Approaches for Integrated Risk Assessment

Human and Ecological Risk Assessment: Vol. 9, No. 1, pp. 267-272 (2003)

Approaches for Integrated Risk Assessment Wayne R. Munns, Jr.,1* Robert Kroes,2 Gilman Veith,3 Glenn W. Suter II,4 Terri Damstra,5 and Michael D. Waters6 1

U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, 27 Tarzwell Drive, Narragansett, RI 02882, USA. 2Institute for Risk Assessment Sciences (IRAS), Utrecht University, PO Box 80176, NL-3508 TD Utrecht, The Netherlands. 3U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, NHEERL Building, MD-87, Research Triangle Park, NC 27711, USA. 4U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, 26 W. Martin L. King Drive, MC117, Cincinnati, Ohio 45268, USA. 5World Health Organization, Interregional Research Unit, P.O. Box 12233, MD EC-10, Research Triangle Park, NC 27709, USA. 6U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, NHEERL Building, MD-51A, Research Triangle Park, NC 27711, USA

ABSTRACT Recognizing the need to enhance the effectiveness and efficiency of risk assessments globally, the World Health Organization’s International Programme on Chemical Safety, the U.S. Environmental Protection Agency, the European Commission, and the Organization for Economic Cooperation and Development developed a collaborative partnership to foster integration of assessment approaches used to evaluate human health and ecological risks. The objectives of this effort included: improving understanding of the benefits of integration, identifying obstacles to the integration process, and engaging key agencies, organizations, and scientific societies to promote integration. A framework with supporting documentation was developed to describe an approach for integration. Four case studies were constructed to illustrate how integrated risk assessments might be conducted for chemical and nonchemical stressors. The concepts and approaches developed in the project were evaluated in an international workshop. The goal of this effort was international acceptance of guidance for integrated risk assessment. Key Words: human health risk assessment, ecological risk assessment, integrated risk assessment. *

Corresponding author: Tel(voice): 401-782-3017, Tel(fax): 401-782-3030; [email protected] This work is a product of the U.S. Government and is not copyrighted.

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INTRODUCTION The goals of chemical safety programs encompass the prevention or management of short-term and long-term adverse effects to humans and the environment from the production, use, transport, and disposal of chemicals. For practical and historical reasons, the tools and assessment methods used internationally to assess and manage the risks of chemicals to human health have generally developed independently from those used to assess risks to the environment. However, recognition is increasing that both humans and the environment can be more effectively protected by more integrated approaches to research, risk assessment, and decision making (e.g., Cirone and Duncan 2000; Harwell et al. 1992; Harvey et al. 1995; Van Leeuwen and Hermens 1995; Mennes et al. 1998; Suter et al. 1995, Vallentyne 1997; Vermeire et al. 1997; Wilson 1998; Five Winds International 2000; Di Giulio and Benson 2002; and others). Such integration supports solutions of multichemical, multimedia, multiroute, and multispecies problems, thereby increasing the effectiveness of risk management and environmental protection decisions. In response to the need for integration, the International Programme on Chemical Safety1 (IPCS), in collaboration with the U.S. Environmental Protection Agency (USEPA), the European Commission (EC), the Organization for Economic Cooperation and Development, and other international and national organizations formed a working partnership to promote international understanding and acceptance of the concepts of and approaches for integrated risk assessment. Three specific objectives were identified to meet this goal: (1) enhance understanding of the benefits of integration, (2) identify and understand obstacles to integration, and (3) engage key scientific organizations to promote an integrated approach to risk assessment. This paper provides an overview of the IPCS project on Approaches to Integrated Risk Assessment (WHO 2001), and introduces seven companion papers describing the products of that effort. INTEGRATION OF RISK ASSESSMENT The term “integration” can have many meanings, and several opportunities for integration exist within risk assessment. For example, human health assessments are usually performed on an endpoint-by-endpoint basis, with limited interaction between the data collection and analysis activities within and between assessments of exposure and effects. Ecological risk assessments can be similarly “stovepiped” as risks to multiple assessment endpoints are estimated individually. There are additional opportunities to integrate assessment activities among classes of chemicals, between chemicals and other (nonchemical) stressors, and between risk assessment and risk management. Suter et al. (2003) describe many of the types of integration possible, offering a way to avoid overcomplication of any particular assessment that attempts to integrate. In the IPCS project, integrated risk assessment was taken to be a science-based approach that combines the processes of risk estimation for humans, biota,

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The IPCS is a program jointly administered by the following United Nations agencies: United Nations Environment Programme, International Labour Organization, and the World Health Organization.

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and natural resources in one assessment. Although risk from chemical exposures was a primary concern, this definition is not limited to evaluation of chemical risks. The project focused on the scientific issues; regulatory and jurisdictional mandates and processes of governmental agencies were not addressed. There are at least two fundamental reasons for integrated assessment of risks to humans and ecological systems: (1) it improves the quality and efficiency of assessments through the exchange of information between human health and environmental risk assessors; and (2) it provides more complete and coherent inputs to the decision-making process. The environmental processes of stressor transport, transformation, and fate have many features in common for humans and other biota — the sources of stressors are often the same, pathways from sources to receptors are similar, and receptors can encounter stressors in comparable ways. These commonalities can be used to advantage by sharing the data and analysis methods used to characterize exposure. Once exposure has occurred, stressors often evoke similar responses in different biological systems, supporting extrapolation and interpretation of effects information among human and nonhuman receptors. Integration of methods and data thereby enhances the value and cost-effectiveness of risk assessments. Further, human health and ecological risk assessors often provide decision makers with inconsistent input that results in contradictory impressions of the nature and severity of risks. The IPCS project developed a generic framework to support communication of the concepts of and possible approaches for integrated risk assessment (Suter et al. 2003). This was made possible by the overwhelming similarities among risk assessment frameworks currently in use internationally (Power and McCarty 1998, 2002). The integrated risk assessment framework is based on USEPA’s framework for ecological risk assessment (USEPA 1998). Ecological risk assessment frameworks have greater general applicability than do frameworks based on human health assessment in that they (1) were developed to deal with a range of environmental stressors, not just toxic chemicals, (2) must describe the nature and role of the environment in the risk assessment process, and (3) must explicitly identify the endpoint to be assessed. Further, a well developed body of concepts and terminology exists in the literature related to ecological risk assessment that supports integration (Bartell et al. 1992; Calabrese and Baldwin 1993; Suter 1993). The framework consists of three assessment phases. The first of these, problem formulation, delineates the overall goals, objectives, scope, and activities of the integrated assessment. One of the products of problem formulation is a conceptual model that represents the hypothesized sources of stressors and the exposure pathways linking sources to human and nonhuman receptors, as well as the direct and indirect mechanisms leading to effects. Because the conceptual model is integrated, it captures the commonalities of health and ecological exposure and response, including the interconnections among human and nonhuman components that can lead to often unconsidered indirect effects. The analysis phase consists of data collection and modeling to characterize exposure in time and space, and the effects on ecological systems and humans resulting from exposure. Integration of the analysis phase takes advantage of commonalities in data sources, measurement and modeling techniques, analysis methods, and modes of stressor action. Exposure and effect information are used to estimate risk in the risk characterization phase. This

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phase estimates risks from comparable and combined evidence and expresses risks to ecological and human endpoints in a consistent manner that supports holistic understanding. The integrated risk assessment framework treats the relationships among risk assessment, risk management, and stakeholder involvement in a general, parallel, and concurrent manner. These activities may interact in various ways depending on the regulatory context and the nature of the assessment problem, yet each offers opportunities to benefit from integration. For example, decision processes that consider risks to ecological and human endpoints fully and simultaneously support management actions that optimize the tradeoffs inherent in any decision. Similarly, stakeholder participation in the integrated risk assessment process provides input that can be used to weigh the value and importance of those tradeoffs from various societal perspectives. All of the interactions among assessors, managers, and stakeholders are supported by communication that expresses risks to humans and ecological systems and the implications of various management options coherently and consistently. Documentation has been developed to describe the framework that details the purpose and activities of each phase of integrated risk assessment and its interactions with risk management and stakeholder involvement (WHO 2001; Suter et al. 2003). This material identifies points of integration, describes advantages and disadvantages of integration, offers examples clarifying key concepts, and defines relevant terminology. The framework received international peer review by organizations and scientific experts representing diverse interests and expertise. CASE STUDIES Case studies were developed to help communicate the integrated risk assessment approach, to illustrate how assessments might be conducted, and to highlight the benefits of integration. Assessment problems were selected for initial case study development based on (1) known linkages between human health and ecological effects and exposures, (2) the availability of information, and (3) the degree of commonality in conceptual models relating stressors to ecological and human receptors. Using these criteria, four case studies were developed by panels of scientific experts. The first case study focuses on the risks of persistent organic pollutants (POPS) to humans and wildlife (Ross and Birnbaum 2003), highlighting the global distribution of these stressors, commonalities in their exposure pathways, and similarities in biological effects in higher trophic level consumers, including humans. A second case study considers ultraviolet radiation effects on amphibian, coral, humans, and oceanic primary productivity (Hansen et al. 2003). It illustrates integrated risk assessment of a naturally occurring, nonchemical stressor and the efficiencies gained by using common data and methods to characterize exposure and effects in seemingly disparate assessment endpoints. It also emphasizes the indirect effects that might occur as a result of interactions among ultraviolet radiation and chemical stressors, and the cascading indirect effects among interdependent endpoints. The third case study is tributyltin and triphenyltin compounds (Sekizawa et al. 2003). It suggests that significant gains in efficiency and completeness would accrue by an integrated risk assessment that recognizes common pathways of transport, fate, and exposure. It also shows the utility of sentinel organisms

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and the potential for indirect effects on human welfare. The fourth and final case study involves risks associated with use of organophosphorous pesticides in a “typical” agricultural setting (Vermeire et al. 2003). Taking advantage of the common mode of action of these chemicals, it stresses use of a common set of evidence, common criteria, and common interpretation of those criteria to support balanced judgment in selecting risk reduction measures. Each of these case studies describes integrated assessment activities for the entire framework. In doing so, they identify key points of integration, critical information needs, and benefits of integration. These are not actual risk assessments in that they do not actually estimate the risks of the stressors in a particular decision context. Rather, they demonstrate how integrated risk assessment can enhance scientific understanding, facilitate high quality regulatory decisions, and assist the identification of emerging issues and thereby provide a resource-efficient alternative to independent assessments. EVALUATION OF APPROACH The final activity undertaken as part of the IPCS project was a workshop to evaluate the concepts, approaches, and framework for integrated risk assessment, promote international understanding and acceptance of integrated risk assessment, and identify the scientific needs of integrated risk assessment. Participants were asked to use the framework and four case studies to focus deliberations on (1) benefits of and obstacles to integrated risk assessment, (2) research needed to facilitate implementation of integrated risk assessment and how an integrated approach informs the international research agenda, and (3) mechanisms and actions that can be taken to facilitate practical application of integrated risk assessment by regulatory bodies. The recommendations of the workshop are described in Munns et al. (2003). Together with the framework and supporting information from the ICPS project, the actions taken in response to these recommendations will help to establish the foundation of internationally accepted guidance for integration of risk assessment. ACKNOWLEDGMENTS Many individuals contributed to this project. Particularly influential were Linda Birnbaum, Stuart Dobson, Nikki Grandy, Jim Hart, Steve Hedtke, Rolaf van Leeuwen, Robert MacPhail, Erminio Marafante, Peter Pärt, Jun Sekizawa, Ted Smith, Glen Van Der Kraak, Theo Vermeire, and Maged Younges. We also thank the numerous international experts who provided review and comment on the concepts and products of this effort. Although some of the authors of this paper are employees of the USEPA, the ideas described in the paper do not necessarily reflect the policies of the Agency, and no official endorsement should be inferred. This is NHEERL contribution number AED-02-032. REFERENCES Bartell SM, Gardner RH, and O’Neill RV. 1992. Ecological Risk Estimation. Lewis Publishers, Chelsea, MI, USA Calabrese EJ and Baldwin LA. 1993. Performing Ecological Risk Assessments. Lewis Publishers, Chelsea, MI, USA

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Cirone P A and Duncan B. 2000. Integrating human health and ecological concerns in risk assessments. J Hazardous Materials 78:1-17 Di Giulio R and Benson W (eds). 2002. Interconnections Between Human Health and Ecological Integrity. SETAC Publications, Pensacola, FL, USA Five Winds International. 2000. Emmitsburg Plan for Fostering the Rational Integration of Human and Environmental Considerations Into Public and Private Decision-Making Processes. Available at: http://www.fivewinds.com/emmitsburg/index.htm Hansen L, Hedtke SF, and Munns WR Jr. 2003. Integrated human and ecological risk assessment: A case study of ultraviolet radiation effects on amphibians, coral, humans, and oceanic primary productivity. (this issue) Harvey T, Mahaffey KR, Velasquez S, et al. 1995. Holistic risk assessment: an emerging process for environmental decisions. Reg Toxicol Pharmacol 22:110-7 Harwell MA, Cooper W, and Flaak R. 1992. Prioritizing ecological and human welfare risks from environmental stresses. Environ Manage 16:451-64 Mennes W, van Apeldoorn, Meijerinick M, et al. 1998. The Incorporation of Human Toxicity Criteria into Integrated Environmental Quality Standards. Rpt. No. 601501-004. RIVM, Bilthoven, The Netherlands Munns WR Jr, Suter GW II, Damstra T, et al. 2003. Integrated risk assessment - Results of an international workshop. (this issue) Power M and McCarty LS. 1998. A comparative analysis of environmental risk assessment/risk management frameworks. Environ Sci Technol 32:224A-31A Power M and McCarty LS. 2002. Trends in the development of ecological risk assessment and management frameworks. Human Ecol Risk Assess 8:7-18 Ross P and Birnbaum L. 2003. Integrated human and ecological risk assessment: A case study of Persistent Organic Pollutants (POPs) risks to humans and wildlife. (this issue) Sekizawa J, Suter GW II, and Birnbaum L. 2003. Integrated human and ecological risk assessment: A case study of tributyltin and triphenyltin compounds. (this issue) Suter GW II. 1993. Ecological Risk Assessment. Lewis Publishers, Chelsea, MI, USA Suter GW II, Cornaby BW, Hadden CT, et al. 1995. An approach for balancing health and ecological risks at hazardous waste sites. Risk Anal 15:221-31 Suter GW II, Munns WR Jr., and Sekizawa J. 2003. Types of integrated risk assessment and management, and why they are needed. (this issue) Suter GW II, Vermeire T, Munns WR Jr, et al. 2003. A framework for the integration of health and ecological risk assessment. (this issue) USEPA (U.S. Environmental Protection Agency). 1998. Guidelines for Ecological Risk Assessment. EPA/630/R-95/002F. Risk Assessment Forum, Washington, DC, USA Vallentyne JR. 1997. Integrating human and ecological health in the Great Lakes basin: The rationale for sunsetting industrial chlorine. Ecosystem Health 3:211-9 Van Leeuwen CJ and Hermens JLM (eds). 1995. Risk Assessment of Chemicals: An Introduction. Kluwer Academic Publishing, Dordrecht, The Netherlands Vermeire TG, Jager DT, Bussian B, et al. 1997. European Union System for Evaluation of Substances (USES): Principles and structure. Chemosphere 34:1823-36 Vermeire T, MacPhail R, and Waters M. 2003. Integrated human and ecological risk assessment: A case study of organophosphorous pesticides in the environment (this issue) WHO (World Health Organization). 2001. Report on Integrated Risk Assessment. WHO/ IPCS/IRA/01/12. World Health Organization, Geneva, Switzerland Wilson EO. 1998. Integrated science and the coming century of the environment. Science 279:2048-9

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