sources of air pollution. The 1990 amendment of the act calls for a ‘‘program of
research, testing, and development of methods for sampling, measurement,
monitoring, analysis, and modeling of air pollutants.’’
Several Water Pollution Control Acts have been passed in the U.S. since
1948; however, the landmark legislation did not come until the 1972 Federal
Water Pollution Control Act was passed. The establishment of the act was in
response to the deep public concern about the environment being voiced in the
late 1960s. This act requires the determination of effluent limitations, i.e., limits
on the materials that can be discharged into waters from factories, sewage
treatment plants, and other point sources of pollution. In addition to water
monitoring, reduction and removal of aquatic pollutants were also included in
the act. Subsequently, the Safe Drinking Water Act was enacted in the U.S. in
1974. This was the first act intended to standardize the purity of water
throughout the U.S.
The Toxic Substance Control Act (TOSCA) (PL 94-469), passed in 1977,
called for regulation of ‘‘chemical substances and mixtures which present an
unreasonable risk of injury to health or the environment.’’ The act is unique
because it gave the EPA the power to insist that new chemicals be considered
guilty until proved innocent. The law recognizes two broad categories of
chemicals, old and new. The EPA was assigned to assess the risks associated
with the old chemicals, while the chemicals industry was to be responsible for
evaluating the health and environmental effects of the new ones. The result of
such legislation has been an intense effort to develop methods for evaluating
toxicity, predicting environmental impacts, monitoring effects, and mitigating
disasters.
1.4 IMPORTANCE OF ENVIRONMENTAL TOXICOLOGY
The field of environmental toxicology is consequently drawn in two
synchronous directions: regulation and research. Regulation ensures standardized testing that is fast and economical, with results that may be applied in a
general fashion. This has resulted in an emphasis on simplified scenarios, such
as the traditional mortality test that uses only one test species and one test
compound. Toxicological research, however, increasingly reveals the importance of complex interactions between individual organisms, species, physiological processes, environmental factors, and multiple anthropogenic chemical
substances.
A comprehensive approach is emerging in the form of ‘‘risk assessment,’’ as
defined by the EPA.
3 This approach incorporates scientifically derived
information with social and economic concerns, to appraise the potential
consequences of particular human-induced stressors on the environment. Risk
assessments often culminate in the development of a model for predicting longterm effects of a toxicant on environmental factors. However, such models may
not be transferable from one site to another as no two sites have identical
characteristics. The challenge of environmental toxicology now is to identify
4
Environmental Toxicology
[16:55 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-001.3d]
Ref: 4365 MING-HO YU Chap-001 Page: 4 1-12
research, testing, and development of methods for sampling, measurement,
monitoring, analysis, and modeling of air pollutants.’’
Several Water Pollution Control Acts have been passed in the U.S. since
1948; however, the landmark legislation did not come until the 1972 Federal
Water Pollution Control Act was passed. The establishment of the act was in
response to the deep public concern about the environment being voiced in the
late 1960s. This act requires the determination of effluent limitations, i.e., limits
on the materials that can be discharged into waters from factories, sewage
treatment plants, and other point sources of pollution. In addition to water
monitoring, reduction and removal of aquatic pollutants were also included in
the act. Subsequently, the Safe Drinking Water Act was enacted in the U.S. in
1974. This was the first act intended to standardize the purity of water
throughout the U.S.
The Toxic Substance Control Act (TOSCA) (PL 94-469), passed in 1977,
called for regulation of ‘‘chemical substances and mixtures which present an
unreasonable risk of injury to health or the environment.’’ The act is unique
because it gave the EPA the power to insist that new chemicals be considered
guilty until proved innocent. The law recognizes two broad categories of
chemicals, old and new. The EPA was assigned to assess the risks associated
with the old chemicals, while the chemicals industry was to be responsible for
evaluating the health and environmental effects of the new ones. The result of
such legislation has been an intense effort to develop methods for evaluating
toxicity, predicting environmental impacts, monitoring effects, and mitigating
disasters.
1.4 IMPORTANCE OF ENVIRONMENTAL TOXICOLOGY
The field of environmental toxicology is consequently drawn in two
synchronous directions: regulation and research. Regulation ensures standardized testing that is fast and economical, with results that may be applied in a
general fashion. This has resulted in an emphasis on simplified scenarios, such
as the traditional mortality test that uses only one test species and one test
compound. Toxicological research, however, increasingly reveals the importance of complex interactions between individual organisms, species, physiological processes, environmental factors, and multiple anthropogenic chemical
substances.
A comprehensive approach is emerging in the form of ‘‘risk assessment,’’ as
defined by the EPA.
3 This approach incorporates scientifically derived
information with social and economic concerns, to appraise the potential
consequences of particular human-induced stressors on the environment. Risk
assessments often culminate in the development of a model for predicting longterm effects of a toxicant on environmental factors. However, such models may
not be transferable from one site to another as no two sites have identical
characteristics. The challenge of environmental toxicology now is to identify
4
Environmental Toxicology
[16:55 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-001.3d]
Ref: 4365 MING-HO YU Chap-001 Page: 4 1-12