Toxicity Testing for Assessment of Environmental Agents


Book Description

Toxicity testing in laboratory animals provides much of the information used by the Environmental Protection Agency (EPA) to assess the hazards and risks associated with exposure to environmental agents that might harm public health or the environment. The data are used to establish maximum acceptable concentrations of environmental agents in drinking water, set permissible limits of exposure of workers, define labeling requirements, establish tolerances for pesticides residues on food, and set other kinds of limits on the basis of risk assessment. Because the number of regulations that require toxicity testing is growing, EPA called for a comprehensive review of established and emerging toxicity-testing methods and strategies. This interim report reviews current toxicity-testing methods and strategies and near-term improvements in toxicity-testing approaches proposed by EPA and others. It identifies several recurring themes and questions in the various reports reviewed. The final report will present a long-range vision and strategic plan to advance the practices of toxicity testing and human health assessment of environmental contaminants.




Toxicity Testing in the 21st Century


Book Description

Advances in molecular biology and toxicology are paving the way for major improvements in the evaluation of the hazards posed by the large number of chemicals found at low levels in the environment. The National Research Council was asked by the U.S. Environmental Protection Agency to review the state of the science and create a far-reaching vision for the future of toxicity testing. The book finds that developing, improving, and validating new laboratory tools based on recent scientific advances could significantly improve our ability to understand the hazards and risks posed by chemicals. This new knowledge would lead to much more informed environmental regulations and dramatically reduce the need for animal testing because the new tests would be based on human cells and cell components. Substantial scientific efforts and resources will be required to leverage these new technologies to realize the vision, but the result will be a more efficient, informative and less costly system for assessing the hazards posed by industrial chemicals and pesticides.




Environmental Toxicity Testing


Book Description

As an integral component of environmental policy, it has become essential to regulate and monitor toxic substances. Past emphasis has been primarily on analytical approaches to the detection of specific, targeted contaminants, thus allowing chemical characterisation. However, toxicity testing or biological assessment is necessary for ecotoxicological evaluation, and this offers marked benefits and advantages that complement chemical analysis. Key issues to be addressed include identification of pertinent tests, reproducibility and robustness of these tests, and cost considerations.This book examines these issues and describes and explains the approaches that have been developed for environmental toxicity evaluations. Advantages, benefits and drawbacks of the strategies and methods are highlighted. Directed equally at ecotoxicologists, industrial chemists, analytical chemists and environmental consultants, this book is written in a way that will prove helpful to both new and experienced practitioners.




Environmental Neurotoxicology


Book Description

Scientists agree that exposure to toxic agents in the environment can cause neurological and psychiatric illnesses ranging from headaches and depression to syndromes resembling parkinsonism. It can even result in death at high exposure levels. The emergence of subclinical neurotoxicity-the concept that long-term impairments can escape clinical detection-makes the need for risk assessment even more critical. This volume paves the way toward definitive solutions, presenting the current consensus on risk assessment and environmental toxicants and offering specific recommendations. The book covers: The biologic basis of neurotoxicity. Progress in the application of biologic markers. Reviews of a wide range of in vitro and in vivo testing techniques. The use of surveillance and epidemiology to identify neurotoxic hazards that escape premarket screening. Research needs. This volume will be an important resource for policymakers, health specialists, researchers, and students.




Pesticides in the Diets of Infants and Children


Book Description

Many of the pesticides applied to food crops in this country are present in foods and may pose risks to human health. Current regulations are intended to protect the health of the general population by controlling pesticide use. This book explores whether the present regulatory approaches adequately protect infants and children, who may differ from adults in susceptibility and in dietary exposures to pesticide residues. The committee focuses on four major areas: Susceptibility: Are children more susceptible or less susceptible than adults to the effects of dietary exposure to pesticides? Exposure: What foods do infants and children eat, and which pesticides and how much of them are present in those foods? Is the current information on consumption and residues adequate to estimate exposure? Toxicity: Are toxicity tests in laboratory animals adequate to predict toxicity in human infants and children? Do the extent and type of toxicity of some chemicals vary by species and by age? Assessing risk: How is dietary exposure to pesticide residues associated with response? How can laboratory data on lifetime exposures of animals be used to derive meaningful estimates of risk to children? Does risk accumulate more rapidly during the early years of life? This book will be of interest to policymakers, administrators of research in the public and private sectors, toxicologists, pediatricians and other health professionals, and the pesticide industry.







In Vitro Toxicity Testing of Environmental Agents


Book Description

These two volumes contain the papers presented at a North Atlantic Treaty Organization (NATO) Advanced Study Institute held on September 22-28, 1979 in Monte Carlo, Monaco. The conference was entitled "In Vitro Toxicity Testing of Environmental Agents: Current and Future Possibilities." This international conference presented an opportunity for the participants to exchange informa tion and ideas on the current approaches (both scientific and po litical) for toxic assessment of environmental agents. The poten tial health effects of these compounds as well as future needs in the environmental research field were discussed. The scientific content of the conference seminars included an overview of the various cellular, subcellular, organ, animal, and genetic systems which have been used to assess the health effects of environmental agents. The scientific principles behind short term assays and an evaluation of their applicability to health effects monitoring and analysis were investigated. Included among major topics were: (1) the biochemistry and pharmacology of selected environmental agents; (2) molecular mechanisms of car cinogenesis, mutagenesis, and transformation; (3) bacterial muta genesis and toxicity; (4) mammalian cell mutagenesis, toxicity, and transformation; (5) in vitro carcinogens and mutagens; (6) teratogenic and other developmental toxic effects; and (7) the development of short-term neuro-behavioral toxicity assays.




Applications of Toxicogenomic Technologies to Predictive Toxicology and Risk Assessment


Book Description

The new field of toxicogenomics presents a potentially powerful set of tools to better understand the health effects of exposures to toxicants in the environment. At the request of the National Institute of Environmental Health Sciences, the National Research Council assembled a committee to identify the benefits of toxicogenomics, the challenges to achieving them, and potential approaches to overcoming such challenges. The report concludes that realizing the potential of toxicogenomics to improve public health decisions will require a concerted effort to generate data, make use of existing data, and study data in new waysâ€"an effort requiring funding, interagency coordination, and data management strategies.




Intentional Human Dosing Studies for EPA Regulatory Purposes


Book Description

The EPA commissioned The National Academies to provide advice on the vexing question of whether and, if so, under what circumstances EPA should accept and consider intentional human dosing studies conducted by companies or other sources outside the agency (so-called third parties) to gather evidence relating to the risks of a chemical or the conditions under which exposure to it could be judged safe. This report recommends that such studies be conducted and used for regulatory purposes only if all of several strict conditions are met, including the following: The study is necessary and scientifically valid, meaning that it addresses an important regulatory question that can't be answered with animal studies or nondosing human studies; The societal benefits of the study outweigh any anticipated risks to participants. At no time, even when benefits beyond improved regulation exist, can a human dosing study be justified that is anticipated to cause lasting harm to study participants; and All recognized ethical standards and procedures for protecting the interests of study participants are observed. In addition, EPA should establish a Human Studies Review Board (HSRB) to evaluate all human dosing studiesâ€"both at the beginning and upon completion of the experimentsâ€"if they are carried out with the intent of affecting the agency's policy-making.