Germs are everywhere, and for most readers, longtime science writer Bakalar's intriguing, solidly based safari through the world of germs will introduce striking discoveries and useful scientific thought processes. For those in the general population, the kitchen is probably the room with the greatest potential for trouble with germs; on the other, er, hand, toilet seats are generally among the home's cleanest locales — surely an encouragement to potential readers of this book and related literature. Although regular hand washing can kill off or slow down infections just about anywhere, Bakalar's scrutiny of other "wisdom" (mostly advertising and popular) yields more mixed assessments. Pet keeping, for instance, can improve the psychological outlook of young and old but also spread germs, because even adopting animals from pounds often requires the exchange of genuinely filthy lucre. Meanwhile, Bakalar's explorations in "cleaner than clean" grocery store aisles and of the bottled water proposed for healthful drinking illuminate the brightest pages of current financial media. A glossary helpfully translates widely used but often not as widely known acronyms and other terms.