Assessment of Field Reentry Exposure to Pesticides: Limitations, Uncertainties, and Alternatives

Dislodgeable Foliar Residue Measurements and Assessment of Dermal Exposure to Captan for Workers in Apple Orchards

“…Only mature leaves were sampled in order to limit the loss of captan due to the dilution effect caused by new leaves in growth. Samples were collected on July 5, 2018, before and after application of captan (at, respectively, 11 am and 5 pm, captan being applied at 2 pm) and over a 2-week period included 8 sampling days (1,4,5,6,7,8,12, and 14 days after the spraying day, each at 11 am; Figure 2). No re-entry tasks (thinning, pruning, etc.)…”

“…However, in recent decades, many authors have suggested adverse health effects associated with long-term pesticide exposure. − Serious concerns have been raised about the health risks resulting from occupational exposure when mixing and applying pesticides or working in treated fields, but knowledge of the occupational exposure levels and determinants is still limited. Previous studies underlined the need to account for exposure during re-entry tasks and during harvesting to assess pesticide exposure. − Bureau et al demonstrated that workers performing re-entry tasks had higher contamination than operators . Activities such as pruning or thinning are performed by workers who enter an agricultural plot that has been treated with pesticides .…”

“…Dermal exposure is one of the most effective primary routes through which agricultural workers are exposed to pesticides. , Dermal exposure is the outcome of direct contact with pesticide residues on, for example, leaf surfaces. The dermal route may represent more than 90% of the total daily exposure of workers performing re-entry tasks. , …”

“…Fantke and Juraske presented several models (e.g., zero-order, first-order, second-order, biphasic kinetic) to fit residual pesticide concentration curves that demonstrate the variability of pesticide dissipation within plants or on the foliage. The foliar dissipation of many pesticides is mostly described by first-order kinetics. ,, Nonetheless, DFR dissipation patterns are often more complex and need to be better understood and described in detail for the appropriate pesticide risk assessment. For example, Whitmyre et al described biphasic dissipation kinetics for DFRs when estimating post-application occupational exposure to endosulfan.…”

“…The dermal route may represent more than 90% of the total daily exposure of workers performing re-entry tasks. 8,13 The dislodgeable foliar residue (DFR) is the amount of pesticides that can be transferred from the two-sided leaf surface of the plant during a well-defined procedure. 14 Many studies have demonstrated the link between pesticide residues on foliage and the dermal exposure of workers re-entering treated crops.…”