Airborne microplastic deposits 219 tonnes across Switzerland each year

Some 219 tonnes of microplastic fall from the air onto Swiss soil and into waterways every year, according to a study reported by SRF.

Researchers from Empa, Eawag and Agroscope systematically examined atmospheric microplastic pollution for the first time, Empa said. Supported by the Federal Office for the Environment, the study collected soil and water samples over one year at five locations: Zurich, Dübendorf, Magadino, Payerne and Chaumont in the Jura.

Extrapolated across all Swiss territory below 2,000 metres, the researchers estimated that around 219 tonnes of microplastic are deposited annually. About 78 tonnes fall directly onto agricultural land and roughly 10 tonnes into bodies of water.

Zurich recorded the highest level, with 881 particles per square metre per day. The other locations recorded between 249 and 331 particles.

The most frequently identified plastics were polyethylene terephthalate, or PET, at 31 percent, polyethylene, or PE, at 26 percent, and polypropylene, or PP, at 21 percent. PET is used in drinks bottles and polyester textile fibres, while PE and PP are mainly used for packaging, films and containers.

Microplastic accounted for only 0.02 to 0.12 percent of the total mass of airborne particles, including desert dust and soot. However, its continuous deposition over large areas adds up to substantial quantities that are barely broken down in the environment.

The effects of microplastic on the environment and human health remain unclear, the researchers said. Christoph Hüglin, an Empa researcher and the study leader, said that under the precautionary principle, people should avoid littering, use plastics selectively where necessary and close material cycles as far as possible.