Board on Environmental Studies and Toxicology – Författare

Pharmacokinetics, the study of the movement of chemicals within the body, is a vital tool in assessing the risk of exposure to environmental chemicals. This book--a collection of papers authored by experts in academia, industry, and government--reviews the progress of the risk-assessment process and discusses the role of pharmacokinetic principles in evaluating risk. In addition, the authors discuss software packages used to analyze data and to build models simulating biological phenomena. A summary chapter provides a view of trends in pharmacokinetic modeling and notes some prospective fields of study.

Mono Basin is a closed hydrologic basin spanning the border between California and Nevada. Los Angeles has been diverting streams since 1941 that normally would flow into Mono Lake. It has been predicted that continued diversion will have major ecological consequences for the natural resources of the Mono Basin National Forest Scenic Area. This book studies the ecological risk assessment that considers the effects of water diversions on an inland saline lake. It examines the hydrology of the Mono Basin, investigates the lake's physical and chemical systems, studies the biological relationships, and predicts the effects of changes in lake levels on the ecosystem.

In the laboratory, testing the toxic effects for a single compound is a straightforward process. However, many common harmful substances occur naturally as mixtures and can interact to exhibit greater toxic effects as a mixture than the individual components exhibit separately. Complex Mixtures addresses the problem of identifying and classifying complex mixtures, investigating the effect of exposure, and the research problems inherent in testing their toxicity to human beings. A complete series of case studies is presented, including one that examines the cofactors of alcohol consumption and cigarette smoke.

Studying animals in the environment may be a realistic and highly beneficial approach to identifying unknown chemical contaminants before they cause human harm. Animals as Sentinels of Environmental Health Hazards presents an overview of animal-monitoring programs, including detailed case studies of how animal health problems--such as the effects of DDT on wild bird populations--have led researchers to the sources of human health hazards. The authors examine the components and characteristics required for an effective animal-monitoring program, and they evaluate numerous existing programs, including in situ research, where an animal is placed in a natural setting for monitoring purposes.

This book presents working principles for assessing the relative importance of anthropogenic emission sources that contribute to haze in U.S. national parks and wilderness areas and discusses various alternative source control methods. Haze in the Grand Canyon evaluates and recommends strategies for improving critical scientific and technical gaps in the information and databases on haze. It examines such topics as methods for determining individual source contributions, regional and seasonal factors that affect haze, strategies for improving air quality models, the interactive role of photochemical exodants, and scientific and technological considerations in choosing emission control measures.

Are environmental pollutants threatening the human immune system? Researchers are rapidly approaching definitive answers to this question, with the aid of biologic markers--sophisticated assessment tools that could revolutionize detection and prevention of certain diseases. This volume, third in a series on biologic markers, focuses on the human immune system and its response to environmental toxicants. The authoring committee provides direction for continuing development of biologic markers, with strategies for applying markers to immunotoxicology in humans and recommended outlines for clinical and field studies. This comprehensive, up-to-date volume will be invaluable to specialists in toxicology and immunology and to biologists and investigators involved in the development of biologic markers.

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.

Assessment of the U.S. Outer Continental Shelf Environmental Studies Program reviews the ecological studies done by the Environmental Studies Program of the Minerals Management Service. This program, which has spent $10 million a year on ecological studies in recent years, is designed to provide information to predict and manage the environmental effects of outer continental shelf oil and gas activities. The book considers studies on marine mammals and endangered species, birds, benthic organisms, fisheries, and marine ecosystems and makes recommendations for future studies.

This book presents key conclusions about the controversial killing of thousands of dolphins each year during tuna fishing in the eastern tropical Pacific. Dolphins drown in nets that are set to catch yellowfin tuna, which tend to swim beneath dolphin herds. After 20 years of intense debate among environmentalists, the tuna industry, and policymakers, this fatal by-product of tuna fishing remains a high-profile public issue. Dolphins and the Tuna Industry provides a neutral examination of the scientific and technical questions at the core of the problem. Recommendations for solutions are offered in two areas: Developing new techniques that promise to reduce dolphin mortality with the existing purse-seine method of tuna fishing, and developing entirely new methods of finding tuna that are not swimming with dolphins. Dolphins and the Tuna Industry provides a comprehensive, highly readable overview of the dolphin-tuna controversy, useful to experts and newcomers to the issue. It explores the processes of tuna fishing and dolphin mortality, the status of the tuna industry, and the significant progress made in reducing dolphin mortality through modifications in fishing practice.The volume includes * An overview of U.S. laws and policies relating to tuna and dolphins. * An illustrated look at how tuna fishing crews use their equipment, focusing on the purse seine, which is the method most economical to the industry but most deadly to the dolphins. * An overview of what is known about tuna and dolphin populations and the remarkable bond between them. * A step-by-step description of the fishing process and efforts to let dolphins escape from the nets. * An analysis of possible approaches to reducing dolphin kill, including more stringent regulatory approaches and incentives for the tuna industry. This book will be indispensible to environmental and animal protection groups, tuna fishing crews and processors, companies that market tuna products, policymakers, regulators, and concerned individuals.

This is the third of four volumes from the Committee to Review the Outer Continental Shelf (OCS) Environmental Studies Program (ESP). The first two dealt with physical, oceanographic, and ecological aspects of the program. This book presents the findings of the panel's investigation of the social and economic relevance of OCS oil and gas activities and the social and economic aspects of the ESP. It describes the potential effects of OCS activities on the human environment, presents an ideal socioeconomic studies program, and comments on the current program in the Atlantic, Gulf of Mexico, Pacific, and Alaska regions.

New National Ambient Air Quality Standards for airborne particles smaller than 2.5 micrometers, called PM2.5, were issued by the U.S. Environmental Protection Agency (EPA) amidst scientific uncertainty and controversy. In response to a request from Congress, Research Priorities for Airborne Particulate Matter, the first of four books in a series, offers a conceptual framework for an integrated national program of particulate-matter research, identifies the 10 most critical research needs linked to key policy-related scientific uncertainties, and describes the recommended timing and estimated costs of such research. The committee concludes that EPA should devote more resources to investigating the relationships between fixed-site outdoor monitoring data and actual human breathing-zone exposures to ambient particulate matter and to identifying the most biologically important constituents and characteristics of particulate matter through toxicological studies. The recommended research activities are critical to determining actual exposures of human subpopulations most susceptible to harm from the most hazardous constituents of particulate matter.Future research will be an investment in public health and a means to ensure that resources spent on control technology and regulatory compliance will have a reasonable probability of success.

Incineration has been used widely for waste disposal, including household, hazardous, and medical waste--but there is increasing public concern over the benefits of combusting the waste versus the health risk from pollutants emitted during combustion. Waste Incineration and Public Health informs the emerging debate with the most up-to-date information available on incineration, pollution, and human health--along with expert conclusions and recommendations for further research and improvement of such areas as risk communication. The committee provides details on: * Processes involved in incineration and how contaminants are released. * Environmental dynamics of contaminants and routes of human exposure. * Tools and approaches for assessing possible human health effects. * Scientific concerns pertinent to future regulatory actions. The book also examines some of the social, psychological, and economic factors that affect the communities where incineration takes place and addresses the problem of uncertainty and variation in predicting the health effects of incineration processes.

Some investigators have hypothesized that estrogens and other hormonally active agents found in the environment might be involved in breast cancer increases and sperm count declines in humans as well as deformities and reproductive problems seen in wildlife. This book looks in detail at the science behind the ominous prospect of "estrogen mimics" threatening health and well-being, from the level of ecosystems and populations to individual people and animals. The committee identifies research needs and offers specific recommendations to decisionmakers. This authoritative volume: * Critically evaluates the literature on hormonally active agents in the environment and identifies known and suspected toxicologic mechanisms and effects of fish, wildlife, and humans. * Examines whether and how exposure to hormonally active agents occurs--in diet, in pharmaceuticals, from industrial releases into the environment--and why the debate centers on estrogens. * Identifies significant uncertainties, limitations of knowledge, and weaknesses in the scientific literature.The book presents a wealth of information and investigates a wide range of examples across the spectrum of life that might be related to these agents.

Although chemical pesticides safeguard crops and improve farm productivity, they are increasingly feared for their potentially dangerous residues and their effects on ecosystems. The Future Role of Pesticides explores the role of chemical pesticides in the decade ahead and identifies the most promising opportunities for increasing the benefits and reducing the risks of pesticide use. The committee recommends R&D, program, and policy initiatives for federal agriculture authorities and other stakeholders in the public and private sectors. This book presents clear overviews of key factors in chemical pesticide use, including: * Advances in genetic engineering not only of pest-resistant crops but also of pests themselves. * Problems in pesticide use--concerns about the health of agricultural workers, the ability of pests to develop resistance, issues of public perception, and more. * Impending shifts in agriculture--globalization of the economy, biological "invasions" of organisms, rising sensitivity toward cross-border environmental issues, and other trends.With a model and working examples, this book offers guidance on how to assess various pest control strategies available to today's agriculturist.

In the effort to reduce the scientific and technical uncertainties over regulation of airborne particulate matter in the United States, Research Priorities for Airborne Particulate Matter: II. Evaluating Research Progress and Updating the Portfolio, the second book in a four-part series requested by Congress, describes the plans of the committee to monitor the progress of the research on particulate matter conducted by the U.S. Environmental Protection Agency (EPA), other federal and state government agencies, and nongovernmental organizations. The book also reviews and updates the committee's portfolio of recommended research in its first volume, Research Priorities for Airborne Particulate Matter: I. Immediate Priorities and a Long-Range Research Portfolio (NRC, 1998). The committee substantially revised two of the ten high-priority research areas recommended in Part I. Part II notes that Congress, EPA, and the scientific community have given strong support to the committee's recommendations and have implemented substantial changes in research efforts in response to Part I of the series.One important research area-studies of the effects of long-term exposure to particulate matter and other major air pollutants-however, does not appear to be underway or planned.

The National Aeronautics and Space Administration (NASA) is aware of the potential toxicological hazards to crew members that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMACs) for contaminants, and to review SMACs for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee.In response to this request, the NRC first developed criteria and methods for preparing SMACs for spacecraft contaminants, published in its 1992 report Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. Since then, the NRC's Subcommittee on Spacecraft Maximum Allowable Concentrations has been reviewing NASA's documentation of chemical-specific SMACs. This report is the fourth volume in the series Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. The first volume was published in 1994 and the second and third in 1996. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants: Volume 4 has been reviewed in draft form by individuals chosen for their technical expertise and diverse perspectives in accordance with procedures approved by the NRC's Report Review Committee for reviewing NRC and Institute of Medicine reports.The purpose of that Independent review was to provide candid and critical comments to assist the NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

Environmental indicators, such as global temperatures and pollutant concentrations, attract scientists' attention and often make the headlines. Equally important to policymaking are indicators of the ecological processes and conditions that yield food, fiber, building materials and ecological "services" such as water purification and recreation. This book identifies ecological indicators that can support U.S. policymaking and also be adapted to decisions at the regional and local levels. The committee describes indicators of land cover and productivity, species diversity, and other key ecological processes--explaining why each indicator is useful, what models support the indicator, what the measured values will mean, how the relevant data are gathered, how data collection might be improved, and what effects emerging technologies are likely to have on the measurements. The committee reviews how it arrived at its recommendations and explores how the indicators can contribute to policymaking. Also included are interesting details on paleoecology, satellite imagery, species diversity, and other aspects of ecological assessment.Federal, state, and local decisionmakers, as well as environmental scientists and practitioners, will be especially interested in this new book.

Since Operation Desert Shield/Desert Storm, Gulf War veterans have expressed concerns about health effects that could be associated with their deployment and service during the war. Although similar concerns were raised after other military operations, the Gulf War deployment focused national attention on the potential, but uncertain, relationship between the presence of chemical and biological (CB) agents and other harmful agents in theater and health symptoms reported by military personnel. Strategies to Protect the Health of Deployed U.S. Forces which is one of the four two-year studies, examines the detection and tracking of exposures of deployed personnel to multiple harmful agents.

Risk management is especially important for military forces deployed in hostile and/or chemically contaminated environments, and on-line or rapid turn-around capabilities for assessing exposures can create viable options for preventing or minimizing incapaciting exposures or latent disease or disability in the years after the deployment. With military support for the development, testing, and validation of state-of-the-art personal and area sensors, telecommunications, and data management resources, the DOD can enhance its capabilities for meeting its novel and challenging tasks and create technologies that will find widespread civilian uses. Strategies to Protect the Health of Deployed U.S. Forces assesses currently available options and technologies for productive pre-deployment environmental surveillance, exposure surveillance during deployments, and retrospective exposure surveillance post-deployment. This report also considers some opportunities for technological and operational advancements in technology for more effective exposure surveillance and effects management options for force deployments in future years.

Deployment of forces in hostile or unfamiliar environments is inherently risky. The changing missions and increasing use of U.S. forces around the globe in operations other than battle call for greater attention to threats of non-battle-related health problems—including infections, pathogen- and vector-borne diseases, exposure to toxicants, and psychological and physical stress—all of which must be avoided or treated differently from battle casualties. The likelihood of exposure to chemical and biological weapons adds to the array of tactical threats against which protection is required. The health consequences of physical and psychological stress, by themselves or through interaction with other threats, are also increasingly recognized. In addition, the military's responsibility in examining potential health and safety risks to its troops is increasing, and the spectrum of health concerns is broadening, from acute illness and injury due to pathogens and accidents to possible influences of low-level chemical exposures, which can manifest themselves in reproductive health and chronic illnesses years later, perhaps even after cessation of military service.Strategies to Protect the Health of Deployed U.S. Forces develops an analytical framework for assessing risks, which would encompass the risks of adversed health effects from battle injuries, including those from chemical- and biological-warfare agents, and non-battle-related health problems. The presumed spectrum of deployment ranged from peacekeeping to full-scale conflict.

The safety of the nation's drinking water must be maintained to ensure the health of the public. The U.S. Environmental Protection Agency (EPA) is responsible for regulating the levels of substances in the drinking water supply. Copper can leach into drinking water from the pipes in the distribution system, and the allowable levels are regulated by the EPA. The regulation of copper, however, is complicated by the fact that it is both necessary to the normal functioning of the body and toxic to the body at too high a level. The National Research Council was requested to form a committee to review the scientific validity of the EPA's maximum contaminant level goal for copper in drinking water. Copper in Drinking Water outlines the findings of the committee's review. The book provides a review of the toxicity of copper as well as a discussion of the essential nature of this metal. The risks posed by both short-term and long-term exposure to copper are characterized, and the implications for public health are discussed. This book is a valuable reference for individuals involved in the regulation of water supplies and individuals interested in issues surrounding this metal.

Ignition of upholstered furniture by small open flames from matches, cigarette lighters, and candles is one of the leading causes of residential-fire deaths in the United States. These fires accounted for about 16% of civilian fire deaths in 1996. On average, each year since 1990, about 90 deaths (primarily of children), 440 injuries, and property losses amounting to 50 million dollars have resulted from fires caused by the ignition of upholstered furniture by small open flames. Certain commercial seating products (such as aircraft and bus seats) are subject to flammability standards and sometimes incorporate FR-treated upholstery cover materials, but there is no federal-government requirement for residential upholstered furniture, and it is generally not treated with FR chemicals. It is estimated that less than 0.2% of all U.S. residential upholstery fabric is treated with flame-retardant (FR) chemicals. The Consumer Product Safety Act of 1972 created the U.S. Consumer Product Safety Commission (CPSC) as an independent federal regulatory agency whose mission is to protect the public from unreasonable risks of injury and death associated with consumer products.CPSC also administers the Flammable Fabrics Act, under which it regulates flammability hazards and the Federal Hazardous Substances Act (FHSA), which regulates hazardous substances including chemicals. In 1993, the National Association of State Fire Marshals petitioned CPSC to issue a performance-based flammability standard for upholstered furniture to reduce the risk of residential fires. The Commission granted that portion of the petition relating to small open flame ignition risks. In response to concerns regarding the safety of FR chemicals, Congress, in the fiscal year 1999 appropriations report for CPSC, requested that the National Research Council conduct an independent study of the health risks to consumers posed by exposure to FR chemicals that are likely to be used in residential upholstered furniture to meet a CPSC standard. The National Research Council assigned the project to the Committee on Toxicology (COT) of the Commission on Life Sciences' Board on Environmental Studies and Toxicology. COT convened the Subcommittee on Flame-Retardant Chemicals, which prepared this report.Subcommittee members were chosen for their recognized expertise in toxicology, pharmacology, epidemiology, chemistry, exposure assessment, risk assessment, and biostatistics. Toxicological Risks of Selected Flame-Retardant Chemicals is organized into 18 chapters and two appendices. Chapter 2 describes the risk assessment process used by the subcommittee in determining the risk associated with potential exposure to the various FR chemicals. Chapter 3 describes the method the subcommittee used to measure and estimate the intensity, frequency, extent, and duration of human exposure to FR chemicals. Chapters 4-19 provide the subcommittee's review and assessment of health risks posed by exposure to each of the 16 FR chemicals. Data gaps and research needs are provided at the end of these chapters.

As part of the effort to phase out the use of stratospheric ozone-depleting substances, such as chlorofluorocarbons (CFCs), the U.S. Navy is considering hydrofluorocarbons (HFCs) as replacements for the CFC refrigerants used aboard its submarines. Before using the HFCs, the Navy plans to set emergency exposure guidance levels (EEGLs) and continuous exposure guidance levels (CEGLs) to protect submariners from health effects that could occur as a result of accidental releases or slow leaks. In this report, the Subcommittee on Exposure Guidance Levels for Selected Hydrofluorocarbons of the National Research Council's (NRC 's) Committee on Toxicology independently reviews the scientific validity of the Navy's proposed 1-hr and 24-hr EEGLs and 90-day CEGLs for two of the candidate refrigerants-HFC-236fa and HFC-404a. In addition, the subcommittee reviews the the EEGLs and CEGL for HFC-23, one of the combustion products of HFC-236fa. This NRC report is intended to aid the Navy in using HFCs safely.

Scientific Frontiers in Developmental Toxicology and Risk Assessment reviews advances made during the last 10-15 years in fields such as developmental biology, molecular biology, and genetics. It describes a novel approach for how these advances might be used in combination with existing methodologies to further the understanding of mechanisms of developmental toxicity, to improve the assessment of chemicals for their ability to cause developmental toxicity, and to improve risk assessment for developmental defects. For example, based on the recent advances, even the smallest, simplest laboratory animals such as the fruit fly, roundworm, and zebrafish might be able to serve as developmental toxicological models for human biological systems. Use of such organisms might allow for rapid and inexpensive testing of large numbers of chemicals for their potential to cause developmental toxicity; presently, there are little or no developmental toxicity data available for the majority of natural and manufactured chemicals in use.This new approach to developmental toxicology and risk assessment will require simultaneous research on several fronts by experts from multiple scientific disciplines, including developmental toxicologists, developmental biologists, geneticists, epidemiologists, and biostatisticians.

Methyl bromide is gaseous pesticide used to fumigate soil, crops, commodity warehouses, and commodity-shipping facilities. Up to 17 million pounds of methyl bromide are used annually in California to treat grapes, almonds, strawberries, and other crops. Methyl bromide is also a known stratospheric ozone depleter and, as such, is scheduled to be phased out of use in the United States by 2005 under the United Nations Montreal Protocol. In California, the use of methyl bromide is regulated by the Department of Pesticide Regulation (DPR), which is responsible for establishing the permit conditions that govern the application of methyl bromide for pest control. The actual permits for use are issued on a site-specific basis by the local county agricultural commissioners. Because of concern for potential adverse health effects, in 1999 DPR developed a draft risk characterization document for inhalation exposure to methyl bromide. The DPR document is intended to support new regulations regarding the agricultural use of this pesticide.The proposed regulations encompass changes to protect children in nearby schools, establish minimum buffer zones around application sites, require notification of nearby residents, and set new limits on hours that fumigation employees may work. The State of California requires that DPR arrange for an external peer review of the scientific basis for all regulations. To this end, the National Research Council (NRC) was asked to review independently the draft risk characterization document prepared by DPR for inhalation exposure to methyl bromide. The task given to NRC's subcommittee on methyl bromide states the following: The subcommittee will perform an independent scientific review of the California Environmental Protection Agency's risk assessment document on methyl bromide. The subcommittee will (1) determine whether all relevant data were considered, (2) determine the appropriateness of the critical studies, (3) consider the mode of action of methyl bromide and its implications in risk assessment, and (4) determine the appropriateness of the exposure assessment and mathematical models used.The subcommittee will also identify data gaps and make recommendations for further research relevant to setting exposure limits for methyl bromide. This report evaluates the toxicological and exposure data on methyl bromide that characterize risks at current exposure levels for field workers and nearby residents. The remainder of this report contains the subcommittee's analysis of DPR's risk characterization for methyl bromide. In Chapter 2, the critical toxicological studies and endpoints identified in the DPR document are evaluated. Chapter 3 summarizes DPR's exposure assessment, and the data quality and modeling techniques employed in its assessment are critiqued. Chapter 4 provides a review of DPR's risk assessment, including the adequacy of the toxicological database DPR used for hazard identification, an analysis of the margin-of-exposure data, and appropriateness of uncertainty factors used by DPR. Chapter 5 contains the subcommittee's conclusions about DPR's risk characterization, highlights data gaps, and makes recommendations for future research.

The Mobile Source Emissions Factor (MOBILE) model is a computer model developed by the U.S. Environmental Protection Agency (EPA) for estimating emissions from on-road motor vehicles. MOBILE is used in air-quality planning and regulation for estimating emissions of carbon monoxide (CO), volatile organic compounds (VOCs), and nitrogen oxides (NOx) and for predicting the effects of emissions-reduction programs.1 Because of its important role in air-quality management, the accuracy of MOBILE is critical. Possible consequences of inaccurately characterizing motor-vehicle emissions include the implementation of insufficient controls that endanger the environment and public health or the implementation of ineffective policies that impose excessive control costs. Billions of dollars per year in transportation funding are linked to air-quality attainment plans, which rely on estimates of mobile-source emissions. Transportation infrastructure decisions are also affected by emissions estimates from MOBILE. In response to a request from Congress, the National Research Council established the Committee to Review EPA's Mobile Source Emissions Factor (MOBILE) Model in October 1998.The committee was charged to evaluate MOBILE and to develop recommendations for improving the model.