Operationalising emission and toxicity modelling of pesticides in LCA: the OLCA-Pest project contribution

Abstract

Purpose Current field emission modelling and toxicity characterisation of pesticides suffer from several shortcomings like mismatches between LCI databases and LCIA methods, missing characterisation factors, missing environmental compartments, and environmental impact pathways. The OLCA-Pest project was implemented to address these aspects and to operationalise the assessment of pesticides in LCA. Based on this effort, we propose an approach to integrate pesticide emissions into LCI databases. Methods The PestLCI Consensus Model has been developed in order to estimate emission fractions to different environmental compartments. The initial distribution fractions should be linked to the compartments air, agricultural soil, natural soil, and freshwater. Emissions to off-field surfaces are hereby distributed between agricultural soil, natural soil, and freshwater by using surface cover data. Deposition on the crop surface should be recorded in an emission compartment crop with 13 sub-compartments for crop archetypes for both food and non-food uses. Default emission fractions are provided to calculate the emission fractions for different pesticide application scenarios. Results and discussion A sensitivity analysis shows the effects of the application technique, drift reduction, crop and development stage, field width, and buffer zone on the initial distribution fractions of field-applied pesticides. Recommendations are given for the implementation of a set of default initial distribution fractions into LCI databases, for the organisation of metadata, and for the modelling of pesticide residues in food along the supply chain (processing, storage). Priorities for further research are: improving the modelling of pesticide secondary emissions, further extending emission modeling (e.g. additional application techniques, including cover crops), considering metal-based pesticides in emission models, and systematically assessing human health impacts associated with pesticide residues in food crops. Conclusions The proposed approach allows to preserve the mass balance of the pesticide emitted after application, to make a consistent assessment of ecotoxicity and human toxicity, to define a clear and consistent interface between the LCI and LCIA phases, to estimate initial emission distribution fractions based on existing data, to document metadata transparently and efficiently within crop datasets, and to model the removal of pesticide residues in food during processing.

Mitigating Ecotoxicity Risks of Pesticides on Ornamental Plants Based on Life Cycle Assessment

“…To evaluate the ecotoxicity impact of pesticide AIs according to the OLCA-Pest project's definition, the ecotoxicity impact score method is utilized, which involves the following three steps [25]:…”

“…Based on the results of the second distribution, the proportions of pesticide emissions to soil, air, surface water, and groundwater, as well as plant compartments, are estimated. In national-scale studies, the OLCA-Pest project recommends using an initial emission allocation fraction [25]. Therefore, this study did not consider the second tier of the model's emission allocation.…”

“…where f intercept,crop is the fraction of pesticide intercepted by crop foliage, the value can be obtained from the fraction of field area covered by crop foliage. More detailed calculation procedures can be found in the calculation files of the PestLCI Consensus model [25].…”

“…To assess the environmental risks associated with pesticide use in ornamental plants while minimizing impacts on crop production, this study utilized advanced models in the LCA pesticide assessment field-the PestLCI and USEtox models from the OLCA-Pest project [25]. The study collected application data on 106 pesticide active ingredients (AIs) commonly used for 15 ornamental plants in the US, which is the largest consumer of ornamental plants and has readily available pesticide use data [26].…”