexus of 30 provinces, municipalities and autonomous regions in China from 2003 to 2019. Taking the problem of decentralized food crop cultivation in China as the breakthrough point and using the Panel Tobit Model to empirically explore the threat of decentralized food crop cultivation to the WLF nexus. The results indicated that: (i) The average level of decentralized food crop cultivation index in China for the period 2003–2019 is 2.599 and the growth rate is −12.64%, while the WLF nexus index is 0.317, and the growth rate is 2.42%. Decentralized food crop cultivation showed a fluctuating downward trend in all regions of China, especially in the southwest and northwest regions. However, the WLF nexus index level belonging to the northeastern and Huang-Huai-Hai regions of China is higher, which presents a trend of first decreasing and then increasing. (ii) While the extent of decentralized food crop cultivation threatens the coordination of the WLF nexus in China, it has a time lag. (iii) The decentralized food crop cultivation in non-food producing areas (NFPA) rather than major food producing areas (MFPA) will threaten the WLF nexus. (iv) Compared with the higher WLF nexus index region, the negative effect of decentralized food crop cultivation is more obvious in the lower index region. (v) WFL nexus in the adjacent provinces of China showed regional clustering. Decentralized food crop cultivation will threaten the WLF nexus both in the inner province and adjacent regions. This study argues that the government can use financial subsidies to correct the problem of decentralized food crop cultivation, optimize the level of agricultural outsourcing services, and improve the market for water and land rights, thereby enhancing the WLF system coordination in China.

Natural resources including water, energy, and food have an increase in demand due to the global population increases. The sustainable management of these resources is an urgent global issue. These resources combined in a very vital nexus are called the water–energy–food (WEF) nexus. The field of nanotechnology offers promising solutions to overcome several problems in the WEF nexus. This review is the first report that focuses on the suggested applications of nanofibers in the WEF sectors. An economic value of nanofibers in WEF sectors was confirmed, which was mainly successfully applied for producing clean water, sustainable energy, and safe food. Biotechnological solutions of nanofibers include various activities in water, energy, and food industries. These activities may include the production of fresh water and wastewater treatment, producing, converting, and storing energy, and different activities in the food sector. Furthermore, microbial applications of nanofibers in the biomedicine sector, and the most important biotechnological approaches, mainly plant tissue culture, are the specific focus of the current study. Applying nanofibers in the field of plant tissue culture is a promising approach because these nanofibers can prevent any microbial contamination under in vitro conditions, but the loss of media by evaporation is the main challenge in this application. The main challenges of nanofiber production and application depend on the type of nanofibers and their application. Different sectors are related to almost all activities in our life; however, enormous open questions still need to be answered, especially the green approach that can be used to solve the accumulative problems in those sectors. The need for research on integrated systems is also urgent in the nexus of WEF under the umbrella of environmental sustainability, global climate change, and the concept of one’s health.

There is a need to address resource security and distributional justice in developing countries. People need water, energy, and food to sustain their livelihoods, grow economies, and achieve sustainable development. The interactions between these resource sectors form the crux of water-energy-food (WEF) nexus assessments. In this study, we have utilised the WEF Nexus Index to analyse the WEF nexus of 54 African nations. The results from the analysis were used to illustrate the opportunities and constraints for future development. Generally, African countries are performing sub-optimally in the WEF Nexus Index due to the insecurity of water, energy and/or food. The performance of countries varies with context, highlighting the need for contextual analysis in identifying challenges and potential solutions. Implementation of interventions for achieving WEF security needs to be planned from an integrated perspective to optimise synergies and minimize trade-offs. Implementation of the WEF nexus approach towards simultaneous security of WEF resources has potential to improve the WEF nexus. For example and for many African countries, policies that undergird investments in energy supply projects are needed to unlock available freshwater resources and meet food requirements—energy is shown to be a critical enabler of development. Such projects can be utilised to enhance the ability of farmers to manage water through drought-proofing rainfed agriculture, an increase in irrigation development, or both. WEF nexus-based studies, policies, and projects must be focused on the direct and indirect achievement of SDGs 1, 2, 6, 7, and 13, both in terms of access and availability, to ensure distributional justice, especially in the African context. Such actions, combined with broad public participation, can have a ripple effect on other SDGs such as SDGs 5, 10, and 17, thereby reducing inequalities and building partnerships to attain these aspirational goals. The assessment of Africa’s relatively low scores in terms of the WEF Nexus Index does not represent a negative narrative. Instead, it provides an entry point to identifying hotspots and understanding the underlying challenges, through which more detailed analyses can lead to identified solutions and policies. Many African countries are trapped in an environment that could be termed a ‘poverty-unemployment-inequality nexus’ (due to the interlinkages that exist between these ‘wicked’ problems). The WEF Nexus Index provides high-level insights into these opportunities.

Microplastics (MP) are plastic particles with dimension up to 5 mm. Due to their persistence, global spread across different ecosystems and potential human health effects, they have gained increasing attention during the last decade. However, the extent of human exposure to MP through different pathways and their intake have not been elucidated. | This work was supported by “la Caixa” Foundation [ID 100010434; code LCF/BQ/DI21/11860062]. We also acknowledge financial support from the Spanish Ministry of Science, Innovation and Universities (Excelencia Severo Ochoa, Project CEX2018-000794-S and Project PID2019-105732 GB-C21 from MCIN/AEI/https://10.13039/501100011033). | Peer reviewed

Land, water, and food resources are essential for human survival, economic development, and social stability. Water and land are the basic resources in irrigated agricultural systems. Sustainable agricultural development entails effective management of the land-water-food nexus. The complex relationship in land-water-food nexus, with large uncertainties encompassed therein. Approaches that interconnect Land-Water-Food have grown significantly in scope and intricacy. In evaluating solutions to accomplish Sustainable Development Goals (SDGs) under the contexts of rising demands, resource paucity, and climate change, nexus techniques are helpful. The nexus analysis includes the important interlinkages that could be addressed. In the water-food-land nexus system, optimization approach can increase irrigation water production and optimise the allocation of scarce resources. Model optimisation considers the uncertainties in the systems to help decision-makers devise effective strategies for allocating water and land resources effectively. Integrated modelling with efficient optimization methods aid in solving real-world nexus management issues and provides the results that could serve as the basis for effective management of land-water-food nexus and formulation of agricultural policies.

Over the past two centuries, Iranian agricultural policy and practice have been developed dramatically, mostly in response to population growth, gradual improvements in technology and science, several revolutions, one major war and recent international sanctions. Until the mid-20th Century, Iran was an agrarian society, barely distinguishable from other countries in the region. It then shifted to an industrial society supported by oil, with agriculture lagging, but since then, major agricultural policy shifts have occurred. First, a series of inappropriate national laws regarding land tenure converted large holdings into small pieces of low-yielding lands. Then, the Islamic Revolution occurred in 1978, followed by a subsequent eight-year war with Iraq, which shook the country's economy and left many farms devastated and abandoned. At that point, the food supply chain and provision were in chaos. The Government prioritised food self-sufficiency by heavily subsidising farm inputs and investment into water management, power plants and food processing plants. By the mid-2000s, despite the pressures of rapid population growth and severe drought conditions, the country became largely self-sufficient in major food crops. Government subsidies rose to unsustainable levels, and a large amount of food was being wasted throughout the food chain. In response, the Government removed subsidies from the food and energy sectors and in 2010 provided financial support for those on low incomes. Recent geopolitical disruptors have contributed further to an unstable food-energy-water nexus.

Finding a balance between the capacity for production and the rising demand for food is the first step toward achieving food security. To achieve sustainable development on a national scale, decision-makers must use an energy, water, and food nexus approach that considers the relationships and interactions among these three resources as well as the synergies and trade-offs that result from the way they are handled. Therefore, this paper evaluates the Energy&ndash:Water&ndash:Food Nexus Profile of Qatar at a superstructural level by applying the Business-As-Usual (BAU) storyline: thus, trends of past data have been used to provide future projections to 2050 using the statistical prediction tools such as the compound annual growth rates of food demand (CAGRFD), international supply (CAGRFI), and the average local food supply change factor (c&macr:). Once the BAU storyline has been generated, the source-to-demand correlations have been defined for each food category. Such correlations include the annual and average ratios of the local food supply to the total demand (i.e., &alpha:i and &alpha:&macr:) and the ratios of the local food supply to the international supply (i.e., &beta:i and &beta:&macr:). In addition, as an effort to identify the required action to reach food self-sustainability, the additional local food supply to achieve (xi,add) and its ratio to the local demand (&gamma:) have been defined. The highest average ratio of the local food supply to the total demand (&alpha:i) was found for the meat category, which was estimated to be 48.3%. Finally, to evaluate the feasibility of attaining food self-sustainability in Qatar, the water consumption (Vw,i) and its corresponding required energy for each food category have been estimated.