Short-Term Bioassays in the Analysis of Complex Environmental Mixtures III


Book Description

In the four years since the 1978 Symposium on the Application of Short-Term Bioassays in the Fractionation and Analysis of Complex Environmental Mixtures the use of short-term bioassays to evaluate potential health hazards of complex environmental mixtures has substantially increased. Increased research activity has been particularly noticeable in mobile source emissions, where initial observations on the mutagenic activity of diesel particulate extracts reported at the 1978 symposium stimulated the development of major research programs in government and industry. In the absence of appropriate reference materials, the U.S. Environmental Protection Agency initiated comparative genotoxicity studies to determine the relative mutagenic and carcinogenic activity and, ultimately, the potential human health risk due to exposure to various complex emission products. Among the materials investigated were those of known health risk, such as coke oven and roofing tar emissions and cigarette smoke condensates, and those of unknown hazard, such as exhaust from diesel-and gasoline-powered vehicles. Studies on diesel emission products proved useful in short term bioassay development, as the diesel exhaust extracts were genetically active with low cellular toxicity and could be obtained in relatively large quantities. Availability of such samples aided chemical characterization, and it was eventually determined that the nitro-polynuclear aromatic hydrocarbons were among the mutagenic components of diesel exhaust particulate.







Short-Term Bioassays in the Analysis of Complex Environmental Mixtures IV


Book Description

With this proceedings of the fourth symposium on complex mixtures, we continue to revise and extend our knowledge of genetic methods for the evaluation of chemical mixtures in the environment. The early chapters of this volume are devoted to new bioassay techniques that are directly applicable to the monitoring of environments contaminated with genotoxic chemicals. Microbiological methods have been further refined to meet the special needs of atmospheric monitoring so that very small samples may now be efficiently tested. New in situ methods utilizing green plants actually avoid many of the usual difficulties of sample collection and preparation and offer special advantages in monitoring wastewater, sludges, and hazardous wastes. Insects also are being employed very effectively in the evaluation of gaseous air pollutants in controlled laboratory investigations. Increased emphasis has been placed on a comprehensive assessment of the potential of complex mixtures t9 cause various kinds of genetic damage. New assays for chromosome structural and numerical aberrations in mammalian cells in vitro have been developed and are being applied in laboratory studies. Efforts to link tests for gene mutation and cell transformation in vitro with assays for tumorigenesis in vivo are contributing to the validation of the short-term testing approach. Studies comparing in vitro and in vivo data on a coal conversion by-product, on polycyclic aromatic hydrocarbons, and on mineral fibers are reported in separate papers. Later chapters are devoted to investigations on the fractionation and biological evaluation of specific chemical components within complex mixtures.




Short-Term Bioassays in the Analysis of Complex Environmental Mixtures II


Book Description

More than one hundred short-term bioassays are now available for detecting the toxicity, mutagenicity, and potential carcinogenicity of chemicals. These bioassays were developed and validated with individual compounds, and their principal application was perceived to be in evaluating the health hazard of such materials. However, man is rarely exposed to single chemicals; his exposure to hazardous chemicals is more commonly a multifactorial phenomenon. Although chemical analysis can be used to detect known hazardous compounds, it would be a staggering and expensive task to analyze large numbers of samples for all known or suspected hazardous constituents. Furthermore, the biological activity of a complex mixture cannot be reliably predicted from knowledge of its components. On the other hand, bioassays alone cannot tell us which components of complex mixtures are responsible for the biological activity detected. Thus, cost effectiveness and technical feasibility dictate stepwise and perhaps iterative application -of both chemical and biological methods in evaluating the health effects of complex environmental mixtures. Through the coupling of reliable biological detection systems with methods of chemical fractionation and analysis, it is frequently possible to isolate the individual chemical species that show biological activity. Initially, complex mixtures may be separated and bioassayed in carefully defined chemical fractions. The results of such short-term screening bioassays then may be used td guide the course of further fractionation and to determine the need for more stringent and comprehensive biological testing.




Genetic Toxicology of Complex Mixtures


Book Description

Contained in this volume are the proceedings of the international conference on the "Genetic Toxicology of Complex Mixtures," held from July 4-7, 1989, in Washington, DC. This meeting was a satellite of the "Fifth International Conference on Environmental Mutagens" and the seventh in a biennial series of conferences on "Short-term Bioassays in the Analysis of Complex Environmental Mixtures. " Our central objective in calling together key researchers from around the world was to extend our knowledge of the application of the methods of genetic toxicology and analytical chemistry in the evaluation of chemical mixtures as they exist in the environment. This conference emphasized the study of genotoxicants in air and water, and the assessment of human exposure and cancer risk. The latest strategies and methodologies for biomonitoring of genotoxicants (including transformation products) were described in the context of the ambient environment. Source character ization and source apportionment were discussed as an aid to understand ing the origin and relative contribution of various kinds of complex mix tures to the ambient environment. Similarly, investigations of genotoxi cants found in the indoor environment (sidestream cigarette smoke) and in drinking water (chlorohydroxyfuranones) were given special attention in terms of their potential health impacts. New molecular techniques were described to enable more precise quantitation of internal dose and dose to-target tissues. The emphasis of presentations on exposures/effects assessment was on integrated quantitative evaluation of human exposure and potential health effects.




Chemistry for the Protection of the Environment


Book Description

Over the last decade and a half, an environmental conference series has emerged to become one of the major international forums on the chemical aspects of environmental protection. The forum is called Chemistry for the Protection of the Environment CCPE). The sponsors of this CPE series have included the Chemical Societies of Poland, France, Belgium, Italy, and the U.S.A., the European Federation of Chemical Societies, the American Institute of Chemical Engineers, the American Society of Testing and Materials, the International Ozone Association, the United Nations Industrial Development Organization, the Ministries of the Environment of Poland, France, Belgium, and Italy, US Environmental Protection Agency, more than twenty universities and institutes of higher learning, and five academies of sciences. The first meeting in this series was organized in 1976 at the Marie Curie-Sklodowska University in Lublin, Poland. The conference dealt with various physicochemical methodologies for water and wastewater treatment research projects that were jointly sponsored by US EPA and Poland.




Environmental Biotechnology for Waste Treatment


Book Description

The use of biotechnical processes in control of environmental pollution and in haz ardous waste treatment is viewed as an advantageous alternative or adduct to phys ical chemical treatment technologies. Yet, the development and implementation of both conventional and advanced biotechnologies in predictable and efficacious field applications suffer from numerous technical, regulatory, and societal uncertainties. With the application of modern molecular biology and genetic engineering, there is clear potential for biotechnical developments that will lead to breakthroughs in controlled and optimized hazardous waste treatment for in situ and unit process use. There is, however, great concern that the development of these technologies may be needlessly hindered in their applications and that the fundamental research base may not be able to sustain continued technology development. Some of these issues have been discussed in a fragmented fashion within the research and development community. A basic research agenda has been established to promote a sustainable cross-disciplinary technology base. This agenda includes developing new and improved strains for biodegradation, improving bioanalytical methods to measure strain and biodegradation performance, and providing an in tegrated environmental and reactor systems analysis approach for process control and optimization.




Environmental Radon


Book Description

This volume is intended for the professional who is a newcomer to the area of environmental radon. It marks the first time that chapters on these subjects have been brought together in a single volume, and it is arranged so that anyone with some basic university-level chemistry and physics can develop a clear understanding of the different aspects involved. The volume is intended to serve as a supplementary textbook in public health, environmental, and health physics courses. It also can be used by the professional to get "up to speed" in this rapidly evolving field. The chapters are not necessarily a discussion of the latest research in this fast-moving field, but are intended to bring the reader to a level at which he can easily understand the current literature. At the back of this volume the reader will find the references for the individual chapters, a general list of reading materials, a glossary, an appendix describing the equations for radioactive decay for a series of progeny, a table of often used conversion factors, and the addresses and brief biographies of the authors and editors. Both historical and SI (International System) units are used throughout the book to provide information for the widest range of readers. Thanks go to Tom Hess for the idea for this volume and to Jessica Barron for help in editing.




Nitroarenes


Book Description

Prior to 1979, consideration of the problem of the carcinogenicity of the aromatic amine class of chemicals took place primarily in poster sessions and symposia of annual meetings of the American Association for Cancer Research and analogous international associations. In November 1979 the first meeting concerned with the aromatic amines was held in Rockville, Haryland under primary sponsorship of the National Cancer Institute. The proceedings from this meeting were published as Monograph 58 of the Journal of the National Cancel' Institute in 1981. The second meeting in this series, the Second International Conference on N-Substituted Aryl Compounds, was held in March/April of 1982 in Hot Springs, Arkansas. The National Cancer Institute and The National Center for Toxicological Research were the primary sponsors of this meeting. The proceedings were published as Volume 49 of the journal En-vil'onmental Health Perspectives in 1983. The third meeting in this series was held in April of 1987 at the Dearborn Hyatt in Dearborn, Michigan. The principal sponsor of this meeting was the Heyer L. Pre ntis Comprehensive Cancer Center of Metropolitan Detroit. The proceedings, Carcinogenic and Mutagenic Responses to Aromatic Amines and Nitroal'enes, were published in 1987 by Elsevier Press. The fourth meeting was held in Cleveland, Ohio, on July 15-19, 1989.




In Situ Evaluation of Biological Hazards of Environmental Pollutants


Book Description

The study of the relationship between environmental pollution and human health is in its infancy. The number of substances and mixtures that have been identified in uncontrolled hazardous waste sites or that have been in advertently released into the environment is large and data on how thes~ substances are modified as they interact with one another as they migrate through soil, air, and water are limited. There are also limits on our un derstanding of how these substances may be ingested, inhaled, or absorbed by people. The complexity of possible interactions between biological, chemical, and physical components in a given environment makes it virtually impossible to evaluate the potential for adverse biological effects ade quately in the laboratory. Other, more comprehensive methods which provide realistic and interpretable results must be used. Many scientists believe that humans represent the ultimate sentinel species of a toxic exposure re sUlting from environmental pollution, however such exposures may also se verely impact environmental health. There exists a wide variety of organ isms in the natural environment that could be used to provide an early warning for potential human health effects as well as to indicate adverse ecological effects. The issue of effective utilization of sentinel species for environment al monitoring is a rapidly developing area of research which has grown in importance during the last decade.