ENVIRONMENT
Learn a little about land pollution with our reference resource.
Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Photograph by Dan Westergren, National Geographic
Discussion Ideas
- A new survey reported finding microplastics in 90% of the soils sampled in Switzerland. What are microplastics?
- Microplastics are just what they sound like—tiny plastic particles no more than 5 millimeters in diameter.
- Where was the new survey conducted?
- Researchers sampled soils from 29 flood plains in nature reserves across Switzerland. Many of these reserves are only accessible by foot.
- How do researchers think so much plastic got into such remote areas?
- wind. Debris from across the country or continent was likely blown to Switzerland’s windswept flood plains. “We think it has to be transported by the wind. There is no other explanation – there are no settlements there [in the mountains], no tourism.”
- Why do social scientists think other nations may have more microplastics in their soil than Switzerland?
- “Almost 100% of the plastic used in Switzerland is either recycled or incinerated, the highest rate in Europe. In places where waste management is poorer and more plastic enters the environment, soil contamination could be higher.”
- How might microplastics in the soil impact the ecosystem?
- Microplastics may have the biggest impact on the producers and decomposers in the ecosystem’s food webs—the beginning and end of food chains.
- producers. Microplastics may impact the growth and development of plants. This is of particular concern in agricultural areas that use sewage sludge as a fertilizer. Sludge is produced at water treatment facilities and carries high levels of microplastics associated with food and garden waste.
- decomposers. New studies indicate that “microplastics in the soil can be harmful to and even kill earthworms in the soil.” Microplastics may also impact the growth of fungi and other decomposers that break down materials into nutrients that are vital to the production of fertile, healthy soil.
- Microplastics may have the biggest impact on the producers and decomposers in the ecosystem’s food webs—the beginning and end of food chains.
TEACHERS TOOLKIT
The Guardian: The hills are alive with the signs of plastic: even Swiss mountains are polluted
Nat Geo: What is pollution?