By Jim Lauria
World Water Day both celebrates clean water and reminds us that 2 billion people live without access to it. Safe drinking water is one of the most fundamental elements of health—healthy water keeps people healthy; sick water makes people sick.
Though we have come to understand a lot more about the biology and chemistry that link health and water, even our early ancestors sensed the connection—as Marq De Villiers notes, one of the signs of the Apocalypse in ancient writings is "the bitterness of waters." Taking the metaphor into the very availability of water, Robin Clarke and Jannet King wrote in The Water Atlas, "Thus do the four horses of the Apocalypse—war, famine, pestilence and death—gallop even faster in times of water shortage."