FACT SHEET: Agency for Toxic Substances and Disease Registry (ATSDR)

Agency for Toxic Substances
and Disease Registry (ATSDR)

September 1999 - TI#20550
Introduction
ATSDR Service Areas
ATSDR's Federal Programs
ATSDR Toxicological Profiles
Coordination Between ATSDR and DoD
Air Force Guidance
ATSDR Activities at AF Facilities
For More Information...
Document References

Introduction
The stated mission of the Agency for Toxic Substances and Disease Registry (ATSDR) is "To prevent exposure and adverse human health effects and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution present in the environment." An agency of the U.S. Department of Health and Human Services, ATSDR is the principal federal public health agency involved with hazardous substance/waste issues. Its Office of Federal Programs coordinates services related to releases of hazardous substances from a variety of government-owned facilities, vessels, and aircraft.

ATSDR is required under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA or "Superfund") to conduct public health assessments of proposed and listed National Priorities List (NPL) sites. ATSDR also provides support to federal agencies in the form of health consultations, health studies, and other related technical assistance. In addition, a federal agency or other government organization may invite the ATSDR to visit their facility and conduct a public health assessment or provide other support. For these reasons, it is important and useful for Air Force Environmental/Bioenvironmental Engineering personnel and Public Health Officers to be familiar with ATSDR and its health assessment capabilities. This fact sheet describes the ATSDR and the important role it plays in the installation restoration process and the release of hazardous substances associated with Air Force activities. It also provides information on the procedures that must be used by Air Force personnel to access ATSDR services.

ATSDR Service Areas
ATSDR operates in 10 regions and has a staff of 400 including epidemiologists, physicians, toxicologists, engineers, public health educators, and support staff. Headquartered in Atlanta, Georgia, ATSDR serves the public in a number of ways, all based on a central need to assess potentially harmful public exposures to hazardous substances. ATSDR's primary service areas are summarized below:

Public Health Assessments - As stated above, the creation of the ATSDR was mandated under CERCLA to conduct public health assessments of all sites of environmental contamination listed on The Environmental Protection Agency's (EPA) National Priorities List (NPL). A public health assessment (PHA) involves the review of all available information about hazardous substances at a site, and an evaluation to determine whether exposures may adversely impact public health. Public health assessments consider the varieties and concentrations of substances present, as well as potential routes of exposure (e.g., inhalation, ingestion, and direct contact). Other dangers, such as unsafe buildings and other physical hazards, are also considered as part of the PHA. The types of data reviewed during a PHA include results from the laboratory analysis of soil, air, and water samples; unusual occurrences of illness, disease, and death in the community; and quality of life concerns expressed by people near to the site.
A PHA identifies additional health studies and other public health actions that may be needed to fully evaluate the health risks. ATSDR actively involves the public in each stage of the PHA via public meetings, community assistance panels, multi-media communications, and solicitation of public comment prior to PHA finalization.
Health Consultations - A health consultation provides advice on a specific public health issue related to actual or potential human exposures to toxic materials. Any agency or group can request a health consultation; however, most of the consultations performed by the ATSDR are for the Environmental Protection Agency (EPA), as well as state and/or local health and environmental agencies. Approximately 1,000 health consultations are performed by ATSDR every year. Health consultations, which are preliminary, and similar to PHAs, consider much the same information as a PHA, but in less detail and with less initial involvement from the public. Conclusions and recommendations presented in the health consultation may lead to other actions such as increased public involvement, implementation of safety measures (such as fencing a site), completion of a PHA, or issuance of a public health advisory.
Health Studies - As a means to increase understanding of the relationship between exposure to hazardous substances and adverse human health effects, ATSDR may conduct a health study using epidemiological, environmental monitoring/sampling, and surveillance methods. Health investigation studies evaluate representative data collected from a specific group (population) to determine potential or actual exposures and health problems that may require more in-depth study. A health outcomes study investigates persons known to have been exposed to hazardous substances as a means to identify exposure risks to the general public.
Public Health Advisories - When hazardous substances released into the environment pose an immediate and significant danger to people's health, ATSDR responds by quickly issuing a public health advisory to the EPA. Other state and local agencies are also notified, and ATSDR works with them and other agencies to ensure the public is protected. A public health advisory can lead to other ATSDR activities - specifically, a public health assessment.
Exposure Registry - The exposure registry is a system for collecting and maintaining information on persons with documented environmental exposure(s). The exposure registry evolved from the need for fundamental information concerning the potential impact on human health of long-term exposure to low and moderate levels of hazardous substances.
Toxicological Profiles - Data on the health effects of particular hazardous substances is summarized and made available to the public in toxicological profiles. ATSDR also initiates research needed to fill identified data gaps associated with substances under review. Additional information on toxicological profiles is presented below.
Applied Research - ATSDR conducts and funds research to increase scientific knowledge about the effects of hazardous substances on human health.
Health Education - Information and materials on the health effects of toxic substances are developed and disseminated to the public, physicians, and health care agencies by the ATSDR.
Emergency Response - Technical support and advice is provided by ATSDR to states, local agencies, and health care providers in order to improve responses to public health emergencies involving exposures to hazardous substances. ATSDR staff members, experienced in providing emergency assistance, are on call 24 hours a day. ATSDR emergency response personnel also routinely participate in regional and local simulations of responses to accidental releases of hazardous substances. Procedures for accessing ATSDR to assist with Department of Defense (DoD) emergency response needs are discussed later in the fact sheet.
Medical Monitoring - ATSDR provides monitoring to screen populations considered to be "at-risk" for specific diseases or health conditions following exposure to hazardous substances. Individuals are referred for additional evaluation and treatment if necessary.

Unlike the EPA, which is a regulatory agency, ATSDR is an advisory agency. Therefore, they are not authorized to provide medical care or treatment to exposed people, relocate affected populations, or fund site cleanups. ATSDR provides recommendations to EPA for specific actions to protect public health. The EPA considers the recommendations in combination with its environmental restoration mandates. In addition, ATSDR recommendations may require the cooperation and resources of local agencies and States.

ATSDR's Federal Programs
ATSDR's Office of Federal Programs conducts activities related to releases of hazardous substances into the environment from facilities, vessels, and aircraft currently or formerly used, owned, or operated by the U.S. government. These activities involve 250 federal facilities used, owned, or operated by the U.S. Departments of Agriculture, Commerce, Defense, Energy, Interior, Justice, and Transportation; and other independent agencies such as the National Aeronautics and Space Administration (NASA) and the EPA. The functions of the ATSDR Office of Federal Programs include planning, management, and policy recommendations pertinent to the agency's own federal programs, other federal agencies, and public organizations at the national level.

There are a variety of environmental health issues addressed by ATSDR. For example, ATSDR provides assessments, training, and other support to the U.S. Agency for International Development, Office of Foreign Disaster Assistance. The Department of Agriculture may rely on ATSDR to conduct health assessments associated with grain bin fumigants and illegal drug labs. ATSDR works with the DoD to address community health issues, chemical agent cleanup, depleted uranium hazards, chemical terrorism hazards, toxicological concerns, and emergency response situations. The Department of Energy may rely on ATSDR to make recommendations regarding radiation risks and medical monitoring. ATSDR has provided toxicological services and support for the Department of Interior at Indian reservations and National Parks. In addition, ATSDR conducts Superfund site assessments for sites at many types of federal facilities, including those operated by the agencies mentioned above, as well as by the Federal Aviation Administration, the Department of Transportation, the Department of Justice, and NASA.

ATSDR Toxicological Profiles
Background
By Congressional mandate, ATSDR produces toxicological profiles for hazardous substances identified at Superfund sites. To date, there have been 275 identified hazardous substances ranked based on: 1) frequency of occurrence at Superfund sites; 2) toxicity; and 3) potential for human exposure. Toxicological profiles have been published for 209 substances and at least 30 more are in development. ATSDR also prepares toxicological profiles for the DoD and the Department of Energy (DOE) on substances related specifically to federal sites. ATSDR has updated 74 of the published profiles and there are 30 more under revision.

Toxicological profiles are first produced as drafts. ATSDR announces in the Federal Register the release of these draft profiles for a 90-day public comment period. Copies of draft profiles may be requested during the comment period by contacting ATSDR's Division of Toxicology (DT) at (888) 422-8737, or by sending requests to the ATSDR Information Center at atsdric@cdc.gov. After the 90-day comment period, ATSDR considers the incorporation of all comments into the profile. The result is the publication of a final profile, which is distributed for a fee by the National Technical Information Service (NTIS). The final profiles are published in booklet form and can contain several hundred pages. The NTIS may be contacted at (800) 553-6847 or accessed through its World Wide Web (WWW) site http://www.ntis.gov.

All ATSDR toxicological profiles currently in print are available on CD-ROM. This WindowsT based collection greatly enhances the accessibility of the information contained within the profiles. Available to the user are several browsing and searching options, as well as the ability to print or word-process all or portions of the profiles. To purchase a copy of ATSDR's Toxicological Profiles on CD-ROM, contact the CRC Press at (800) 272-7737. Public Health Statements and ToxFAQsT (Answers to frequently asked questions) for many of the toxicological profiles, as well as links to many other sources of toxicological information, are available at the ATSDR WWW site at http://www.atsdr.cdc.gov/.

ATSDR is required by law to provide copies of both draft and final toxicological profiles to state health and environmental agencies, and to make them available to other interested parties. The ATSDR Division of Toxicology maintains an updated and verified mailing list of groups and individuals qualified to receive free copies of profiles. These recipients include health professionals at federal, state, and local levels; academicians; nonprofit/environmental groups; members of the public involved with Superfund sites; and parties with special needs (considered case-by-case). All Bioenvironmental Engineers (BEEs) at installations with Superfund sites should be on the ATSDR mailing list.

Elements of a Toxicological Profile
ATSDR's Toxicological Profiles have been available to the public for many years. The profiles characterize the toxicological and adverse health effects of a particular hazardous substance. Each profile identifies and reviews the key peer-reviewed literature that describes a hazardous substance's toxicological properties. Findings from other pertinent literature are also presented, but these findings are described in less detail than the key studies. The profiles are not intended to be exhaustive documents, and sources that are more comprehensive are referenced.

Each profile begins with a public health statement (PHS) that describes, in non-technical language, a substance's relevant toxicological properties. Following the PHS, detailed information is provided about the health effects of the substance, including discussions of routes of exposure, exposure concentrations, and methods for reducing toxic effects. Additional sections of the profile provide information about the chemical and physical properties of the substance; its use, storage, and disposal; releases to the environment and environmental fate of the substance; and recommended analytical methods for the detection and quantification of the substance in humans and the environment. The adequacy of all information presented, and identification of the need for additional data, are also described. An index of all finalized toxicological profiles by chemical name and NTIS order number is available for viewing at http://www.atsdr.cdc.gov/toxpro2.html.

Coordination Between ATSDR and DoD
ATSDR and the Department of Defense (DoD) have initiated an interagency effort to promote timely execution of ATSDR activities at DoD installations. To meet this goal, ATSDR and DoD entered into a Memorandum of Understanding (MOU) on the development of toxicological profiles for hazardous substances, public health assessments, and related activities at DoD facilities. In addition, guidance has been established to facilitate the exchange of accurate, complete, and current information. Guidelines for the Coordination of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Activities Between the Agency for Toxic Substances and Disease Registry (ATSDR) and the Department of Defense (DoD), February 1995 (Updated December 1996), was prepared jointly by the two agencies. During preparation of the guidance, the DoD was represented by all military components, including the Air Force.

The guidance includes, in part, lists of information needed about CERCLA sites in order for ATSDR to conduct public health assessments. Upon completion of the PHA, installations are expected to annually update ATSDR on actions taken in response to the public health action plan and the public health recommendations in the final release of the PHA. The guidance includes procedures and responsibilities applicable to ATSDR and installations involved in restoration projects and community relations activities. The military department will have an opportunity to review and comment on the draft PHA during the public comment period. If the PHA recommends the performance of additional health studies and/or other activities by the ATSDR, a "notice of intent" and funding requirements will be provided to the DoD military department. Copies of the MOU and Guidance document are available from PRO-ACT, by contacting ATSDR's toll-free information line (888) 42ATSDR or (888) 422-8737, or from the U.S. Army Center for Health Promotion Preventive Medicine (USACHPPM)/ATSDR WWW site http://chppm-www.apgea.army.mil/atsdr/atsdr.htm.

Air Force Guidance
Interactions between the Air Force and ATSDR, including how requests for and responses to ATSDR services are managed, are outlined in Air Force Instruction (AFI) 48-119, Medical Service Environmental Quality Programs, 25 July 1994 and AFI 48-136, Agency for Toxic Substances and Disease Registry Programs, 30 September 1994.

AFI 48-119 identifies Medical Service roles and responsibilities as a member of the Air Force Environmental Quality team in implementing Air Force Policy Directive 32-70, Environmental Quality, 20 July 1994. Section 8 of the AFI describes roles and responsibilities associated with environmental restoration projects.

AFI 48-136 implements Air Force Policy Directive (AFPD) 48-1, Aerospace Medical Program, 22 July 1993, as well as the 14 June 1993 Memorandum of Understanding (MOU) between the Department of Defense (DoD) and the Agency for Toxic Substances and Disease Registry (ATSDR). AFI 48-136 provides detailed guidance and direction for Air Force activities in which ATSDR may play a role. Topics addressed in the AFI include ATSDR's legal mandates, responsibilities of various personnel and organizations within the Air Force, public meetings, public health, emergency response, and funding/programming.

AFI 48-136 also defines the roles and responsibilities of various players in the PHA process. A few of these key roles are discussed below:

The Air Force Institute for ESOH Risk Analysis (AFIERA) provides technical assistance and consultation services to help installations prepare for and respond to ATSDR site visits. AFIERA interfaces directly with ATSDR to discuss technical questions.

The installation Commander is responsible for the installation's interaction with ATSDR and signs review comments prepared in response to ATSDR documents.

The installation Bioenvironmental Engineer (BEE) is the ATSDR point of contact and coordinates activities through the Medical Treatment Facility Commander. Among other duties, the BEE also assembles, maintains, and provides to ATSDR all pertinent information and documents and communicates health assessment and health risk information to installation officials.

The installation Civil Engineering (CE) Squadron or Environmental Management (EM) Flight, as applicable, provides existing environmental and operational reports and data as requested to the BEE for ATSDR's use, and advises and assists with ATSDR activities. CE/EM also is responsible for incorporating ATSDR recommendations, as appropriate, into the installation's Planning, Programming, and Budgeting System (PPBS) process.

During the process of conducting a PHA at an installation, the ATSDR will review contaminant data and exposure pathways from fenceline to fenceline. The BEE is the central coordinator for comments from the installation and command levels on draft profiles prepared for their installation. Comments are then submitted to the Air Force Medical Operations Agency (AFMOA), who upon coordination with the Deputy Assistant Secretary of the Air Force (Environment, Safety, and Occupational Health) (SAF/MIQ), will approve the comments for submittal to ATSDR.

Refer to AFI 48-136 for more detailed information about Air Force requirements and interaction with ATSDR.

ATSDR Activities at AF Facilities
ATSDR has conducted a number of public health assessments and health consultations at Air Force facilities and installations. The agency has also assisted the Air Force by providing health education about environmental hazards, such as contaminated fish, and by providing information and training about toxic substances and emergency response. In addition, ATSDR emergency response staffs are available 24 hours a day to provide technical information and assistance for Air Force emergencies, such as spills or releases of hazardous substances.

During the last 3 years, ATSDR has had a major focus on assessing DoD Base Realignment and Closure (BRAC) sites that are on the National Priorities List (i.e., Superfund sites). ATSDR is working to complete public health assessments for six Air Force installations by the end of fiscal year (FY) 2000. The objective of these assessments is to evaluate past, present and future environmental situations that might affect public health. For BRAC sites planning to transfer land to local communities, ATSDR evaluates information about hazardous substances present at the site, as well as potential future uses of the land, and assesses any risks to individuals who may live or work at the site in the future. ATSDR works with the Air Force and land reuse/rezoning authorities to develop public health recommendations applicable to future public uses of the property.

Example of a Public Health Assessment (PHA) at an AF Facility
Contaminated Groundwater at Castle AFB Not a Public Health Hazard, PHA Concludes
ATSDR issued a public health assessment (PHA) in March 1999 for Castle Air Force Base (AFB), an inactive military base in the San Joaquin Valley of California. The PHA concluded that trichloroethylene (TCE) contamination of groundwater at the base did not pose a public health hazard.

The 2,777-acre installation is surrounded primarily by agricultural areas, but suburban residential areas in several nearby cities are rapidly growing. The installation, which opened in 1941, provided basic flight training and military support for more than 50 years. Before closing in September 1995, Castle AFB employed up to 7,300 individuals.

TCE was detected in groundwater beneath Castle AFB and off site, particularly west and southwest of the base. Routine monitoring of the base drinking water wells, nearby public water supply wells, private wells in the area, and irrigation wells near Castle AFB, indicated that the water used by the public had contained low-level TCE concentrations in the past. These past exposures, however, were minimized by the Air Force's aggressive efforts to provide bottled water and alternative drinking water sources to affected individuals. Because of the short duration of exposure, low exposure doses, and timely Air Force remediation efforts, ATSDR found, upon review of all existing groundwater data, that no public health hazard existed in on-site and off-site areas where people had ingested TCE-contaminated groundwater at levels above health-based guidelines. Currently, all public water supplies in the area meet EPA's health-based drinking water standards. In addition, Castle AFB has several active remediation systems in place to treat and capture the contaminated groundwater. To ensure the continued delivery of safe drinking water to nearby communities, Castle AFB has agreed to supply alternate drinking water sources should it become necessary in the future.

Examples of Health Consultations at AF Facilities
ATSDR Health Consultation Reassures AF About Safety of Using Site at Former Plattsburgh AFB, NY
ATSDR assisted the Air Force in maintaining good community relations in the wake of a Health Consultation conducted by the agency at the former Plattsburgh Air Force Base, NY. In July 1996, ATSDR responded to an Air Force request for assistance in assessing safety issues associated with on-base areas designated for attendees of a 3-day music festival.

ATSDR evaluated analytical data representative of standing surface water and surface soils present in swales (low areas) along the former flight line. It was determined that any residual chemicals in the swales did not pose a health concern to attendees who would be camping in the swale areas.

Because of ATSDR's health consultation and recommendation, thousands of community members were able to enjoy a 3-day concert event, and the Air Force was reassured that this activity posed no health hazard to the attendees.

Groundwater Not a Public Health Hazard at Brooks AFB, TX
Members of the Brooks AFB community were concerned about the potential health effects of relatively low levels of trichloroethylene (TCE) present in groundwater beneath the base. The aquifer affected by the TCE had never been used as a drinking water supply because of its otherwise poor quality. However, the community was concerned about possible exposures to potential TCE vapors in soils or local surface waters that may have received discharge from the affected aquifer. ATSDR was invited to Brooks AFB to perform a health consultation. ATSDR evaluated existing environmental data and made a determination about whether the TCE contamination in groundwater posed a health hazard to the community.

ATSDR's 1998 health consultation concluded that due to the low contaminant concentrations, the groundwater did not present any public health hazard. It was further determined that it was unlikely that TCE vapors would be generated that could migrate from the groundwater to the ground surface, or that TCE-contaminated groundwater would migrate the distance to local streams. The ATSDR health consultation provided reassurance to the Brooks AFB community that the groundwater was not a health threat.

For More Information...

The ATSDR WWW site contains a variety of information and links to related sources. The home page is located at http://www.atsdr.cdc.gov. The ATSDR Science Corner (http://www.atsdr.cdc.gov/cx.html) is a gateway to environmental health information and resources. It provides a simple and user friendly menu of ATSDR information and other related environmental health information on the WWW. The primary focus of the ATSDR Science Corner is to find and share global information resources with the public on the linkage between human exposure to hazardous chemicals and adverse human health effects. The menu is dynamic and new environmental health information resources are cited, searched, and documented as they come on-line.
The EPA Office of Pollution Prevention and Toxics (OPPT) maintains a WWW site at http://www.epa.gov/opptintr/. OPPT has the responsibility, as delegated by the Toxic Substances Control Act (TSCA), for assuring that chemicals made available for sale and use in the United States do not pose any adverse risks to human health or to the environment. OPPT also manages the Toxics Release Inventory (TRI), the new Chemical Right-To-Know Initiative, the Design for the Environment (DFE), Green Chemistry programs, and the lead, asbestos and Polychlorinated Biphenyls (PCBs) programs. The OPPT WWW site allows users access to a variety of information on chemicals in the environment and the potential health risks they pose. OPPT Chemical Fact Sheets are available at http://www.epa.gov/chemfact/.
The Air Force Institute for Environment, Safety, and Occupational Health (ESOH) Risk Analysis (AFIERA) is headquartered at Brooks AFB, TX. The Environmental Science Branch of AFIERA's Risk Assessment Division provides scientific and professional risk analysis consultation and investigation in environmental and occupational health to protect the environment and human health. They develop and apply tools for enhancing site-specific risk assessment and toxicology support. They also serve as the Air Force focal point for activities involving the Agency for Toxic Substance and Disease Registry (ATSDR). AFIERA's ESOH Service Center offers one-stop shopping to customers in need of environment, safety, and health information or support. Contact the ESOH Service Center at DSN 240-5454, COMM 210-536-5454, or (888) 232-ESOH (3764). In addition, the AFIERA WWW site (http://sg-www.satx.disa.mil/iera/) contains links to the various branches and divisions within AFIERA, including the ESOH Service Center.
The United States Air Force School of Aerospace Medicine (USAFSAM), located at Brooks AFB, TX, provides training, education, and consultation in support of Air Force medical operations, human performance enhancement, occupational health, disease prevention, environmental quality, and aeromedical evacuation. A broad spectrum of training courses is offered by USAFSAM to Bioenvironmental Engineers and Public Health Officers. Visit the USAFSAM WWW site at http://wwwsam.brooks.af.mil/.
The United States Air Force Medical Service, Medical Operations Agency, Environmental & Occupational Health Division (AFMOA/SGOE), Bolling AFB, DC, is the home of USAF Bioenvironmental Engineering (BEE). The AFMOA/SGOE POC for ATSDR-related issues is Mr. Charles Weir, ATSDR Contact, AFMOA/SGOE, Bolling AFB, DC, DSN 297-4323, charles.weir@usafsg.bolling.af.mil. Visit the AFMOA/SGOE WWW site at http://sg-www.satx.disa.mil/moasgoe/index.htm. AFMOA/SGOE is the Office of Primary Responsibility (OPR) for most of the Air Force Occupational Safety & Health (AFOSH) Standards (48 Series - Aerospace Medicine). Links to downloadable versions of current AFOSH Standards can be found at the Air Force Electronic Publications WWW site: http://afpubs.hq.af.mil/pubs/publist.asp?puborg=AF&series=48.
The Office of the Deputy Assistant Secretary of the Air Force (Environment, Safety, & Occupational Health) (SAF/MIQ) is responsible for providing guidance, direction, and oversight to the formulation, review, and execution of plans, policies, programs, and budgets for a broad spectrum of environmental health concerns. The POC within SAF/MIQ is LtCol John W. Coho, Bioenvironmental Engineer Fellow, (703) 693-9534, cohoj@pentagon.af.mil. The SAF/MIQ World Wide Web (WWW) site is located at http://www.safmi.hq.af.mil/saf-miq/miq.htm.

Document References

Air Force Instruction (AFI) 48-119, Medical Service Environmental Quality Programs, 25 July 1994.
Air Force Instruction (AFI) 48-136, Agency for Toxic Substances and Disease Registry Programs, 30 September 1994.
ATSDR informational materials including ATSDR Fact Sheet, About ATSDR, ATSDR Agency Overview, ATSDR Health Consultations, ATSDR Public Health Assessments, Office of Federal Programs, and Public Health Advisories.
Toxicological Profile for Titanium Tetrachloride, ATSDR, September 1997.
Environmental Data Needed for Public Health Assessments - A Guidance Manual, ATSDR, June 1994.
ATSDR Toxicological Profile Information Sheet and Index of Finalized Toxicological Profiles, continuously updated, http://www.atsdr.cdc.gov/toxpro2.html.
Guidelines for the Coordination of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Activities Between the Agency for Toxic Substances and Disease Registry and the Department of Defense, Deputy Under Secretary of Defense (Environmental Security) (DUSD[ES]), February 1995.
Agency for Toxic Substances and Disease Registry Program Management Plan, USACHPPM, 1995.
Memorandum of Understanding Between the Agency for Toxic Substances and Disease Registry, U.S. Public Health Service, and the U.S. Department of Defense on the Development of Toxicological Profiles for Hazardous Substances and Public Health Assessments and Related Activities at DoD Facilities, 14 June 1993.
ATSDR Public Health Assessment Guidance Manual, available at http://www.atsdr.cdc.gov/HAC/HAGM/.