Application Of Modern Toxicology Approaches For Predicting Acute Toxicity For Chemical Defense

The US Department of Defense (DOD) is faced with an overwhelming task in evaluating chemicals that could potentially pose a threat to its deployed personnel. There are over 84,000 registered chemicals, and testing them with traditional toxicity-testing methods is not feasible in terms of time or money. In recent years, there has been a concerted effort to develop new approaches to toxicity testing that incorporate advances in systems biology, toxicogenomics, bioinformatics, and computational toxicology. Given the advances, DOD asked the National Research Council to determine how DOD could use modern approaches for predicting chemical toxicity in its efforts to prevent debilitating, acute exposures to deployed personnel. This report provides an overall conceptual approach that DOD could use to develop a predictive toxicology system. Application of Modern Toxicology Approaches for Predicting Acute Toxicity for Chemical Defense reviews the current state of computational and high-throughput approaches for predicting acute toxicity and suggests methods for integrating data and predictions. This report concludes with lessons learned from current high-throughput screening programs and suggests some initial steps for DOD investment.

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.

Extremely hazardous substances can be released accidentally as a result of chemical spills, industrial explosions, fires, or accidents involving railroad cars and trucks transporting EHSs. Workers and residents in communities surrounding industrial facilities where these substances are manufactured, used, or stored and in communities along the nation's railways and highways are potentially at risk of being exposed to airborne EHSs during accidental releases or intentional releases by terrorists. Pursuant to the Superfund Amendments and Reauthorization Act of 1986, the U.S. Environmental Protection Agency (EPA) has identified approximately 400 EHSs on the basis of acute lethality data in rodents. Acute Exposure Guideline Levels for Selected Airborne Chemicals, Volume 20 reviews and updates the technical support document on acute exposure guideline levels (AEGLs) for selected chloroformates. This update focuses on establishing AEGL-3 values for n-propyl chloroformate and isopropyl chloroformate, but will also consider whether any new data are available that would affect the proposed values for the other 10 chloroformates. AEGLs represent threshold exposure limits (exposure levels below which adverse health effects are not likely to occur) for the general public and are applicable to emergency exposures ranging from 10 minutes (min) to 8 h. Three levels - AEGL-1, AEGL-2, and AEGL-3 - are developed for each of five exposure periods (10 min, 30 min, 1 h, 4 h, and 8 h) and are distinguished by varying degrees of severity of toxic effects. This report will inform planning, response, and prevention in the community, the workplace, transportation, the military, and the remediation of Superfund sites.

Human spaceflight is inherently risky, with numerous potential hazards posed at each phase of a mission. Potential health risks during spaceflights include short-term health consequences from being in microgravity, as well as long-term health consequences that arise, or continue, months or years after a flight. Additional health considerations are risks posed by exposure to environmental contaminants onboard spacecraft. Because the International Space Station and spacecraft are closed environments that require recirculation of air and water supplies, some contamination of the air and water will occur. Even with onboard air and water purification systems, chemicals will accumulate in the air and water as they recirculate or are recycled onboard. Therefore, it is necessary for the National Aeronautics and Space Administration (NASA) to identify hazardous contaminants and determine exposure levels that are not expected to pose a health risk to astronauts. NASA uses spacecraft maximum allowance concentrations (SMACs) and spacecraft water exposure guidelines (SWEGs) to provide guidance on acceptable exposures to air and water contaminants during normal operations and emergency situations. Refinements to the Methods for Developing Spacecraft Exposure Guidelines updates the methods for establishing SMACs and SWEGs and assists NASA with identifying chemicals that need updated SMACs or SWEGs and new chemicals for which these guidelines should be developed.

Over the last decade, several large-scale United States and international programs have been initiated to incorporate advances in molecular and cellular biology, -omics technologies, analytical methods, bioinformatics, and computational tools and methods into the field of toxicology. Similar efforts are being pursued in the field of exposure science with the goals of obtaining more accurate and complete exposure data on individuals and populations for thousands of chemicals over the lifespan; predicting exposures from use data and chemical-property information; and translating exposures between test systems and humans. Using 21st Century Science to Improve Risk-Related Evaluations makes recommendations for integrating new scientific approaches into risk-based evaluations. This study considers the scientific advances that have occurred following the publication of the NRC reports Toxicity Testing in the 21st Century: A Vision and a Strategy and Exposure Science in the 21st Century: A Vision and a Strategy. Given the various ongoing lines of investigation and new data streams that have emerged, this publication proposes how best to integrate and use the emerging results in evaluating chemical risk. Using 21st Century Science to Improve Risk-Related Evaluations considers whether a new paradigm is needed for data validation, how to integrate the divergent data streams, how uncertainty might need to be characterized, and how best to communicate the new approaches so that they are understandable to various stakeholders.

The U.S. Environmental Protection Agency (EPA) has a mission and regulatory responsibility to protect human health and the environment. EPA's pursuit of that goal includes a variety of research activities involving human subjects, such as epidemiologic studies and surveys. Those research activities also involve studies of individuals who volunteer to be exposed to air pollutants intentionally in controlled laboratory settings so that measurements can be made of transient and reversible biomarker or physiologic responses to those exposures that can indicate pathways of toxicity and mechanisms of air-pollution responses. The results of those controlled human inhalation exposure (CHIE) studies, also referred to as human clinical studies or human challenge studies, are used to inform policy decisions and help establish or revise standards to protect public health and improve air quality. Controlled Human Inhalation-Exposure Studies at EPA addresses scientific issues and provides guidance on the conduct of CHIE studies. This report assesses the utility of CHIE studies to inform and reduce uncertainties in setting air-pollution standards to protect public health and assess whether continuation of such studies is warranted. It also evaluates the potential health risks to test subjects who participated in recent studies of air pollutants at EPA's clinical research facility.

Handbook of Toxicology of Chemical Warfare Agents, Third Edition, covers every aspect of deadly toxic chemicals used in conflicts, warfare and terrorism. Including findings from experimental as well as clinical studies, this essential reference offers in-depth coverage of individual toxicants, target organ toxicity, major incidents, toxic effects in humans, animals and wildlife, biosensors and biomarkers, on-site and laboratory analytical methods, decontamination and detoxification procedures, and countermeasures. Expanding on the second edition, Handbook of Toxicology of Chemical Warfare Agents has been completely updated, presenting the most recent advances in field. Brand new chapters include a new chapter on emergency preparedness, coverage of the chemical warfare agents used in Syria, the use of the Novichok agent in the UK, and more. Unites world-leading experts to bring you cutting-edge, agent-specific information on Chemical Warfare Agents (CWA) and their adverse effects on human and animal health, and the environment Provides you with all the information you need on CWA modes of action, detection, prevention, therapeutic treatment and countermeasures New to this edition: a full update to reflect the most recent advances in the field and new chapters on emergency preparedness, the chemical warfare agents used in Syria, and the use of the Novichok agent in the UK

Animal experimentation has been one of the most controversial areas of animal use, mainly due to the intentional harms inflicted upon animals for the sake of hoped-for benefits in humans. Despite this rationale for continued animal experimentation, shortcomings of this practice have become increasingly more apparent and well-documented. However, these limitations are not yet widely known or appreciated, and there is a danger that they may simply be ignored. The 51 experts who have contributed to Animal Experimentation: Working Towards a Paradigm Change critically review current animal use in science, present new and innovative non-animal approaches to address urgent scientific questions, and offer a roadmap towards an animal-free world of science.