Conceptualizing risk assessment methodology for genetically modified organisms

Abstract

Risk assessment methodology for genetically modified organisms (GMOs) has evolved over the last several years. At a conceptual level, the methodology has been adapted from the existing paradigm for environmental risk assessment, which was developed for chemicals and other types of environmental stressors since at least the 1980s (see Hill and Sendashonga (2003) for discussion). Many of the people who are or will be involved in assessing risks of GMOs are geneticists, ecologists, plant scientists, toxicologists, or other experts with in-depth knowledge of relevance to one or more aspects of risk assessment. A common understanding of the conceptual framework for risk assessment is important so that these various experts and other actors can work together effectively. Furthermore, a common conceptual framework allows all of the various components of risk assessment to be appropriately organized and brought together in a way that supports decision-making regarding the use, release and/or import of GMOs. Unfortunately, common understanding regarding the conceptual basis for risk assessment is a challenge. There is considerable variation among risk assessment frameworks for GMOs regarding the steps or components of risk assessment, as well as terminology (SCBD, 2005). There is no need, nor is it possible, to standardize so that everyone agrees on the number of steps in risk assessment and the associated terminology. It is important, however, that when one person refers to a particular component of risk assessment, using a particular term, others can relate that step and that term to whatever framework they use. Here, I attempt to dissolve some of the misunderstanding by illustrating some of the core elements that are common to many frameworks for risk assessment methodology, and by pointing out two common sources of confusion. Figure 1 aims to show some of the most commonly delineated steps and associated terminology used in risk assessment frameworks. Somewhat similar versions of this figure can be found in some of the frameworks reviewed in SCBD (2005), such as those from the U.S. Environmental Protection Agency (USEPA, 1998) and the European Union (EU, 2002). Not all of the steps shown in Figure 1 are found in all frameworks. The first step (hazard identification) is considered in some frameworks as a separate initial process (or part of such a process) that precedes risk assessment entirely. In addition, the fifth step (mitigation options) is also not universal among frameworks, as most frameworks clearly separate risk assessment from risk management. Some frameworks, however, consider only certain aspects of risk management (e.g., monitoring) as separate from risk assessment but other aspects of risk management (e.g., consideration of risk mitigation options) to be part of risk assessment methodology, since a final characterization of risks must take into account the effects of any mitigation options that reduce risks. The important aspect is, of course, the iterative and inter-linked relationship between risk assessment and risk management. Even when frameworks delineate the components of risk assessment in similar ways, there is considerable variation in terminology used to describe each component (Fig. 1). Furthermore, there is also additional terminology confusion when risk assessment is considered in a broader context, including its relationship to risk management and decision-making. For example, the entire process of risk assessment, combined with risk management (and risk communication in some cases), is sometimes referred to as risk analysis. This is the case for a few international bodies and standards. In addition, some frameworks consider risk management to encompass decision-making, while others consider decision-making as separate (in the latter case, risk management has a narrower scope).