Which of the following is NOT a common pollutant in local water sources?

Oxygen is not a common pollutant in local water sources because it is a necessary component of water that supports aquatic life. In fact, dissolved oxygen is crucial for the survival of fish and other organisms living in water. While low levels of dissolved oxygen can indicate pollution or eutrophication, oxygen itself is not a contaminant.

In contrast, pesticides, lead, and plastic waste are recognized pollutants that can have harmful effects on water quality and aquatic ecosystems. Pesticides can run off from agricultural areas and enter water bodies, leading to toxicity for wildlife. Lead can leach into water supplies from old pipes or industrial sources, posing significant health risks. Plastic waste contributes to widespread environmental issues, affecting marine life and overall water quality. Each of these substances represents a distinct threat to the health of local water sources, emphasizing the importance of monitoring and managing pollution in aquatic environments.