A new laboratory method to study the impact of leaf texture on pesticide dislodgeable foliar residues (DFR)

Abstract

Pesticides are vital in meeting the challenge of feeding the rapidly increasing world population. However, it is crucial that they are used in a way that does not compromise the safety of humans or the environment. Non-dietary worker risk assessments consider the amount of residue which can be transferred from plant foliage to the skin or clothes, known as dislodgeable foliar residues (DFRs). DFR data scarcity due to the costly and seasonal characteristics of DFR studies is an obstacle to the extrapolation of DFR data to different crops/leaves. This paper validates a new proof-of-concept technique to investigate factors that may affect DFR (leaf texture) using the fungicide difenoconazole EC 10% as an example on various leaves (i.e., French bean, soybean, tomato, oilseed rape, and wheat). DFR was the lowest in the case of oilseed rape (31.0 ± 3.4%) and the highest in French beans (82.0 ± 2.9%). This significant difference in DFR in the findings of this study sheds light on the importance of the leaf surface as a major factor affecting DFR and supports the application of the laboratory method for more extensive data generation. More data generation would enable the extrapolation saving money and resources.

Keywords:

• Dislodgeable foliar residue
• DFR
• pesticides
• non-dietary risk assessment
• worker exposure
• pesticide risk assessment
• pesticide residue analysis
• difenoconazole
• DFR proof of concept

Acknowledgments

The authors would like to thank the University of Hertfordshire Knowledge Exchange Program (HKEP) and Syngenta, UK for funding this project as well as providing the data used in this project.

Author contributions

Mohamed H. Badawy: conceptualization, writing–review and editing, data curation, formal analysis, writing–original draft. Neil Morgan, Kathleen Lewis, and Darragh Murnane: conceptualization, review and editing, funding acquisition, project administration, supervision.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

This work was supported by Funds provided by the University of Hertfordshire Knowledge Exchange Program (HKEP) in collaboration with Syngenta, UK.