An analytical procedure using accelerated solvent extraction and capillary gas chromatography with electron capture and flame photometric detections was developed to simultaneously determine residues of different pesticides in fruits and vegetables. Single laboratory validation of the method was carried out for 28 compounds selected from eight pesticide classes, in blank and fortified samples of fresh pear, cantaloupe, white potato, and cabbage. The method had to meet specific established validation criteria for regulatory purposes applicable to our laboratory. At each of the two fortification levels studied, 24 of the 28 pesticides gave recoveries of more than 70% with a coefficient of variation of less than 10%. With respect to existing procedures, the method showed acceptable limits of detection (from 0.0019 to 0.14 microg/g depending on the pesticide and matrix) while minimizing environmental concerns, time, and labor.

Losses of honeybee colonies are intensely debated and although honeybees suffer multiple stressors, the main focus has been on pesticides. As a result, the European Food Safety Authority (EFSA) revised the guidance for pesticide risk assessment for honeybees. The European Food Safety Authority reported a protection goal of negligible effect at 7% of colony size and then used the Khoury honeybee colony model to set trigger values for forager losses. However, the Khoury model is very simplistic and simulates colonies in an idealized state. In the present study, the authors demonstrate how a more realistic published honeybee model, BEEHAVE, with a few simple changes, can be used to explore pesticide risks. The results show that forage availability interacts with pesticide-induced worker losses, and colony resilience increases with forage quality. Adding alternative unexposed forage to the landscape also substantially mitigates the effects of pesticide exposure. The results indicate that EFSA's reported protection goal of 7% of colony size and triggers for daily worker losses are overly conservative. The authors conclude that forage availability is critical for colony resilience and that with adequate forage the colonies are resilient to even high levels of worker losses. However, the authors recommend setting protection goals using suboptimal forage conditions to ensure conservatism and for such suboptimal forage, a total of 20% reduction in colony size was safe. Environ Toxicol Chem 2017;36:254-264. #