Illinois Pesticide Applicator Practice Test

What are the two main ways pesticides can move downwind to non-target areas?

1. By runoff and leaching

2. By vapor drift and particle drift

3. By soil erosion and microbial degradation

4. By aerial application techniques

The correct answer is: By vapor drift and particle drift

In the context of pesticide movement to non-target areas, vapor drift and particle drift are the two primary mechanisms. Vapor drift occurs when volatile pesticide compounds evaporate into the air and are carried by wind currents to unintended locations. This can happen even at significant distances from the original application site, leading to potential contamination of sensitive areas. On the other hand, particle drift refers to the physical movement of pesticide droplets or particles that are carried by the wind. When pesticides are sprayed, especially using aerial application or ground equipment, small droplets can be entrained in the air and blown off-site. This is particularly concerning for chemicals that could affect neighboring crops, aquatic habitats, or residential areas. Other answer options present mechanisms that are not primarily concerned with downwind movement. For instance, runoff involves pesticides being moved by water due to rainfall or irrigation, and leaching refers to the downward movement of pesticides through soil, primarily influenced by water movement below the surface rather than air currents. Soil erosion and microbial degradation also do not directly relate to how pesticides drift through the air to non-target areas. Lastly, while aerial application techniques can increase the chances of drift, they do not represent the mechanisms of movement itself.