pollution

/pəˈluʃən/
noun
  1. The presence or introduction of harmful substances or waste into the environment.
    • Air pollution from factories can cause breathing problems.
    • The river is full of pollution from nearby farms.
    • Many cities are working to reduce plastic pollution in the ocean.
  2. Something that makes a place or thing dirty, impure, or harmful.
    • The pollution from the old cars made the street smell bad.
    • Light pollution makes it hard to see the stars in the city.
    • Noise pollution from the airport keeps people awake at night.