Microplastics ‘significantly contaminating the air’, scientists warn
Abundant levels of microplastic pollution have been found in snow from the Arctic to the Alps, according to a study that has prompted scientists to warn of significant contamination of the atmosphere and demand urgent research into the potential health impacts on people.
Snow captures particles from the air as it falls and samples from ice floes on the ocean between Greenland and Svalbard contained an average of 1,760 microplastic particles per litre, the research found. Even more – 24,600 per litre on average – were found at European locations. The work shows transport by winds is a key factor in microplastics contamination across the globe.
The scientists called for research on the effect of airborne microplastics on human health, pointing to an earlier study that found the particles in cancerous human lung tissue. In June, another study showed people eat at least 50,000 microplastic particles per year.
Many millions of tonnes of plastic are discarded into the environment every year and are broken down into small particles and fibres that do not biodegrade. These particles, known as microplastics, have now been found everywhere from high mountains to deep oceans and can carry toxic chemicals and harmful microbes.
The latest study was led by Dr Melanie Bergmann of the Alfred Wegener Institute for Polar and Marine Research in Germany. She said: “We really need research on the human health aspect. There are so many studies being published now on microplastics but nothing on human health, and that is really strange in my opinion.” Bergmann added that microplastics should be included in air pollutant monitoring schemes.
Bergmann had previously found 12,000 microplastic particles per litre in samples of Arctic sea ice: “So we asked where does it all come from?” Some is carried from populated regions by ocean currents, but analysis of snow samples shows much is blown by the wind.
“Microplastic concentrations in snow were very high, indicating significant contamination of the atmosphere,” concluded the study published in the journal Science Advances.
“It basically gets everywhere with the wind,” said Bergmann. Pollen and dust from the Sahara are already known to be blown over long distances. As well as the Arctic ice floes, the team’s 22 samples included snow from Svalbard, an island well north of the Arctic circle, the German and Swiss Alps and the city of Bremen.
The team found that the smallest particles were the most abundant, but their equipment could not detect particles smaller than 11 microns.
“I am convinced there are many more particles in the smaller size range beyond our detection limit,” said Bergmann. “The worry with smaller particles is they can be taken up by a greater range of organisms and, if they reach nano-scale, they could penetrate cell membranes and translocate into organs much more easily than the larger fraction.”