Climate variability is heavily impacting human health all around the globe, in particular, on residents of developing countries. Impacts on surface water and groundwater resources and water-related illnesses are increasing, especially under changing climate scenarios such as diversity in rainfall patterns, increasing temperature, flash floods, severe droughts, heatwaves and heavy precipitation. Emerging water-related diseases such as dengue fever and chikungunya are reappearing and impacting on the life of the deprived; as such, the provision of safe water and health care is in great demand in developing countries to combat the spread of infectious diseases. Government, academia and private water bodies are conducting water quality surveys and providing health care facilities, but there is still a need to improve the present strategies concerning water treatment and management, as well as governance. In this review paper, climate change pattern and risks associated with water-related diseases in developing countries, with particular focus on Pakistan, and novel methods for controlling both waterborne and water-related diseases are discussed. This study is important for public health care, particularly in developing countries, for policy makers, and researchers working in the area of climate change, water quality and risk assessment.

The impact of heavy metal toxicity on the shoot and root lengths, total protein, fiber characteristics, moisture content and nutrient composition of spinach (Spinacia oleracea) was evaluated. Plants were grown in pots containing soil and treated with different concentrations (mg/kg) of lead (Pb; 300, 400 and 500), cadmium (Cd; 0.5, 1 and 1.5) and zinc (Zn; 250, 500, and 700) as well as mixtures of Cd and Pb (0.5/300, 1/400, 1.5/500), Cd and Zn (0.5/250, 1/500, 1.5/700), and Pb and Zn (300/250, 400/500, 500/700). Soil contaminated by long-term irrigation with wastewater containing heavy metals was simulated. An increase in concentrations of heavy metals both individually and as mixtures significantly (p < 0.05) reduced the growth parameters and nutrient contents of S. oleracea. The uptake patterns of heavy metals in mixtures showed antagonistic impacts on each other. The toxicities of the mixtures Cd and Pb, Cd and Zn as well as Pb and Zn were higher than those observed in separate heavy metal applications but less than their additive sums. The toxicity caused by individual heavy metals was the highest for Cd followed by Pb and Zn. The highest toxicity was observed in plants grown in soil contaminated by Cd and Pb.

Water-related impacts due to change in climatic conditions ranging from water scarcity to intense floods and storms are increasing in developing countries like Pakistan. Water quality and waterborne diseases like hepatitis, cholera, typhoid, malaria and dengue fever are increasing due to chaotic urbanization, industrialization, poor hygienic conditions, and inappropriate water management. The morbidity rate is high due to lack of health care facilities, especially in developing countries. Organizations linked to the Government of Pakistan (e.g., Ministry of Environment, Ministry of Climate Change, Planning and Development, Ministry of Forest, Irrigation and Public Health, Pakistan Meteorological Department, National Disaster Management, Pakistan Agricultural Research Centre, Pakistan Council for Research in Water Resources, and Global Change Impact Study Centre), United Nation organizations, provincial government departments, non-governmental organizations (e.g., Global Facility and Disaster Reduction), research centers linked to universities, and international organizations (International Institute for Sustainable Development, Food and Agriculture, Global Climate Fund and World Bank) are trying to reduce the water-related impacts of climate change, but due to lack of public awareness and health care infrastructure, the death rate is steadily increasing. This paper critically reviews the scientific studies and reports both at national and at international level benefiting generalists concerned with environmental and public health challenges. The article underlines the urgent need for water conservation, risk management, and the development of mitigation measures to cope with the water-related impacts of climate change on agriculture and subsequently on public health. Novel solutions and bioremediation methods have been presented to control environmental pollution and to promote awareness among the scientific community. The focus is on diverse strategies to handle the forthcoming challenges associated with water resources management.

Nanotechnology has a wide range of applications. This makes it a very important technology of the future. Its application in water and wastewater purification is of great interest not only in developing countries but also in the developed countries. The application of nanometals (silver and gold) and nanomembranes can help in developing of water treatment technologies which can be used for solving water-related problems such as waterborne pathogens, biofouling, removal of toxic metals (lead, arsenic, and chromium), etc. Moreover, nanotechnology can also be used to increase the efficiency of water filters. In this paper, we review the emerging nanotechnology-based methods for water purification, the potential applications of nanotechnology in the form of nanosensors, nanomembranes, nanometallic particles, and photocatalysis for water purification, nanosensors for detection of contaminants in water, novel magnetic nanoparticles for water desalination, and finally we present the possible risks associated with the use of this technology.

Climate variability is highly impacting on mosquito-borne diseases causing malaria and dengue fever across the globe. Seasonal variability change in temperature and rainfall patterns are impacting on human health. Mosquitoes cause diseases like dengue fever, yellow fever, malaria, Chikungunya, West Nile and Japanese encephalitis. According to estimations by health organizations, annually one million human deaths are caused by vector-borne diseases, and dengue fever has increased about 30-fold over the past 50 years. Similarly, over 200 million cases of malaria are being reported annually. Mosquito-borne diseases are sensitive to temperature, humidity and seasonal variability. Both conventional (environmental, chemical, mechanical, biological etc.) and nanotechnology-based (Liposomes, nano-suspensions and polymer-based nanoparticles) approaches are used for the eradication of Malaria and dengue fever. Now green approaches are used to eradicate mosquitoes to save human health without harming the environment. In this review, the impact of climatic conditions on mosquito-borne diseases along with conventional and nanotechnology-based approaches used for controlling malaria and dengue fever have been discussed. Important recommendations have been made for people to stay healthy.