Fundamentals of Ecotoxicology. 2nd ed. Michael C. Newman and Michael A. Unger. Lewis Publishers, Boca Raton, FL, 2003. 458 pp., illus. $59.95 (ISBN 1566705983 cloth).
Michael Newman, a professor at the Virginia Institute of Marine Sciences at the College of William and Mary, has revised his previous edition of this book with the assistance of his colleague Michael Unger, a research associate professor at the same institution. Like the first edition, this is a readable, comprehensive text for graduate students and for advanced undergraduates who have the requisite chemical and biological background. It is also a good general reference. The authors take an all-encompassing approach to the topic of ecotoxicology, covering all levels of biological organization from the molecular level to the global. The definition of the field, as used in this book, includes molecular and cellular studies, though some would argue that ecotoxicology ought to have an ecological focus. (The term has certainly been misused in some places—I have seen collections of articles that focused almost entirely on subcellular effects, but were defined as “ecotoxicology” research because they dealt with fish rather than humans or their rodent surrogates.) Human health considerations, while a secondary consideration, also appear in this book, interwoven with the ecological effects of toxic chemicals.
There are 15 chapters, each with suggested additional readings. A number of people besides the authors have contributed to this volume. All the chapters and some chapter subheadings are introduced with appropriate quotations, sometimes from ecotoxicologists, but also from noted people from other areas of life, including Thoreau, Teasdale, Ibsen, and Descartes. Each chapter contains vignettes written by experts in the particular field under discussion, which give more details and explanations of the topics.
The introduction offers background on the historical incidents spurring the development of this relatively new integrative science: the Minamata mercury tragedy in Japan, DDT in wildlife, oil spills, hazardous wastes, acid rain, and more. It includes a vignette by John Cairns, a father of the field, discussing the emergence and future of ecotoxicology. Cairns encourages a broad view, advocating a multidimensional research strategy that emphasizes ecosystem complexity, dynamics, resilience, and interconnectedness, and he decries the role of funding for “contract” research of limited scope, which hinders the development of visionary long-term projects.
The chapter that follows the introduction covers the different classes of inorganic and organic environmental contaminants of concern (including nutrients) and their chemistry, sources, fates, and cycling in the terrestrial, freshwater, and marine ecosystems. I was glad to see coverage of nutrients and eutrophication issues, which are often omitted in this kind of book because they are not “toxic chemicals.” The text also covers radionuclides, which also are frequently left out of books on environmental toxicology.
The next several chapters discuss bioaccumulation. These chapters cover uptake, transformation, and elimination (the processes responsible for bioaccumulation) and include kinetics and models of contaminant accumulation. A chapter on bioavailability includes the characteristics of a chemical, an organism, and its environment that can affect the chemical's bioavailability. The last of the chapters on bioaccumulation deals with the transfer of contaminants in the food chain. The vignette in this chapter, by Bryan and Jagoe, gives an in-depth treatment of the dietary exposure of fish-eating birds to mercury. This sequence of chapters is appropriate and logical.
The chapters on bioaccumulation are followed by several others on toxicant effects at different levels of biological organization, from the molecular level to cellular, organismal, population, community, ecosystem, landscape, and global levels. Overall, plants are not given enough space in these chapters, despite the fair amount of research that has been done on them and despite their obvious importance in the biosphere.
The molecular chapter covers topics such as detoxification pathways, metallothioneins, stress proteins, DNA damage, and enzyme dysfunction; Roesijadi, one of the foremost experts on metallothioneins, contributes a very informative vignette.
The chapter on cells, tissues, and organs covers histopathology, damage to chromosomes, and carcinogenesis and shows how these effects link to effects at higher levels of organization. A vignette by McBee covers the topic of chromosome damage in greater detail, while one by Vogelbein deals with liver carcinogenesis in fish—these two authors are leading researchers in their respective fields.
The chapter on sublethal toxic effects on individual organisms deals with growth, development, reproduction, physiology, and behavior. The vignette by Schultz on environmental estrogens gives insight into why the field of endocrine disruption is such a hot topic these days. I particularly liked the vignette by Sandheinrich on behavior, which is a sensitive indicator and a type of effect that clearly links to higher (population and community) and lower (biochemical and cellu lar) levels of organization.
The chapter on acute and chronic toxic effects on individuals (lethality) covers the various types of toxicity tests and models that are still in use for most regulatory purposes. These tests, which are relatively inexpensive and easy to perform, are the basis for numerical water quality criteria under the Clean Water Act. They are also used extensively in ecological risk assessment procedures. The regulatory side of the field has a lot of catching up to do to be in synchrony with the state of the science, which started out with a “kill 'em and count 'em” approach that sadly still prevails in the regulatory realm. There is considerable doubt about the applicability of such short-term lethal toxicity tests, performed on selected standard species, to environmental impacts in the real world.
The next chapter covers the effects of toxicity on populations, demographic approaches, and epidemiology. These topics, which are clearly relevant to organisms in the field, put the “eco” into “ecotoxicology.” The chapter's introductory quote from Barnthouse and colleagues says it clearly: “There is an enormous disparity between the types of data available for assessment and the types of responses of ultimate interest. The toxicological data usually have been obtained from short-term toxicity tests performed using standard protocols and test species. In contrast, the effects of concern to ecologists performing assessments are those of long-term exposures on the persistence, abundance, and/or production of populations” (p. 203). This chapter also covers changes to population genetic structure involving the acquisition (evolution) of tolerance to contaminants, and it includes a vignette by Grant on industrial melanism.
The chapter on community- and ecosystem-level effects of toxicity deals with the types of interactions between and among species that may be affected by contaminants (e.g., predator–prey interactions, competition), with measures of changes in communities, with study designs such as micro- and mesocosms, and with the use of community indices (species richness, evenness, and diversity) for field assessments. The vignette by Karr on indices of biological integrity is informative and interesting.
The chapter on effects at the landscape to global levels includes the topics of acid rain, ozone depletion by chlorofluorocarbons, global transport of persistent organic pollutants, and global warming. This fairly short chapter could have been developed further—the issues it covers have great importance because they are global in nature.
The chapters on risk assessment focus on the basic frameworks for human and ecological risk assessment and include a vignette from Suter, a leading expert in the field.
After a concluding chapter, there are study questions for each chapter and a number of other appendices, including regulatory aspects of the field. There are brief descriptions of US and European laws and regulations dealing with toxic substances. Only one paragraph is devoted to each major US law: the National Environmental Policy Act; the Clean Air Act; the Clean Water Act; the Safe Drinking Water Act; the Federal Insecticide, Fungicide, and Rodenticide Act; the Toxic Substances Control Act; the Marine Protection Research and Sanctuaries Act; the Resource Conservation and Recovery Act; and the Comprehensive Environmental Response, Compensation, and Liability Act (or Superfund). I would have liked to have seen a bit more description of these laws and of how toxicity tests or risk assessments are used in the regulations associated with them, because in many ways they have driven the development of the field of environmental toxicology. One might argue that without these laws and the funding derived from them, the science in this field might have become more sophisticated more rapidly. Since we are still saddled with LC50 tests, scientists who might otherwise be involved in advancing our knowledge of sublethal effects, mechanisms, or the big picture of long-term ecological effects are involved in these less intellectually challenging efforts. Another appendix contains equations for the estimation of contaminant exposure. There are abundant references, a long glossary, footnotes, and illustrations.
Fundamentals of Ecotoxicology provides a broad overview of the field and, like its predecessor, should be of great use to both students and practitioners. The vignettes are a clever and enjoyable addition to a well-written and well-organized presentation of a complex field. A quibble, however: The vignettes are printed in somewhat smaller type than the rest of the chapters and might be skipped over by some readers. This would be most unfortunate, because they are major assets of this new edition.
