Oregon Pesticide Practice Test

Which property of a pesticide would increase the likelihood of it moving in surface water runoff?

1. Low volatility

2. High solubility

3. Low toxicity

4. High persistence

The correct answer is: High solubility

The property that would increase the likelihood of a pesticide moving in surface water runoff is high solubility. When a pesticide is highly soluble, it readily dissolves in water, making it more likely to be carried away by runoff. This is particularly important during rainfall or irrigation events, where water can wash the pesticide off the treated areas and into nearby surface water bodies. In contrast, low volatility refers to a pesticide's tendency to vaporize; low volatility is less likely to contribute to runoff because the substance remains in the applied area rather than being lost to the atmosphere. Low toxicity does not relate directly to runoff potential but instead indicates how harmful a pesticide may be to non-target organisms. High persistence refers to a pesticide's ability to remain in the environment for a long time, but it doesn't necessarily correlate with its mobility in water. A pesticide may persist in the environment without being water-soluble, thus reducing its chance of moving with runoff.