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Earth and Environmental Sciences

Students compare point source and nonpoint source pollution.

What You Need

  • Plastic bin (as big as a shoebox, no lids necessary, low sides preferred) 
  • Sand (or flour, sugar, rice, potting soil, etc.)
  • Ribbon (120 cm)

Guide:

Safety Notes

Ensure you are familiar with Let's Talk Science's precautions with respect to safe delivery of virtual outreach to youth.

What To Do

  • Fill the bin with at least 10cm of sand (or other substitute) to represent your "environment".
  • Cut two lengths of ribbon about 60cm long each. 
  • Cut one of the ribbons into short pieces, no longer than 1cm.
  • Add both the long and short lengths of ribbon into the bin and mix them in. 
  • Have participants try to clean out all of the pieces of ribbon out of the "environment bin".

Discovery

What's Happening?

The long length of ribbon represents point source pollution, which is pollution that comes from a single, definite source, like a factory dumping toxins, or an oil spill. These kinds of pollution are easier to identity, regulate, and stop. The small bits of ribbon represent non-point source pollution (NPS), which is pollution that comes from many small sources, like runoff water that collects drops of gasoline, salts, and chemicals from the city pavement. Nonpoint source pollution is much harder to regulate and is very difficult to solve without widespread engagement. Nonpoint source pollution is something that we can all work to solve. 

What's Happening?

The long length of ribbon represents point source pollution, which is pollution that comes from a single, definite source, like a factory dumping toxins, or an oil spill. These kinds of pollution are easier to identity, regulate, and stop. The small bits of ribbon represent non-point source pollution (NPS), which is pollution that comes from many small sources, like runoff water that collects drops of gasoline, salts, and chemicals from the city pavement. Nonpoint source pollution is much harder to regulate and is very difficult to solve without widespread engagement. Nonpoint source pollution is something that we can all work to solve. 

Why Does It Matter?

Pollution can harm ecosystems and sometimes contributes to climate change. For example, a common type of pollution is when synthetic fertilizers used in gardening and agriculture run off into other environment. Fertilizers give plants nutrients that help them to grow, but they also contribute to global warming since lots of fossil fuels are burned when producing synthetic fertilizers. When these fertilizers are used they also undergo chemical reactions that form a gas called nitrous oxide NO2, which is another greenhouse gas.

Why Does It Matter?

Pollution can harm ecosystems and sometimes contributes to climate change. For example, a common type of pollution is when synthetic fertilizers used in gardening and agriculture run off into other environment. Fertilizers give plants nutrients that help them to grow, but they also contribute to global warming since lots of fossil fuels are burned when producing synthetic fertilizers. When these fertilizers are used they also undergo chemical reactions that form a gas called nitrous oxide NO2, which is another greenhouse gas.

Resources

Guide:

Web

National Geographic: Point Source and Nonpoint Sources of Pollution

United States Environmental Protection Agency: Nonpoint Source Pollution: The Largest Water Quality Problem

Climate Portal: Fertilizer and Climate Change