Mock assessment: Chronic prospective cumulative risk assessment

Abstract

This Mock assessment is a part of the Framework Partnership Agreement between ANSES and EFSA with the help of RIVM to investigate the feasibility of a tiered approach proposed by EFSA for prospective chronic cumulative risk assessment (CRA). Three tiers address successively (i) a need for prospective CRA (Tier 0) using a deterministic approach to estimate the foreground exposure based on IEDI equation, (ii) a first estimation of prospective CRA (Tier I) using a probabilistic approach to estimate the background exposure at P99.9 and a deterministic approach to estimate the foreground exposure at mean or P97.5 consumption and (iii) a second estimation of prospective CRA (Tier II) using a probabilistic approach to estimate the background and foreground exposure at P99.9. ANSES tested this approach with an MRL application for the active substance fenamidone (with chronic effects on the thyroid) on lettuce, based on a new intended use currently under assessment at national level. For each Tier, the Margin of Exposure (MOE) was calculated for 9 populations with MCRA software using input data provided by EFSA and settings according to EFSA protocol. Different combinations of settings were tested as part of sensitivity analyses (consumption data, adjustment for additional uncertainties, cycle of monitoring data, etc.) and were used as the basis for discussion of different open points (trigger value in Tier 0, use frequency for the focal combination in tier II, ad hoc uncertainty analysis to account for additional uncertainties, etc.) to be addressed before prospective CRA could be implemented as a routine exercise. Finally, based on these discussions, recommendations were made to consolidate the approach for chronic prospective CRA.