It is the thesis of this book that, everyday, at virtually every meal, Americans are ingesting known poisons and untested chemicals and that the food and drug laws are designed to protect commercial interests first and the consumer afterward. William Longgood, who is the author of The Suez Story -- Key to the Middle East, musters documentation from both medical and popular sources in his attack on the argument advanced by industrial chemists -- that because additives and preservatives of a toxic nature are consumed in small quantities they are harmless. In his attempt to demonstrate that the American public is both overfed and undernourished he deals with: the general state of the nation's health and questions whether the reduced death rate is an indication of superior health; the pesticides -- the main source of poisonous DDT which, he says, is potentially more dangerous than radioactive fallout; the prevalence of carcinogins -- cancer causing substances that appear regularly in the nation's diet; the use of emulsifiers which have made it possible to replace natural ingredients of high nutritional value -- fats, oils, eggs and milk -- in baked goods; and the nutritionalist's perennial target -- synthetically enriched but impoverished white bread. What can the public do about it? Individually, not very much, it seems, except for buying foods more intelligently --restraint in the use of frozen or ready mixed foods, less fatty meats, more natural-grown foods. But Longgood does advocate that testing procedures be made more stringent and that the problem be dealt with by an agency independent of the pressures of industry and government. This is not a book to be dismissed as the carping of a food fadist and the cranberry scare has already focused general attention on the subject.