4
Recommendations and Next Steps

Throughout this report, the committee notes the value of the NIOSH Roadmap in bringing together a substantial body of research across several varying disciplines. In assessing the draft Roadmap and making suggestions for improvement, the committee provides the following findings and recommendations toward ensuring that research is focused on addressing the potential for health concerns of workers and communities exposed to asbestos and the other elongate mineral particles. The report concludes with the committee’s thoughts on next steps for facilitating a sustained effort to implement and disseminate the findings of the research.

FINDINGS

In its statement of task the committee was charged with providing a review of the Roadmap document and answering five specific questions detailed below. The text of the previous three chapters discusses the issues presented in the task and provides the specific details that form the basis for the findings, each of which answers one of the task questions.

Statement of Task Question 1: Is the document consistent with the state of scientific understanding of the toxicity, occupational exposures, epidemiology, and sampling or analytical methods? Should any of the content of this section be modified, based on the state of scientific understanding of these issues? Are there any significant studies that have been overlooked?



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4 Recommendations and Next Steps Throughout this report, the committee notes the value of the NIOSH Roadmap in bringing together a substantial body of research across sev- eral varying disciplines. In assessing the draft Roadmap and making sug- gestions for improvement, the committee provides the following findings and recommendations toward ensuring that research is focused on ad- dressing the potential for health concerns of workers and communities exposed to asbestos and the other elongate mineral particles. The report concludes with the committee’s thoughts on next steps for facilitating a sustained effort to implement and disseminate the findings of the research. FINDINGS In its statement of task the committee was charged with providing a review of the Roadmap document and answering five specific questions detailed below. The text of the previous three chapters discusses the is- sues presented in the task and provides the specific details that form the basis for the findings, each of which answers one of the task questions. Statement of Task Question 1: Is the document consistent with the state of scientific understanding of the toxicity, occupational expo- sures, epidemiology, and sampling or analytical methods? Should any of the content of this section be modified, based on the state of scientific understanding of these issues? Are there any significant studies that have been overlooked? 77

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78 REVIEW OF THE NIOSH ROADMAP Finding 1: The NIOSH Roadmap is generally consis- tent with the state of scientific understanding of the toxicity, occupational exposures, epidemiology, and sampling or analytical methods. The committee iden- tified several areas that could be strengthened and references those areas in the narrative and in the committee recommendations. The Roadmap would be made more coherent and useful if it included or refined four key components: vision or purpose, ra- tionale, goals, and framework (systematic plan for conducting the research). Statement of Task Question 2: Does the document clearly and ade- quately explain the scientific rationale for research on the mineral- ogy, morphology, dimensions, and surface characteristics of elongate mineral particles, and is its treatment of this issue consis- tent with the state of scientific understanding of the toxicity, occupa- tional exposures, and epidemiology of elongate mineral particles? Finding 2: The Roadmap explains the scientific ra- tionale for research on the mineralogy, morphology, dimensions, and surface characteristics of elongate mineral particles. This is presented primarily through discussions of toxicological studies of asbes- tos and of synthetic fibers that provide the back- ground on why research is needed to examine mineral particle characteristics and their impact on toxicity. However, the mineralogical discussions were found lacking in many areas. Adding more informa- tion on the occupational and environmental health rationale for research in this area would be helpful, including available data on the types of occupations and environmental situations likely to result in expo- sure to more specific types of elongate mineral parti- cles. As noted in its recommendations, the committee urges that the Roadmap include a clear statement of the overarching vision for the research. The commit- tee also believes that since the term elongate mineral particle covers a broad range of mineral particles of interest in this research, its use should be limited to

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79 RECOMMENDATIONS AND NEXT STEPS research efforts and emphasizes that this term is not a rigorous mineralogical term. Statement of Task Question 3: Does the document discuss the most significant issues regarding mineralogy, morphology, dimensions, and surface characteristics of elongate mineral particles? Should any of the discussed issues be omitted or revised, based on the state of scientific understanding of these issues? Are there any significant issues that should be added? Finding 3: The NIOSH Roadmap provides a reason- able discussion of some of the significant issues re- garding mineralogy, morphology, dimensions, and surface characteristics of elongate mineral particles as related to their potential to cause disease, but as noted in response to Question 4 below, the commit- tee urges a greater emphasis on the relevant minera- logical research, in particular on mineralogical characterization. The committee notes significant in- consistencies and deficiencies in mineralogical termi- nology and nomenclature and provides a series of recommendations to clarify and make more rigorous, consistent, and complete the terminology used in the text and the glossary in the Roadmap. Statement of Task Question 4: Is the research proposed likely to ef- fectively address the most significant issues regarding mineralogy, morphology, dimensions, and surface characteristics of elongate mineral particles? Should any of the discussed research be omitted or revised, based on the state of scientific understanding of these is- sues? Is there any significant research that should be added? Finding 4: The research effort proposed is likely to address some of the most significant issues regarding mineralogy, morphology, dimensions, and surface characteristics of elongate mineral particles. How- ever, as noted throughout this report and in its rec- ommendations, the committee calls for more details to be included on mineralogical research, with an emphasis on a systematic approach to characteriza-

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80 REVIEW OF THE NIOSH ROADMAP tion of the minerals that is integrated in a meaningful way into toxicological and other studies to better un- derstand the relative disease-causing potential of a range of elongate mineral particles relevant to hu- man exposures. This effort is part of a consistent strategy for characterizing and testing the relative toxicities of elongate mineral particles and mixtures. Exploration of additional opportunities for epidemi- ological research is needed as well as careful exami- nation of the exposure assessment methodologies. The effort is likely to be more successful if it involves interdisciplinary collaboration and integration. Statement of Task Question 5: Was the process that was used to de- velop and revise the document and that is described in the Foreword, including the mechanisms for input from the scientific and stake- holder communities, appropriate from a scientific perspective? Finding 5: The process used by NIOSH to develop and revise the document that is described in the Foreword was, in the opinion of the committee, gen- erally appropriate in being open and transparent with multiple opportunities for input into the Road- map document. The process would have benefited from greater involvement of the mineralogical com- munity throughout its formulation. An interdiscipli- nary approach may have been better applied in the development process. RECOMMENDATIONS Clarify Roadmap Structure and Vision Because the NIOSH Roadmap brings together a great deal of infor- mation and a wealth of ideas on future directions for research, it is neces- sary for the document to have a clearly stated vision and rationale. The details of the Roadmap can all too easily overtake the view of the larger objective, and therefore the committee urges that the vision and rationale be clearly laid out in the early part of the Roadmap. Further, it is the

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81 RECOMMENDATIONS AND NEXT STEPS committee’s hope that a more systematic and tiered approach to the re- search agenda will allow research to be conducted in a manner that will answer the questions regarding which physical and chemical characteris- tics of elongate mineral particles are primary determinants of toxicity to humans, thus allowing unambiguous identification of specific types of mineral particles that would be of concern to human health. Recommendation 1 Clarify the Vision and Rationale NIOSH should revise the Roadmap to clearly state the over- arching vision and rationale for the research program. • The overarching vision should point toward research that will differentiate effects from exposure to a range of elongate mineral particles and help deter- mine the influence of size, shape, and other physical and chemical characteristics of these particles on human health. This research would identify which elongate mineral particles, or what characteristics of those particles, should be included in recommenda- tions to protect the public and workers from hazard- ous occupational and environmental exposures. • The rationale for the Roadmap should clearly articu- late the influence that ongoing and future research can have on improving public and occupational health. • A clearer vision and purpose would help strengthen the goals that the research is intended to support. The research should be prioritized as to the hazard and exposure. Recommendation 2 Include Key Components NIOSH should ensure that four key components are included or refined in the Roadmap: (1) vision, (2) rationale, (3) goals, and (4) framework. Improve Terminology As discussed in Chapter 3, terminology and nomenclature have been an ongoing challenge for this area of research. Because of the ambiguous and confusing terms for asbestos and the other mineral particles used in the past, it is important for the Roadmap to place strong emphasis on

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82 REVIEW OF THE NIOSH ROADMAP specificity in its use of terminology and nomenclature and on providing references to definitions from standard reference texts in each field. The Roadmap needs definitions for all technical terms, given the interdisci- plinary nature of the research and the need to maintain consistency across disciplines. The umbrella term elongate mineral particles provides an important starting point for discussions on the broad range of mineral particles un- der investigation. However, because considerable uncertainty remains regarding the range of potential toxicities within the spectrum of elongate mineral particles, it is the committee’s view that at this time the term elongate mineral particles should not be used for regulatory purposes. Recommendation 3 Improve Terminology NIOSH should revise its Roadmap with careful attention to consistency in the use of nomenclature and terminology. The goal is that authoritative terminology should permeate re- search and regulatory efforts, specifically: • For research purposes, the term elongate mineral par- ticles is useful for encompassing a broad category of mineral particles of a certain dimension and aspect ratio; more specific mineralogical terminology would be needed for regulatory purposes; • Revisions should be made to the Roadmap glossary using accepted mineralogical terminology or nomen- clature from the current American Geological Insti- tute’s Glossary of Geology or other standard texts; citations should be provided for each definition; non- standard terms should be removed from the glossary and the main text; and • Terminology used in sections referring to epidemiol- ogy and toxicology should also use definitions from current standard texts and be included in the glos- sary with citations.

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83 RECOMMENDATIONS AND NEXT STEPS Strengthen the Emphasis on Mineralogy The Roadmap outlines a set of studies to improve knowledge on the potential health effects of elongate mineral particles and the ways in which human exposures could best be studied. A key piece of this re- search plan is the development of well-characterized reference mineral samples that could then be incorporated in toxicological studies to assess the variability in the toxicity of different types of elongate mineral parti- cles. The identification, classification, and characterization of unknown mineral particles from workplace or environmental exposures require knowledge of and comparison to similar, well-characterized mineral par- ticles and associated geological locales. Similarly, toxicological experi- ments require well-characterized reference mineral samples to allow systematic intra- and interlaboratory comparisons of results. While the Roadmap notes the need for standardized reference minerals, the com- mittee believes that there is a need for a more detailed approach for de- veloping a central repository of these samples. Priorities for the repository should focus on those minerals with the greatest potential for human exposures. Although the epidemiological and toxicological dis- cussions in the Roadmap were generally thorough, greater depth and rigor is needed in the mineralogical discussions. Recommendation 4 Strengthen the Emphasis on Mineralogi- cal Research NIOSH should revise the Roadmap to give greater attention to the mineralogical foundations of the proposed research. Discussions of mineralogy in the Roadmap should be strengthened by incorporating current understanding in this field using accepted terminology and by proposing research on the fundamental mineralogical properties relevant to toxicology, epidemiology, and exposure assessment. Specifi- cally, mineralogical research is needed on physical and chemical properties, biopersistence, and mineral source characterization, including the development of standard sets of tests and methodologies. Recommendation 5 Develop a Reference Mineral Repository NIOSH should work with other federal agencies and organi- zations to develop a repository of well-characterized and standardized reference minerals for use in research.

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84 REVIEW OF THE NIOSH ROADMAP Focus the Research Efforts NIOSH has put together a comprehensive and broad-based re- search Roadmap that could be improved through further emphasis on implementing a systematic and interdisciplinary approach to the out- lined research. Improved efforts on characterizing the elongate min- eral particles used in toxicological research could go a long way toward ensuring that study results can be compared. Additionally, us- ing a tiered systematic process to study the toxicity of various types of mineral particles, as outlined in Chapter 3, would assist in bring- ing clarity to the range of toxicities and help to identify any specific mineralogical properties of concern to human health. A wider focus in epidemiological studies and new approaches to exposure assess- ment will also be of great benefit in addressing these issues. Recommendation 6 Emphasize Interdisciplinary Efforts NIOSH should revise the Roadmap to emphasize the need for collaboration and integration of research among the min- eralogical, toxicological, epidemiological, and exposure as- sessment disciplines. Recommendation 7 Develop a Systematic Strategy for the Toxicological Assessment of Elongate Mineral Particles NIOSH should revise the Roadmap to describe a systematic tiered strategy for characterizing and testing the relative tox- icities of elongate mineral particles and/or their mixtures. The strategy should include the following: • Characterizing the chemical and physical properties of the elongate mineral particles beginning with petrographic analysis and proceeding through X-ray diffraction, transmission and scanning electron mi- croscopy, and other techniques; and • Using tiered panels of in vitro and in vivo assays of increasing complexity to identify and characterize biological responses and categorize the potential hazards.

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85 RECOMMENDATIONS AND NEXT STEPS Recommendation 8 Emphasize Additional Research Areas NIOSH should revise the Roadmap to include an emphasis on the following: • Incorporating petrographic analysis and developing new exposure assessment tools using electron micros- copy methods that are mineralogically and toxico- logically relevant and that minimize reliance on phase contrast microscopy methods; • Toxicological mechanisms of action of a range of well-characterized elongate mineral particles with at- tention to early biomarkers of human health effects; • Additional opportunities for epidemiological research including studies of Libby, Montana, worker and resident populations, as well as cohorts exposed to elongate mineral particles in other countries; and • Statistical methods for addressing analytical variabil- ity and determining the relationships between min- eralogical and exposure variables and health outcomes. STEPS TOWARD A RESEARCH STRATEGY As discussed in Chapter 2, a research roadmap is one component of a larger research strategy. The final section of the NIOSH Roadmap notes that the research agenda “will require a substantial investment of time, scientific talent, and resources by NIOSH and its partners to formulate research programs and prioritize research projects to achieve the pro- posed goals” (NIOSH, 2009, p. 92). The committee urges NIOSH to continue its work with other federal agencies (e.g., the U.S. Environ- mental Protection Agency, the National Institute of Environmental Health Sciences, the U.S. Geological Survey, the Occupational Safety and Health Administration, the Mine Safety and Health Administration, and the Agency for Toxic Substances and Disease Registry) and private sector and nonprofit organizations with a focus on developing a research strategy that details the resources, priorities, responsibilities, and com- mitments needed to accomplish and evaluate this research effort. Many of the issues that require additional research to better understand the rela- tive disease-causing potential of various types of elongate mineral parti- cles are common both to the fields of occupational health, as pertaining

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86 REVIEW OF THE NIOSH ROADMAP to work-related exposures, and environmental health, as related to expo- sure of the general public. Too often research programs present broad goals for important research but do not back them up with a concrete and realistic plan for accomplishing the goals. Such a strategy might contain, in addition to the research framework and goals elaborated in the Roadmap, the following elements: • An interdisciplinary system for prioritizing research activities to ensure maximum efficiency in an environment in which not eve- rything possible can reasonably be undertaken at once and mul- tiple disciplines need to work together to determine the priorities; • An approximation of the resources needed to carry out high- and middle-priority efforts; and • A plan for review, evaluation, and accountability for those re- ceiving support for research contained in the Roadmap. As NIOSH and other partners move forward in implementing the Road- map, discussions are needed on successful models of establishing effective partnerships and management of research efforts to ensure a coordinated ap- proach to address specific information gaps. REFERENCE NIOSH (National Institute for Occupational Safety and Health). 2009. Revised draft. NIOSH current intelligence bulletin. Asbestos fibers and other elongated mineral particles: State of the science and roadmap for research. January 2009. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. http://www. cdc.gov/niosh/docket/pdfs/NIOSH-099b/099B-040109AsbestosNA ReviewDoc.pdf (accessed September 18, 2009).