Water Water everywhere

With growing concern about future water shortage and the increasing world population, in 2007 the world population is estimated to reach 6.5 billion. This plus the claim that the average human body contains enough water to fill a ten gallon tank makes a lot of water walking on the planet.

"The average human body contains enough: iron to make a 3 inch nail, sulfur to kill all fleas on an average dog, carbon to make 900 pencils, potassium to fire a toy cannon, fat to make 7 bars of soap, phosphorous to make 2,200 match heads, and water to fill a ten-gallon tank.The average human produces 25,000 quarts of spit in a lifetime, enough to fill two swimming pools.

The average person releases nearly a pint of intestinal gas by flatulence every day. Most is due to swallowed air. The rest is from fermentation of undigested food."

"The world's population has reached 6.5 billion this year, a billion more than 1993, despite low fertility in developed countries and high mortality in developing countries, a new United Nations report says. It estimates that the world's population could reach 7 billion in 2012 and could stabilize at 9 billion in 2050. The rate of growth has fallen, however, to 1.2 per cent now from 2 per cent in the late 1960s."

I wonder how much longer it takes for a body to decompose due to the preservatives and chemicals added to food?
Perhaps we could compare 1960 with today.