Which characteristic of pesticides affects their movement in surface water runoff?

The characteristic of pesticides that most significantly affects their movement in surface water runoff is solubility. Pesticides that are highly soluble in water are more likely to be transported with runoff water during rainfall or irrigation events. When these pesticides dissolve easily in water, they can wash off from treated areas and enter surface water bodies, potentially leading to contamination. This characteristic is crucial in assessing the environmental impact of pesticides, as it directly influences how far and how quickly a pesticide can move off-site.

While absorption, persistence, and volatility are important factors in understanding the behavior of pesticides in the environment, they do not specifically dictate the movement of pesticides in surface water runoff as solubility does. Absorption relates to how well a pesticide binds to soil or plant materials, which can limit its movement in water. Persistence refers to the length of time a pesticide remains active in the environment, affecting long-term exposure but not immediate movement in runoff. Volatility pertains to the ability of a pesticide to evaporate into the atmosphere, which primarily influences air quality rather than surface water movement.