Which term describes a pesticide moving from a surface into the air?

• A. Drift
• B. Leaching
• C. Runoff
• D. Volatilization

Answer: (D)

When a pesticide moves from a surface into the air, the process is volatilization. It means the chemical that’s on a surface—like sprayed leaf tissue, soil, or water—evaporates into a gas and becomes part of the air. This often happens more on warm days or with formulations that have higher vapor pressure, so the substance is more prone to turning into vapor.

Volatilization is different from other ways a pesticide can move away from the application site. Drift refers to droplets being physically carried through the air during spraying. Leaching is the downward movement of the chemical through soil with water. Runoff is water flow over the surface that carries pesticide to other areas, like streams or drains.

Understanding volatilization helps explain how pesticides can travel off the treated surface even after application, potentially affecting areas downwind and contributing to airborne exposure.