Which of the following is a common pollutant found in stormwater runoff?

Nutrients like nitrogen and phosphorus are common pollutants found in stormwater runoff primarily due to their presence in fertilizers, animal waste, and various agricultural practices. When it rains, these nutrients can wash off surfaces and enter local water bodies, leading to nutrient pollution. This can cause adverse effects such as algal blooms, which deplete oxygen in the water and harm aquatic life. The presence of these nutrients in stormwater runoff is a significant concern for water quality management, as it can lead to eutrophication, negatively impacting ecosystems and water usability.

In contrast, oxygen and carbon dioxide are naturally occurring gases that are not considered pollutants in this context. Helium, while a gas, does not have any significant role in environmental pollution or impacts on water quality. Therefore, the focus on nitrogen and phosphorus as prevalent pollutants highlights the environmental challenges associated with stormwater runoff and the importance of effective management practices.