Optimising environmental risk assessments

R egulated products such as genetically modified organisms (GMOs), plant protection products (PPPs) or feed additives for livestock are subject to an environmental risk assessment before they can be approved for use in agriculture. This assessment aims to evaluate any possible risk that the deployment of such products may pose to the environment. Robust environmental risk assessments require an explicit formulation of potential problems to identify plausible and relevant exposure scenarios and potential adverse effects from predicted exposures. The actual risk is then characterised by testing specific hypotheses about the likelihood and severity of these adverse effects [1–4]. The ultimate decision on what is an acceptable level of risk, and thus whether a GMO, PPP or feed additive can be commercialised, is taken by risk managers—policymakers and regulators— who have to weigh different policy options to accept, minimise or reduce the risks that were characterised through the environmental risk assessment. The first step of an environmental risk assessment is to establish the context for the assessment by identifying which components of the environment—species, habitats, services, etc.—are valued by civil society and/or protected by relevant laws or policies. This exercise establishes the so-called environmental policy protection goals: environmental components that should be protected and taken into account when conducting environmental risk assessments to support regulatory decision-making. These protection goals can vary between jurisdictions, but their overall aim is to minimise harm to the environment, including biodiversity and ecosystems, caused by human activities. However, policy protection goals, such as protecting biodiversity, are often too generic and vague to be useful for scientific risk assessment, and need to be translated into specific, operational ones. Because protecting everything, everywhere, forever is not always tenable, operational protection goals, also termed specific protection goals, have to delineate the environmental components that need to be protected, where and over what time period, and the maximum impacts that can be tolerated [1,2]. The definition of operational protection goals is therefore crucial for environmental risk assessments and regulatory decision-making [4]. Since 2010, the European Food Safety Authority (EFSA), which provides scientific advice to European policymakers on possible risks to human, plant and animal health and the environment from the deployment of GMOs, PPPs and feed additives, has been developing a science-based framework to specify operational protection goals in its environmental risk assessments (http://www. efsa.europa.eu/sites/default/files/corporate_ publications/files/583e.pdf). This framework accounts for the importance of ecosystems and biodiversity, and focuses in particular on the benefits these provide to humans, the so-called ecosystem services. T he Millennium Ecosystem Assessment, which is widely applied, distinguishes four categories of ecosystem services: provisioning services (products such as food/feed, water, fibre or energy); regulating services, such as pollination, pest control, water and air purification; cultural services (recreation, tourism or cultural heritage); and supporting services that are necessary for the other ecosystem services to function, such as nutrient cycling, soil formation, oxygen production or habitat provision. Irrespective of the various classifications for ecosystem services (Box 1), ecosystem services are highly interconnected and interdependent, and involve multiple species, ecosystems, environmental compartments in ecosystems, and habitats. Different types of ecosystems will therefore offer different types of ecosystem services, and the role of a specific species in providing a specific ecosystem service may differ between ecosystems [3].