Scientists find microplastics in Arctic snow, suggesting significant air pollution even in remote locations
Analysis shows microplastics are transported by the atmosphere and then washed out of the air, especially by snow even in such remote regions like the Arctic and the Alps. Researchers call for urgent studies on its effects on human and animal health.
Plastic contamination has now reached the remote regions of the Arctic and the Alps. A team of scientists has discovered large quantities of microplastics - very small pieces of plastic waste - in the Arctic snow, suggesting widespread and considerable air pollution. While microplastic particles have repeatedly been detected in sea-water, drinking water, and even in animals over the past several years, this is the first study to show that there are high concentrations of microplastics in snow, which indicates it is an airborne pollutant that must be monitored.
“This is the first scientific study to our knowledge that shows microplastics in snow as such, and also in Arctic snow. The quantities that we found are quite high. The third most polluted site was snow from an Arctic ice floe. The results, together with those from other scientists (from France, India, and China) suggest that microplastics constitute a widespread airborne pollutant, that we should be monitoring along with other pollutants,” Dr. Melanie Bergmann, marine ecologist from Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Germany, told MEA WorldWide (MEAWW). She led the research team along with Dr. Gunnar Gerdts from AWI.
“In this study, we showed that microplastic particles can be transported on large scales even into environments far from larger settlements like the Arctic. Together with our previous findings on microplastics in sea ice or Artic sediments, we have to state again the anthropogenic impact on the polar regions is significant,” Dr. Sebastian Primpke from AWI told MEAWW.
The researchers state that the high microplastic concentrations detected in snow samples (the image above by Mine Tekman, Alfred-Wegener-Institut, shows scientists collecting snow samples) from continental Europe to the Arctic indicate significant air pollution and stress the urgent need for research on human and animal health effects focusing on airborne microplastics. “The potential impacts on human health mainly depend on the size of the particles, as very small particles might translocate into organs/tissues/cells, possibly leading to inflammation, etc. However, currently, only a few studies investigating the impact of MP on human health are available,” says Dr. Primpke.
Previous studies have shown that microplastics may contribute to lung cancer risk, highlighting an urgent need to further assess the health risks of inhaling them, says the team. “The fact that we find microplastic in snow implies that microplastics may be in the air that we breathe. Therefore, it is really important to assess if microplastics also reach lung tissues. In a study from 1989, plastic fibers were found in lung tissue,” Dr. Bergmann told MEAWW.
What’s more, the team of experts from AWI found that these microplastic particles are transported over tremendous distances by the atmosphere and subsequently washed out of the air by precipitation, particularly snow - and even in such remote regions as the Arctic and the Alps.
The researchers analyzed snow samples from Helgoland, Bavaria, Bremen, the Swiss Alps, and the Arctic. The findings, published in Science Advances, confirm that the snow at all sites contained high concentrations of microplastic - in remote reaches of the Arctic, on the island Svalbard, and in the snow on drifting ice floes. The researchers are convinced that a major portion of the microplastic in Europe, and even more so in the Arctic, comes from the atmosphere and snow. According to them, wind plays a role in carrying microplastics to both the snowy streets of European cities and remote areas of the Arctic Ocean – where ecosystems are already stressed by the effects of climate change. “The high amounts of microplastics in snow, suggest that atmospheric transport and deposition could represent a significant pathway for these materials to places far afield,” they add.
“It is readily apparent that the majority of the microplastic in the snow comes from the air. In earlier studies, we have found very high concentrations of microplastics in Arctic sea ice and deep-sea sediments. Here, we have found one new mode of transport to the North and to Earth surfaces in general: snow deposition. Atmospheric transport and fall-out via snow seem to be an important pathway for microplastics,” Dr. Bergmann said.
Microplastic is any piece of plastic measuring less than five millimeters. They are usually formed by the breakdown of larger pieces of plastic - for example, from shopping bags to the wear and tear on tires. Microplastics might contain varnish, rubber, or chemicals used in synthetic fabrics and cause significant air pollution.
“Plastic pollution is a problem of growing environmental concern, and annual waste production is projected to rise to 3.4 billion metric tons (MT) in the next 30 years. Many countries still have inefficient waste management and water treatment systems allowing leakage to the environment, which is exacerbated by littering behavior. Mismanaged plastic waste could triple from 60 million to 99 million MT in 2015 to 155 to 265 million MT by 2060, assuming a business-as-usual scenario. In addition, plastic is designed to be durable. Therefore, it persists in the environment for long periods,” says the study.
The fact that our oceans are full of plastic litter has by now become common knowledge: year after year, several million tonnes of plastic litter find their way into rivers, coastal waters, and even the Arctic deep sea. Due to the motion of waves, and even more so because of UV radiation from the sun, the litter is gradually broken down into smaller and smaller fragments - referred to as microplastic. This microplastic can be found in marine sediment, in sea-water, and in marine organisms that inadvertently ingest it. In comparison, there has been little research to date on whether, and if so, to what extent, microplastic particles are transported by the atmosphere. Only a handful of works are available, for example, from researchers who were able to confirm the ’particles’ presence in the Pyrenees and near major urban centers in France and China.
In the current study, the researchers used an imaging technique to analyze snow samples collected between 2015 and 2017 from floating ice in the Fram Strait, a passage between Greenland and Svalbard to the Arctic Ocean. They visited five ice floes by ship-based helicopters or dinghies during three expeditions. For comparison, the researchers investigated samples from the remote Swiss Alps and the City of Bremen in northwest Germany. While concentrations of microplastics in Arctic snow were lower than the concentrations in European snow, the levels of this pollutant in the far North were still substantial. Most of the particles were in the smallest measurable size range of less than 11 micrometers.
The research team found the highest concentration in samples gathered near a rural road in Bavaria - 154,000 particles per liter. Even the snow in the Arctic contained up to 14,400 particles per liter. “The highest microplastic concentration was found in Bavarian snow. Since we took this sample next to a country road, traffic could play a role in terms of automotive emissions, dispersion of settled microplastics by cars, and subsequent scavenging by falling snow,” says the study.
The types of plastic found also significantly varied between sampling sites: in the Arctic, the researchers primarily found nitrile rubber, acrylates, and paint, which are used in a host of applications. “Given 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 in several different areas, for example, to coat the surfaces of buildings, ships, cars, and offshore oil rigs. Near the rural road in Bavaria, the samples especially contained various types of rubber, which is used in countless applications, such as automotive tires,” say the researchers in their findings.
An intriguing aspect of the study, say the researchers, is that the microplastic concentrations found are considerably higher than those in studies conducted by other researchers, for example, on dust deposits. The researchers attribute this to one of two reasons. “First of all, snow is extremely efficient when it comes to washing microplastic out of the atmosphere. Secondly, it could be due to the infrared spectroscopy we used, which allowed us to detect even the smallest particles - down to a size of only 11 micrometers.” says Dr. Gerdts.
According to the researchers, the large concentrations of microplastics and microfibers in snow highlight the importance of the atmosphere as a source of airborne microplastics and microfibers. “Through this pathway, microplastics likely find their way into the soil and aquatic environments and therefore, also into food chains. In populated areas, it is a common practice to remove snow from streets and transport it ‘away.’ Our results show that these locations should be chosen wisely to avoid contamination of sensitive areas,” the findings state.