Lesson 6: Impact categories in LCA – Eutrophication

Understanding the Environmental Impact of Eutrophication in Life Cycle Assessment


  • Eutrophication is a significant environmental issue caused by excessive nutrient inputs, primarily nitrogen and phosphorus, into aquatic ecosystems.
  • This process accelerates the growth of algae and aquatic plants, potentially leading to adverse consequences for water bodies and ecosystems.


  • Vehicles contribute to eutrophication through various mechanisms:

Nitrogen Oxide (NOx) Emissions

  • Vehicles emit nitrogen oxides (NOx) during combustion, primarily from internal combustion engines.
  • NOx compounds released into the atmosphere can eventually deposit into water bodies, increasing nitrogen levels.
  • Excessive nitrogen in water can stimulate algal growth and disrupt aquatic ecosystems.

Phosphorus Runoff

  • Vehicles, especially those involved in agriculture, can introduce phosphorus into water bodies through runoff.
  • Phosphorus-containing substances from fertilizers can be carried by rainwater or irrigation runoff, encouraging plant and algae overgrowth, leading to eutrophication.

Storm Water Contamination

  • Vehicles contribute to the accumulation of pollutants on road surfaces, including oil, grease, heavy metals, and chemicals from exhaust emissions.
  • These contaminants can be washed into stormwater systems during rainfall and reach water bodies, contributing to eutrophication.

Fuel Spills and Leaks

  • Accidental fuel spills or leaks from vehicles can contaminate soil and water bodies.
  • This can introduce nitrogen and phosphorus compounds, speeding up algal and aquatic plant growth, ultimately leading to eutrophication.

Improper Waste Disposal

  • Incorrect disposal of vehicle-related waste, such as motor oil or cleaning agents, can introduce nutrients into water bodies.
  • If these substances end up in water or drainage systems, they can fuel algal growth and eutrophication.


  • In freshwater ecosystems, such as lakes, rivers, and ponds, excessive nutrients cause freshwater eutrophication.
  • Algal blooms and oxygen depletion are common consequences.
  • Agriculture, sewage discharge, and fertilizer misuse are primary sources of nutrient pollution.


  • Marine eutrophication, occurring in coastal environments, features nutrient enrichment in estuaries, coastal zones, and seas.
  • Similar to freshwater eutrophication, it leads to algal blooms, fish kills, and ecological disturbances.
  • Nutrient pollution sources in marine systems include agricultural runoff, wastewater discharge, and nutrient-rich sediment deposition.


  • Eutrophication, due to excess nutrients, affects aquatic ecosystems.
  • Vehicles contribute to this issue, emphasizing the need for eco-friendly practices.
  • Controlling eutrophication in freshwater and marine ecosystems is vital for preserving water quality and aquatic life.
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