MDARD Michigan Core Pesticide Applicator Practice Exam

Which of the following conditions increases the likelihood of pesticide volatility?

1. High relative humidity

2. Low temperatures

3. High temperatures

4. Heavy rainfall

The correct answer is: High temperatures

High temperatures significantly increase the likelihood of pesticide volatility. Volatility refers to the tendency of a substance to vaporize or turn into gas. When temperatures are high, the kinetic energy of pesticide molecules increases, making them more likely to escape from their liquid state and enter the atmosphere as vapor. This can lead to off-target movement of the pesticide, affecting surrounding areas and potentially causing harm to non-target organisms. In contrast, conditions such as high relative humidity can help keep pesticides in a more stable, liquid phase, as moisture in the air can absorb some of the vapor. Low temperatures can reduce molecular movement, limiting vaporization. Heavy rainfall can wash pesticides from the target area, minimizing the potential for volatilization. All of these other conditions do not promote volatility to the extent that high temperatures do.