Oak Ridge National Laboratory  
Administration Area
Administration Area Core Capabilities Toxicology Chemical Risk Assessment Radiological Risk Assessment Improving the Science Toxicological Assessment Methods Development Database Development Integration and Application of Risk Assessment National Security Pesticide Safety Toxicogenomics Risk Assessment for Environmental Cleanup Risk Informaed Prioritization Disease Cluster Causation Assessment Decision Assessment Risk Communication Food Safety
HHRA's Core Capabilities

Human Health Risk Assessment
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Human Health Risk Assessment (HHRA)

HHRA can identify solutions to a broad range of problems related to human health risk. The breadth and depth of risk assessment expertise at ORNL are needed to solve these significant risk problems. Ranging from basic toxicology to development and application of integrated predictive paradigms, this expertise supports development and integration of methods to determine causation and predict consequences. ORNL is well-positioned to apply current state-of-the-art risk assessment techniques to challenging problems and continually develops new tools for risk assessment.

The ffigure to the right contains links to descriptions of HHRA's core capabilities. Information also is provided on research that improves the related sciences and enables integration of risk assessment into a broad range of problem-solving applications. [top]

CORE CAPABILITIES

In the United States and internationally, a profusion of regulations focuses on the prevention and mitigation of various chemicals and hazardous agents (radiation and biological agents) in the environment. Public concern for safeguarding human health will likely continue with even greater determination and a demand for accountability, with cost-effective and timely application of resources.

ORNL has the technical expertise and information resources needed to assist federal, state, and private sponsors in meeting regulatory mandates. By increasing the integration of science into decision making, ORNL plays an important role in finding cost-effective solutions to today's problems.

Toxicology and risk assessment research span a broad biological spectrum, from molecular toxicology to risk-based integrated assessments. ORNL research includes genetic toxicology, human genome research, aquatic and environmental toxicology, mammalian toxicology, human and animal physiology, biochemistry, reproductive and developmental physiology, and cancer and disease etiology. This research is integrated in HHRA's core capabilities of toxicity assessment and quantitative risk assessment of chemicals, pesticides, chemical and biological carcinogens, radionuclides, and chemical and biological warfare agents. In addition, ORNL has the capability to develop toxicology databases and information systems essential to the evaluation of toxicological hazards and to support computational biology research.

Since beginning work with the U.S Environmental Protection Agency (EPA) in the mid to late 1970s, ORNL has played an integral role in many federal health risk assessment initiatives. Over the past 25 years, a multidisciplinary team of health scientists, information specialists, and risk assessment professionals has provided toxicology and risk assessment support to the following:

Toxicology

ORNL has one of the largest groups of toxicologists in the country, with 13 staff members holding certification in general toxicology from the American Board of Toxicology. In addition, ORNL has risk assessors with expertise in areas including neurotoxicology, immunotoxicology, reproductive toxicity, carcinogenicity, genotoxicity, and evironmental toxicology. Research staff expertise includes genetics, gene and protein expression monitoring, and computational bioinformatics. ORNL is also home to the "Mouse House," a unique world-class facility housing over 75,000 mice with various genetic mutations.

The toxicology staff facilitate interaction among federal and state agencies and private organizations by providing initial health assessments of hazardous chemicals and radioactive materials. HHRA resources include a knowledge base of 30,000 chemicals that were evaluated for toxicity endpoints (e.g., systemic, genetic, reproductive, and carcinogenic) in 2000 human health and ecological risk assessments. This information is used by ORNL staff to develop reference doses, concentrations, slope factors, and short term inhalation exposure levels. (Contact: Po-Yung Lu or Bob Ross) [top]

Chemical Risk Assessment

ORNL staff members are experienced in all facets of this phase of the HHRA process, including (1) individual release sites or complexes comprising possibly hundreds of sites, (2) screening and baseline risk assessments, and (3) risk evaluations of remedial alternatives. In addition, ORNL develops and implements long-term strategic plans for conducting risk assessments at large complex sites. This work includes identification and standardization of appropriate methods and reviews to ensure that quality information is provided to the decision process in a cost-effective manner. Hundreds of these risk assessments have been conducted for numerous agencies, including DOE, DoD, and ATSDR. (Contact: Wilson McGinn) [top]

Radiological Risk Assessment

ORNL's dosimetry research program provides technical support to national and international bodies responsible for radiation-protection guidance. This program develops methods for use in retrospective exposure assessments of both workers and members of the public in support of epidemiological studies. Resources include extensive computational tools and databases of physiological, anatomical, and radiological parameters—those that enter into assessment of radiation dose to body tissues at risk for both acute and chronic health effects. (Web site: ORNL Center for Biokinetic and Dosimetric Research) (Contact: Keith Eckerman)

Low Dose Radiation Research

The human population is constantly exposed to low levels of natural background radiation, primarily from environmental sources, and to higher levels from occupational sources, medical therapy, and other human-mediated events. Because most radiation exposures to humans are at low levels (10 rem or less), research to date has not yielded the type of information that can be readily used in assessing health risks from such exposures. To help overcome this information gap, ORNL is involved in an effort that brings together the recent biological data necessary to make an up-to-date and informed assessment of the health effects of low dose radiation and low dose rate radiation (Web site: Low Dose Radiation Research Program) (Contact: Po-Yung Lu) [top]

IMPROVING THE SCIENCE

ORNL is making significant contributions to improving the science of risk assessment. From the development of new methods to the creation of smart systems, ORNL researchers are involved in a wide range of activities that will strengthen the decision-making process. [top]

Toxicological Assessment Reports

ORNL staff members have participated in a variety of toxicological assessment projects over the past 20 years. Over 2000 documents have been written addressing the health effects and environmental fate/effects of chemicals and chemical classes. The report titles are compiled and can be retrieved from our document database.

Search our Documents Database

Search our database of chemicals evaluated for toxicity endpoints in health- and eco-risk assessment documents. Enter a chemical in the field below and click the "Find Documents" button. You may enter either the name of the chemical or its Chemical Abstract Service (CAS) number. If you are not sure of the chemical name, enter the first few characters, and the Web page will return all matches (e.g., "ace" will return "acenaphthene," "acetaldehyde," "acetamide," etc.). You may enter the CAS number with or without dashes and with and without leading zeros. If you cannot find a chemical, please contact: Po-Yung Lu by email or phone 865-574-7587.

Chemical:

Search For Documents Types

To generate a listing of our risk-related documents by type of document, select a document type from the drop-down list below and click on the "Get Documents" button.

Type of Document:

 

Methods Development

ORNL researchers are constantly looking for ways to improve the risk assessment process. As shown in the following examples, method development often is the result of customer need. (Contact: Wilson McGinn)

Integration Point Assessment

The integration point assessment is a flux-based risk assessment developed to assist decision makers in identifying the most significant sources contributing to risk from surface-water exposure. Flux is the mass of a chemical that migrates through a cross-sectional area in a given time. It is an important concept for controlling contaminant sources because of the number of actual and potential sources of contaminants that exist and the variability in flow rates of the different surface-water systems transporting contaminants. Flux data are used to determine the percent contribution of each source to the integration point, which is used as the basis for ranking the relative importance of the different sources.

Prioritization Methods

ORNL has developed methods to incorporate quantitative risk information in the prioritization models used for business planning of environmental cleanup. A standard approach that incorporates the same risk information used to make remediation decisions has been developed in support of the prioritization process. This approach ensures consistency between business planning and the risk assessment decision process.

Sociocultural Risk Assessment

Impacts to sociocultural end points are often overlooked in most risk assessments. A decision or risk management framework must be created to enable decision makers to use risk information to contrast the cultural impacts to human health and ecological endpoints. ORNL has been involved in efforts to develop methods to assess impact to this important end point so that decision makers can make better-informed decisions.

Probabilistic Risk Assessment

Probabilistic risk assessment (PRA) presents the opportunity to place the risks of pollutants to human health and the environment onto a much more realistic level. Pitfalls of deterministic risk assessment, which has been applied almost exclusively until recently, include inevitable overstatements of risk (sometimes to absurd levels) and a poor communication of the uncertainties inherent in the estimates. Probabilistic risk assessment can be sufficiently protective while leading to considerable savings on cleanup costs.

Risk Assessment Information System (RAIS)

RAIS was developed to provide a service-oriented environmental risk assessment expert system. Initially, this Web-based system was designed to support the site-specific needs of the DOE Oak Ridge Operations Environmental Management Program. Since that time, the system has been applied nationally and continues to grow to meet DOE risk information needs. This system provides the framework for consistent and high-quality risk activities, eliminates the tedious collection of up-to-date toxicity values and other parameters used in risk assessments, automates the exposure assessment, and provides the means for site comparisons.

Integrated Worker-Risk Evaluation System

The objectives of a worker-risk evaluation system are to provide an online repository for resources and applications and to identify and address the critical data gaps in methods and science that must be addressed to improve the assessment process. Specifically, the system provides databases, tools, and models that enable consistent assessment of worker risks associated with exposures and accidents resulting from implementation of remediation, waste management, or surveillance and maintenance activities.

Petroleum Industry Risk Assessment

Risk assessment is a critical component to the decision-making processes of the petroleum industry, ensuring that significant problems are addressed in a cost-effective manner. Consequently, such assessments are conducted on an international scale by the petroleum industry at exploration, production, and refining. This approach provides a centralized resource for industry guidance, information, and tools in support of risk assessment and risk management activities. It also ensures consistency in approach, data quality and cost effectiveness while providing information essential to the protection of human health and the environment.

Methods to Reduce Costs

The application of risk assessment to the decision-making process and implementation of risk-informed actions often are not optimized to reduce cost. Although there must be a balance among the many factors that influence decisions, risk is many times not given appropriate weight or is used inappropriately to justify an action, possibly resulting in unnecessary costs. This task provides a strategy and risk assessment approaches that work best in a given situation based on an understanding of how decisions are currently made and how the process can be improved or corrected, if necessary, to reduce costs. [top]

Database Development

ORNL has compiled and maintains database and information systems to support DOE and other governmental programs. Below are some of the databases currently maintained:

INTEGRATION AND APPLICATION OF RISK ASSESSMENT

The basic areas of toxicology and risk assessment provide opportunities to interact within broader research agendas, thereby obtaining the synergism necessary to address complex issues. [top]

National Security

ORNL has a national reputation for development of ingestion and vapor-exposure limits for hazardous materials. These limits are used to determine "how clean is clean" during Superfund and Army Chemical Demilitarization site cleanup and restoration. The same logic and analytical skills are applicable to developing cleanup limits for biowarfare toxins, limits that are critical to decisions concerning safe return of any evacuated population.

An interactive, multimedia instructional program, "Medical Management of Biological Agent Casualties," has been developed with support from the U.S. Army Medical Research Institute of Infectious Diseases and FEMA. The program presents medical treatment protocols for immediate care of both military and civilian casualties, as well as information on agent detection and containment, decontamination, and self-protection strategies (e.g., use of vaccines and personal protective equipment). Available on CD-ROM, the program delivers training for medical professionals, field or hospital medical support personnel, and nonmedical personnel. (Contact: Annetta Watson) [top]

Pesticide Safety

ORNL staff members are involved in evaluating the environmental fate and effects of pesticides and in the efficacy of antimicrobial and biological pesticides. Staff members are developing GIS-based watershed assessment tools to assist in assessing the risks of pesticides to drinking water intakes. Antimicrobial efficacy data are evaluated to determine the effectiveness of numerous chemicals on pathogenic microorganisms (including fungi, bacteria, and viruses), which humans may contact in air or water or on inanimate surfaces. Evaluations are conducted of the biological pesticide efficacy of such natural materials as animals, plants, and bacteria. Included in these evaluations are microbial agents in which bacteria are the active ingredient, genetically modified plants possessing pesticidal substances, and other naturally occurring biopesticides. (Contact: Bob Ross or Anthony Armstrong) [top]

Toxicogenomics

Having the complete sequence of the human genome (and that of other organisms) has enabled scientists to determine, at the genome level, how organisms respond to physical, chemical, and biological agents, and to evaluate the effect of natural genetic variation on this response. This new field is known as toxicogenomics. The organism's response is characterized by changes in mRNA expression and protein expression patterns. Using bioinformatics tools to manage these complex data, toxicologists and risk assessors evaluate the implications on human health of the toxicant-induced genomic changes. (Contact: Po-Yung Lu)

With ORNL's capabilities in characterizing and interpreting the risk of toxicant-induced molecular changes, it can develop ultrasensitive, mechanism-based strategies for predicting toxicity. The effects that age (including children's vulnerability), sex, and polymorphisms in specific genes have on the population's response to toxins can be examined. In vitro systems can be developed to replace or reduce animal testing, predict toxicity of unknown agents including complex mixtures and pharmaceuticals, and monitor response to medical intervention. (Contact: Sylvia Milanez) [top]

Risk Assessment for Environmental Cleanup

This R&D area involves (1) strategic planning for risk considerations important to large facilities; (2) site-specific project scoping support and work-plan development for chemical and radiological risk considerations; (3) fate, transport, and exposure modeling; (4) statistical and geostatistical analyses of data for decision making; and (5) site prioritization and site-wide assessments. Support is available to the DOE Center for Risk Assessment and the DOE Oak Ridge Operations Environmental Management Risk Assessment Program. ORNL staff members conduct various risk assessment activities for EPA, DOE, DoD, and other agencies. (Contact: Wilson McGinn) [top]

Risk-Informed Prioritization

The concept of prioritizing activities is key to effective management of resources and to ensure that the most critical tasks are completed in a timely manner. To establish a program budget and plan for the completion of activities, the prioritization process must address numerous attributes (i.e., program concerns used in decision making). These may include public safety and health, environmental protection, regulatory milestones, logical progression of cleanup, mortgage reduction, environmental justice, mission impacts, and stakeholder concerns. This tool determines the relative risk of each project for any number of attributes such as public health and safety, environmental protection, and site personnel safety and health, providing a consistent and systematic framework for evaluating and quantifying the estimated risk reduction achieved by the completion of each activity. (Contact: Wilson McGinn) [top]

Disease Cluster Causation Assessment

As biological, chemical, physical, or psychological agents become more prevalent in our environment, groups of sensitive populations may develop disease states in response to these agents. These states are manifested as disease clusters or other expressions of human dysfunction. In this country and many others, there is a significant public concern and a high interest in assessing causality. ORNL has undertaken an initiative to integrate its capabilities in areas including ecological indicators, molecular genomics science and technology, ecological modeling, and predictive toxicology to address new scientific challenges related to understanding exposure- or stress-response behavior in the context of human-ecosystem interactions. In attempting to decipher the root cause of human and environmental health impacts from contaminants, global change, and emerging pathogens, a system-level approach that addresses scales of investigation, from molecular to regional is needed. (Contact: Tim Borges) [top]

Decision Assessment

The development of decision frameworks to address site-, facility-, and institution-level problems is a growing area. Many ORNL sponsors realize that decision makers are often overwhelmed by information because no decision framework or method is available to organize the data-evaluation process. Clearly there are multiple impacts if information is not appropriately applied to the decision process.

Life Cycle Assessment provides environmentally conscious, cost-effective solutions. It gives an opportunity for large-scale implementation in a wide variety of settings, such as reindustrialization, decontamination and decommissioning, pollution prevention, and global climate change.

Spatial Analysis Decision Assistance (SADA)

Spatial Analysis and Decision Assistance is an environmental analyses software package which integrates human health and ecological risk assessment with powerful geospatial analyses, geographic information systems, cost-benefit analysis, and decision analysis in one dynamic and interactive platform. It includes integrated modules for visualization, geospatial analysis, statistical analysis, human health and ecological risk assessment, cost-benefit analysis, sampling design, and decision analysis. SADA creates a user-friendly software package for environmental characterization and decision making. This problem-solving environment integrates a wide variety of algorithms and contemporary scientific methodologies that can be used either in a stand-alone fashion or in direct support of ecological or human health risk assessment. The software produces information in a clear, transparent manner, directly supporting decision processes; it also serves as a communication tool between technical and nontechnical audiences. Visit the SADA Web site for more details and a free download (Contact: Robert Stewart)

Decision Software Verification

EPA has instituted an Environmental Technology Verification (ETV) Program to verify the performance of innovative technical solutions to problems that threaten human health or the environment. ORNL provides technical support to ETV for verifying the performance of environmental decision support software. (Contact: Anthony Armstrong) [top]

Risk Communication

The communication of information and results is no less important than any step within the decision process. The benefits of R&D science are quickly lost if information is not made available in an understandable and useful context. ORNL staff members continue to strive to improve the communication of science to scientists, sponsors, governmental agencies, and the public by developing online educational tools and information sites. ORNL also participates in public meetings to provide a risk perspective to community concerns. (Contact: Wilson McGinn) [top]

Food Safety

ORNL is collaborating with University of Tennessee staff members in the Food Safety Center of Excellence (UTFSCOE) to integrate previously segregated areas of research. Areas such as environmental science have been studied in the context of pollutant exposure in a specific microenvironment or watershed. Integrating the expertise of agricultural engineers, environmental scientists, and risk assessors can elucidate the full impact of farming practices on contaminant uptake in food; the migration of agricultural chemicals through soil, air, and water; and the overall impact of farming practices on human health. Indeed food safety encompasses all aspects of food production from the farm to the consumer. Many scientific disciplines and fields will benefit from the Center's research and products as a result of this multidisciplinary approach. The following examples illustrate ORNL involvement in Food Safety Risk Assessment: Contact: Anthony Armstrong)

Risk Assessment

Microbial risk assessment is an emerging science, but because of the accidental nature of exposure, it lacks much significant foundational information, such as dose-response data and an understanding of confounding factors. An improved understanding of these factors and resultant food-safety risk assessment methods will directly benefit the science of risk assessment by enabling improved predictive models for contaminant movement through food chains, integration of multiple risk endpoints to provide a more realistic paradigm, and incorporation of risk assessment into a framework to support solutions to real-life large-scale problems. Although this information may be developed in the scope of gaining a greater understanding of food safety, it also can be applied to such safety and health issues as water purification and sanitation, hazardous-waste cleanup, or even biological warfare agents. There also are complex issues involved in assessing risks to children and adults from exposure to pesticides in foods, which have similar mechanisms of toxicity. The development and refinement of these new risk assessment methods and their application to real-life situations will significantly advance the science of risk assessment.

Human Health/Pharmaceutical

The environmental impacts associated with accepted agricultural practices have implications for various other aspects of human health. For example, the prevalent issues of endocrine disrupters and resistance to pesticides and antibiotics are very much within the scope of the UTFSCOE. Exposure to natural or manufactured endocrine-disrupting chemicals is currently of great physiologic and economic concern. Research is needed in this area to provide an understanding of the toxicological mechanisms of this group of chemicals that will apply to any exposure context. The understanding of the development of resistance to pesticides and antibiotics can be well understood in the context of food production. Benefits of this research would certainly impact the environmental and medical sciences. In addition, understanding the transmission of food-borne organisms or toxicants serves to identify the role of the pharmaceutical industry in developing new agents or treatment protocols to combat these imposing health threats.

Worker Health and Safety

FSCE also embodies the need for safety in all aspects of food production, including worker safety on the farm and in manufacturing facilities. This Center is strategically positioned to configure to a better understanding of farm-child safety and pesticide exposure in rural households and other environments, migrant worker concerns, ergonomic needs of food manufacturers, and the need to balance economics with safety.

Agriculture

Increasing economic development pressures in rural areas often lead to more "industrialized" forms of agricultural production. The development of megafarms for producing swine, cattle, and poultry brings with it not only the prospects of economic gain but also the potential for adverse effects to human health and the environment. The safety of industrialized agriculture is within the scope of this Center. Issues such as the potential toxicity of farm waste products, quality of life, water supply, centralization of food supply, and bioterrorism threats are all relevant and timely cooperative research topics. In addition, the large-scale impacts of biotechnology on agricultural practices has national and global implications to health, environment, and quality-of-life issues. [top]