A Simplified Population-Level Landscape Model Identifying Ecological Risk Drivers of Pesticide Applications, Part One: Case Study for Large Herbivorous Mammals

Abstract

Environmental risk assessment is a key process for the authorization of pesticides, and is subjected to continuous challenges and updates. Current approaches are based on standard scenarios and independent substance-crop assessments. This arrangement does not address the complexity of agricultural ecosystems with mammals feeding on different crops. This work presents a simplified model for regulatory use addressing landscape variability, co-exposure to several pesticides, and predicting the effect on population abundance. The focus is on terrestrial vertebrates and the aim is the identification of the key risk drivers impacting on mid-term population dynamics. The model is parameterized for EU assessments according to the European Food Safety Authority (EFSA) Guidance Document, but can be adapted to other regulatory schemes. The conceptual approach includes two modules: (a) the species population dynamics, and (b) the population impact of pesticide exposure. Population dynamics is modelled through daily survival and seasonal reproductions rates; which are modified in case of pesticide exposure. All variables, parameters, and functions can be modified. The model has been calibrated with ecological data for wild rabbits and brown hares and tested for two herbicides, glyphosate and bromoxynil, using validated toxicity data extracted from EFSA assessments. Results demonstrate that the information available for a regulatory assessment, according to current EU information requirements, is sufficient for predicting the impact and possible consequences at population dynamic levels. The model confirms that agroecological parameters play a key role when assessing the effect of pesticide exposure on population abundance. The integration of laboratory toxicity studies with this simplified landscape model allows for the identification of conditions leading to population vulnerability or resilience. An Annex includes a detailed assessment of the model characteristics according to the EFSA scheme on Good Modelling Practice.

Harnessing Modeling for Assessing the Population Relevance of Exposure to Endocrine‐Active Chemicals

“…Any model can be assessed against these criteria using the checklist from the EFSA Good Modelling Practice Scientific Opinion (EFSA, 2014). This strategy is commonly applied when one is proposing models for use in regulatory risk assessment (see Tarazona et al, 2021).…”

Using environmental monitoring data from apex predators for chemicals management: towards better use of monitoring data from apex predators in support of prioritisation and risk assessment of chemicals in Europe

“…Regulatory risk assessments focus on premarket authorisations, and should be complemented with post-market environmental vigilance. Landscape aggregated exposure models have been conceptualised [35,36], but are still under early development, particularly in connection with population dynamics [37]. In this context, monitoring data using apex predators can be used to improve the current risk assessment methods as well as for realistic retrospective assessments.…”

A meta-analysis of ecotoxicological models used for plant protection product risk assessment before their placing on the market

“…Based on our review, it seems that guidance documents and transfer of knowledge is a crucial step for new modelling approaches to be implemented. The recommendations on good practices in modelling (EFSA PPR Panel, 2014) as well as the recent publications going in this direction for PPP ERA (Arlos et al, 2020;Raimondo et al, 2021;Roeben et al, 2020;Tarazona et al, 2021), constitute one step further in the acceptance of model categories like population models or TKTD in assessment reports.…”