Which of the following is a potential environmental impact of pesticide use?

The potential environmental impact of pesticide use that stands out is the contamination of water sources. This issue arises when pesticides are washed away from treated areas, either by rainfall or irrigation, leading to runoff that can carry these chemicals into rivers, lakes, and groundwater. Such contamination can have serious consequences for aquatic ecosystems, wildlife, and human health, as many pesticides are toxic to non-target organisms.

The other options focus more on benefits or neutral effects rather than negative impacts. Improvement in crop yield is often a desired outcome of pesticide use, enabling farmers to produce more food. Reduction of soil acidity involves chemical changes that may not directly relate to the use of pesticides, but rather to other agricultural practices. Increased biodiversity in ecosystems typically suggests a healthy environment where various species coexist, which is generally not supported by pesticide application, as these chemicals often harm non-target species and reduce overall biodiversity. Thus, highlighting water contamination accurately reflects a real environmental concern associated with pesticide use.