What type of pesticide application could lead to environmental contamination?

The application of pesticides can significantly impact the environment, particularly when there is over-application. When pesticides are applied in excessive amounts, the likelihood of runoff increases, which can contaminate nearby waterways, soil, and non-target organisms. Additionally, over-application can lead to chemical buildup in the ecosystem, affecting plant and animal health. This practice not only poses risks to human health and wildlife but can also disrupt the balance of local ecosystems.

Factors such as improper storage can lead to issues, but they generally do not directly involve the act of application as over-application does. Similarly, professional application by certified technicians typically adheres to guidelines designed to minimize environmental impact. Therefore, the concern with over-application arises from the direct consequences of misjudging the quantity needed for effective pest control, making it a significant risk for environmental contamination.