Which term describes the movement of a pesticide from the soil into the air as a vapor?

• A. Bioconcentration
• B. Leaching
• C. Photodecomposition
• D. Volatilization

Answer: (D)

The movement of a pesticide from soil into the air as a vapor is volatilization. This process happens when a chemical has enough vapor pressure to escape from the soil surface into the atmosphere, effectively removing it from the soil. Factors like higher temperature, dry soil, wind, and a large surface area around the soil increase volatilization risk, making the pesticide more likely to become airborne.

Bioconcentration refers to accumulation in organisms from water or food, not from soil to air. Leaching is the downward movement of soluble pesticides with infiltrating water through soil toward groundwater. Photodecomposition is the breakdown of the chemical by light, not its transfer into the air.