Warning: you might want to finish anything you are eating before you read the opening paragraph of this article. Spend a day walking around any major city in the world. London is a good example. Visit museums, grab a bite to eat, travel on the Tube. Do nothing out of the ordinary. Except, when you get back to your house or hotel at the end of the day, take a look at your fingernails. Most likely you will see a thick collection of dirt under each nail. Now grab a tissue and blow your nose. You might see the same ... Full Story

