Review of the U.S. Naval Medical Research Institute's Toxicology Program (1994)

During the 1950s, the growth in the variety and uses of synthetic chemicals, the increasing complexity of weapon systems, and the potential for mission impairment resulting from health effects of exposures to chemical contaminants caused the U.S. Navy to develop its own formal in-house toxicology program. Fleet personnel were exposed to many chemical substances used aboard Navy ships and submarines. Those substances included fuels, fuel additives, propellants, hydraulic fluids, and lubricants. Many toxicological questions were raised concerning long-term habitability of nuclear submarines. Other questions involved the exposure of Navy divers to chemical contaminants under hyperbaric conditions and the lack of regulatory standards for many chemicals used only by the Navy or for exposure scenarios unique to Navy personnel. Therefore, the Navy Toxicology Unit was established in 1958 at the National Naval Medical Center in Bethesda, Maryland.

In its early stages, the Navy's toxicology program focused on exposures occurring under special Navy and Marine Corps operating conditions, such as continuous exposures for up to 90 days during submarine missions, and on materials developed for use under those conditions. The exposures, predominantly by inhalation, ranged from intermittent to continuous for periods of minutes to months. The issues were limited to how nonstandard exposure durations altered the expression of toxicity. Based on findings from toxicity studies, permissible exposure limits were derived for emergency and continuous exposures.

The emphasis of the Navy's toxicology program gradually shifted over the years from setting exposure standards to developing or adapting research methods that would improve the toxicity characterization process. This shift in emphasis within the toxicology program increased the need for mechanistic and predictive research studies.

In 1975, personnel and resources of the Navy Toxicology Unit were reassigned to the Toxicology Division of the Environmental Bioscience Department of the Naval Medical Research Institute (NMRI) in Bethesda, Maryland. However, in 1976, it was decided that the Navy's Toxicology Division and the U.S. Air Force's toxicology program (the Aerospace Medical Research Laboratory) at Wright-Patterson Air Force Base (WPAFB) near Dayton, Ohio, would mutually benefit from collocation and joint use of resources and personnel. This association would foster collaboration and joint execution of their research and toxicity-characterization efforts. Thus, NMRI created the NMRI Toxicology Detachment (NMRITD) at WPAFB.

NMRITD's mission is to (1) develop the biomedical data necessary to characterize the toxicity of materials of interest to the Navy; (2) use these data to formulate occupational and environmental health-hazard evaluations and risk assessments, including appropriate personnel exposure limits, which address Navy-specific circumstances of exposure; and (3) develop and maintain a cadre of naval personnel skilled in the discipline of toxicology and its application to health-hazard evaluation and risk assessment.

NMRITD currently employs 34 naval and civilian personnel and has an annual budget of approximately 3 million dollars. It recently identified a need for further growth in its toxicology program and began to prepare a “Ten-Year Strategic Plan” for the future direction of its toxicology program. This plan is intended to maintain scientific credibility in the field of toxicology and to be responsive to the Navy's requirements as they arise. Before formalizing such a comprehensive document and proceeding with significant changes in its toxicology program that would involve substantial expenditures, the Navy decided that a critical review of current activities and future plans for the toxicology program would be useful. Therefore, the chief of the Navy's Bureau of Medicine and Surgery requested the National Research Council (NRC) to review NMRITD's current toxicology program and identify its strengths and weaknesses, review the initial draft of its Ten-Year Strategic Plan and

determine its appropriateness, and make recommendations for their improvement.

In response to the Navy's request, NRC assigned the project to the Committee on Toxicology (COT), which established the Subcommittee to Review the U.S. Naval Medical Research Institute's Toxicology Program. The subcommittee members visited NMRITD at WPAFB, where its officers and associated personnel gave tours of its facilities and made presentations on its ongoing research efforts. During subsequent meetings, the subcommittee evaluated NMRITD's current toxicology program, its preliminary Ten-Year Strategic Plan, and other issues related to improving the toxicology program. The subcommittee's recommendations, which are based on observations from the site visit and from subcommittee deliberations, are listed below.

The subcommittee recommends the following changes in NMRITD's current toxicology program:

• The toxicology program should be expanded to

  • Place greater emphasis upon predicting toxicity of materials used in Navy operations.

  • Place greater emphasis upon developing permissible exposure limits for exposure scenarios encountered by Navy personnel.

  • Evaluate degradation in field-personnel performance resulting from sublethal exposures.

  • Assess the impact of toxicity on field operations.

• The major emphasis of NMRITD should be on applied toxicology with some long-range basic research that is targeted to solving the Navy 's toxicological problems. Although the Navy's primary need is for applied toxicology, support should be given to basic research on matters that are unique to the Navy.

• Staffing: Since the tours of duty of military personnel typically are of short duration, greater emphasis should be given to the core group of

civilian scientists to provide the continuity necessary for long-term program execution, for staying abreast of current trends in toxicology, and for conducting high-quality scientific studies to support the Navy's needs. In addition, assignments should be stabilized for Navy personnel at NMRITD, and rank-advancement opportunities should be provided within NMRITD.

• Space and Facilities: The current laboratory buildings are old and thus have potential problems with leaking pipes, ventilation, and air handling. Therefore, attention to adequate and suitable space is necessary to support state-of-the-art toxicological research.

• Equipment: Although a few pieces of equipment are state of the art, some obvious deficiencies remain. For example, some of the equipment at NMRITD, such as gas chromatography/mass spectrometer and nuclear magnetic resonance instrumentation, is outdated. Such equipment should be modernized.

• Computerization: The subcommittee recommends that NMRITD install a computer system that would permit use of advanced methods of data accumulation and analysis and establish a computerized data base for known and suspected toxic chemicals of current (and possible future) interest to the Navy. This system would aid in addressing risks in current studies and assist in decision-making regarding future research.

• Funding: It is extremely difficult to build a quality research program with the current 1- to 2-year funding cycle. Therefore, serious consideration should be given by the appropriate administrative office within the Navy to coordinate and improve funding procedures for NMRITD. The funding in NMRITD is project-directed rather than problem-directed, which leads to funding of projects that are not capable of supporting the critical personnel and the equipment needed to do state-of-the-art research.

The subcommittee recommends the following on NMRITD's strategic plan:

• The long-term plan should focus on generating data to establish limits for occupational and environmental exposures to chemicals that are under consideration for use in weapons and other systems.

• NMRITD currently does not have the expertise required to conduct state-of-the-art work in reproductive and developmental toxicology, neurotoxicology, immunotoxicology, and genetic toxicology. Therefore, a section of the long-term plan should be dedicated to increasing NMRITD's competency in those areas of toxicology to enable it to fulfill its mission.

• Additional expertise and programs should be added to NMRITD to conduct health-based risk assessments. The Navy's needs suggest that reproductive and developmental toxicology, neurotoxicology, immunotoxicology, and genetic toxicology should be given greater emphasis. Other specialties might be necessary as needs evolve. However, the primary focus should remain on research directly applicable to solving the Navy's toxicological problems.

• The Navy's process for acceptance of proposals and for funding should dictate the mixture of applied and basic research studies as defined by immediate and long-range needs.

• Annual review of the research plan with the best projections of need on a multiyear basis should be done to maintain efficiency, ensure scientific focus, and keep costs at a minimum.

• External peer review by experts in each subspecialty of toxicology is essential for a state-of-the-art effort; external peer review might be achieved through a science advisory board.

The subcommittee made recommendations on other related issues:

• Highly competent individuals with expertise in various subspecialty fields of toxicology are essential to conducting human health risk assessments. To meet this need, access to a multidisciplinary group of scientists should be provided.

To satisfy its mission, NMRITD should

• Develop a world-class biomedical data base on the toxicity of materials of interest to the Navy.

• Identify chemicals with potential for exposure to naval personnel and determine the toxicity of those chemicals.

• Identify biomarkers of exposure, effect, and susceptibility relevant to the same chemicals.

• Develop a state-of-the-art analytical testing laboratory for chemical identification.

• Conduct research to produce data and information for risk-assessment purposes to meet the Navy's needs.

• Serve as a resource to conduct occupational and environmental health-hazard evaluations and risk assessments for chemicals and exposure scenarios particular to the Navy.

• The scientific awareness and professional development of staff can be enhanced by

  • Improved access to information resources, such as libraries and electronic data banks and data bases.

  • Improved opportunities and encouragement to publish in the scientific open literature.

  • Participation of scientists in professional scientific activities (meetings, advisory committees, etc.).

  • Recognition by the Navy that longer assignments of its scientific personnel at NMRITD would enhance the efficiency of the detachment and the development of its scientists.

• Establishment of a triservice toxicology program (comprising the Navy, Army, and Air Force) would be cost effective; Air Force and Army participation in a team effort would ensure a viable and dynamic toxicology unit.

• Use of an on-site contractor as an integral part of the team is highly encouraged. The contractor could provide expertise and facilities that are lacking in the Navy or other branches of the armed services. Coordination and communication between contractor scientists and military

scientists could substantially improve the overall productivity of the toxicology unit, which should eventually become a prototypical institute at WPAFB. The triservice program would provide resources for the military in applied and basic toxicology and in toxicity characterization and testing.

• NMRITD should continue to expand its relationships with other sources of scientific knowledge, such as other DOD organizations (e.g., the Armed Forces Institute of Pathology, the Armed Forces Epidemiology Board, and the Army Corps of Engineers), federal agencies (e.g., the Environmental Protection Agency, the National Institutes of Health, and the Occupational Safety and Health Administration), industry, foreign governments, and international organizations (e.g., the World Health Organization's International Program for Chemical Safety). Through these relationships, NMRITD should take advantage of professional resources while benefiting from research data on current health and environmental issues that might be of interest to the Navy. These contacts might also lead to participation in new areas of research and new program development.

• External contracts should be used to complement internal projects where additional, highly specialized information is required. External contracts could ensure that work products from NMRITD represent state-of-the-art scientific toxicological information. Contracts should also be funded to support external scientific review processes.