What is an example of environmental contamination from a non-point source?

The choice of movement of pesticide into streams after application represents a clear case of environmental contamination from a non-point source. Unlike point source contamination, which originates from a specific, identifiable location such as a leak or a spill, non-point source pollution is diffused over a wide area and cannot be traced to a single source.

In this scenario, pesticides that are applied over a large agricultural area can be carried away by rain or irrigation runoff, which then flows into nearby streams and water bodies. This movement is influenced by various factors such as rainfall, land topography, and soil conditions, making it difficult to pinpoint a specific location as the source of contamination.

The other options describe situations that are more characteristic of point sources of contamination, where there is a specific and identifiable origin for the pollutants. For example, spillage during transport and disposal of empty containers suggest direct incidents that can be traced to a specific point, while runoff from sealed storage indicates that the pollutants should ideally be contained and controlled.