This document discusses the importance of a clean environment for human health and existence. It notes that pollution from human activities threatens both organisms and nature. A clean environment requires clean air, water, land, and energy. The document outlines various types of pollution like exhaust, waste in water/soil/air, and deforestation that harm the environment. Maintaining a clean environment is important to avoid issues like climate change and health problems. Some ways to help include planting trees, using bicycles more, cleaning coasts/forests, and not littering. The overall message is that caring for the environment is our duty.