Many U.S. citizens believe that thanks to our advanced technology and enlightened public policy we can consume without risk the food and water that are readily available to most of us, as citizens of a rich and privileged country. Some of those who subscribe to this buoyant and comforting attitude, however, may have lately experienced second thoughts. Because of various recent and widely reported incidents, many people are feeling concern about the quality and safety of our food and water. This is not surprising; some of these incidents have resulted in serious, widespread sickness, even death.