Few epidemiological studies use exposure determinants specifically tailored to assess pesticide or plant protection product (PPP) exposures when assessing presumed association between occupational exposure and health outcomes among agricultural workers. This lack of exposure specificity could lead to results that fail to detect an association. It could be related to the lack of consensus on exposure assessment methods and the choice of exposure determinants. We conducted a meta-analysis following the PRISMA checklist to identify PPP exposure determinants used in occupational studies and identified exposure determinants that best characterized agricultural exposures to PPPs. Out of 1436 studies identified, 71 were included. The exposure determinants identified were active ingredients, chemical classes, types of PPP, crops, tasks, frequencies, duration, lifetime exposure days, and intensity-weighted exposure days. Only six over 17 associations between exposure determinants and health outcomes were found with moderate quality of evidence. Overall, epidemiological studies had difficulty defining relevant determinants to characterize PPP exposures for agricultural workers. We recommend that a standardized list of determinants for PPP exposures in occupational exposure studies should include information on formulations, intensity, duration, and frequency of PPP exposure. Harmonized data collection on exposure and health outcomes are required as well as standard units for each exposure determinant.

Milk allergy is among the most common food-related allergies. Milk-based products are recognized as plant protection products (PPPs) in several countries as alternatives to synthetic pesticides. The potential health risk for allergic workers, as well as the general population, is yet to be assessed. An investigation was conducted in the Vaud Canton of Switzerland, where milk-based products are sprayed by helicopter over vineyards. Air lactose concentration was measured at 14 locations via 25 mm IOM Multidust samplers. Residual lactose concentration was measured on the surface of leaves over 7 days following spraying. Surface contamination downwind from the treated area was estimated through computer-based modeling using AgDRIFT^® software. The average milk protein concentration inside and outside the vineyard was 0.47 and 0.16 µg/m³, respectively. Milk residues persisted on the leaf surface for an average of three days. Modelling results revealed an estimated order of magnitude of 0.1–0.5 µg/m³ in milk proteins within one hour after the treatment in the close vicinity of the treated area. Our results reveal that the potential exposure to milk proteins in and around helicopter-treated vineyards is not negligible and that prevention messages targeted to individuals with severe allergies should be considered.