the common principles that might allow extrapolation and prediction of the
effects of toxicants on the environment.
Environmental toxicology diverges from traditional pharmacology or
toxicology. The traditional methods for testing rely on the use of standard
test organisms and laboratory methods to indicate relative toxicity of the
various compounds in question. Instead, ecotoxicology addresses a more
elaborate set of concerns. How are pollutants transformed after their release
into the environment? How are organisms exposed, and how do physiological
alterations impact on population dynamics and community structures? What
indirect impacts occur to unexposed organisms when their prey, predators,
or competitors are affected? How do the impacts of multiple compounds
differ from those of a single one? Such questions are beyond the domain of
one-organism, one-compound laboratory tests. Ultimately, ecotoxicological
impacts will be elucidated through a combination of long-term field
observations and use of assays and models.
The tools of the environmental toxicologist include biological assays, such
as for studying individual growth, mortality, reproduction, metabolic rate,
enzyme induction, etc. Field observations, including tissue concentrations of
toxicants, species number and density, and population dynamics, are crucial.
Field experiments, such as the containment of test organisms at contaminated
sites and environmental simulations (microcosms and mesocosms), aid in the
construction and testing of theories. Finally, data are often integrated into
theoretical models – mathematical predictions of bioaccumulation or of species
survival, for example. The goal of this test is to provide essential knowledge
concerning the biological responses of individual organisms to pollutants.
Direct toxicity to the organism is the fundamental route by which other effects,
such as the influence of altered prey populations on predators, are mediated.
With a thorough understanding of the nature of the major pollutants found in
the environment and their biological impacts, the environmental toxicologist
will hold the basic tools for research integrating other aspects of the field.
Environmental toxicology is a multidisciplinary science that encompasses
several diverse areas of study, such as biology, chemistry (organic, analytical,
and biochemistry), anatomy, genetics, physiology, microbiology, ecology, soil,
water, and atmospheric sciences, epidemiology, statistics, and law (Figure 1.3).
Compared with many other fields of study, environmental toxicology is a
relatively young branch of science. However, its importance as an area of study
has been widely recognized. Indeed, it is one of the most rapidly growing fields of
study. This is obvious based on the large number of papers and books published
in the past two to three decades that relate to environmental toxicology.
Similarly, courses of environmental toxicology and related subject areas are
being taught at a growing number of colleges and universities. Such a trend is not
limited to the U.S. and Canada alone. Rather, it is widespread globally.
The founding of the Society of Environmental Toxicology and Chemistry
(SETAC) is another example. This international society was launched in 1980,
and 85 people participated in the first meeting held in Washington, D.C. The
society’s membership has grown markedly during the past two decades,
Introduction
5
[16:55 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-001.3d]
Ref: 4365 MING-HO YU Chap-001 Page: 5 1-12
effects of toxicants on the environment.
Environmental toxicology diverges from traditional pharmacology or
toxicology. The traditional methods for testing rely on the use of standard
test organisms and laboratory methods to indicate relative toxicity of the
various compounds in question. Instead, ecotoxicology addresses a more
elaborate set of concerns. How are pollutants transformed after their release
into the environment? How are organisms exposed, and how do physiological
alterations impact on population dynamics and community structures? What
indirect impacts occur to unexposed organisms when their prey, predators,
or competitors are affected? How do the impacts of multiple compounds
differ from those of a single one? Such questions are beyond the domain of
one-organism, one-compound laboratory tests. Ultimately, ecotoxicological
impacts will be elucidated through a combination of long-term field
observations and use of assays and models.
The tools of the environmental toxicologist include biological assays, such
as for studying individual growth, mortality, reproduction, metabolic rate,
enzyme induction, etc. Field observations, including tissue concentrations of
toxicants, species number and density, and population dynamics, are crucial.
Field experiments, such as the containment of test organisms at contaminated
sites and environmental simulations (microcosms and mesocosms), aid in the
construction and testing of theories. Finally, data are often integrated into
theoretical models – mathematical predictions of bioaccumulation or of species
survival, for example. The goal of this test is to provide essential knowledge
concerning the biological responses of individual organisms to pollutants.
Direct toxicity to the organism is the fundamental route by which other effects,
such as the influence of altered prey populations on predators, are mediated.
With a thorough understanding of the nature of the major pollutants found in
the environment and their biological impacts, the environmental toxicologist
will hold the basic tools for research integrating other aspects of the field.
Environmental toxicology is a multidisciplinary science that encompasses
several diverse areas of study, such as biology, chemistry (organic, analytical,
and biochemistry), anatomy, genetics, physiology, microbiology, ecology, soil,
water, and atmospheric sciences, epidemiology, statistics, and law (Figure 1.3).
Compared with many other fields of study, environmental toxicology is a
relatively young branch of science. However, its importance as an area of study
has been widely recognized. Indeed, it is one of the most rapidly growing fields of
study. This is obvious based on the large number of papers and books published
in the past two to three decades that relate to environmental toxicology.
Similarly, courses of environmental toxicology and related subject areas are
being taught at a growing number of colleges and universities. Such a trend is not
limited to the U.S. and Canada alone. Rather, it is widespread globally.
The founding of the Society of Environmental Toxicology and Chemistry
(SETAC) is another example. This international society was launched in 1980,
and 85 people participated in the first meeting held in Washington, D.C. The
society’s membership has grown markedly during the past two decades,
Introduction
5
[16:55 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-001.3d]
Ref: 4365 MING-HO YU Chap-001 Page: 5 1-12