"The third edition of a bestseller, this book describes how chemical toxins and biological hazards impact the environment and people. Addressing how pollutants can alter the environment by contributing to global climate change, the author explores a broad range of environmental and health aspects of chemical and biological hazards. He includes numerous examples of the intimate relationship between ecosystem health and human health and emphasizes the need to consider this relationship whenever human activities are likely to have a significant environmental impact"-- Provided by publisher.

"1 1 Principles of Pharmacology and Toxicology The right dose differentiates a poison and a remedy. Paracelsus, 1493-1541 Introduction The past century has seen a tremendous expansion in the number of synthetic chemicals employed by humankind as materials, drugs, preservatives for foods and other products, pesticides, cleaning agents, and even weapons of war. The American Chemical Society maintains a chemical registry. Since 1907 it has recorded 33 million organic and inorganic substances and 58 million sequences as of 2008. About 4000 new chemicals are added each day. A study by the Danish Environmental Protection Agency calculated that 13.4% of them possess acute toxicity, 2.5% reproductive toxicity, 3.9% are mutagens, 1.8% carcinogens, and 3.5% are dangerous to the aquatic environment. Four thousand chemicals are used as medicinals and at least 1200 more as household products. Add to this the numerous natural substances, both inorganic and organic, that possess toxic potential, and it is little wonder that the public expresses concern and even, sometimes, panic about the harmful effects these agents may exert on their health and on the environment. Tens of thousands of these agents have never been subjected to a thorough toxicity testing. According to the Danish study, thousands of chemicals are potential carcinogens but the number that has been confirmed to be human carcinogens is much smaller. About 500 chemicals have been evaluated for carcinogenic potential. Some 44 have been designated as possible human carcinogens on the basis of evidence, either limited or conclusive, obtained from human studies. "-- Provided by publisher.