Chemical Warfare in Nature
Pesticides and other industrial chemicals are at the root of many pollution problems. In view of the toxic effects of industrial chemicals found in the water, soil, and air, Ecotoxicology: Effects of Pollutants on the Natural Environment considers the impact of chemicals on the environment from a wider perspective: the evolution of plant toxins—and defense mechanisms against them in animals as a consequence of plant–animal warfare. Comparisons are made between this and the development of resistance by insects towards man-made insecticides.
Pesticides and Drugs
The text focuses particularly on problems posed by pesticides and, to a lesser extent, by drugs. This material specifically addresses the problems that pesticides pose and explores the development of resistance to them. It focuses on the history of pesticides, pesticide selectivity between target species and beneficial organisms, and types of pesticides. It discusses mandatory ecotoxicity testing as part of the process of risk assessment of environmental chemicals. The text considers the effects of pollutants at the population level, with respect to changes in numbers and genetic composition. It factors in the sublethal effects of pollutants on population levels, and cites an increase in the concentration of persistent pollutants in natural food chains as a cause of the decline of certain vertebrate predators.
Overall the text:
• Considers plant toxins as models for pesticides
• Emphasizes principles illustrated with practical examples
• Includes a glossary of terms
Divided into three sections, this text uses a variety of examples and case studies to examine the effects of pollutants—including naturally occurring ones—on natural processes. It guides the reader through the basic issues and principles; outlines the science of ecotoxicology, which is the study of the effects of chemicals upon ecosystems; and introduces various strategies for pollution control.
Table of Contents:
Section I Basic Issues
Toxicology and EcotoxicologySome Definitions
The Discipline of Ecotoxicology
Selective Toxicity
Summary
Further Reading
EcotoxicityIntroduction
What Determines Ecotoxicity?
Pesticides and Other Biocides
Industrial Chemicals Other Than Pesticides
Protocols for Ecotoxicity Testing
Determination of Median Lethal Dose and Median Lethal
Concentration
Ecotoxicity Testing That Uses Sublethal Endpoints
Bioassays for Measuring Toxicity
Model Ecosystems
Ethical Issues
Summary
Further Reading
A History of Chemical WarfareAn Evolutionary Perspective
Plant Toxins as Pesticides
The Coevolutionary "Arms Race"
Plant Toxins as Models for Pesticides
Chemical Weapons and Predation
Chemical Weapons of Attack and Defense
Microbial Toxins
Ecotoxicology against the Background of Chemical Warfare in Nature
Summary
Further Reading
Toxic Effects at Different Organizational LevelsSequential Effects of Pollutants
Effects upon the Individual Organism
Effects at the Population Level
Effects upon Population Genetics
Communities and Ecosystems
Effects upon Structure and Function of Communities and Ecosystems
Monitoring Changes in the Composition of Communities
Field Trials
Summary
Further Reading
The Development of ResistanceIntroduction
Population Genetics and Evolutionary Theory
Pollutants as Stress Factors
Mechanisms of Resistance
Cross-Resistance
Overcoming Problems of Pesticide Resistance
The Evolution of Metal Tolerance in Plants
Resistance as an Indicator of Pollution
Summary
Further reading
Pesticides and Their DesignIntroduction
Early History of Pesticides
The Importance of Selectivity
Types of Pesticides
Ways of Using Pesticides
Objectives in the Design of New Pesticides
Mass Screening
Modeling of New Pesticides Based upon the Structures of Sites of Action
Summary
Further Reading
Natural Pollutants and Natural CyclesIntroduction
Eutrophication
Acid Rain
Radiation and Radioisotopes
Oil Pollution
Greenhouse Gases and Global Warming
The Ozone Layer
Global Processes and the Gaia Theory
Summary
Further Reading
Section II Examples of PollutantsEarly Problems Connected with Urbanization and MiningIntroduction
Detergents in Surface Waters
Air Pollution
Mines and Smelting
Summary
Further Reading
The Organochlorine InsecticidesIntroduction
DDT and Related Pesticides
The Environmental Fate of p,p’-DDT and Related Compounds
The Cyclodiene Insecticides
The Environmental Fate of Cyclodienes
Effects of DDT and Cyclodienes on Birds of Prey
Decline of Predatory Birds Related to Eggshell Thinning Caused by p,p’-DDE
Other Effects of Organochlorines
Resistance to Organochlorine Insecticides
More Ecofriendly Cyclodienes
Summary
Further Reading
Organophosphorous and Carbamate InsecticidesIntroduction
Mode of Action of Anticholinesterases
The Organophosphorous Insecticides
Some Examples of Organophosphorous Insecticides
Toxic Effects of OPs
Effects of OPs in the Natural Environment
Resistance to OPs
Carbamate Insecticides
Toxicity of Carbamates in the Field
Longer-Term Effects on Soil Microorganisms
Summary
Further Reading
Organometallic CompoundsIntroduction
Tributyl Tin Compounds
Organomercury Compounds
The Biomagnification of Methylmercury
Poisoning of Predatory Birds in the Field
Methylmercury Levels in Piscivorous Vertebrates in North America
Organolead Compounds
Organoarsenic Compounds
Summary
Further reading
Pyrethroid and Neonicotinoid InsecticidesIntroduction
The Synthetic Pyrethroids
Environmental Fate and Concerns
The Development of Resistance to Pyrethroids
The Neonicotinoids
Development of Resistance to Neonicotinoids
Potentiation of the Toxicity of Pyrethroids and Neonicotinoids
Effects of Pyrethroids and Neonicotinoids on Honeybees
Summary
Further Reading
PCBs and DioxinsIntroduction
The Polychlorinated Biphenyls (PCBs)
Early Pollution Incidents Involving PCBs
The Dioxins
The Combined Toxicity of PCBs and Dioxins
Summary
Further Reading
HerbicidesIntroduction
The Impact of Herbicides on Agricultural Ecosystems
The Aerial Movement of Herbicides
Contamination of Surface Waters with Herbicides
Herbicides That Have Significant Toxicity toward Animals
Summary
Further Reading
Endocrine DisruptorsIntroduction
The Feminization of Fish Caused by Estrogens
Endocrine Disruption Involving the Ah Receptor
Disturbances of the Metabolism of Steroid Hormones by Pollutants
The Diversity of Endocrine-Disrupting Chemicals (EDCs) in the Environment
Summary
Further Reading
Anticoagulant RodenticidesIntroduction
Mode of Action of the Anticoagulant Rodenticides (ARs)
Secondary Poisoning of Predators and Scavengers
Resistance to Anticoagulant Rodenticides
Summary
Further Reading
Section III Further IssuesPollution Problems WorldwideIntroduction
International Approaches to Pollution Problems
Developed and Developing Countries
Aerial Application of Pesticides
Plastics
Nanoparticles
Summary
Further Reading
Risk Assessment and LegislationIntroduction
Risk Assessment of Chemicals
Statutory Requirements for Risk Assessment of Environmental Chemicals
The REACH Proposals of the European Union
Ethical Issues
Summary
Further reading
Current Issues and Future ProspectsIntroduction
Diclofenac and Vultures
The Large-Scale Decline of Bees and Other Pollinators
Marine Pollution by Polyisobutene (PIB)
Effects of Mixtures of Environmental Chemicals
The Design of More Ecofriendly Pesticides and Biocides
Improved Methods of Ecotoxicity Testing
Improvements in Procedures for Statutory Risk Assessment of Environmental Chemicals
Summary
Further Reading
Glossary
References
Index
About the Author :
Colin Walker originally qualified as an agricultural chemist. He was responsible for chemical and biochemical studies of environmental pollutants at the Monk’s Wood Experimental Station during the mid-1960s when certain effects of organochlorine insecticides were established. This work led to restrictions on the use of cyclodienes and DDT. He subsequently joined the University of Reading where he taught and conducted research on the molecular basis of toxicity with particular reference to ecotoxicology. Now retired, he is currently affiliated with the Department of Biosciences at the University of Exeter where he contributes to the teaching of a course in ecotoxicology.
