A Global Health Problem
Every human being needs to consume water to survive, but 768 million people worldwide lack access to safe drinking water (WHO & UNICEF, 2013). That's more than 10% of the world's population.
Unsafe drinking water is a major cause of diarrheal diseases (WHO, 2008). The diseases kill as many as 1.8 million people per year, most of whom are young children in developing countries (WHO, 2013).
Some people in low-income countries use point-of-use water-treatment methods, but these pose health risks. Boiling, the most popular, not only exacerbates the problems of fuel overuse, but also poses indoor air quality problems and other health risks (UNICEF & WHO 2011).
Affecting the Rural & the Poor
83% of the people who lack access to safe drinking water live in rural areas (WHO & UNICEF, 2013).
Among all the people who have gained access to safe drinking water since 1990, two thirds live in urban areas (WHO & UNICEF, 2013).
Moreover, while less than 4% of urban dwellers use unsafe drinking-water sources, 19% of people in rural areas face the problem (WHO & UNICEF, 2013).
Large disparities exist between rich and poor countries. Almost everyone in the top 25% of countries in the world has access to clean drinking water, but more than one third of people in the bottom 25% of countries lack such access (WHO, 2013).
This means that in order to effectively fix the problem, a solution that is appropriate for under-resourced settings is needed.
Deadly to Children
In 2011, unsafe drinking water killed about 760,000 of children under the age of five – a number equivalent to 90 school buses filled with kindergartners crashing with no survivors, every day for a year (UNICEF, 2013).
Expanding and Erratic
Climate change and the resulting increasingly erratic weather make more people susceptible to losing access to clean drinking water. Extreme droughts and floods often paralyze water-treatment facilities in rural communities, forcing people to resort to unsafe drinking-water sources.
An effective solution to the unsafe-drinking-water problem has to be able to adapt to the changing weather conditions.