Water pollution refers to any chemical, physical, or biological change in water that harms living things. Over 1 billion people lack access to safe drinking water, and 5,000 people die daily from dirty water. Global warming will exacerbate droughts, floods, and waterborne diseases. Approximately 46% of American lakes are too polluted for activities like fishing, swimming, and supporting aquatic life. Simple actions like not littering and cleaning up litter can help address this issue.