Climate change is reshaping global hydrological cycles, intensifying scarcity and heightening health risks in vulnerable regions. This study examines the health impacts of climate-driven water scarcity across the Middle East, South Asia, and Sub-Saharan Africa using data on water availability, climate variability, and health outcomes. The study uses a multi-regional mixed methods approach that brings together climate, hydrology, governance, and health data to explore how climate-driven water scarcity affects public health in South Asia, Sub-Saharan Africa, and the MENA region. It combines quantitative climate and health indicators with qualitative evaluations of water system vulnerability to compare exposure pathways and health outcomes across regions. Findings show that rising temperatures, altered rainfall, declining groundwater, and recurrent droughts undermine water security, leading to increased disease burdens through four pathways: (1) waterborne illnesses from unsafe or insufficient supplies; (2) reduced hygiene due to limited access; (3) food insecurity from crop failures; and (4) mental health stress, conflict, and displacement from water competition. Women, children, and low-income households face disproportionate impacts. Current adaptation measures are fragmented, highlighting the need for integrated water governance to build climate resilience. Recommended strategies include community-based water safety planning, digital water monitoring, and embedding health metrics in climate–water policies. This cross-regional analysis supports equitable, climate-resilient health systems and informs interventions to mitigate water scarcity under accelerating climate change. This study directly supports global policy agendas by providing evidence that advances the objectives of the Sustainable Development Goals and international frameworks on climate resilience, water security, and food and health protection.

Remote and resource-constrained regions experience a disproportionate burden of waterborne diseases due to inadequate water quality monitoring, limited laboratory capacity, and delayed risk detection. Emerging digital and community level water monitoring methods are helping strengthen surveillance, improve early warning systems, and reduce exposure to unsafe water.

Rapid urbanization in sub-Saharan Africa (SSA) is placing increasing pressure on waste management systems and urban air quality, with significant health implications. This study integrates cross-city analysis of waste systems, air quality, and health burdens in rapidly urbanizing SSA. It examines the links between waste practices, pollution, and health outcomes in fast-growing SSA cities using international and national data sources. Inadequate collection, open dumping and burning, and poorly regulated landfills elevate pollutant concentrations, particularly PM_2.5, frequently exceeding World Health Organization guidelines. Resulting exposures are associated with respiratory and cardiovascular diseases, childhood infections, and premature mortality, disproportionately affecting low-income settlements. These inequities reflect deficits in governance and infrastructure. The study highlights the cumulative health burden of urbanization and calls for strengthened waste systems, reduced open burning, improved monitoring, and integration of health considerations into urban planning to support sustainable African cities. A comparative analysis of waste management, air quality, and related health impacts is conducted across four rapidly urbanizing SSA cities.

Water quality management is a growing global priority due to increasing pressures from climate change, population growth, urbanisation, industrialisation, agricultural intensification, and emerging contaminants. These challenges threaten freshwater ecosystems, public health, economic development, and progress towards Sustainable Development Goal 6 (SDG 6). This critical review employed a PRISMA-guided systematic literature review to evaluate future directions in water quality management from sustainability, resilience, and social equity perspectives. A total of 11,485 records were identified, with 3632 duplicates removed. Following the screening of 7853 records and assessment of 1441 full-text articles, 117 studies met the inclusion criteria for qualitative synthesis. Geographical analysis showed that 88 studies (75.2%) adopted a global perspective encompassing both developed and developing countries, while 24 studies (20.5%) focused on developing countries and 5 studies (4.3%) on developed countries. The review identified notable progress in water quality monitoring, wastewater treatment, pollution control, and integrated water resources management. Emerging technologies such as smart monitoring systems, artificial intelligence, advanced treatment processes, and resource recovery approaches were consistently highlighted as promising tools for improving water quality and enhancing adaptive capacity. Despite these advances, significant barriers remain, including fragmented governance systems, climate-related risks, emerging contaminants, and persistent inequalities in access to safe water resources. The findings underscore the importance of integrating sustainability, resilience, and social equity within water governance frameworks. Achieving long-term water security will require coordinated and transformative approaches that strengthen links between science, policy, and practice while promoting inclusive, resilient, and sustainable water management.