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Microplastics fall across rural Switzerland, adding 219 tons a year to land and water

A new Empa-led study estimates that about 219 metric tons of microplastic settle across Switzerland every year, with similar levels found far outside cities, including about 78 metric tons on farmland and 10 metric…

Step by step

  1. 1

    Plastic litter turns brittle in weather

  2. 2

    Mechanical forces break it into microplastic

  3. 3

    Wind carries particles through the atmosphere

  4. 4

    Rain and snow wash particles down

  5. 5

    Dry particles settle onto land and water

Researchers at Empa, working with colleagues from Eawag and Agroscope, have produced the first systematic estimate of how much microplastic falls from the air onto Swiss soil and into Swiss water. The study, supported by Switzerland's Federal Office for the Environment (FOEN) and published in the journal Atmospheric Chemistry and Physics, estimates that about 219 metric tons of microplastic settle each year across Switzerland at elevations below 2,000 meters. Of that, roughly 78 metric tons land on agricultural fields and about 10 metric tons fall directly into water bodies annually.

The team collected monthly samples of wet deposition (particles washed out by rain and snow) and (particles settling by gravity) over a full year at five sites, including Zurich and Mount Chaumont in the Jura Mountains, identifying particles 20 to 215 micrometers wide. Zurich, the urban site, averaged 881 particles per square meter per day, more than twice the 249 to 331 particles found at the other, less populated sites. Team leader Christoph Hüglin said the similarity among the non-urban sites was unexpected: "The closer the location is to densely populated areas, the higher the levels we would have expected. But we don't see such a difference."

The most common plastics found were polyethylene terephthalate (PET, 31%), polyethylene (PE, 26%) and polypropylene (PP, 21%). PE and PP are widely used in packaging and containers, while PET is common in bottles and polyester textile fibers, suggesting clothing fibers may also contribute.

Dry deposition accounted for the larger share of the mass reaching the ground, about 60%, even though precipitation is an efficient way of cleansing the atmosphere. Direct atmospheric input into water bodies came to about 10 metric tons a year, versus about 5 metric tons a year via treated wastewater, a parallel Eawag study found. Against all airborne particles, made up only about 0.02% to 0.12% of the total.

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The story so far

  1. A Child's Genetic Risk for Lung Disease Only Shows Up in Polluted Air, Study Finds
  2. New Epoxy Composite Lets Aircraft Cabin Panels Be Taken Apart and Recycled
  3. WMO Report: Wildfire and Heat-Wave Pollution Threatens Global Air Quality Efforts
  4. Brisbane's Bulimba Creek Tops Waterways for Hazardous Microplastics
  5. Scientists Buried 2,000 Pairs of Underwear Across Switzerland to Measure Soil Health
  6. ETH Zurich Feeds 100 Petabytes of NASA Data Into a Supercomputer to Speed Up Disaster Forecasting
  7. Microplastics fall across rural Switzerland, adding 219 tons a year to land and water
#microplastics#plastic pollution#Switzerland#air pollution#environment
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