Monday 26 August 2019

Microplastics found in snow from Alps to Arctic

Hunt for information: A helicopter is used to collect snow samples. Photo: AWI/SLF/PA
Hunt for information: A helicopter is used to collect snow samples. Photo: AWI/SLF/PA

Nina Massey

TAKING a tumble in the Alps is sure to result in a mouthful of snow, but what you are not expecting is a mouthful of plastic.

However, new research indicates microplastics are infiltrating the white stuff which otherwise appears pristine.

The minute particles are transported by the atmosphere and subsequently washed out of the air, especially by snow - even in regions such as the Arctic and the Alps.

Dr Melanie Bergmann, from the Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, in Germany, said: "It's readily apparent that the majority of the microplastic in the snow comes from the air."

She added that this raises questions about how much plastic humans are inhaling.

A study published in the journal Science Advances conducted analysis on snow samples from Heligoland, Bavaria, Bremen, the Swiss Alps and the Arctic.

Microplastics were found in high concentrations in snow at all of the sites - even in remote areas of the Arctic, on the island of Svalbard, and in snow on drifting ice floes.

Researchers say the hypothesis is supported by past research conducted on grains of pollen, in which experts confirmed that pollen from the middle latitudes is transported by the air to the Arctic.

These grains are around the same size as the microplastic particles.

Similarly, dust from the Sahara can cover distances of 3,500km or more, reaching the north-east Atlantic.

The samples with the highest concentration were gathered near a rural road in Bavaria - 154,000 particles per litre. The snow in the Arctic contained up to 14,400 particles per litre.

The types of plastic found also varied greatly between sites.

In the Arctic they primarily found nitrile rubber, acrylates and paint, which are used in a host of applications.

Because of its resistance to various types of fuel and broad temperature range, nitrile rubber is often used in gaskets and hoses.

Paints containing plastic are used to coat the surfaces of buildings, ships, cars and offshore oil rigs.

Researchers say the microplastic concentrations found were considerably higher than those in studies conducted by other researchers on dust deposits, for example.

The scientists melted the snow and poured it through a filter before examining the trapped residue with an infrared microscope.

Depending on the type of plastic, different wavelengths of the infrared light are absorbed and reflected.

According to the researchers, a major portion of the microplastic in Europe, and even more in the Arctic, comes from the atmosphere and snow.

Dr Bergmann said: "This additional transport route could also explain the high amounts of microplastic that we've found in the Arctic sea ice and the deep sea in previous studies.

"Most research has focused on how animals or human beings absorb microplastic from what they eat.

"But once we've determined that large quantities of microplastic can also be transported by the air, it naturally raises the question as to whether and how much plastic we're inhaling."

Meanwhile, it's raining multicoloured plastic in the Rocky Mountains, according to the latest research that suggests microplastics are found in even the most remote parts of our planet.

Plastic shards, beads and fibres were identified in more than 90pc of rainwater samples taken from across Colorado, including at more than 3,000 metres high in Rocky Mountain National Park, according to researchers reporting from the US Geological Survey.

Irish Independent

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