2019-2023: PhD project: Determination of the key parameters influencing dislodgeable foliar pesticide residues

This PhD sought to better understand the factors that affect the amount of pesticide residue on plant foliage that, on contact, can be transferred to human skin and clothing (Dislodgeable Foliar Residues - DFRs). This type of information can help evaluate:

• Occupational exposure: Of farmers in their working environment. For example, by establishing the period of elapsed time needed following greenhouse spraying before it is safe to re-enter.
• Bystander exposure: Ensuring that members of the public entering treated crop areas, do not encounter unacceptable risks.

Previous research showed that there was a relationship between the proportion of residue that is dislodgeable and a range of factors including the pesticide application rate, chemical characteristics, product formulation, environmental conditions (including temperature and humidity), and the plant architecture and leaf type. These issues were not fully understood, therefore the purpose of this 4-year work programme was to explore some of these issues with the intention of enabling the refinement of re-entry risk assessments.

The project was being run jointly by the University of Hertfordshire and Syngenta’s prestigious international research centre at Jealott's Hill, Berkshire.

Contact

Prof Kathy Lewis

Appointed student

Mohamed Badawy

Publications

• Badawy, M.H., Morgan, N. & Lewis, K.A. (2021). Correlation between dietary and dislodgeable foliar (DFR) crop residues decline data: a proposed approach to refine non-dietary risk assessment. Regulatory Toxicology and Pharmacology, 127: 105049. DOI.
• Badawy, M.H., Murnane, D., Lewis, K.A. & Morgan, N.(2022). Development of a New Dislodgeable Foliar Residue Analytical Laboratory Method for Pesticides. Annals of Work Exposure and Health, 66(8): 1070-1080. DOI.
• Badawy, M.H., Murnane, D., Lewis, K.A. & Morgan, N.(2023). A new laboratory method to study the impact of leaf texture on pesticide dislodgeable foliar residues (DFR). ). Journal of Environmental Science and Health, Part B, 58(8): 555-564. DOI.
• Poster: Determination of the Key Parameters Influencing DislodgeableFoliar Pesticide Residues ̔DFR ̓- View Poster.

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