Iowa Pesticide Applicator Practice Exam

What can increase the likelihood of pesticide volatilization?

1. High moisture content

2. Increased temperature

3. Cool wind

4. High soil organic matter

The correct answer is: Increased temperature

Increased temperature is a significant factor that can elevate the likelihood of pesticide volatilization. When temperatures rise, it enhances the rate at which pesticides can transition from a liquid or solid state into vapor, making it more probable that these chemicals will escape into the atmosphere. This process occurs because higher temperatures provide more energy for the molecules in the pesticide, allowing them to break free from the surface and enter the air more readily. The other factors mentioned, such as high moisture content, cool wind, and high soil organic matter, do not promote volatilization. In fact, high moisture can lead to better pesticide solubility in soil, potentially reducing the volatile fraction. Cool wind may help dissipate warm air but generally would not facilitate the vaporization process. Similarly, high soil organic matter can hold onto pesticides more effectively, limiting their ability to volatilize. Therefore, increased temperature is clearly the key driver in enhancing the volatility of pesticides.