Proposed prospective scenarios for cumulative risk assessment of pesticide residues

Abstract

To ensure a high level of consumer protection, Article 14 of Regulation (EC) No. 396/2005 stipulates that decisions on applications concerning the setting, modifying and deletion of maximum residue levels (MRLs) of pesticides shall take into account the cumulative effects, when the methods to assess such effects are available. This report investigates the feasibility of a tiered approach for prospective cumulative risk assessment (CRA). This report describes 15 case studies for the cumulative assessment group (CAG) associated with an effect on the motor division of the nervous system and 15 for the CAG associated with an effect on hypothyroidism. For each case study, Tier 0, Tier I and Tier II calculations were performed. The Tier II assessment was performed for three different scenarios representing three different risk assessment questions related to the exposure of a focal substance/focal commodity combination: 1) the MRL scenario assessing exposure at the MRL, 2) the Good Agricultural Practice (GAP) scenario assessing exposure to the focal commodity treated with the focal substance at the critical GAP and 3) the actual scenario, assessing actual exposure of pesticides, and taking into account use frequency of the focal substance. Additionally, three sensitivity analyses were performed addressing the impact of changing parameters or assumptions made in the comparison. The results revealed that prospective CRA could be performed more efficiently if a trigger value (e.g. a certain percentage of the Health Based Guidance Value (HBGV)) is implemented at Tier 0. For the tiered approach, however, although Tier II calculations should in principle result in a higher total Margin of Exposure compared to Tier I, this was not the case for all scenarios and case studies. Final criteria will need to be discussed and agreed by the Standing Committee of Plants, Animal, Food and Feed.