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Food and feed safety risk assessment uses multi-parameter models to evaluate the likelihood of adverse events associated with exposure to hazards in human health, plant health, animal health, animal welfare and the environment. Systematic review and meta-analysis are established methods for answering questions in health care, and can be implemented to minimise biases in food and feed safety risk assessment. However, no methodological frameworks exist for refining risk assessment multi-parameter models into questions suitable for systematic review, and use of meta-analysis to estimate all parameters required by a risk model may not be always feasible. This paper describes novel approaches for determining question suitability and for prioritising questions for systematic review in this area. Risk assessment questions that aim to estimate a parameter are likely to be suitable for systematic review. Such questions can be structured by their "key elements" (e.g., for intervention questions, the population(s), intervention(s), comparator(s) and outcome(s)). Prioritisation of questions to be addressed by systematic review relies on the likely impact and related uncertainty of individual parameters in the risk model. This approach to planning and prioritising systematic review seems to have useful implications for producing evidence-based food and feed safety risk assessment.

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Individuals ofSitobion avenae (F.) (Homoptera: Aphididae) were marked with the stable isotope 15N through feeding on cereal seedlings which were immersed in a15N‐enriched nutrient solution. Increased 15N‐contents were obtained in all aphids with no detrimental effect on survival and fertility. When 15N‐marked aphids were transferred to non 15N‐enriched seedlings, after a short initial decreasing phase, 15N‐contents remained nearly constant in time. A content of 10% 15N in the nutrient solution of the seedlings was sufficient for marking the aphids.