<P> The SDC basic drinking water service is one in which a "round trip to collect water takes 30 minutes or less ." Only Australia, New Zealand, North America and Europe have almost achieved universal basic drinking water services . </P> <P> According to the World Health Organization, "access to safe drinking - water is essential to health, a basic human right and a component of effective policy for health protection ." </P> <P> The amount of drinking water required is variable . It depends on physical activity, age, health, and environmental conditions . In a temperate climate under normal conditions, adequate water intake is about 2.7 litres (95 imp fl oz; 91 US fl oz) for adult women and 3.7 litres (130 imp fl oz; 130 US fl oz) for adult men . Physical exercise and heat exposure cause loss of water and therefore may induce thirst and greater water intake . Physically active individuals in hot climates may have total daily water needs of 6 litres (210 imp fl oz; 200 US fl oz) or more . The European Food Safety Authority recommends 2.0 litres (70 imp fl oz; 68 US fl oz) per day for adult women and 2.5 litres (88 imp fl oz; 85 US fl oz) per day for adult men . </P> <P> In the United States, the reference daily intake (RDI) for total water is 3.7 litres per day (L / day) for human males older than 18, and 2.7 L / day for human females older than 18 which includes drinking water, water in beverages, and water contained in food . An individual's thirst provides a better guide for how much water they require rather than a specific, fixed quantity . Americans, on average, drink one litre of water a day and 95% drink less than three litres per day . </P>

Who has the lowest percentage of body water