Introduction

This chapter highlights widely held public opinions that raise an understandable concern about ubiquitous chemical threats in our foods, water, ambient air, or the environment. Although the theme is topical, the information is often incomplete and unbalanced because the real risks are not always discussed. We are exposed to many different chemicals each day, but to gauge the human health risk, a quantitative assessment must be made, as opposed to just pointing out the hazard of a chemical. This chapter also briefly introduces the different sections of this book.