**2.4.5 Water as a fluid of choice**

Only air is more crucial for life than water. Access to safe drinking water is a basic human right, as well as a condition for achieving and sustaining optimal health (WHO, 2011e).

However, contaminated water is a great health risk. Inorganic arsenic from drinking water is a proven risk for lung cancer and there is limited evidence that it is also a risk factor for kidney and bladder cancer (WCRF & AICR, 2007).

Safe drinking water is a nutrient *per se*. Because it plays many important roles in the human body, water is the fluid of choice as a part of healthy lifestyle. There has been a steady growth in the sales of bottled water (6.1% in 2007) (Zenith International, 2008) which is an encouraging fact in accordance with today΄s active and healthy lifestyle.

Daily requirements for water depend on age, gender, pregnancy, lactation, physical activity level, diet and external conditions (Smolin & Grosvenor, 2010; ILSI, 2004).
