One Smart Book About Number Two

It may not be fodder for dinner discussion. Or book clubs. Or, come to think of it, polite conversation of any kind. But journalist Rose George, author of "The Big Necessity: The Unmentionable World of Human Waste and Why It Matters," was undaunted, delving deep into the history and implications of a daily act that dare not speak its name. Warning: what follows is, in a word, gross.

The idea: The poop paradox, George writes, is that "it can be both food and poison. It can contaminate and cultivate." Fecal matter plays a role in 80 percent of illnesses worldwide, but it can also be used as an energy resource, fertilizer—even medicine.

The evidence:Martin Luther reportedly ate a spoonful of his own waste daily, and ladies of the French court used a powdered version as snuff. Today excrement helps power 15.4 million homes in China, where it also increases crop yields by an estimated 50 to 60 percent. But harnessing the power of waste takes infrastructure—something lacking for the 2.6 billion people without toilets.

The conclusion: Potty humor may make you giggle, but world sanitation standards should make you cringe. We can put our waste to work for us, but not until we get over the taboo of discussing it.

© 2008