Aaldrik Tiktak Aaldrik Tiktak is a Senior Researcher Soil and Water at the PBL Netherlands Environmental Assessment Agency in The Hague. He is involved in policy evaluation and environmental risk assessment of pesticides and is one of the chief developers of the PEARL model. He has been a member of the EFSA Panel on Plant Protection Products and their Residues (PPR) since 2012. From May 2022 up to May 2023 he was chair of the EFSA working group on the Statement of the PPR Panel on design and conduct of groundwater monitoring studies. He is also co-chair of the SETAC working group on Spatially Distributed Leaching Models (SDLM).