Water use has been growing at more than twice the rate of population increase in the last century. Though there's enough water on Earth but that is not enough for the world; only 2.5 percent of it is fresh, and out of which two-third is snow and ice. According to one estimate, only 8 percent of the planet's fresh water supply goes to domestic use and about 70 percent is used for irrigation and 22 percent in industry. Over a billion people lack access to clean drinking water, and over 2 billion live without adequate sanitation, leading to the deaths of 5 million people, mostly children, each year from preventable waterborne disease. There is thus urgent need to tackle the ‘water risks’, and that include droughts and insufficient rainfall, floods and contamination. We need integrated water resource management that takes into account who needs what kind of water, as well as where and how to use it most efficiently.
Waterborne infectious diseases are major health risks. Microbial risk assessment (MRA) addresses questions like which water treatment option is best for preventing illness and death. What are the most dangerous pathogens found in water? How did they get there? How do we set standards for water quality? Who are the most sensitive members of the population, and how can we protect them? What should we do for the optimal utilization of the resources to prevent waterborne diseases? MRA is an evolving procedure. It allows evaluation of even delayed risks. There are still gaps in the understanding of human exposure to pathogens in water. Interpretations of analytical methods for specific pathogens or “marker” pathogens are necessary to provide a robust capability in this area. Researchers are working on the development of rapid, inexpensive, and easy to use methods to resolve clean water crisis.