What constitutes water pollution?

Water pollution is defined as the introduction of harmful substances or agents into water bodies, which adversely affects the quality of the water and can harm aquatic ecosystems, human health, and overall environmental quality. The presence of contaminants such as chemicals, heavy metals, pathogens, and various pollutants can render water unsafe for consumption, recreation, and support of aquatic life.

The correct choice highlights that harmful agents degrade water quality, aligning with established definitions of water pollution. Understanding this concept is crucial in environmental science as it emphasizes the impact of human activities and natural processes on water bodies. It also underlies the importance of regulations, conservation efforts, and technologies aimed at preventing and mitigating pollution to ensure safe and sustainable water resources.